Population dynamics and production of crustacean zooplankton in two mountain lakes in the Italian Alps (Lake Paione Superiore and Lake Malghette).

Abstract

We estimated production of three populations of zooplanktonic crustacea from two lakes in the Italian Alps sampled within the EC-Project MOLAR (ENV-CT95-0007) "Measuring and modelling the dynamic response of remote mountain lake ecosystems to environmental change" (Lake Paione Superiore) and the EC- Guideline 78/659 "On the amelioration and the protection of freshwaters suitable for fish life" (Lake Malghette). The former is a fishless lake, while the latter, in addition to the native Phoxynus phoxynus, hosts populations of Salmo trutta fario and Oncorhynchus mykiss. The Allen curve method was used to estimate production of Acanthodiaptomus denticornis and Daphnia longispina in Lake Malghette and of Cyclops abyssorum tatricus in Lake Paione Superiore. Values of daily production of the three populations are similar to those found by other Authors in oligotrophic and high mountain environments.

Keywords

• zooplankton, secondary production, acidification, high mountain lakes