**ABSTRACT NOT FOR
CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for
this completion report are provided below. For a copy
of the full completion report, please contact the author via e-mail at vandergo@msu.edu.
Questions? Contact the GLFC via email at frp@glfc.org
or via telephone at 734-662-3018.**
Identifying
migration patterns and spatial ecology of a reef spawning stock of walleye in
the western basin of Lake Erie
*Principal Investigator. 1Michigan
State University, Center for Systems Integration and Sustainability, 115 Manly Miles
Building, East Lansing, MI 48823, USA. 2Ohio
Department of Natural Resources, Division of Wildlife, Sandusky Fisheries
Research Station, 305 East Shoreline Drive, Sandusky, OH 44870, USA. 3U.S.
Geological Survey, Lake Erie Biological Station, Great Lakes Science Center,
6100 Columbus Avenue, Sandusky, OH 44870, USA.
July 2019
ABSTRACT:
Previous
tagging studies conducted with Lake Erie walleye suggests this population
consists of multiple discrete spawning aggregations; however, a comprehensive
understanding of stock-specific movement patterns, spawning ecology/ phenology,
bioenergetics, thermal ecology and vertical distribution is lacking. Walleye
from open-lake reef and tributary spawning aggregations were tagged with
acoustic transmitters and their movements monitored for up to four years to
understand spatial and temporal habitat use, spawning site fidelity, spawning
repetitiveness (i.e., do they spawn annually or exhibited “skipped spawning”
behavior) and post-spawning movement patterns. Overall, open-water reef walleye
(i.e., both sexes) exhibited higher spawning site fidelity than fish tagged in
the Maumee River. Male and female walleye exhibited a similar probability (0.10
– 0.15) of skipping a spawning event regardless of spawning local (i.e., open
water reef and tributary). Male walleye arrived earlier, departed later and
spent more time on the spawning grounds (i.e., tributaries and open-water
reefs) than females. Walleye spawning on the open-water reef complex moved out
of the western basin earlier than fish spawning in the Maumee River. Movement
out of the western basin following the spawning period seemed to be influenced, at least partially, by fish sex and size. Female
walleye vacated the western basin earlier than males, and larger (and
presumably older) female walleye moved out of the western basin sooner than
smaller females; however, a size-dependent pattern for males was not evident.
Outmigration of walleye from the Maumee River was approximately two weeks later
than fish spawning on the open-water reef complex. Although the majority of
fish tagged from western basin spawning populations migrated toward the central
and eastern basins following the spawning period, a contingent of the
population (4-8%) from the Maumee River migrate annually north toward Lake Huron
via the Huron-Erie corridor. Using surgically implanted thermal loggers (i.e.,
in combination with acoustic transmitters), thermal occupancy was compared between walleye in lakes Erie and Huron. Lake
Erie walleye experienced higher temperatures during spring and summer months
compared to Lake Huron resulting in Lake Erie walleye
growing at nearly double the rate of Lake Huron walleye. Ultimately, these
sex-specific differences in growth were attributed to
higher forage availability in Lake Erie compared to Lake Huron. The
stock-specific movement, spawning ecology and population dynamics information
observed during this study provides Lake Erie scientists with a new conceptual
model of how this ecologically and economically important fish stock functions
within the Great Lakes ecosystem. Consequently, this information has provided
Lake Erie managers with a more in-depth understanding of walleye behavior in
Lake Erie and can be used to establish sustainable
harvest regulations via stock assessment population modeling.