Culling trout for a purpose

[JeffK]

IMHO, the brookies did fatten up in the larger rivers in many places like NJ, PA, and Maine. Back in the day when there were no smallmouth, rainbows, browns, walleyes, pike, muskies, rock bass, largemouth, bluegills, channel catfish, or crappie in NJ rivers the brookies lived 8 months or so of the year in the larger rivers and only had to head to cold water refuges a few months a year. That allowed them to utilize the food of the larger rivers to attain large sizes.

This only works if when the brookies return home after their summer vacation in the tribs no one else is living in their big river home. At one time brookies and pickerel were the top predators in NJ and this worked out. However, the wide variety of introduced predatory game fish can take over all the available niches in the larger rivers so that the river trout are out of house and home when they drop down to the rivers. This leaves only the little ones that live full time in the tribs.

Something similar happened to many Maine brookie ponds. The brookies fattened up in the fertile shallows in the cold months and retreated to the depths in the summer. That allowed them to take advantage of food production in the more productive shallows. Then smallies got stocked. The smallies took over the shallows in the summer and the brookies found that much of summer's bounty had been gobbled up when they moved shallow in the fall. Maine ponds aren't fertile enough to support both, so the brookies suffered. Pyramid Lake cutthroats work the same way. The shallow fringes are productive in the desert summer and the prey gets fat and soft without any predators. When cold water comes back the trout go on a feeding spree on the shallow flats. That allows the trout to get so big it takes an 8 lbs fish to get noticed and 20" fish are snubbed as small guys. Fortunately, with a pH of 9.4 alien species are only found near the inlet since few fish can tolerate water that alkaline other than the native lahontan cutthroats. No smallies can ruin their party.