Smallmouth bass (Micropterus dolomieu)
Lake Michigan   (Fertilized Egg)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
424             Waugoshance             Turbidity          Lethal                ­                  174                     110
                  Point

Details
­ Carp spawning increased turbidity so much in one area that bass nests
  were unsuccessful. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
        (Fertilized Egg)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
411             ­                                Temperature       Lethal                ­                       118                     110

Details
­ Egg mortality of smallmouth bass eggs collected at the 16­cell stage at 19°C,
  transferred to water at 17°C, 20°C, 23°C, 26°C and 29°C, and covered ranges
  35% at 23°C, 84% at 17°C, and 95% at 29°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
412             ­                                Temperature       Lethal            ­                      135                     110
                                Oxygen         Limit              ­

Details
­ Survival of smallmouth bass eggs to 14 days at 20°C was:  50% at 8.7 ppm DO,
  39%­42% at 4.4 ppm, and at 25°C it was 29%­31% at 4.4 ppm.  There was no egg
  survival at 2.5 ppm, and almost no hatch at 1.2 ppm DO.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
413             Cayuga Lake           Water Level        Example                 ­                      115                     110
                                Turbidity           Example                ­

Details
­ Sudden increases in stream level and turbidity did not seem to damage
  smallmouth bass nests with eggs, sac, or black fry (unless flood
  proportions were reached).  
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
414             Ohio                  Water Level       Lethal         ­                   237                     110

Details
­ High water levels destroy smallmouth bass nests.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
417             Cayuga Lake           Turbidity            Example               ­               115                     110
                                Water Level        Lethal         ­

Details
­ Smallmouth bass eggs are laid in shallower, turbid water than when water
  is clear.  Increased drying could exist if water levels recede.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
418             ­                               Pred/Prey           Example                 ­                   110                     -

Details
­ Carp, common suckers, white perch and sunfishes prey on smallmouth
  bass eggs and fry. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
419             Ontario                   Temperature       Lethal          ­                    126                     110

Details
- A rapid rise in temperature from 16.1°-23.0°C (just before hatching)
  resulted in heavy mortality, although newly hatched fry were not affected.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
420             Saskatchewan         Temperature       Lethal         ­                    155                     110

Details
- Any drop in smallmouth bass temperatures below 15.6°C (particularly for an
  extended period) may result in nest desertion, death of eggs (and to a 
  lesser extent) death of fry which have not risen from the nests. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
421             ­                              Temperature       Lethal          ­                 228                     110

Details
­ Smallmouth bass egg survival was uniformly high at 15°­25°C, but
  survival dropped at lower or higher temperatures.  No survival existed
  at 10°C or 30°C and only 45% of eggs survived at 12.5°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1464            ­                              Depth           Characteristic  0.3­0.9 m       1023                    1011

Details
­ Smallmouth bass nests are usually in water 0.3­0.9 m deep. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1465            ­                               Depth            Limit             7 m             775                     1011
                                                                                        1055
Details
­ Smallmouth bass nests may be built in water up to 7 m deep.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1472            Cayuga Lake,            Temperature       Characteristic   13°­25°C                115                     1011
                  New York                                                                       1023

Details
­ Smallmouth bass embryos develop normally at temperatures of 13°­25°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1473            ­                                Temperature       Limit              ­                   115                     1011
                                                                                        1045
Details
­ Extreme fluctuations in temperature cause smallmouth bass embryo mortality
  from acute thermal shock.  Fluctuation also cause males (the caretakers) to
  leave the nest unprotected from predators and/or fungus may grow. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1475            ­                                Oxygen          Limit            ­                        135                     1011

Details
­ In a laboratory study, 42% of the smallmouth bass embryos survived >14
  days at 4.4 ppm DO and 29°C.   No embryos survived at levels <2.5 ppm.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1476            ­                               Oxygen        Requirement      >6 ppm     1016                    1011

Details
­ DO levels >6 ppm are necessary for maximum smallmouth bass embryo 
  survival.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1479            ­                               Water Level        Limit           ­                   1063                    1011  
                                Temperature       Limit            ­               1045

Details
­ Rising water may flush smallmouth bass nest areas with cold water.  This causes
  nest desertion and halts embryo development.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1480            ­                                Water Level       Limit            ­                      159                     1011
                                Temperature       Limit           ­               1045

Details
- Falling water levels may drive guarding males off, limit water circulation
  around eggs, and increase predation.  This results in lower smallmouth bass
  reproductive success. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Erie       (Juvenile)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
447             ­                               Temperature       Prefer            ­                244                     110

Details
­ Temperature experiments in a laboratory with fingerling smallmouth bass
  from Lake Erie were: 29°­31°C in the summer, 26°­30°C in the fall, 24°­28°C
  in the winter, and 22°­28°C in the spring.
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Huron      (Juvenile)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
386             South Bay                Temperature       Example                 ­                     228                     110

Details
­ First-year growth of smallmouth bass in South Bay was more rapid in warmer
  summers.
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
        (Juvenile)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
382             Iowa                 Water Level       Example                ­                   156                     110
                                Area of Water   Example                   ­
 
Details
­ In the Des Moines River, Iowa, best growth of smallmouth bass was during 
  the year with the lowest, average water levels.  Correlations between water
  levels and growth increments of age-1, age-2, and age-3 bass were all
  negative, but significant.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
383             Ohio                Water Motion    Example                 ­                 237                     110
                                Area of Water   Example               Streams
                                Temperature      Example               ­

Details
­ In Ohio streams, slowest smallmouth bass growth was in years of high stream
  flow and lower temperatures.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
438             Cayuga Lake           Movement             Characteristic   ­                   115                     110
                                Phys. Assoc.     Characteristic  ­
                                Area of Water   Example                    ­
                                Temperature       Example               ­

Details
­ In Cayuga Lake, bass congregate along limestone ridges.  They often arrive
  in early September when temperatures were only slightly lower.  Larger
  bass form less-compact aggregations then bass 150­200 mm long.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
449             ­                                Temperature       Prefer         ­                       229                     110

Details
­ Preferred temperatures of smallmouth bass acclimated at various tempera-
  tures were: 20.2°C from 15°C, 22.9°C from 18°C, 26.5°C from 21°C, 29.8°C
  from 24°C, 30.1°C from 27°C, and 31.3°C from 30°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
450             ­                           Temperature       Lethal          ­                 198                     110

Details
­ The 96­hour LD50 temperatures for juvenile smallmouth bass (29 g mean 
  weight) acclimated at various temperatures were: 1.6°C from 15°C, 3.7°C
  from 18°C, 6.7°C from 22°C, and 10.1°C from 26°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
454             ­                               Oxygen         Tolerate              40 ppm        117                     110

Details
- Smallmouth bass fingerlings up to 127 mm long withstood 40 ppm oxygen
  with no distress. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
456             ­                               pH                 Example                ­                 230                     110
                                Movement            Example                 ­               

Details
­ No significant difference in smallmouth bass activity was observed
  at a pH of 7, 6, 5, and 4.  However, more testing and acclimation is
  needed. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
463             ­                               Pred/Prey           Characteristic  ­                  110

Details
­ By the time bass are 40 mm long, they eat insects and small fish.
  Fish and crayfish soon form most of the food. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
472             Arizona                  Pred/Prey           Example                 ­                  255                     110

Details
­ In Bull Shoal's Lake, Arizona, young shad were the major summer food,
  centrarchids and crayfish in late autumn and winter, and mayflies in
  spring. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
646             ­                               Pred/Prey             Characteristic  ­                  111                     -

Details
­ A number of fish species feed on walleye fry.  These species include yellow
  perch, white bass, yellow bass, smallmouth bass, rainbow smelt, stugers, 
  bullheads, burbot and (most importantly) northern pike.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1419            ­                              Pred/Prey            Characteristic   ­                   1025                    1011
                                                                                        115
Details
­ Juvenile smallmouth bass eat larger insects, crayfish, and fish.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1433            ­                              Light           Avoid            ­                        1023                    1011
                                                                                        771
Details
­ Smallmouth bass exhibit strong, cover­seeking behavior and prefer 
  protection from light during all life stages. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1497            Iowa                  Phys. Assoc.     Characteristic   ­                        156                     1011
                                                                                        1049
Details
­ Juvenile smallmouth bass spend most of their time in quiet water near or
  under a dark shelter (brush or rocks). 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1498            ­                               Water Motion    Prefer            ­                    1011                    -
                                Depth           Characteristic   ­

Details
­ Juvenile and adult smallmouth bass prefer low velocity water near a current,
  but juveniles are often found in slightly shallower water than adults.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1499            ­                                Temperature       Prefer            28°­31°C            751                     1011
                                                                                        244

Details
­ In laboratory studies, juvenile smallmouth bass preferred temperatures
  ~28°-31°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1500            ­                                Temperature       Optimum                25°­29°C                 198                     1011
                                                                                        229
Details                                                                         1058
­ Maximum smallmouth bass growth occurred at 25°­29°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1501            ­                                Temperature       Lethal          35°C                 229                     1011

Details
­ The upper lethal temperature for juvenile smallmouth bass is ~35°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1502            ­                                Movement             Limit             20°C           1023                    1011

Details
­ Activity of juvenile smallmouth bass is reduced below 20°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1503            ­                                Temperature       Limit              16°C              198                     1011

Details
­ Little growth of juvenile smallmouth bass occurs below 16°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1504            Middle Snake            Phys. Assoc.     Characteristic  ­                 164                     1011
                  River

Details
­ Juvenile smallmouth bass seek shelter in crevices and fissures of the rock
  substrate at very low temperatures. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1505            ­                                Temperature       Lethal          ~0°C              198                     1011

Details
­ Lower lethal temperatures for juveniles occur near freezing. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Ontario    (Larva)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1491            St. Lawrence            Depth           Limit           4.6­6.1 m         150                     1011
                  River

Details
­ Some smallmouth bass fry may be found in water 4.6­6.1 m deep. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
        (Larva)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
385             ­                              Temperature       Example                ­                 200                     110
                                Oxygen          Example                ­ 

Details
­ Smallmouth bass fry (11 days after hatching) averaged 12.9 mm at 25°C and 
  4.4 ppm oxygen, 9.4 mm at 20°C and 4.4 ppm oxygen, and 9.9 mm at 20°C and
  8.7 ppm DO.  A temperature drop from 23°C to 14.4°C in 3 days resulted in
  decreased growth of young bass.  
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
413             Cayuga Lake           Water Level       Example               ­                  115                     110
                                Turbidity            Example              ­

Details
­ Sudden increases in stream level and turbidity did not seem to damage 
  smallmouth bass nests with eggs, sac, or black fry (unless flood 
  proportions were reached).  
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
414             Ohio                  Water Level        Lethal         ­                   237                     110

Details
- High water levels destroy smallmouth bass nests.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
415             Iowa                        Water Level       Lethal           ­                    222                     110
                                Pred/Prey           Characteristic  ­

Details
­ Floods destroy the microcrustaceans needed by smallmouth bass fry. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
416             ­                               Water Motion    Prefer           ­                        179                     110

Details
­ Smallmouth bass fry selected a flow of 9 cm/sec in preference to quiet
  water, but could not be maintained in flows of 27 cm/sec. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
418             ­                              Pred/Prey           Example              ­                   110                     -

Details
­ Carp, common suckers, white perch, and sunfishes prey on smallmouth bass
  eggs and fry. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
419             Ontario                    Temperature       Lethal         ­                    126                     110

Details
­ A rapid rise in temperature from 16.1°-23.0°C (just before hatching)
  resulted in heavy mortality, although newly hatched fry were not affected. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
420             Saskatchewan         Temperature       Lethal              ­                 155                     110

Details
­ Any drop in smallmouth bass temperatures below 15.6°C, (particularly for
  an extended period) may result in nest desertion, death of eggs (and to a
  lesser extent) death of fry which have not risen from the nests.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
425             Ohio                    Pred/Prey           Limit           ­                  190                     110

Details
­ Survival of smallmouth bass fry may be low if entomostracans are scarce.  
  Backswimmers, dragonfly larvae, cannibalism, and Ichthyophthirius may also
  cause fry losses.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
455             ­                               pH                 Tolerate               ­                   117                     110

Details
­ Smallmouth bass fry tolerated sudden pH changes from 9.3­6.0 and 7.7-9.7.   
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
462             ­                               Pred/Prey           Characteristic   ­                    110                     -

Details
­ The first food of young bass is usually copepods and cladocerans and 
  dipteran larvae and rotifers.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
546             ­                                pH                Lethal         ­                      117                     110

Details
­ Largemouth bass fry were less resistant than smallmouth fry to high
  pH values.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
646             ­                               Pred/Prey           Characteristic  ­                 111                     -

Details
­ A number of fish species feed on walleye fry.  These species include yellow
  perch, white bass, yellow bass, smallmouth bass, rainbow smelt, saugers, 
  bullheads, burbot and (most importantly) northern pike.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1418            ­                             Pred/Prey          Characteristic   ­                    1011                    -

Details
­ Smallmouth bass fry feed on microcrustaceans. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1433            ­                              Light           Avoid           ­                   1023                    1011
                                                                                        771
Details
­ Smallmouth bass exhibit strong, cover­seeking behavior, and prefer 
  protection from light during all life stages.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1481            ­                              Temperature       Optimum                25°­29°C              164                     1011
                                                                                        1058
Details
­ The optimum temperature range for smallmouth bass growth in the laboratory
  was 25°­29°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1482            ­                             Temperature       Optimum               ­                 751                     1011

Details
­ Smallmouth bass fry inhabit areas with near-optimum temperatures in summer.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1483            -               Area of Water   Characteristic  ­               1049                    1011
                                                                                        1023
Details
­ Smallmouth bass fry use calm, shallow, marginal areas with rocks and 
  vegetation in summer.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1484            ­                              Temperature       Limit            35°C             1058                    1011

Details
­ Growth of smallmouth bass fry ceases at 35°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1485            ­                              Temperature       Lethal         38°C             179                     1011

Details
­ The upper lethal temperature of smallmouth bass is ~38°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1486            ­                               Movement             Limit           ­                 1023                    1011

Details
­ Activity levels of smallmouth bass fry drop at 20°C, and swimming is
  greatly reduced at 10°C.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1487            ­                            Phys. Assoc.    Characteristic  ­                      115                     1011
                                                                                        188
Details
­ Smallmouth bass fry seek rocky shelters in littoral or shore areas when 
  the water temperature is 7°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1488            ­                               Temperature       Lethal            4°C                 179                     1011

Details
- The lower lethal temperature for smallmouth bass fry is ~4°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1490            ­                 Depth           Characteristic  ­                        1025                    1011
                                                                                        212
Details
­ Most smallmouth bass fry remain in shallow water.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1492            ­                                Water Motion    Limit           200 mm/sec        179                     1011

Details
- Smallmouth bass fry 20­25 mm long cannot maintain themselves in current
  velocities >200 mm/sec.                            
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1493            ­                                Turbidity           Limit           2,000 JTU             1130                    1011

Details
­ Smallmouth bass fry cannot tolerate and are displaced at high 
  turbidities (2,000 JTU) combined with an increase in water velocity.
  However, they are not displaced at moderate turbidities (250 JTU). 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1494            ­                               Oxygen        Limit                 <1 ppm       1016                    1011

Details
­ Smallmouth bass fry cease feeding at DO levels <1 ppm.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1495            ­                                Oxygen        Lethal               <2.5 ppm            135                     1011

Details
­ Survival of smallmouth bass fry is low at levels <2.5 ppm. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1496            ­                             Oxygen          Optimum                >6 ppm        1011                    -

Details
­ Levels >6 ppm are considered optimum for smallmouth bass fry.
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Ontario    (Non-spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
446             ­                               Depth            Example               ­                 152                     110
                                Water Motion    Example                Storms

Details
­ After storms, smallmouth bass were taken in water 23­24 m deep in Lake
  Ontario.
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Erie       (Non-spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
427             ­                               Movement            Characteristic   ­                       223                     110

Details
­ Tagged returns of smallmouth bass indicated limited movement.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
448             ­                                Temperature       Prefer         ­                        244                     110

Details
­ In laboratory experiments with adult smallmouth bass from Lake Erie,
  temperatures were:  30°­31°C in summer, 21°­27°C in fall, 13°­26°C in winter,
  and 18°­26°C in spring.
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Huron      (Non-spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
387             South Bay                Temperature       Example                 ­                    233                     110

Details
­ Annual increments of age-3 to age-4 smallmouth bass in South Bay, Lake
  Huron (and in several other waters) were related to mean surface 
  temperatures from July-September. This relationship was not evident in 
  Lake Opeongo, nor for older bass in South Bay.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
429             Manitoulin Island       Movement             Characteristic  ­                     210                     110

Details
­ Tagged returns of smallmouth bass indicated limited movement. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Michigan   (Non-spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
388             Waugoshance             Temperature      Example               ­                   174                     110
                  Point

Details
­ Slow growth of smallmouth bass in Lake Michigan (1950-51) was related to
  cold, rainy summers. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
426             Waugoshance             Movement             Characteristic  ­                  174                     110
                  Point

Details
­ Tagged returns of smallmouth bass indicated limited movement. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
465             ­                       Pred/Prey           Example               ­                    121                     110

Details
­ Alewives were a major forage in Lake Michigan. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
        (Non-spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
376             Wisconsin                 Pred/Prey           Example                    ­                 209                     109
                                                                                        288
Details
­ Introduction of muskellunge into two Wisconsin lakes eliminated most of the 
  yellow perch and largemouth bass >100 mm long.  Enough muskellunge remained,
  apparently in secure habitats, to reproduce successfully each year.  
  Smallmouth bass were relatively secure from muskellunge predation and
  increased in abundance as largemouth bass decreased.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
377             Nebraska                Alkalinity         Tolerate              <900 ppm CO3    167                     110
                  (Hatchery)              Sodium         Tolerate                    200 ppm K+Na
                                Potassium          Tolerate              200 ppm K+Na 

Details
­ Smallmouth bass were suggested as suitable for stocking in slightly alkaline
  lakes (<900 ppm total carbonate alkalinity and 200 ppm K+Na).
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
378             West Virginia       pH                 Example                ­                    142                     110
                                Conductivity     Example              ­ 
                                Pred/Prey            Example               ­

Details
­ A positive correlation between smallmouth bass growth and pH, conductivity,
  and higher sucker populations has been reported.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
379             Missouri                  Area of Water   Example             Pond            254                     110
                                Turbidity         Example              ­

Details
­ The growth rate of smallmouth bass was inversely related to clay turbidity. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
380             Quebec                  Eutrophication  Example              ­                  158                     110

Details
­ Smallmouth bass growth was better in eutrophic waters of the Montreal 
  plain than in oligotrophic waters of the Laurentides.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
381             Hatchery               Eutrophication  Example                ­                      199                     110
                                Oxygen          Limit                   -
                                Clarity              Limit           ­
                                Amnonia              Limit                  ­

Details
­ Growth of smallmouth bass was slower in fertilized ponds than in less-fertile 
  ponds.  Increased diurnal DO flux, decreased transparency, or increased
  ammonia may be pertinent factors.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
384             ­                              Temperature      Optimum                28°­29°C             245                     110

Details
­ Maximum smallmouth bass growth occurred at 28°­29°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
422             Missouri                      Water Level       Limit                  ­                        214                     110
                                Temperature       Limit           ­

Details
­ Floods and low temperatures were related to smallmouth bass low year-class
  success in Big Piney River, Missouri. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
428             ­                             Movement           Characteristic   ­                       207                     110
                                                                                        150
Details                                                                         151
­ Tagged returns of smallmouth bass indicated limited movement. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
430             Hatchery                Movement             Characteristic  ­                       250                     110
                                Area of Water   Example             ­

Details
­ Hatchery-reared bass moved more (up to 113 km) than marked native 
  bass in Massie Creek, Ohio. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
431             ­                              Movement           Characteristic  ­                   213                     110
                                Area of Water   Example               ­
                                Phys. Assoc.    Example              ­

Details
­ Stream disturbance by gravel operations caused bass to desert their home
  range. In water 100-2845 m deep, 15 tagged bass voluntarily moved to other
  pools and later homed. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
432             ­                              Temperature      Characteristic  ­                    196                     110
                                Water Motion    Characteristic   ­
                                Area of Water   Characteristic   ­
                                Clarity           Characteristic  ­

Details
­ Smallmouth bass are usually found in cool, flowing streams and large, clear lakes.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
433             Wisconsin              Depth         Optimum              >9 m           196                     110
                                Temperature     Optimum              ­               239
                                Clarity             Optimum                Clear, No Color
                                Phys. Assoc.    Optimum              -
                                Pred/Prey         Optimum              ­

Details
­ Ideal smallmouth bass lakes are: >40; >9 m deep and thermally stratified;
  not dark colored and clear; scantily vegetated; large shoal areas of rock, 
  gravel, or sand with gravel patches; amply foraged (small fish, crayfish,
  or insects); and moderate in temperature during summer.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
434             ­                            Area of Water   Example              Streams              201                     110
                                Temperature       Optimum            ­
                                Clarity                  Optimum              Clear, No Color
                                Phys. Assoc.    Optimum               Gravel, Rock
                                Water Motion    Optimum                ­

Details
­ Smallmouth bass streams should have a good current; clear, cool water;
  and a good gravel or rock bottom.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
435             ­                           Phys. Assoc.     Example                Shelter               201                     110
                                Area of Water   Example             Streams

Details
­ Stream bass readily used artificial shelters.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
436             ­                            Phys. Assoc.     Prefer           ­                   164                     110
                                Area of Water   Example              Streams 

Details
­ A definite preference by smallmouth bass for a broken rock substrate over
  solid rock or sand was shown in the Middle Snake River.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
437             ­                             Movement           Characteristic  ­                       196                     110
                                Temperature       Example                 ­

Details
­ During winter, smallmouth bass tend to be inactive in the northern portion
  of their range. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
438             Cayuga Lake         Movement           Characteristic  ­                        115                     110
                                Phys. Assoc.     Characteristic   ­ 
                                Area of Water   Example               ­
                                Temperature      Example             ­

Details
­ In Cayuga Lake, bass congregate along limestone ridges.  They often arrive
  in early September when temperatures were only slightly lower.  Larger 
  bass form less-compact aggregations then bass 150­200 mm long.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
439             ­                           Temperature       Example              ­                 164                     110
                                Depth      Example              ­
                                Area of Water   Example              ­

Details
­ In the Middle Snake River, smallmouth bass were not found in shallow 
  water in the late fall after water temperatures reached 15.5°C, but only
  in quiet pools at least 3.6 m deep.  Most of the fish remained under 
  rocks at temperatures <6.7°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
440             Ohio                      Temperature      Example              <10°C     131                     110
                                Movement         Characteristic  Lethargy

Details
­ Smallmouth bass tend to be lethargic at temperatures <10°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
442             Lake Simcoe           Phys. Assoc.     Characteristic  Weed Beds            122                     110

Details
­ In August, adult bass were found mostly in Potamogeton weed beds. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
443             ­                               Water Level       Example                 -               201                     110
                                Area of Water   Example                Streams 
                                Water Motion    Example                 ­
                                Phys. Assoc.     Prefer         ­ 
                                Light       Prefer         ­

Details
­ Stream bass prefer shelter as water velocities increase.  When water
  levels decrease they seek darker areas for shelter.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
444             Cayuga Lake           Depth     Example                   ­               115                     110
                                Temperature      Example               ­

Details 
­ In Cayuga Lake, most bass in the summer were taken in the epilimnion, water
  depth was no deeper than 12 m, but a few were taken at 24 m deep. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
445             Cayuga Lake       Pred/Prey          Example                ­                    208                     110
                                Movememt         Example              ­
                                Depth          Example              ­

Details
­ Smallmouth bass at  a depth of 17-24 m in Cayuga Lake were thought to
  be following alewives. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
451             ­                             Temperature       Prefer          ­               215                     110

Details
­ The final preferred temperature for smallmouth bass was 28°C, but 
  (in the field) smallmouth bass were usually at 20.3°­21.3°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
452             ­                                Temperature       Limit           ­                133                     110

Details
­ The LD50 temperature for smallmouth bass was 29°­32°C, but smallmouth
  bass have been seen in 34°C water. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
453             ­                            Oxygen         Lethal               0.87, 0.96 ppm    249                     110
                                Temperature       Example                21°C 

Details
­ At 21°C, lethal concentrations of DO were 0.87 ppm and 0.96 ppm.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
457             ­                              Movement             Example              ­                  164                     110
                                Light           Characteristic   ­
                                Depth           Characteristic   ­
    
Details
­ Smallmouth bass tend to be inactive at night.  At midday, they may
  remain quietly sunning in shallow water. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
458             Ontario                         Movement             Example               ­                 219                     110
                                Light           Characteristic   -
                                Depth       Characteristic   ­

Details
­ At night, smallmouth bass move to deeper water, rest on the bottom, and 
  are often readily approached by divers. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
459             Ontario                         Pred/Prey           Characteristic   ­               219                     110
                                Light         Characteristic  ­
 
Details         
­ Smallmouth bass feed opportunistically during the day, but peak feeding
  occurs at dusk and early sunlight. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
460             ­                            Pred/Prey           Characteristic  ­                  196                     110

Details
­ The smallmouth bass is essentially carnivorous with small amounts of 
  vegetable matter taken probably by accident.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
461             Ohio                       Pred/Prey            Characteristic  ­                   190                     110
                                Light           Characteristic  ­  
                                Clarity               Requirement       ­
Details
­ Bass are dependent upon sight to feed.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
464             Oneida Lake           Pred/Prey         Example                ­                     216                     110

Details
­ Alewives were a major forage in Oneida Lake.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
466             ­                             Pred/Prey         Example              ­                     196     124             110
                                                                                        164     154
Details                                                                         206 
­ Where crayfish are abundant, they frequently comprise over 2/3 of the food.   182
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
467             ­                                Pred/Prey           Prefer               ­                 178                     110

Details 
­ Smallmouth bass took crayfish and tadpoles in preference to bluegills and 
  golden shiners. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
468             ­                              Competitors       Example              ­                   206                     110

Details
­ Although smallmouth bass eat many of the same items as walleyes, major
  use of crayfish by bass made competition minimal.                               
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
469             Maine               Competitors       Example                    ­                 116                     110

Details
­ Smallmouth bass will replace trout and salmon in marginal trout lakes.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
470             ­                                Competitors       Example                ­                   251                     110
                                Area of Water   Example                Warmwater
                                                                           Ponds
Details
- In warmwater ponds, smallmouth bass could not compete successfully with
  largemouth bass, bluegills, green sunfish, and bullheads. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
471             Cayuga Lake           Pred/Prey           Example                ­                  115                     110

Details
­ There is little seasonal change in diet.  Bass were still feeding in late
  November but less than in September. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
472             Arizona                        Pred/Prey           Example               ­                        255                     110

Details
­ In Bull Shoal's Lake, Arizona, young shad were the major summer food; 
  centrarchids and crayfish, in late autumn and winter; and mayflies 
  in spring. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
473             Ontario                    Pred/Prey            Example                ­                        188                     110

Details
- Bass stomachs examined in mid­April in Ontario were shrunken and full of
  mucous. This indicated little or no winter feeding. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
474             Quebec            Pred/Prey           Example                 ­                  158                     110
                                Temperature       Example              ­

Details
­ Bass do not feed in winter.                                                                        
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
475             ­                               Pred/Prey         Example              ­                  243                     110
                                Temperature       Example               ­

Details
­ Bass begin active feeding when temperatures near 15°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
646             ­                              Pred/Prey           Characteristic   ­                      111                     -

Details
­ A number of fish species feed on walleye fry.  These species include yellow
  perch, white bass, yellow bass, smallmouth bass, rainbow smelt, saugers, 
  bullheads, burbot and (most importantly) northern pike.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
658             ­                             Competitors        Example                 ­                      63                      -

Details
­ Walleye compete with such piscivorous fish as northern pike, yellow perch,
  sauger, and smallmouth bass.  Northern pike is probably the most important.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
659             Minnesota              Competitors        Example               ­                  480                     110

Details
­ After smallmouth bass were introduced into some northeastern Minnesota 
  walleye lakes,  bass generally became the dominant species (over walleye) 
  in boulder and rubble­lined lakes with high shoreline development factors
  and low populations of minnows and small fish.  However, in lakes with 
  little shoreline irregularity; moderate to extensive shoreline; shoal
  areas of gravel, sand and muck; and sizeable populations of forage
  fish; walleyes remained dominant. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
765             ­                             Competitors        Example               ­                    63                      112

Details
­ For food, perch may compete with any or all other predatory fishes present 
  in the same water.  These fish include brook trout, ciscoes, lake whitefish,
  basses (Morone spp. and Micropterus spp.), crappies, and bluegill.                      
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
770             ­                              Pred/Prey            Example                ­                      63                      -
                                                                                        112
Details
­ Almost all warm- to cold-water predatory fish will eat perch, including basses
  (Morone spp. and Micropterus spp.), sunfish, crappies, walleye, sauger, pike, 
  muskellunge, and lake trout. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1420            ­                              Pred/Prey           Characteristic   ­                  1011                    -

Details
­ Adults primarily feed on fish and crayfish in both lakes and streams. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1426            ­                              Area of Water   Example                ­                 110                     1011
                                Phys. Assoc.     Optimum               ­       

Details
­ Optimum riverine habitat for smallmouth bass is cool, clear, mid-order
  streams >10.5 m wide. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1427            ­                               Area of Water   Example              ­                   1056                    1011
                                Phys. Assoc.     Optimum                ­               1055
                                                                                        1023
Details                                                                         1053
­ Optimum riverine habitat for smallmouth bass is deep pools, moderate current,
  and a gravel or rubble substrate.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1428            ­                              Area of Water   Example              ­                   1060                    1011
                                Phys. Assoc.     Optimum                ­               1029
                                                                                        1055
Details                                                                         1023
­ Streams with gradients of 0.75­4.70 m/km, (providing alternating              1028
  pools and riffles), support the largest stream populations of
  smallmouth bass. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1429            ­                               Depth            Optimum                >1.2 m            1055                    1011
                                                                                        1050
Details                                                                         1021
­ Standing crop is generally largest in pools deeper than 1.2 m. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1430            ­                           Area of Water   Example                 ­                  129                     1011
                                Phys. Assoc.      Optimum              ­               1023
                                Depth           Optimum                >9 m            771
                                                                                        1053
Details                                                                         
­ Optimum lacustrine habitat is characterized by large, clear lakes and
  reservoirs with an average depth >9 m with rocky shoals.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1431            Northeastern            Depth            Characteristic   ­                  1033                    1011
                  Wisconsin                                                                      129
                Ontario

Details
­ Smallmouth bass are found almost exclusively in the epilimnion during summer
  stratification in northeastern Wisconsin and Ontario.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1432            Cayuga Lake,            Depth           Characteristic  £12 m          115                     1011
                  New York

Details
­ Smallmouth bass frequent depths up to 12 m in all seasons in northern 
  New York.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1433            ­                               Light            Avoid              ­                 1023                    1011
                                                                                        771
Details
­ Smallmouth bass exhibit strong, cover­seeking behavior and prefer
  protection from light during all life stages. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1434            ­                           Light           Avoid                 ­                 1023                    1011

Details
­ Deep, dark, quiet water is used for smallmouth bass cover.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1435            Illinois                         Phys. Assoc.     Example                 ­                     1041                    1011
                                                                                        1035
Details
­ Bass use all forms of submerged cover (boulders, rocks, stumps, root
  masses, trees, and crevices) without preference. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1436            Michigan                  pH                  Example                 5.7                1020                    110

Details
­ Smallmouth bass occur at pH levels of 5.7.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1437                Iowa             pH                Example                   9                   1050                    1011

Details
­ Smallmouth bass occur at pH levels of 9.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1438            Missouri                pH                  Optimum              7.9­8.1               1028                    1011

Details
­ The optimum pH level for smallmouth bass is 7.9­8.1. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1439            ­                            Area of Water   Example                 ­                   1036                    1011
                                Dissolved       Optimum                100­350 ppm     759
                                  Solids

Details
­ Smallmouth bass populations are more ppm productive in clearer, less-
  fertile reservoirs several years after impoundment with low total
  dissolved solids (TDS=100­350 ppm).
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1440            ­                              Oxygen           Optimum                >6 ppm           1016                    1011

Details
­ Smallmouth bass require >6 ppm DO for optimal growth.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1441            ­                               Oxygen         Limit                  ­                       1016                    1011

Details
­ Smallmouth bass production rates are reduced by 10% when the amount of 
  oxygen is lowered to 3 ppm at 15°C.  Production rates are reduced by 20%
  if oxygen is lowered to 4 ppm at 20°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1442            ­                         Oxygen          Lethal          ~1 ppm at       1016                    1011
                                                                          20°-25°C       249

Details
­ Smallmouth bass frequently die at DO concentrations approaching 1 ppm at
  20°­25°C.  
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1443            Cayuga Lake,            Turbidity           Tolerate              ­                      115                     1011
                  New York                                                                       222

Details
­ Smallmouth bass can apparently tolerate periodic turbidity.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1444            Tennessee                  Turbidity           Characteristic  £25 JTU             1035                    1011

Details
­ A typical smallmouth bass habitat has very low turbidity (usually
  £25 JTU) and almost never >75 JTU (except under flood conditions 
  when turbidity is sometimes as high as 250 JTU).
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1445            ­                               Area of Water   Example              ­                    182                     1011
                                Water Motion    Characteristic   ­               164
                                                                                        1028
Details                                                                         1053
­ In streams, adults smallmouth bass occupy pools or deep areas behind rocks
  where there is no perceptible current. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1446            ­                             Water Motion    Characteristic  ­                     222                     1011
                                                                                        164
Details
­ Smallmouth bass adults are often near the edge of the current during the day. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1447            ­                               Movement           Characteristic  ­                    1015                    1011
                                                                                        164
Details                                                                         1045
­ Movement of smallmouth bass adults in streams is restricted during a single
  season to a single pool. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1448            ­                           Phys. Assoc.    Characteristic  ­                 63                      1011
                                Depth         Characteristic  <12 m           1023

Details
­ In lakes and reservoirs, smallmouth bass adults often use cooler areas
  (such as dropoffs) away from vegetation and in water <12 m deep.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1449            Tennessee               Depth           Example               ­                       1035                    1011

Details
­ In a Tennessee River reservoir, smallmouth bass adults were frequently
  in water >10 m deep during the summer. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1450            Tennessee               Water Motion    Characteristic  10.9­32.0 cm/s    1035                    1011

Details
­ Seasonal mean current velocity in bass habitats varied from 10.9-32.0 cm/sec.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1451            ­                              Temperature       Limit                  ­                      1055                    1011
                                                                                        751
Details
­ Temperature may be the single most important factor limiting distribution 
  of smallmouth bass.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1452            ­                              Temperature      Characteristic  ­                      751                     1011

Details
­ During summer, bass inhabit warmer, shoreline areas of large lakes in the
  north and deeper, cooler waters in the south.                                         
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1453            ­                               Temperature       Limit            10°­14°C               1023                    1011

Details
­ Smallmouth bass growth begins when water temperatures reaches 10°­14°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1454            Montana                   Temperature       Prefer          21°­27°C               1021                    1011

Details
­ Field data indicate that smallmouth bass adults prefer temperatures of
  ~21°­27°C in the summer.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1455            ­                               Temperature       Prefer          ­                       1043                    1011

Details
 ­ Smallmouth bass acclimated at 2.2°­30.0°C selected temperatures of 20°-32°C
   in laboratory tests. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1456            ­                               Temperature      Prefer          28°­31°C         215                     1011
                                                                                        1128
Details
­ Adult bass in the laboratory preferred temperatures of 28°-31°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1457            ­                               Temperature       Optimum                26°­29°C                  1051                    1011
                                                                                        1058
Details                                                                         1065
­ Optimal smallmouth bass growth rates in the lab occurred at temperatures 
  of 26°­29°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1458            ­                                Temperature      Lethal               32.2°C             1023                    1011

Details
­ Upper lethal temperatures for adult smallmouth bass were >32.2°C.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1459            ­                              Phys. Assoc.     Characteristic   ­                       115                     1011
                                                                                        164
Details
­ When temperatures drop to 15°­20°C, adult smallmouth bass seek deep, 
  dark areas.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1460            ­                                Phys. Assoc.     Characteristic   ­                     1023                    1011
                                                                                        1058
Details
­ At ~10°C, bass become inactive and seek shelter.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1461            Middle Snake            Phys. Assoc.     Characteristic  ­                       164                     1011
                  River

Details
­ At 6°­7°C, most smallmouth bass are beneath the rock substrate, with few
  remaining on the top.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1462            ­                               Temperature       Lethal          ~0°C                1023                    1011

Details
­ The lower lethal temperature is near freezing.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1463            ­                               Temperature       Prefer           ­                       751                     1011

Details
­ Bass will congregate around warm springs in winter, when available. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1498            ­                               Water Motion    Prefer          ­                       1011
                                Depth         Characteristic   ­

Details
­ Juvenile and adult smallmouth bass prefer low-velocity water near a 
  current, but juveniles are often found in slightly shallower water than
  adults. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1506            ­                             Turbidity           Optimum               £25 JTU                  1011
                                Area of Water   Example                    ­
                                Phys. Assoc.     Optimum               ­
                                Temperature       Optimum              21°­29°C
 
Details
­ Optimal riverine habitat for smallmouth bass is characterized by:
  clear (£25 JTU) water; a second-order stream with a gradient of
  0.75-4.7 m/km; at least 25% pools; at least 25% cover and/or >1 m
  depth in the pools; warm (21°­29°C) summer temperatures; and gravel,
  rubble, or boulder substrate.                                         
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1507            ­                            Temperature       Optimum              21°­29°C               1011                    -
                                Area of Water   Example               ­
                                Phys. Assoc.     Optimum              ­
                                Turbidity         Optimum              £25 JTU

Details
­ Optimal lacustrine habitat for smallmouth bass is characterized by:
  lakes and reservoirs with warm (21°­29°C) strata available during 
  midsummer; abundant cover and/or depth; gravel, rubble, or boulder
  substrate or rocky shoals; and clear (£25 JTU) water. 
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
Lake Ontario    (Spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
389             ­                               Depth          Characteristic   ­                      151                     110
                                Area of Water   Characteristic   ­

Details
­ In Lake Ontario, smallmouth bass do not spawn until late June or July,
  except for some that enter shallow bays or streams to spawn in late May
  or early June. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
408             ­                               Phys. Assoc.     Example                ­                     151                     110

Details
­ Smallmouth bass nests have been reported as far as 10 m from shore.
                                                                                                                                                             

Smallmouth bass (Micropterus dolomieu)
        (Spawning Adult)

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
390             ­                          Temperature      Limit            ­                        157                     110
                                Water Level        Limit             ­               155
                                                                                        159
Details                                                                         222
­ Sometimes a second smallmouth bass spawning period may take place, 
  particularly if a temperature drop or high water interferes with the
  first spawn.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
391             ­                              Temperature       Characteristic   ­               237                     110
                                                                                        159
Details
­ Smallmouth bass spawning activity occurs in rising water temperatures
  when the daily minimum is not <13°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
392             ­                             Temperature       Characteristic   ­                    160                     110

Details
­ Smallmouth bass spawning occurs at 13°­21°C. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
393             ­                               Temperature       Characteristic   ­                    129                     110

Details
­ Smallmouth bass spawning occurs at 15°­18°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
394             Saskatchewan         Temperature       Characteristic  ­                    155                     110

Details
­ Smallmouth bass spawning occurs at 19°­21°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
395             ­                            Temperature       Characteristic  ­                        180                     110

Details
­ Smallmouth bass spawning occurs at 15°­21°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
396             Cayuga Lake           Temperature       Characteristic   ­                 115                     110

Details
­ Smallmouth bass spawning occurs at 11.7°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
397             ­                              Temperature       Characteristic   ­                     196                     110

Details
­ If the water temperature rises gradually, smallmouth bass spawning
  can be expected at ~15°C.  If water temperature rises rapidly, 
  temperatures may be ~18°C before spawning begins.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
398             Ohio                      Temperature       Characteristic   ­                     237                     110

Details
­ Smallmouth bass nesting may occur at temperatures below temperatures
  of egg laying.  Nesting occurred at 9.4°­21.0°C. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
399             Iowa                       Phys. Assoc.      Characteristic  ­                  222                     110

Details
­ Smallmouth bass nests are usually dished out down to coarse, egg­sized
  rubble, or bedrock. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
400             ­                              Phys. Assoc.      Characteristic  ­                        129                     110

Details
­ Smallmouth bass nests may be found in sand areas.  The bottom of the 
  bowl may be covered with woody debris and broken clam shells. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
401             ­                              Phys. Assoc.     Characteristic  ­                 251                     110

Details
­ Smallmouth bass nests may be on soft bottoms. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
402             Maine                     Depth         Characteristic  ­                      159                     110

Details
­ Smallmouth bass nests were usually 40­80 cm in diam. in water 66­100 cm
  deep. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
403             Lake Oneida           Depth           Characteristic  ­                  212                     110

Details
­ Most smallmouth bass nests in Lake Oneida were in water 3.7­5.5 m deep. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
404             ­                                Depth          Characteristic  ­                      222                     110
                                Area of Water   Example              Streams         157
                                Phys. Assoc.    Characteristic   ­

Details
­ In streams, most smallmouth bass nests were in water <75 cm deep.
  The nests are often near overhead cover or stumps, logs, stones, 
  or steep banks. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
405             ­                             Depth          Characteristic  ­                        222                     110
                                Water Motion    Example               ­               141
                                Phys. Assoc.     Characteristic   ­

Details
­ Smallmouth bass nests were usually in margins of deeper pools to take
  advantage of minimum current.  Lack of minimum-velocity pools eliminated
  spawning. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
406             ­                               Area of Water   Example             Lakes         129                     110
                                Depth           Characteristic   0.6­1.2 m       196
                                Water Motion    Example               Leeward Shore   174

Details
­ In lakes, smallmouth bass nests are usually at a depth of 0.6­1.2 m
  and 0.3-2.4 m from the leeward shore.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
407             ­                               Depth         Example                3.5 m           238                     110

Details
­ Smallmouth bass nests have been reported in water 3.5 m deep.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
409             Iowa                        Area of Water   Characteristic  ­                197                     110
                                Water Level      Limit           ­               222

Details
­ Smallmouth bass nesting was usually in tributaries instead of the
  Des Moines River or other rivers (particularly when river water levels
  were high). 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
410             Iowa                 Area of Water   Characteristic  Streams               222                     110
                                Water Level       Limit           ­
                                Phys. Assoc.     Example                ­
                                Movement             Characteristic   ­

Details
­ High water levels from April-May 15 were important to allow bass
  migration to suitable tributary stream areas.  High water also 
  rejuvenated gravel areas in streams by flushing away silt.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
417             Cayuga Lake           Turbidity         Example               ­                   115                     110
                                Water Level      Lethal          ­

Details
- Smallmouth bass eggs are laid in shallower, turbid water than when 
  water is clear.  Increased drying could exist if water levels recede.  
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
420             Saskatchewan       Temperature       Lethal                ­                        155                     110

Details
­ Any drop in smallmouth bass temperatures below 15.6°C (particularly
  for an extended period) may result in nest desertion, death of eggs 
  (and to a lesser extent) death of fry which have not risen from the 
  nests. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
423             Cayuga Lake        Temperature       Limit            ­                        115                     110
                                Water Level        Limit                  ­
                                Clarity             Limit            ­

Details
­ Male bass may desert the nest if there are sharp or prolonged drops in 
  temperature, external disturbances (such as humans), drops of water level,
  clearing of water, and development of egg fungus.  Males guarding nests
  in late May deserted when temperatures dropped from 18.3°C to slightly
  <10°C.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
441             Cayuga Lake           Area of Water   Example                 Large Lakes      115                     110
                                Movement          Characteristic   ­

Details
­ In the spring, adult bass in some larger lakes enter tributaries to spawn. 
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1421            ­                              Area of Water   Characteristic   ­                     1011                    -
                                Phys. Assoc.      Characteristic  ­

Details
- Smallmouth bass spawn on rocky lake shoals, river shallows, or backwaters,
  or move into creeks or tributaries to spawn. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1422            ­                            Phys. Assoc.     Requirement       ­                     1055                    1011

Details
­ Smallmouth bass require a clean, stone, rock, or gravel substrate for spawning.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1423            Montana                    General             ­                           -               1021                    1011

Details
­ Studies show that habitat condition during spawning is the most 
  important factor for year-class strength in smallmouth bass.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1424            ­                             Temperature       Characteristic   12.8°­21.0°C    129                     110
                                                                                        63
Details                                                                         1058
­ Smallmouth bass nest building and spawning occur when water temperature
  is 12.8°­21.0°C.  
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1425            ­                              Temperature       Characteristic   >15°C        1032    1058            1011
                                                                                        174
Details                                                                         203
­ Most smallmouth bass spawning activity occurs ³15°C.                               102
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1466            ­                               Phys. Assoc.       Characteristic   ­                      174                     1011
                                                                                        775
Details
- Smallmouth bass nests are commonly in gravel or broken rock.       
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1467            Montana                   Area of Water   Characteristic   ­                   1021                    1011

Details
­ Smallmouth bass nests are commonly in shallows or backwaters of streams.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1468            -               Area of Water   Characteristic   ­                 1055                    1011

Details
­ Smallmouth bass nests are commonly in protected bays or shoals in lakes.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1469            ­                               Phys. Assoc.      Characteristic   ­                     222                     1011
                                                                                        174
Details                                                                         63
­ Smallmouth bass nests are made over bedrock, rootlets in silt, or sand.  
  However, these substrates are less commonly used. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1470            Courtois Creek     Water Motion    Characteristic   ­                     1053                    1011

Details
­ Smallmouth bass nests are usually in areas of quiet water.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1471            ­                              Water Motion    Characteristic   ­                  1055                    1011

Details
­ Smallmouth bass nests are usually in areas of very slow current. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1473            ­                         Temperature      Limit                  ­                   115                     1011
                                                                                        1045
Details
­ Extreme fluctuations in temperature cause smallmouth bass embryo mortality
  from acute thermal shock.  Fluctuation also cause males (the caretakers)
  to leave the nest unprotected from predators and/or fungus may grow.                                   
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1474            ­                             Temperature       Limit           ­                   1011                    -

Details
­ There may be another smallmouth bass spawning period if there is a
  sudden drop in temperature during the first spawning attempt.
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1477            Courtois Creek     Water Level        Optimum              ­                    1053                    1011

Details
- Ideal spawning conditions include one or more substantial increases in
  water level a week or two prior to bass nesting. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1478            Maine                    Water Level       Optimum                ­                    116                     1011
                                                                                        1053
Details
­ Ideal smallmouth bass spawning conditions include relatively stable
  water levels while nesting is in progress. 
                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1479            ­                               Water Level       Limit                  ­                 1063                    1011
                                Temperature       Limit            ­               1045

Details
­ Rising water may flush smallmouth bass nest areas with cold water.  This 
  causes nest desertion and halts embryo development.
                                                                                                                                                             

                                                                                                                                                             
Ref. No.        Locality (Stock)        Factor(s)       Influence(s)    Data            Primary Ref. No.                Review No.
1480            ­                            Water Level       Limit             ­                        159                     1011
                                Temperature       Limit                  ­               1045
Details
­ Falling water levels may drive guarding males off, limit water circulation
  around eggs, and increase predation.  This results in lower smallmouth bass
  reproductive success.