The prior Atlantic Salmon program by the href=”http://www.ontario.ca/mnrf” target=”_blank”>Ontario Ministry of Natural Resources and Forestry (MNRF) was a research program, designed to study the potential of Lake Ontario’s tributaries for young Atlantic Salmon. Assessment of adult returns was never pursued and reported only incidentally. The research was strictly intended to be the first step of a longer-term plan to eventually restore Atlantic Salmon; this research came to the conclusion that Atlantic Salmon fry and juveniles can successfully survive in the streams in their current state, and because of this we are now taking the program to the next stage.

Because the research focused on juveniles, there were never enough Atlantic Salmon stocked to produce the number of adults needed for successful restoration. At most approximately 200,000 fry went into any one stream in any one year. Current production targets for 2006, to be spread across three streams, are 400,000 fry, plus 100,000 fall fingerlings (equivalent to 1,000,000 wild fry) and 50,000 yearlings (equivalent to 5,000,000 wild fry). Production targets are slated to increase further in 2007 and beyond.

While migration to the ocean was possible for Lake Ontario’s Atlantic Salmon prior to the construction of the Saunders dam on the St. Lawrence River, growth histories recorded in the scales of two museum specimens demonstrate an exclusively freshwater life. Further, the timing of historical spawning runs would not have been possible if all Atlantic Salmon were returning from the ocean, and fish would not have been in the prime condition noted by early harvesters if they had run 2,400km from the Atlantic Ocean to Lake Ontario’s tributaries to spawn. Genetic evidence does suggest there was some gene flow between Lake Ontario and sea-run populations. Therefore the population was primarily freshwater, but with low levels of in- and out-migration to the Atlantic Ocean. Additionally, there are several extant and extirpated entirely freshwater Atlantic Salmon populations throughout their range.

Planned Atlantic Salmon stocking will avoid saturating all reaches of the target streams, leaving entire stretches of streams available for other salmonid species. In particular, upper reaches dominated by Brook Trout will be avoided. Also, research has shown that with abundant habitat, both Rainbow Trout and Atlantic Salmon will thrive, and the restoration program has a major component dedicated to habitat improvement, which will benefit all species.

It will be several years before there is an Atlantic Salmon population in Lake Ontario large enough to have a demonstrable impact on the overall forage base of Lake Ontario. Further, Atlantic Salmon are opportunistic and are expected to utilize a broader prey base, such as more bottom-dwelling fish species and invertebrates, than most other salmonids. The fish prey base of the Great Lakes has shown itself to be cyclic and often driven by factors other than predation.

As mentioned, Atlantic Salmon are opportunistic and have a broad prey base. Thiamin deficiency in Lake Ontario salmonids has not prevented Chinook and Coho Salmon and Rainbow Trout from establishing themselves in the lake and tributaries.

We expect the quality and quantity of fishing opportunities to increase with the addition of a legendary sportfish species that has a later running time in streams. Other stream-dwelling species will also benefit from the extensive stream habitat restoration that is integral to the overall program. This program meets Lake Ontario’s Fish Community Objectives of the Great Lakes Fisheries Commission and the Strategic Plan for Ontario Fisheries (SPOF II) objectives of maintaining viable populations of native fish species. Atlantic Salmon restoration has also previously been incorporated into Fisheries Management Plans for watersheds on Lake Ontario.