Simcoe County Bird and Nature Board. POSTS MUST INCLUDE FULL NAME AND EMAIL ADDRESS OR THEY WILL BE DELETED FROM THE BOARD. Banners at top of page cannot be blocked but are not part of the page. BOB BOWLES
Emerald Shiners at the Barrie Waterfront


I checked the Barrie waterfront today for gulls: Herring, Ring-billed, Great Black-backed, Bonaparte's, Glaucous, and Iceland were all to be found. Others had seen Thayer's, Lesser Black-backed, and Little earlier in the day.

I decided to do some reading about the Emerald Shiners which can be seen in such huge numbers in the shallows of the lake, in particular at the pier at the bottom of Bayfield Street.

These fish are mostly young-of-the-year (not spawning adults), which are known to leave their usual deep-water habitats and move inshore to shallows in the autumn. With the advancing season (ice-cover?) they move to deeper water to overwinter. Populations fluctuate widely in abundance from year-to-year. Periods of scarcity followed by highs of great abundance are characteristic of this speciesóboom and bust. Burbot, Smallmouth Bass, Lake Trout, and "most other sport fish in some season" use this species as their principle source of food. One study found that 64% of Lake Trout diet consisted of Emerald Shiners. As far back as 1956, McCrimmon noted that the Emerald Shiner was the most common minnow in Lake Simcoe. The information above comes largely from Scott and Crossman's Freshwater Fishes of Canada, where they go on to say "many fish-eating birds, such as gulls, terns, mergansers, and cormorants feed heavily open emerald shiners, whose surface swimming habits makes them particularly susceptible to this kind of predator."

There doesn't seem to be any explanation given as to why the young take refuge in the shallows, but it could be to access a food source found only there, or to avoid predation by fish (which, though hard to picture, might be worse than the bird depredation they face that we see).


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