Ecology of the Cladocera of the North Atlantic and the North Sea. 1960-1967

• Main Author: Gieskes,W. W. C.
• Other Authors: MCGILL UNIV MONTREAL (QUEBEC) MARINE SCIENCES CENTRE
• Format: Text
• Language: English
• Published: 1971
• Subjects: Biological Oceanography; (*CRUSTACEA; *NORTH SEA); (*ECOLOGY; CRUSTACEA); MARINE BIOLOGY; ATLANTIC OCEAN; DISTRIBUTION; CLIMATOLOGY; PERIODIC VARIATIONS; AQUATIC ANIMALS; CANADA; *CLADOCERA; SEASONAL VARIATIONS; Canada; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/AD0735569; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0735569

The distributions, and seasonal and annual variations in abundance, of five species of Cladocera are described and analysed. The material was collected by Continuous Plankton Recorders from 1960 to 1967 inclusive at a standard depth of 10 m in the North Atlantic and the North Sea. Evadne nordmanni and Podon intermedius were neritic and oceanic, Podon leuckarti appeared to be typically neritic, Evadne spinifera typically oceanic, and 'Podon' polyphemoides indicative of estuarine waters. Species are never abundant as long as the water column is not stratified. This phytoplankton-like dependence on stratification suggests, that Cladocera need near-surface conditions for their successful propagation, both in neritic and in oceanic regions. It is shown that Cladocera are dispersed very effectively, so that almost as soon as environmental conditions have become suitable, whether in the open ocean or in coastal waters, animals will appear and populations become established. Evadne nordmanni and E. spinifera seemed to be mutually exclusive in all reas, as were Podon leuckarti and P. intermedius. Congeners have different temperature tolerances and different temperature optima. Podon leuckarti and Evadne nordmanni are cool-water species, most abundant in spring and early summer; the larger Podon intermedius and Evadne spinifera are warm-water species. (Author) See also AD-735 568.