Chronology of Lake Ontario ecosystem and fisheries

The Lake Ontario drainage basin has been considered the most productive of all the deepwater Laurentian Great Lakes for fish production and extremely valuable for its historical commercial fisheries catches. Historical accounts are replete with this productivity, especially when referencing Atlantic Salmon populations. In addition to Atlantic Salmon, Lake Ontario contained a diverse coldwater fish community dominated by Lake Trout, whitefishes (Coregoninae), and Burbot along with rich cool and warmwater fish communities. Lake Ontario also contained marine relict species, such as Harbour Seal, Threespine Stickleback, and possibly Sea Lamprey, Rainbow Smelt and Alewife along with the catadromous American Eel. Following European colonization of the watershed, extensive land-use change, overfishing, dam construction, habitat degradation, pollution, and invasive species all contributed to the decline and extirpation of many native species and shifts in aquatic species communities. This chronology is meant to provide context and inform expectations regarding productivity of Lake Ontario and contributing watersheds for developing more comprehensive resource management plans, guidelines, and policy.