David, I would question whether the light would actually increase food availability. It definitely would concentrate flying insects over the water and so would concentrate the insects dropping on the water surface. almost all of the insects would be the aerial stages of aquatic forms, and most of those would have come from the stream in question (though not all).
Would it increase predation on the feeding fish? Well, I can't speak to the salmon system, and I will rely on non-scientific experience for the general thought. In the southern U.S. people use lights to attract insects and "bait fish" to their fishing spots. I have not seen any science that supports their beliefs, but they definitely believe that they catch a lot more of their target species when they fish with lights. Of course, the target species are predators on the bait fish that the insects attract, and that the lights may also attract directly. Hope this helps. David McNeely ---- David Inouye <[email protected]> wrote: > My brother is involved in restoring habitat for small salmon on a > side channel stream in WA. He's considering putting a small solar > light over a beaver pond, to increase insect drops onto the water, as > fish food. Would the fish be likely to feed on such insects, and > could there be other consequences, such as increased predation on > fish attracted to the light at night? > > David Inouye -- David McNeely
