The comparative limnology of some New Zealand lakes

Abstract

The 24 New Zealand lakes studied include the largest and deepest lakes in the country. Of 17 North Island lakes, all but 2 are on the Volcanic Plateau; the 7 South Island lakes all lie in the mountains of Otago and Southland. The phytoplankton of the South Island lakes was not studied. The seasonal variation in genera of phytoplankters in seven regularly sampled lakes on the Volcanic Plateau, North Island, showed that Melosira was the most abundant genus in all but one. It reached a maximum in winter, but the next most abundant genus, Dinobryon, had its maximum in summer. Among zooplankters, Boeckella dilatata was present in all the South Island lakes, and Calamoecia lucasi in all but four of the North Island lakes; Boeckella propinqua and B. hamata each occurred in two North Island lakes. Bosmina meridionalis, the common cladoceran in all lakes, occurred in 22 of the lakes, Ceriodaphnia dubia in 20, but Daphnia carinata in only 8. Discussion of the relative productivity of those lakes sampled frequently is based on mean numbers of cladocerans and copepods and mean volumes of phytoplankton.