Rainbow (steelhead) are originally from the west coast.
Rainbow trout first stocked in Lake Huron in 1876 in Michigan waters.
First seen in Ontario waters in 1903.
Abundance increased after the demise of lake trout in 1940-50s.
Numbers increased further with lamprey treatment in 1960s.
Hurricane Haze in 1956 opened many rivers for spawning.
Dam removal and fishways increased numbers to peak in 1970s and early 1980s.
Loss of habitat and access is a concern for natural reproduction
Increasing abundance resulted in more angling.
Sanctuaries, varying open seasons, bag limit changes, and stocking were all used to reduced the effects of increasing angler pressure.
In 1970 and 1980s most of fishing pressure was from stream anglers.
With the creation of a significant salmon fishery in the mid to late 1980s the boat fishery increased dramatically.
Rainbow were caught from both targeted and incidental boat fisheries.
The bulk of the cold water streams accessible to annadromous salmonids occur in the Ontario waters of Lake Huron The bulk of natural reproduction therefore occurs in Ontario waters.
Stocking was relatively stable through the 1970s
In the mid 1980s volunteer groups were allowed to develop private hatcheries for stocking in Ontario waters which increased the levels of stocking
Stocking levels have been relatively stable in the 1990s
In Ontario waters declining rainbow numbers were evident in late 1980s early 1990s in southern Georgian Bay.
Some indications of declines also occurred on Manitoulin Island
Six fishways on streams in Ontario waters allow for monitoring rainbow trout spawning runs
Significant fluctuations in abundance occur between years at fishways. Indications indicate that declines have occurred in rainbow trout runs. This supports anecdotal reports from anglers that populations were down. At the same time increased stocking levels at some tributaries has resulted in increased abundance of stocked fish in spawning runs. Although declines have occurred stocking may have helped to dampen the effects of declining populations it masked the loss of natural reproduction.
Concurrent assessment of Main Basin tributaries did not indicate any decline in rainbow trout abundance.
There has however been some indications of increased numbers of stocked rainbow trout in the Main Basin As more stocked fish are marked (Michigan) the percentage of clipped fish could be increasing. Although any reduction in abundance of wild fish could be masked by stocking levels, the harvest levels of fish in the Ontario waters of the Main Basin are lower than Georgian Bay.
In looking at the data it was determined that rainbow trout populations were depressed due to a series of dry years in the late 1980s early 1990s which resulted in poor year classes
The increase in angling pressure prevented rainbow numbers from rebounding once more favourable weather conditions occurred.
Climatic conditions depressed the populations but angling pressure kept them down.
Harvest is much larger in Georgian Bay than in the Main Basin. Although low water flows affected both areas, Georgian Bay had the addition of high harvest levels to keep the depressed populations down.
Initially many of the public looked on stocking as the salvation of rainbow trout.
Eventually through education they came to realize that stocking is only part of any solution.
Through public consultation and discussions between PAC members and OMNR staff the recommendations were revised in the spring of 1997.
The changes were finally accepted and were passed in December of 1998.
The bag limit reduction was retained for Georgian Bay, the southern main basin and the watershed rivers in Divisions 3 and 4.
Many river specific changes were included in the package which created seasonal sanctuaries and changes rainbow trout closed seasons.
These changes were intended to either reduce harvest or address areas identified with poaching problems.
Reduced seasons, sanctuaries, salmon seasons
MDNR started stocking mainly Little Manistee River strain rainbow trout in 1993 (naturalized stock 130 years in Lake Michigan). They since moved to cessation of stocking domestic strain rainbow trout. The catch rates of rainbow trout in U.S. waters of Lake Huron jumped in 1995 due to this change in strain. Catch rates declined in 1998 but have increased since and the 2000 catch rate was above the long-term average.
Due to little natural reproduction and the resulting dependance on stocking, reductions in rainbow trout were not evident in Michigan waters of Lake Huron. No evidence of declines in rainbow trout runs are evident in Main Basin tributaries in Ontario waters. Possibly Michigan planted fish are sustaining numbers which are therefore not dependent on natural reproduction. Recent marking of rainbow trout by Michigan will soon determine the level of natural reproduction that is occurring in Ontario rivers on the Main Basin.
For Ontario waters, where naturally reproducing populations are desired and important, there is a need to continue monitoring the populations
If the rainbow trout populations decline further more stringent regulations will need to be considered.
The concern is that changes made by that time could be too late to avert a decline, making rehabilitation a much longer process.
The future of the rainbow trout populations is unknown.
There is concern that the regulation changes made will not go far enough.
The current drought conditions and low water levels will result in more poor year classes in the future.
Additional monitoring is required.