Document Vjw5Qk7DDyJZk14ZQRpzDE1pp

Marino Biology 11, 101 -- 107 (1071) O lprl&4rVrl44 1071 ' Toxicity and distribution of Aroclor 1254 in the pink shrimp Penueus duorarum* D. R. Nimmo, R. R. Blackman, A. J. Wilson, Jr. one! J. Fowcstsu Environmental Protection Agonoy, Gulf Breoto Laboratory; Sabins Ialand, Gulf Brooie, Florid*, USA Abnlruct Tlio polychlorinated biphenyl Arcelor 1254 wo* re lented in an neruh'utol tcnknRC of hent-cxrhnngo fluid from an industrial plant, into tho Kucnmbio ltivcr, near Ponaacola, Florida, USA. Thu material tea* carried downstream, and it now found in tho fauna of E*cninbia Bay and it* contiguous water*, prime nurwry aroas for fltho* and invertebrates uch aj peuaoid ihrinip. Tno significance of pollution by thi* chem ical wot ojacascd by establishing toxicity levels, determining routea of entry, and investigating ita movement and distribu tion in various tiaauaa of shrimp under oontrolied oonditiona in ibe laboratory. Aroolor 1254 added to the water waa toxio to the juvenile pink ahrimp Ptnaeui duoramm at a concen tration of 1.0 part per billion within 15 daya, but wa* leee Registered trademark, Monaanto Company, St. Louia, Missouri. Mention of commercial produot* doe* not oonstitute endorsement by the Environmental Protection Agenoy. * Contribution No. 128, Gulf Breeie Laboratory. toxio 1o adult pink ahrimp. Shrimp obtained tho contaminant from water and food and concentrated it to 510.0 part* por million in tho hopatopancroa*. Aroclor 1254 reaidue data from ahrimp oollootod in tho oatuary aro included in tha atudy. Introduction Sinco 1906, pesticide toxicologists and ecologists havo become increasingly aware of polychlorinated biphenyls (PCBs). First discovered in fishes, feathers, and human hair (Jensen, 1666), residues have since been found in many organisms from diverse areas of the world. Structurally, PCBs resemble chlorinated hydrocarbon pesticides such as DDT, and are widely used in formulating plastics, resins for rubber-based laoquers, varnishes, paints, lubricants, heat-transfer fluids end electrical insulators. PCBs are relatively Fig. 1. Residue* of Aroclor 1254 fin ppm) found in shrimp hepstopanoremm from Eaoambia Bay and eontiguou* water* during 1869/1970. Each aample listed rspresante eomposita tissue* of at Isaat 6 individual* t IbllH BMocr, Vet n DSW 026446 STLCOPCB4010407 J02 D. R. NlHKO et *1.: Arcelor In Pntuni* JwororvM Mar. Btol. Fig. 2. Residues of Aroolor 1294 (Is ppm) fouod in sediments from Esoambia Bay and contiguous waters during 1999/1970. N.D.: leas than 0.03 ppm insoluble in water, but solublo in lipid and lipid sol and distribution of this PCB in the organs of the pink vents. In addition to their thormal stability they are shrimp Penatut duorarum. also resistant to acid and base, and therefore, persist in the environment, PCOs aro toxio to trout and blue gill (spp. not Materials and methods given) -- Gustafson, 1970; shrimp (Ptnatut duora- Shrimp for laboratory studies were obtained from ram] and oysters (Craitoslrta virpintieo) -- Duke et al., two sources. Juvenile (2.5 to 3.8 cm) pink shrimp 1070; and a fish (Larjodon rhomboidu) -- IIaNBen (Penatua duorarum) were collected with a small net ct al., 1971. Also, a 1*CB used as a binder in epoxy paint from Santa Rosa Sound at Pensacola Beach. Florida, was toxic to chickens (Gustafson, 1070). Abnormally in June through September. Adult pink shrimp from thin-shollcd eggs of birds in Great Britain and North Tampa. Florida, were purchased from a live-bait America woro associated with rcsiduos ofohlorinated dealer. Background concentrations of chlorinated hv- hydrocarbons including tho FOB* (Riseb&ouoii ot al., drooarbon compounds in the hepatopancrcascs ot all 1008). In 1000, a I'CB (Aroclor 1254) was discovorod shrimp never exceeded 0.0 parts per million (ppm), as a contaminant in water, sediment and fauna of whole-body residues were less than 0,01 ppm. Escambia Bay, Florida (Duke et al., 1070). Ono sourco All shrimp were acclimated in flowing sea uatcr of this material was traced to an accidental luak in a for sovcral days in tha laboratory. Juveniles fed on hcat-cxchango system of an industrial plant located dotritus carried in by the (lowing unfiltercd sea hKt several kilometers upstream in Escambia River. It is and adults were fed mullet [Mvijil ccphnltt*) muscle now present in cstuarino organisms, inoluding shrimp containing loss than 0.03 ppm organoehlorinc com captured from Escambia Bay and contiguous waters pounds each day. Bench sand with no detectable (l''ig. 1). Sediments from the rivor and upper bay appear ' organoehlorinc compounds was provided as a sub to bo a reservoir for the compound (Fig. 2). In oarlior strata for tho shrimp. experiments, shrimp exposed to theso sedimonts for Shrimp wero exposed to Aroclor 1254 (hereafter 30 days accumulated tho chemical (Nimmo at al., callod Aroolor) in flowing-water systems. The Aroclor 1971). In this paper wo report toxicity of Aroclor 1254 was diosolvod in polyethylene glycol 200, infused into in water, rates of accumulation from food and wator, the flowing water with syringe pumps, then mixed by QSW 02644? STLCOPCB4010408 ; w. it, Xn. .1 nnt I). It. Niumo i'( ft!.: Aroolor in /'nmnn Jimriinim IU3 a scries of balTIcs a* il- (towed into aquaria. The volume of (Uo aquaria varied from 18 to 1110 1 com nnmsu rale wild the numbers aiul si/.cs of teat animals ami flowrato of water. Animal to vnlmno ratio was 1 animal per 2 l water. Concentrations of Aroclor woro routinely measured by gas chromatography. No attempt was mndo to control salinities which ranged from 25 to 32%,. but electric aquarium heaters woro used to main tain water temperatures botweon 20* and 30 *C. Fig. 3. Aroclor chromatograms. (A) Aroolor 1254 standard, (B) Aroclor 1254, recovered from Psrtaeus duarantm hopatopancreas after shrimps had been fed fish containing material (see Table 4). Concentrations of DDT and ita metabolites were negligible, therefore, no attempt was made to separate them from Aroolor isomers. Gas flow 29 ml/rain, nitrogen; injection temperature 210 *C, oven temperature 100*0, detector temperature 210*C; H* electron capture doteotor; 192.4 0.317 om glass-oolumn packed with 2% OV-1 on 100/120 Gas Chrom Q Concentrations of Aroolor in shrimp wero deter mined from pooled samples by gas ohromstography. When a group of 10 shrimp was exposed to a constant concentration of Aroolor in flowing-water, individual residues differed by a factor of 10. Consequently, laboratory analyses are from oompoeito samples of at least 10 individuals, unloss stated otherwise. All analytes on Pinaeus dttorantm from Escambia Bay and contiguous waters wore on composite samples of at L-st 5 individuals. M' Depending on type and weight of the samples, four methods of preparation were employed. (1) Sample* of shrimp or food item* larger than 1 g were mixed with anhydrous sodium sulfate in a blender and oxtractcd for 4 h with petroleum cllici in a Soxhlet apparatus. Extracts were concentrated and eluted from a Floruit column with 0% ethyl ether in petro leum other. (2) Samples less than 1 g wero analyzed by a modification of the micro-method of Enos (private communication). Samples were weighed in Duall1 tissuo grindors and oxtraotod with threo 2.0 ml portions of acctonitrilo. The acetonitrile extracts were combined and diluted with (j ml of 2% ,Va, SO, in distilled water, tiien agitatod and extracted with threo 2.0 ml portions of hoxone. These extracts were com bined and concentrated to about 0 5 ml, then transforred to a Sizo "B" Chromaflcx1 column containing 1.0 g of Florisil topped with 1.0 g of anhydrous sodium sulfate, The residue was eluted from tho column with 20.0 ml of 1 % othyl other in hexane. (3) Water samples were extraoted with petroleum ether, then the extracts woro dried with anhydrous sodium sulfate and re duced to ftn appropriate volume. (4) Sediments were analyzed by tho method of Nimmo ct al. (1071) All eluotes woro adjusted to an appropriate volume for onalysis by clcctron-eapturo gas chromatographs equipped with OV-1 columns. Quantitation of Aroclor 1254, a multiple-peaked compound, was mado by averaging the heights of 5 major peaks which had retention times relotivo to aldrin of 1.31 {IV), 1.55 (F), 2.32 (VIII), 2.74 (IX) and 3.27 (A") (Fig 3). Interference from DDT was negligible due to the relatively high residues of Aroclor 1254 in most sain pics. Laboratory test* indicated recovery rates above S0%, but data In this report do not inciudo a correction fac tor for recovery. The presence of Aroclor 1254 in shrimp and sediments was verified by mass spectro scopy at the Environmental Protection Agency La boratory, Athena, Georgia. Results Acute and chronic biosassays Acute toxicity tests at this laboratory showed that Aroolor was about one tenth as toxic to juvenile Penaeas duorarum os DDT (Table 1). For example, 10.0 parts per billion (ppb) DDT in the water Icilled 100% of a population of shrimp in 9G h, whereas 100.0 ppb in tho water was necessary to obtain tho same results with Aroclor. In chronio flowing-water bioassays, Aroclor at O.D`1 ppb killed 51% of the juvenilo shrimp (2 5 to 3 8 cm) within 15 days (Table 2). Juvenile shrimp were moro sensitive to Aroclor than adults. Exposure to 3.5 ppb for 35 days resulted in a mortality of 50 % in a group of adult shrimp (0.5 to 12.5 cm). Tho data 1 Kontos Glass Co., Viiioiand, N. J., USA. DSW 026448 STLCOPCB4010409 104 D. R, Kzmmo et *1.1 Aroolor In /'nwww dMoramm Mar, Biol. show th nood for challenging soveral stages in ths lifo cycle of shrimp with cl 10mioils suoh as Aroolor. Wo hnvo observed thnt symptom* of Aroclor poisoning in shrimp nr* different from those of most organocltlorino insooticidos. Pink shrimp whioh we oxposed to 0.18 ppb or more DDT showod norvous impairments such os tremors, loss of equilibrium and, finally, paralysis as dofinod by cessation of locomotor movements. In tests with Aroclor, rogardless of its concentration, shrimp showod delayed mortality and died at a rate of one or two per day with no apparont prior symptoms of poisoning. Like others (Duxx, et al., 1070; Wildish, 1070), we suggest that orustaceans may be more sueoeptible to the ohemloal during molting. Accumulation and transfer of Aroclor in tissues The uptake of Aroolor from water by adult Penaeui duorarum (3.8 to 7.6 om) and the transloca tion to the hopatopaneroas, wholo body and ab dominal muscle was measured (Fig. 4). Accumulation was linear with timo in the hopatopaneroas (r ~ 0 97) and wholo body (r-- 0.00), but a plateau was reached Teblo 1. Penaeui duorarum. Companion oj toxioitiee of p, p' DDT n> 1 Aroclor 1254 to thrimp in flowing-wata lull. Jucan temperature and taliniltj of eta water in DDT experiment were 21 'C and 28 X., reepeclively; for Aroclor 1234, 10 `C and 31 X> DDT* Test concentration (Ppb) Mortality 48 h Mh (%) i%) Aroolor 1254* Test concentration (PPb) Mortality 48 h 80 b (%) (%) 10.0 1.0 0.5 0.1 Control 100 100 30 80 0 40 10 20 00 100.0 10.0 1.0 Control 80 100 00 00 00 * Personal oommuniostion, J. I. Lows, Environmental Protection Agency. Gulf Brews. Florida 82561) U8A. * Dox* et al., 1970. EXPOSURE TIME (days) Fig. 4. Ptnacut duorarum. Rates of absorption of Aroclor 1254, in various tissues of shrimp exposed to 2.5 ppb of tho chemical in flowing water. Unexposed shrimp showed no detectable residue, r -- correlation coefficient Table 2. RerulU of chronic Moansye with Aroclor 1234 and Uks pink ehrimp Ptnacue duorarum in flowing water Shrimp rostrum-tolson longth (cm) Concentration* Aver*g (PPb) alinity U) Average No. of teat Replicate* Day* temper*tun individuals exposed CO) Average mortality (%) Level of aignificanoe 2.5 - 3.8 2 5 - 3.8 2.5 - 3.3 2.5 - 3.8 2.5 - 3.8 4.2 - 7.2 4.2- 7.2 4.2 - 7.2 0.0 - 0.0 0.0 - 0.0 7.0 - 6.5 7.0 - 8.5 0.5- 12.5 0.5 -- 12.5 Control 0.57 0.04 9.4 10.0 Control 2.4 3.1 Control 4.3 Control 4.0 Control 3.5 32 32 32 32 32 20 29 20 20 20 III 31 28 28 20 29 29 20 20 28 28 28 20 20 29 20 20 20 * Average of st least throe determinations. * Student's t-test. * Chi-square. 65 5 15 12 20 3 15 .70 0.10- 45 3 15 51 o.oo;* 20 2 15 00 0.001 20 2 15 100 0 001* 23 1 32 4 -- 20 1 17 G5 0.001* 25 1 32 80 0.001* 43 1 53 2G -- 40 1 53 83 0.001' CO 1 18 0 -- 00 1 IS 41 0.001* 50 1 35 8 -- 60 t 35 GO o.oot* OSW 026449 STLCOPCB4010410 Vol. 11, No. 3, 1071 D. 11. NiilHO ot al.: Aroclor in Penasus ituomrv.s too can LO cc O--i u o cr 200 1<-- ioo O 104 Fig. 5. Penaeus duorarum. Rite* of elimination from hop*topnor** and aubtequent increius in remaining tuuuo. Shrimp were expotod to 7.5 ppb Aroclor 1254 in flowing water for 10 day*, then plaoed in Aroolorfroe environment. Composite tiuue lample* from 8 individual* were analyzed for eaoh determination. Unexpoted ehrimp thowed no detectable residues. r - correlation coefficient in the muscle within 2 days, with little increase there after. Residues in the hcpatopancreae reaohed 510.0 ppm after 22 days and represented a 2.04 x 101 in crease over the 2.5 ppb Aroclor in the teat water. During this experiment, 30% of the exposed and 7% of the unexposed shrimp died. In a subsequent experiment, most of the Aroclor wa* lost from tho hepatopancreas and transferred to other tissues (Fig. 5). Adult shrimp (0.5 to 11.5 om) were first exposed to 7.5 ppb Aroolor in the water for 10 days, then placed in an Aroclor-free environment for 5 weeks. Total weight (pg) in the hepatopancreas decreased by SO % in 5 weeks, but that in the remain ing tissues almost doubled. Whole-body low was from 731 to 400 pg or about 60% in 5 weeks. A slightly different pioture exists concerning tho loss of Aroclor from the tissues if wo express tho amount in parts per million (Fig. 5). Aroolor (in ppm) showed little cliango in tissues othor than tho hepatopancrcas during post oxposuro. In contrast, tho rato of elimination from tho hepatopancreas was oonetant ond linear with time (r-- 0.00), tho biologioal halflifo in this organ boing 17 days. Aroolor is more persistent in tho other tissues of shrimp than DDT, the in secticide being completely eliminated in 3 woeks (Xiumo et al., 1970). While tho Penatus dvorarum wero hold in tho Aroclor-froe environment, 23% of the exposod shrimp diod, with no Iom of the unexposed. Accumulation in body organs Residues found in laboratory experiments arc com pared with those in natural populations of shrimps in Escambia and Pensaoola Bays in Table 3. In all tests, the shrimp incorporated the chemical. The propor tion of Aroclor in tissues of shrimp which were exposed to 0.2 ppb in the water for 50 days was nearest to that found in shrimps captured alivo from the bays. The distribution of Aroclor in the tissues of shrimp is much the somo as DDT, maximum amounts oc curring in the hepatopancreas and least in abdominal muscle or exoskelcton (Nimmo ct al., 1970). Generally, the distribution of Aroclor in the tissues of Penatus duorantm corresponded to the amount of lipid in the tissues. We believe water and food aro sources of Aroclor to shrimp, but we do not know which contributes more. FauFantB (1900) summarized earlier work on tho fooding habits of shrimp and reported that the throo oommoreially-importont penneid shrimps, pink Pe.nac.us duorarum, whito P. setijeruj, and bi c>" n P. actecus, arc omnivorous. Some of tho contcnLs found in digestive tracts by other investigntors include inorganio dobris, detritus, and a variety of algae, in cluding diatoms. Aroclor attached to dctrital material in aquaria or in field substrates was probably ingested by the shrimp. DSM 026450 STLCOPCB4010411 too D. R. NiwmO ot el.: Aroolor in Penasus duorarum 2Iar. B\ol. Tablo 3. Dutribuhon of Aroclor 12S4 intissues of exposed Penasus duorarum which had accumulated ehemteal from water and joed arui in penasid shrimps from natural populations in the Pensacola estuary, Plorula, USA '' Method* of oxpoauro Hcpato- Ventral Digcativo Hoart Gills Rxo- Abdominal pancreas norvo traot ikoloton muaclo PPTM___________ ______________________ _________________ Wafer I'm!* nhrimp exposed to 3.5 ppb Aroolor In l'mk shrimp oxpated to 0.2 ppb Aroolor in water for 30 day. Fooil Pink shrimp fed .pot* (43.0 ppm whole body) for 18 days Pmi; shrimp fed .pot (fiold-oaptured, 0.2 ppm whole body) for 10 day. P.n!t shrimp fod croakor* (0.6d ppm in rauaoJa) for 30 days Natural populations Pink shrimp captured 10. I. 19704 Pink shrimp captured 3. IV. 1070* White shrimp capturod 28. VIII. 1070* Brown shrimp captured 2S. VIII. 1670* 108 30 146 0.8 0.8 15 4.8 17 68 120 3.3 32 3.2 39 18 0.8 <0.1 2.0 1.0 8.4 0.6 4.0 14 1.1 0.5 1.5 9.7 77 60 14 2.8 1.4 0.8 25 38 6.5 0.3 0.3 0.2 1.3 0.9 0.6 -- 0.5 1.0 4.2 1.4 0.6 0.3 0.2 0.8 0.8 3.1 2.2 * Tho spot Ltiojtomus xanlhunu were previously exposed to 5.0 ppb Aroolor 1254 in the water for 12 days. * Atlantic cronkor Micropogon \tndulaiu* were captured in Saoamoia Bay, Florida. e Pensacola Bay. * Escambia Boy. 15 0.7 67 <0.1 0.6 0.0 0.1 1.3 0.0 Table 4. Ptrctutagta* of 5 pcaJcj in Aroclor 2254 recovered molecutee or differential solubilities in the various from water, fish and Penatus dvorarvm systems. Item Peak (%) IV V VIII IX X Standard 10.0 18.5 23.0 22.2 20.0 Wnicr (30 & S) 8.2 15.0 30.0 22.8 23.1 Fish muscle* 5.1 10.8 27.4 27.9 28.4 Shhmphop*top*noxoM* 2.8 10.9 23.9 31.1 31.1 poak height x 1(x) Miin of 5 polite Tho Atlantic croakerificrvpogaa undulatus were captured from Escambia Day and contained 0.08 ppm Aroolor 1254. Tho ihrimp Psnasus duorarum were fed Atlontio croaker rousclo. Wc investigated" differences in the proportion of Aroclor peak* with respect .0 tho standard; the chango is greatest in tho licpntopancroaa of ehrimp (Fig. 3; Tabic 4). Heights of 5 peaks used for quantitation of the thcinicu! show tlic greatest reduction in peaks IV and V, with somo increase in IX and A'. Wo do not know whether this reflect* actual alterations in tho Results of field, studies Distribution of 3hrimp in the estuary in relation to salinity is a factor which regulates the amount of Aroclor in the body (Fig. 1). The brown shrimp Ptnaeus azltcus from upper Escambia Bay had the highest residues (132.0 ppm in the hepatopancreas). The white shrimp P. setijtrus from the mouths of small streams emptying into Escambia Bay had a maximum residue of 59.0 ppm. The highest residue in the pinlc shrimp P. duorarum captured in Penj.ieola Bay was 15.0 ppm. P. setiferus is most abundant in low salinity waters of less than 10%, and P. nzlccus occurs mostly in waters of 10%, or more, the abun dance of P. duorarum is not as dependent on salinity (Fakfantb, 10G9). Although this (listribut ion may vary with locale, types of substrate and seasonal tempera tures, shrimp with the highest residues in this study u ere thoso captured in the lower salinities. Because higher concentrations of Aroclor occur in the sediments of upper Escambia Bay (Fig. 2), it is possible that burrowing activities of brown shrimp in these sedi ment* could havo caused additional absorption of leached chomical through tho gills (Ximmo et al.. 1071) as well as ingestion of contaminated food. DSW 026451 I 'at. 11, .Vo. J, 1071 D. It. Vi41 MO ol nl.: Aroolor ill Pr.nacui duorarum 107 Discussion nml conclusions 111 our invostigHtioiis, (hero bn* been no evidence thal. Aincbir in (ho walcr, kciIi'iiumiU, or hioln in Escnnibin liny w:ih toxin to idiiiiiqi. Wo fomnl no ileiul or dying shrimp in .uins of "fish 1<il 1m" which occurred frequently during glimmer months of (ho jmsl ( wn veil is. Amelin- in waloi snmplcs onllccU'd 48 ein above (lie Nciliincnts in I In- njij'er Day was below llml considered toxic lo .shrimp, but it wag dolccloblo (O.OG ppb in unliiii'iud water). It probably leached from the sediments or wag attached to suspended particulars matter. Adult shrimp in livo cages placed directly on sediments in upper Escambia Bay for 3 weeks did not dio nor did tho "controls" held 48 era above in an uncontaminated substratum. Shrimp on lower sediments accumulated almost 3 times more Aroclor (6.7 ppm in the hopatopancrcos) than did controls. Nevertheless, our laboratory investigations show that Aroclor 1254 in solution is toxic in the 1 ppb range to shrimp. Therefore, the occurrence of this chemical in tho water of Escambia llay or in othor estuarine areas is reason for concern. Wo also believo the residues found in shrimp from the Escambia Bay are high enough to be of importance, although we have not found n correlation between residues and mortality. If posilarvnl or juvenile shrimp were exposed directly to tho sediments in upper Escambia Bay for o period of weeks, a threat could exist because of availability of PC.B-lftdcn detritus and also the leaching of the chemical at tho water-substrate interface. We are now investigating this possibility. Deaths of shrimp due to this or any othor con taminant in natural environments would be difficult to observe. Except as larvae, shrimp are primarily benthic, secretive animals, and hide by burrowing in the sediment. If they are active at night, they usually reuiain below the substrate by day. Here, they may obtain higher concentrations of Aroclor than when swimming, and if they die, dead shrimp do not surface after dying as do fish, ratlior they decompose rapidly or arc quickly eaten by predators. Aroclor occurs in the tissues of shrimp which wero captured several kilometers from the original sources of the material in Escambia Bay (Fig. 1). This suggests the potential of this material to be dispersed through the ecosystom, and it might be available to man through his seafood. We believe this contamination should serve as a warning to increaso monitoring of the environment for Aroclor and related industrial mate rials. Summary . i. A concentration of 1.0 part per billion of Aroclor in the water kill* the juvenile pink shrimp PvnatM.i duorarum within 15 days in the laboratory. Adult shrimp are not ns susceptible, bill, higher concentra tions of 2.4 to 4.3 ppb hill within 17 to 5.'! days _ depending on the maturity of test individuals. 2. In laboratory tests in which Aroclor wax added to tho water, J'. duorarum absorbed the material and concentrated it in the bepatopancrcas. Subsequently, it was transferred to other tissues, then lost. It was moro persistent in the tissues of shrimp than the ohcmieolly-rclatod pcsticido, DDT. 3. Aroclor was absorbed from the water and its subsequent distribution in tissues was similar to tint found in wild shrimp from contaminated areas. In tho laboratory, shrimp also obtained the Aroclor from food, and wo concludo that both sources aro available to shrimp in tho Pensacola estuary. 4. Concentrations of Aroclor in P. duorarum from the estuary appear to reflect distribution patterns in shrimp. Aroclor in shrimp captured at considerable distances (up to 24 km) from tho original sourco demonstrate tho potential for dispersion and concen tration of this material in an ocosystcm. Literature cited Dckk, T. W., J. I. Lows and A. J. Wilson, Jr.: A poly chlorinated biphenyl (Aroclor 1254) in the water, sediment, and biota of Escambia Bay, Florida. Bull. Envir. Centura. Toxicol. 6, 171--180 (1070). Farfan?*, I. P.i Western Atlantio shrimps of the genus Penatut. Fiahery Bull. Fish Wildl. Serv. L'.S. 07, 401--(91 (1909). Gustafson, C. G.i PCB's-provalont and persistent. Envir. Sci. Technol. 4, 814--819 (1070). Hansen, D. J., V. It. Parrish, J. I. Lowe, A. J. Wresos, Jr. and P. D. Wilson: Chronio toxioity, uptake, and reten tion of Aroclor 1254 in two estuarine fishes. Bull. Envir. Contain. Toxicol. C, 113--119 (1971). Jensen, S.: Report of a new chemical hazard. New Sci. .12, 612 (19G0). Nimmo, D. It., A. J. Wilson, Jr. and It. It. Blackman: I-acalization of DDT in tho body organs of pink and wliilo shrimp. Bull. ICnvir. Contain. Toxicol. I, 333--341 (1970). --, IV I), Wh.son, It. It. Blackman and A, J. Wilson, Jr.. Polychlorinated biphenyl absorbed from sediments by fidcilor orabs and pink shrimp. Nature, Lond. 231, 50--52 (1071). ItUEDnonou, It. W,, P. ItiEcits, D. B. Plakall. S. G Her. xian and M. N. Iurven: Polycldormatcd biphenyls ra global ecosystem. Nature, Lond. 220, 1096--1102 (1`IG.s). Wildish, D. J.: The toxicity of polychlorinated biphenyls (PCB) in soa wstor to dominants ocean reus. Bud. Envir. Contam. Toxiool. 4, 202--204 (1970). First author'a address: Dr. D. It. Nimvo Environmental Protection Agency Gulf Breeze Laboratory Sabine Island Gulf Breeze, Florida 32561 usa Data of final manuscript aooeptanoe: June 23, 1071. Communicated by J. Bunt, Miami DSW 026452 STLCOPCB4010413