Kinds and Abundance of Zooplankton Collected by 

 the USCG Icebreaker Glacier in tlie Eastern Chukchi Sea, 



September-October 1970 



BRUCE L. WING" 



ABSTRACT 



Zooplankton samples were taken at 39 oceanographic stations in the eastern Chukchi Sea in Sep- 

 tember and October 1970. Sampling was done by vertical tows from near bottom to the surface with a 

 0.5-m diameter No. (0.57 mm) mesh NorPac standard plankton net. Data are presented on the distribu- 

 tion and relative abundance of 63 categories of zooplankton at the onset of winter. Zooplankton abun- 

 dance generally was lowest in waters with temperatures below 0°C; it did not appear to be associated with 

 the distribution of salinity; and it tended to be inversely related to dissolved oxygen concentration. 

 Comparison of zooplankton abundance in 1970 with published observations on the Chukchi Sea in 1947 

 shows probable seasonal variation of meroplankton abundance and yearly variation of holoplankton 

 abundance. 



INTRODUCTION 



In September and October 1970, the U.S. Coast 

 Guard icebreaker Glacier made the first of the West- 

 ern Beaufort Sea Ecological Cruises (WEBSEC-70). 

 The WEBSEC program is carried on principally by the 

 Coast Guard, but several other Federal agencies and 

 universities cooperate in obtaining the many types of 

 data required for a complete ecological assessment of 

 the Beaufort Sea. The work of WEBSEC-70 was actu- 

 ally done in the eastern Chukchi Sea because excep- 

 tionally heavy pack ice prevented work east of Bar- 

 row, Alaska. 



I participated in the WEBSEC-70 cruise from 26 

 September to 17 October. During that time I took 

 zooplankton samples at 39 of the 92 stations occupied 

 by the Glacier (Fig. 1, Table 1). The area covered was 

 between lat. 68°54'N-70°34'N and long. 162°24'W- 

 168°56'W. My objective was to determine the kinds 

 and abundance of zooplankton in the eastern Chukchi 

 Sea at the onset of winter. Previously, with the excep- 

 tion of MacGinitie (1955), information on the zoo- 

 plankton of the eastern Chukchi Sea was limited to the 

 summer months of July and August (Johnson, 1936, 

 1953, 1956, 1958; Hand and Kan, 1961; English, 1966). 



This paper lists the kinds and abundance of zoo- 

 plankters collected in 1970. It then relates the 

 zooplankton distribution to the distribution of temper- 

 ature, salinity, and dissolved oxygen and compares my 

 abundance data for 1970 with Johnson's (1953) data for 

 the 1947 summer cruise of the USS Nereus. 



METHODS 



My zooplankton sampling was limited to those sta- 

 tions at which the Coast Guard took hydrographic 

 casts to measure physical and chemical characteristics 

 of the water. Of the 92 stations occupied by the 



Table 1 .--Location, depth, date, time and number of species of zooplankton 

 collected for 39 stations occupied by the USCG icebreaker Glacier , 26 

 September to 17 October 1970. 



Station 

 number 



Lonp. M Lat. N 



Sampling 

 depth 



(BST) 



Number 



■>' 2 

 species- 



'Auke Bay Fisheries Laboratory. National Marine Fisheries Ser- 

 vice. NOAA, P.O. Box 155, Auke Bay, AK 99821. 



-Qualitative phytoplankton samples also taken at this station. 



