Using tiny syringe-like stomach pumps, researcher Jared Studinski removed the stomach contents from live 3- to 4-inch brook trout and returned the trout to the stream from whence they came.
The study purpose was to determine whether young brook trout ate better in heavily forested areas or in areas where the forest had been cleared.
If you'd asked me before I watched the presentation, I would have said brookies in the forest-covered part of the stream would have eaten much better.
I would have been wrong.
Studinski found that brookies in areas where the forest canopy had been removed consistently had fuller stomachs than their deep-forest brethren. The reason appears to be that aquatic insect populations undergo a bit of a boom when the stream gets exposed to sunlight.
In the forested areas, the little brookies relied heavily on terrestrial insects - ants, bees, beetles, etc. - for their food.
In the timbered areas, they relied more on aquatic insects in general and on small mayfly larvae in particular. Studinski said populations of one particular mayfly genus, the Baetids, tripled in areas where the canopy had been cut away. Trout, being opportunistic feeders, were quite happy to chow down on the sudden bonanza.
Studinski's study will definitely affect my approach toward fly-fishing small brook-trout waters. From now on I'll focus on terrestrial flies when I'm fishing heavily canopied streams, and on mayfly nymphs size 18 and smaller when I'm fishing streams where loggers have opened the canopy.
Better fishing - one of the hidden benefits of being a diehard science geek.
Reach John McCoy at johnmc...@wvgazette.com or 304-348-1231.