COMPOSITION, ABUNDANCE, AND DISTRIBUTION OF ZOOPLANKTON 

 IN THE NEW YORK BIGHT, SEPTEMBER 1974-SEPTEMBER 1975 



David C. Judkins,' Creighton D. Wirick,' and Wayne E. Esaias^ 



ABSTRACT 



Zooplankton taxa were counted in 8 to 19 samples from each of 11 cruises in the New York Bight 

 between September 1974 and September 1975. Meyor seasonal events were an influx into the region of 

 tropical-subtropical copepod species during autumn 1974 and summer 1975, an offshore ( >50 m water 

 depth) zooplankton abundance maximum in March dominated by the pteropod Limocina retroversa, a 

 second offshore maximum in May characterized by high abundance of the copepods Pseudocalanus 

 sp., Calanus finmarchicus, and Oithona similis, and an onshore ( <50 m water depth) maximum in 

 July characterized by high abundance of the copepods Centropages typicus and Temora longicornis. 

 The offshore maxima occurred during or shortly after the local spring phytoplankton bloom 

 (March-April). Advection of pteropod and copepod stocks into the region from the northeast probably 

 contributed to these peaks. The July C. typicus-T. longicornis peak was associated with summer 

 warming of the water column within the highly productive waters in the Bight apex and off the New 

 Jersey coast. Comparison of our results with those of a study conducted in 1959-60 shows that the 

 most abundant species of copepods were essentially the same during the two periods. 



The New York Bight is the section of continental 

 margin and overlying water within the bend of the 

 Atlantic coastline bounded by Long Island on the 

 north and New Jersey on the west (Figure 1). It is 

 one of the most heavily used coastal regions of the 

 world for a variety of human activities, including 

 transportation, fisheries, recreation, and waste 

 disposal (Gross et al. 1976). Exploration for and 

 exploitation of potential offshore petroleum de- 

 posits may place additional burdens on the re- 

 gion's environment. Efforts to document changes 

 in the biota because of these activities have gener- 

 ally been inadequate, especially in regards to the 

 zooplankton. In a recent review, Malone (1977) 

 observed that studies of the zooplankton of the 

 New York Bight generally have been restricted to 

 small geographic areas and to short periods of 

 time, and consequently little data on species 

 abundance and distribution exist for most of this 

 heavily exploited area. 



In this paper, we examine seasonal and 

 onshore-offshore trends in occurrence and abun- 

 dance of zooplankton taxa in waters of the New 

 York Bight. These observations are based on 

 analysis of the most comprehensive set of zoo- 

 plankton samples obtained to date within the re- 

 gion and thus are invaluable for comparison with 



'Oceanographic Sciences Division, Brookhaven National 

 Laboratory, Upton NY 11973. 



^Marine Sciences Research Center, State University of New 

 York, Stony Brook, NY 11794. 



future studies. We compare our results with previ- 

 ous studies for evidence of the year-to-year varia- 

 tions in mean abundance of dominant species and 

 in timing of peaks in their standing stocks. Fi- 

 nally, we examine occurrences of offshore water 

 within the study area, and discuss zooplankton 

 abundance maxima in relation to seasonal and 

 regional variations in temperature and phyto- 

 plankton standing stocks and the environmental 

 requirements of the dominant species. 



METHODS 



The station grid (Figure 1) was occupied 13 

 times between 25 July 1974 and 15 September 

 1975, vidth a cruise every month except December 

 1974 and January 1975. These cruises were part of 

 an ichthyoplankton survey by the National 

 Marine Fisheries Service (NMFS) Laboratory at 

 Sandy Hook, N.J., funded by the Brookhaven Na- 

 tional Laboratory. Zooplankton were analyzed in 

 collections from the 11 cruises between 24 Sep- 

 tember 1974 and 15 September 1975 (Table 1). 



Standard NMFS MARMAP gear was used that 

 consisted of 60 cm diameter paired 333/xm and 505 

 fim mesh nets mounted on a "bongo" sampler 

 without an opening-closing mechanism. Sampling 

 accessories (flovraneters, depth recorder, depres- 

 sor, towing cable) were rigged as specified by 

 Smith and Richardson (1977). To obtain better 

 estimates of small-bodied copepods, nets with 253 



iVlanuscnpt accepted Februar\' 1979. 

 FISHERY BULLETIN: VOL.77, NO. 3, 1980. 



669- 



