Vertical Distribution of Zooplankton in Eastern Lancaster Sound and Western Baffin Bay, July-October 1978

Abstract

at 19 oceanographic stations were analyzed for species composition, abundance, biomass and vertical distribution. Sampling was by closing nets hauled vertically at five depth intervals between O and 1900 m. At least 116 species were present in the macro-zooplankton of the study mea. Species not previously reported from the area included the copepods Spinocalanus horridus, Chiridiella reducta, Derjuginia tolli, Neoscolecithrix farrani?, Pachyprilus pacificus, Haloptilus longicirrus?, Mormonillapolaris, and Monstrilla longicirrus?. In addition, small numbers of the previously undescribed adult male stages of the copepods Aetideopsis multiserrata and A. rostrata were found. Three copepod species that appear to be new to science were also collected. The high numbers of species, new records for the area, and previously undescribed species or stages collected reflect the relatively intensive sampling, particularly in deep water. In general, the zooplankton was numerically dominated by copepods, particularly the calanoids Calanus glaciulis, C. hyperboreus, Pseudocalanus minutus, Metridia longa and Microcalanus spp. and the cyclopoid Oithonu similis. Most of these species (exceptions: Metridia longa and Microcalanus spp.) were most abundant in the upper 50 m; total zooplankton numbers were also greatest there. However, one or more stages of each of these copepod species, except P. minutus, were present in depths as great as 1900 m. Factor analysis identified 10 zooplankton assemblages. Of these, two were virtually restricted to the upper 50 m, two were mainly in the upper 50 m but were also found throughout the water column, five were primarily deepwater groups (one almost entirely restricted to deep water), and one was primarily an intermediate depth group.

Population densities, growth, and respiration of the chaetognath Parasagitta elegans in the Canadian high Arctic

“…Studies in north Baffin Bay and Lancaster Sound showed that Eukrohnia hamata (Möbius) was the most abundant chaetognath, being present throughout the water column. Sagitta elegans was less abundant and restricted to Arctic Ocean water (0-200 m), mostly the upper 50 m (Buchanan and Sekerak 1982;Sameoto 1987). The much larger Sagitta maxima was most abundant in deep (>400 m) water in south Baffin Bay (Sameoto 1987).…”

Seasonal variations in distribution and population structure of Microcalanus pygmaeus and Ctenocalanus citer (Copepoda: Calanoida) in the eastern Weddell Sea, Antarctica

“…M. pygmaeus is an abundant member of the plankton in mid-water layers of the Southern Ocean (e.g. Hopkins 1985a; Schnack et al 1985a;Hopkins and Torres 1988) Buchanan and Sekerak 1982), whereas C. citer is a com--50~ mon species in the Antarctic epiplankton (Kaczmaruk 1983;Zmijewska 1983;Schnack et al 1985 a;Tanimura et -55~ al. 1986;Hopkins 1987;Hopkins and Torres 1988;Tucker and Burton 1990).…”

Effect of daylength and food concentration on in situ diurnal feeding rhythms in Arctic copepods

“…The light cycle limits the period in which photosynthetic production is possible, and for the pelagic algal community, this is further restricted by ice cover in spring. In the eastern Canadian Arctic the abundant pelagic zooplankton community is dominated by the copepod herbivores Calanus hyperboreus and C. glacialis (Buchanan & Sekerak 1982, Longhurst et al 1984, which crowd into the surface layers to feed during the summer and then descend to overwinter at depths greater than 300 m (Dawson 1978, Kosobokova 1978, Longhurst et al 1984. During this intense feeding period there is no significant diurnal migration in C. hyperboreus or C. glacialis (Bbmstedt 1984, Longhurst et al 1984, which contrasts with the behavior of C. finmarchicus when found in the Arctic (Sameoto 1984) and also in Calanus species in temperate regions (Bohrer B Inter-Research/Printed in F. R. Germany 1980, Herman et al 1981, Huntley & Brooks 1982, Williams & Conway 1984, Simard et al 1985.…”