Some Observations on the Shore Fauna of Baffin Island

Abstract

From June to Sept., 1953 collections were made and intertidal environment was studied at stations in Frobisher Bay, Cumberland Sound, Pangnirtung Fiord, Pond Inlet, Padloping, Craig Harbour and Clyde River. Collections of the following groups were made Anthozoa, Nemertinea, Ectoprocta, Priapulida, Polychaeta, Cirripedia, Amphipoda, Gastropoda, Pelecypoda, Echinoderma, Tunicata and fishes. Shore fauna in Frobisher Bay is similar to that in Cumberland Sound. N. of Cumberland Sound there is a change in abundance and variety of shore fauna, and in the vicinity of Padloping Island and farther n. intertidal zone is almost barren. Intertidal spp. can be divided into 2 groups, depending upon 2 methods of adaptation to intertidal environment. One group includes animals that usually live only between tide-marks and normally die when immersed for any length of time; these are specifically intertidal spp. and include the barnacle, Balanus balanoides, and the periwinkle, Littorina saxatilis. The other group includes spp. generally found in shallow water, but which can withstand exposure to air for short periods and are able to colonize the lower levels of shores. They include the clam, Modiolaria discors, and the scale-worm, Harmothoe imbricata. There are 2 intertidal transitions, one which affects the panarctic shallow-water spp., and the other the specifically intertidal spp. 2 transitions coincide in Baffin Island; they do not coincide in east Greenland. Once panarctic species that are limitied vertically by ice and low salinity are recognized, n. limit of subarctic in Baffin Island appears to coincide with the n. limit of the specifically intertidal spp. || ABSTRACT AUTHORS: W. W. Judd