The smelt move from lakes into tributaries in early spring to spawn. Spawning is related to spring thaw and often begins after consistent warming rain showers when water temperatures reach 5-7 degrees Celsius (C) or 42-44 degrees Fahrenheit (F).

What triggers a smelt run?

At 38 to 40 degrees, April Lake Michigan water temperatures have been too cold to trigger a run, with 42-45 ideal for a smelt spawn. ... ''Temperature acts as a trigger for many species when it comes to spawning. For smelt increasing temperature acts as their trigger.

Where do smelt run?

Smelts are a family of small fish, the Osmeridae, found in the North Atlantic and North Pacific Oceans, as well as rivers, streams and lakes in Europe, North America and Northeast Asia.