Effects of Neutralization and Addition of Brook Trout (Salvelinus fontinalis) on the Limnetic Zooplankton Communities of Two Acidic

Abstract

The zooplankton communities in two acidified lakes in the Adirondack region of New York changed considerably following liming and the reintroduction of brook trout (Salvelinus fontinalis). Most rotifer taxa were greatly reduced in numbers within a week following base addition. Keratella taurocephala declined by orders of magnitude in both lakes. Rotifer species that replaced K. taurocephala were far less abundant. The crustacean communities were also affecting by liming. Diaptomus minutus, the dominant in both lakes, declined following base addition. Longer-term population responses appeared to be related to the dynamics of the individual populations, and changes in predation pressure. Four additional crustacean species became prominent in the lakes after liming: the cladocerans Bosmina longirostris and Daphnia catawba in Cranberry Pond, and D. catawba and the cyclopoid copepod Cyclops scutifers in Woods Lake. Over the longer-term liming and the introduction of brook trout tended to have an overall positive effect on the zooplankton communities in the two lakes.