There are 79 fish species in the Credit River Watershed. Different fish species prefer different habitats.
The Credit is the most accessible and productive native Brook Trout river in Southern Ontario for catch and release fishing. It is most popular for fly fishing given the ample room for casting and the variety of healthy insect hatches.
Just below the Niagara Escarpment, Brook Trout mix with the introduced and naturalized Brown Trout, last stocked in 1962. The Brook Trout disappears by Inglewood as the Brown Trout thrives where the river widens and warms.
Rainbow Trout (or Steelhead) are commonly found in the spring from Lake Ontario to Norval but may also be found in lower Silver and Black Creeks. Due to stocking, these fish, along with their Pacific Coast cousins, the Chinook Salmon, are now an integral component of Lake Ontario’s ecology. Their return spawning migrations are controlled by two dams on the lower Credit River at Streetsville and Norval.
Chinook Salmon are closely regulated in the Great Lakes as part of an International Agreement to maintain them as an effective top predator. Their function is to replace the native predators (Lake Trout and Atlantic Salmon). To reduce potential impacts to other fisheries, Chinook Salmon, along with Sea Lamprey, are prevented from moving upstream of Streetsville.
Atlantic Salmon were once the most abundant migratory fish to use the Credit River. This species disappeared from Lake Ontario in the late 1800’s as a result of dams, over harvesting, and habitat destruction. In 2006, an experimental feasibility program for this “heritage species” became a large-scale reintroduction program. Anglers are currently not allowed to harvest this fish from the Credit River.
Smallmouth Bass at present are limited from expanding their range further upstream on the Credit by the Streetsville Dam. Studies are starting to investigate their reintroduction as far upstream as Norval. This would provide a valuable predator species and summertime fishery through urban areas of the lower Credit River.
Largemouth Bass are a good top predator for stocking ponds and angling opportunities. It is hoped that voluntary no harvest rules at Island Lake Conservation Area will help to improve the fishing for this popular species. Largemouth Bass are also found at Ken Whillans Resource Management Area and Fairy Lake in Acton.
Northern Pike are native to the river mouth and nearshore waters of Lake Ontario where only a few marshes remain. Pike angling and harvest is encouraged in the headwaters where they were illegally introduced. Pike reduce Largemouth Bass and Yellow Perch in Island Lake and prey on Brook Trout and other species as they colonize downstream. Northern Pike also exist in Fairy Lake.
The introduced Common Carp are considered a species that can offer anglers good opportunities, large size and great sport. They are established in Lake Ontario and the lower river. In other areas, controls such as the use of carp barriers, are considered as this introduced, invasive species can be harmful to valuable coastal wetlands.
Black Crappie, Pumpkinseed (Sunfish), Rock Bass, Yellow Perch and Brown Bullhead (Catfish) represent smaller panfish that are widespread and common to many small lakes and ponds, and are also found in slow moving river sections. At Island Lake Conservation Area, Black Crappie and Yellow Perch create winter fishing opportunities.
Suckers, Minnows, like Dace and Chub, Brook Lamprey, Darters, Sculpin and Stickleback represent other species that are recognized as part of a healthy aquatic ecosystem.