8.1.3 Organochlorine Contamination of 

 Sediments, Fish, and Invertebrates 



CLIFFORD P. RICE\ ALEXANDER J. KRYNITSKY*, and PASQUALE F. ROSCIGNO* 



''Patuxent Wildlife Research Center, US Fish and Wildlife Service. Laurel. Maryland. USA 



*US EPA, Analytical Chemistry Laboratory. Beltsville. Maryland. USA 



*National Wetlands Research Center. US Fish and Wildlife Service. Slidell. Louisiana. USA 



Introduction 



Organochlorine (OC) contamination in the Bering Sea and 

 Chukchi Sea ecosystems is relatively unstudied. Some data are 

 available on walrus (Odobenus rosmarus divergens) from 

 Little Diomede (Taylor et ai. 1989), and some fish, seals 

 (.Leptonychotos weddelli), and lower food chain organisms 

 from the southern Bering Sea Tanabe & Tasukawa, 1980; 

 Kawanoe/fl/., 1986;Kawanofrfl/., 1988),butnocomprehensive 

 study of OC"s in the northern Bering Sea and Chukchi Sea 

 ecosystems has been attempted. The present account fills this 

 data gap and was made possible through the Third Joint US- 

 USSR Bering & Chukchi Seas Expedition aboard the research 

 vessel (RfW) Akademik Korolev. 



Atmospheric sampling in other regions of the Arctic 

 suggested that hexachlorocyclohexanes (HCH's), 

 polychlorinated biphenyls (PCB's). hexachlorobenzenes 

 (HCB ■ s ), and toxaphene might be found in the food webs of the 

 Bering and Chukchi Seas (Bidleman era/., 1989; Pattone/rt/., 

 1989). Toxaphene was of special interest as few reports exist 

 for this purported global contaminant despite evidence since 

 1978 that it occurs in biota in remote pristine environments 

 (Zell & Ballschmitter, 1980). 



Materials and Methods 



Samples 



All samples were collected from the WW Akademik Korolev 

 while participating on a joint US-USSR expedition to the 

 Bering and Chukchi Seas from 26 July to 2 September 1988. 

 The stations that were occupied are shown on the frontispiece 

 to this volume and the numbering here corresponds to numbering 

 shown in that figure. Zooplankton and phytoplankton were 

 collected by net tows. Surface fihn organisms — neuston — 

 were collected using a special surface trawl described by 

 Zaitsev (Subchapter 5.2.5, this volume). All samples were 

 stored in precleaned 1-Chemjars (I-Chem Research Inc., New 

 Castle, Delaware) after excess water was decanted. Samples 

 were stored frozen (-10°C). 



A bottom trawl was used to obtain benthic organisms, 

 including shrimp, family Pandalidae; crabs, family Paguridae; 

 molluscs, family Nuculidae; and urchins, family 

 Strongyloccntrotidae. Large samples were placed in plastic 

 Whirl-pak bags and frozen forstorage. Fish (pollack, Theragra 



chalcogramma; and a sculpin, Cottus sp.) were obtained by 

 hook and line, wrapped in aluminum foil, and kept frozen until 

 analysis. 



Sediments were obtained using a box corer provided by 

 Texas A&M University. To secure the core samples from this 

 collector, 10-cm core tubes were pushed into the box cored 

 samples so that vertical profiles of the bottom samples could be 

 obtained for later sectioning. Cores containing the sediment 

 samples were capped and frozen in an upright position and 

 were kept frozen until they were sectioned. Additional bulk 

 samples were also taken from the box core collections. 

 Nearsurface, 0-2 -cm layers were scraped off and placed directly 

 in I-Chem jars. Deeper cuts, 0- 10-cm layers were collected 

 using a stainless steel spoon. These samples (4-8 kg) were 

 placed in 1-gal polyethylene jars, thoroughly mixed and 

 subsampled in 1 00-200 g portions for OC and metals analyses. 

 All collected sediment samples were kept frozen until 

 preparation for gas chromatography (GO analysis. 



Analysis 



All samples were analyzed for organochlorines by electron 

 capture gas chromatography; selected samples were analyzed 

 for toxaphene using negative chemical ion GC mass 

 spectrometry (GC/MS). 



Biota samples were homogenized whole without any 

 separation of soft tissues from shells and exoskeletons, mixed 

 with ignited Na2S04 (150 g to 10 g wet biota sample), dried 

 overnight in a desiccator, then Soxhlet-extracted for 7 h using 

 pesticide grade hexane. Biota extracts were split into two equal 

 portions; one was dried and weighed for lipid determinations, 

 the other was processed further prior to GC analysis. The 

 sediment samples ( 20 g of slightly moist material ) were extracted 

 by Soxhlet using a 50:50 mixture of pesticide grade acetone 

 and hexane. To remove the water and acetone from the 

 extracts, they were alternately washed with water and then 

 hexane. The final hexane extract was dried by passing it 

 through a column of ignited Na^SOj. The entire soil extract was 

 processed for GC analysis. 



For initial removal of fats and other interfering materials 

 from the extracts, we used the florisil column cleanup method 

 ofCromartieandassociates(Cromartiee/a/., 1975). Silica gel 

 column chromatography was used to separate PCB's in the 

 extracts from the majority of OC pesticides (Cromartie et ai, 

 1975; Kaiser era/., 1980). For removal ofphthalates and traces 



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