9.1.2 Effects of Hexachlorocyclohexane on 

 Nitrogen Cycling in Natural Plankton 

 Communities 



RAYMOND N, SAMBROTTO', DANIEL A. HINCKLEY* . ROGER B. HANSON*, and NILA V. MAMAEVA* 



^Lximont-Doherty Geological Obsenatoiy of Columbia University. Palisades, New York. USA 



*EA Engineering Science and Technology. Hunt Valley. Maryland, USA 



*Skidaway Institute of Oceanography, Savannah, Georgia, USA 



"Southern Division of the Oceanographic Institute of the USSR Academy of Sciences, Gelendzhik-7, Oceanologiya, USSR 



Introduction 



Man-made substances find their way into the ocean by 

 both direct run off from land and by atmospheric transport. In 

 the case of atmospheric transport, pollutants can be spread to 

 areas far from their point of origin (Flegal & Patterson, 1983); 

 therefore, the question arises as to what effects this input will 

 have on the plankton of the open ocean. The gamma isomer of 

 hexachlorocyclohexane (y-HCH) has been used widely as the 

 pesticide lindane. This report describes the results of on-board 

 experiments designed to investigate the effects of 

 hexachlorocyclohexane (HCH) on natural plankton 

 communities in the Bering Sea. 



A variety of pollutants produce measurable toxic effects 

 on marine plankton. These pollutants include a wide variety of 

 herbicides, insecticides, fungicides, and organochlorines such 

 as DDT (Butler, 1977). Most relevant to this work, the 

 pesticide y-HCH exhibited toxic effects on marine algae in 

 laboratory studies (Ukeles, 1962; Daste & Neuville, 1974; 

 Moore & Dorward, 1974; Neuville era/., 1974). Additionally, 

 HCH can be transported by the atmosphere to the open ocean. 

 High latitude seas appear to be particularly susceptible to such 

 inputs because HCH is more soluble at the low temperatures 

 commonly found there (Hinckley etai. Subchapter 8.1.1, this 

 volume). 



However, it is difficult to extrapolate most laboratory 

 studies into accurate predictions as to the specific effect of 

 pollutants on marine plankton. In the ocean, pollutant 

 concentrations are much lower than those used in most laboratory 

 experiments. Also, laboratory experiments cannot duplicate 

 the community diversity of most ocean plankton systems. Our 

 goal in the present work is to provide a better basis on which to 

 assess the effects of HCH on marine biota by examining the 

 effects of HCH on natural communities at concentrations 

 approaching the actual pollutant levels measured in the ocean. 



Methods 



Results of two separate experiments carried out during the 

 cruise of the RA' Akademik Korolev to the Bering Sea in 

 August and September 1988 are presented here. The basic 



protocol for both experiments was similar. Near-surface (5 m) 

 water was collected using clean techniques that included the 

 use of a go-flow ™ bottle on a kevlar^"^ wire. The samples were 

 then transferred to acid-cleaned 5-1 polyethylene containers 

 and incubated on-deck in incubators cooled with surface 

 seawater. 



The source water for the two experiments was chosen to 

 provide contrasting high latitude plankton communities. The 

 first experiment was started 2 1 August 1 988 with surface water 

 collected at 65°5.2'N and 170°42.7'W (Station 96) that had a 

 total water depth of 42 m. This experiment will hereafter be 

 called the shelf experiment. The second experiment was 

 started 26 August 1 988 with surface water collected at 54°25.3'N 

 and 176°43.7'W (Station 108) that had a total water depth of 

 3,835 m; this will be referred to as the "oceanic experiment." 

 Selected ambient characteristics of each sampling site are 

 shown in Table 1 . 



Table 1 



Characteristics of the water collected for the two HCH 

 experiments. 



364 



