Document kDJ7bpmrjk2ne9JyRNmvZrpdE

The fact thru not only sui face-born bacteria (/) hut also microorganisms collected at the deep-sea floor are ex hibiting extremely slow metabolic rates v.'bcn incubated in situ may be inter preted in two ways. Life processes in general may be slower at deep-sea conditions than at surface pressures and temperatures for reasons other than the low nutrient supply. Studies on the deep-sea benthic fauna (7), have reported (i) extreme diversity of species, (ii) small brood size, (iff) preponderance of adult in dividuals in most species, and (iv) abun dant cases of endemism. These charac teristics suggest slow growth and long life of the individual animal and could be the result of a relative retardation of certain critical metabolic processes. The slow metabolic rate may also lead to the argument that an active, adapted microflora does not exi.-d in the deep-sea sediment. The high colony counts usually found when deep-sea sediment samples are streaked on nu trient agar (5) may originate solely from surviving and viable cells that reached the ocean floor with sedimenting detri tus particles. Particulate organic mat ter readily available for microbial de composition will hardly reach the deep ocean. It will largely be degraded dur ing the slow sedimentation, estimated to take from several weeks to more than a year per 1000 m of depth (8). The particulate organic matter in deep waters was shown to be "refractory" (S'), that is, no degradability could be demonstrated. The total amount of larger particulate material (for instance, animal carcasses) reaching the deep sea undegraded will probably be very small, although of considerable significance for the highly diverse but scanty fauna of benthic scavengers. Nothing is known about the quantity of nonrefractory or ganic matter reaching the deep-sea floor with the relatively fast-sinking fecal pel lets of zooplankton (8). Thus, the top sediment being virtu ally void of nonrefractory organic mat ter readily' available for degradation, the activity' of microorganisms in the deep sea may be largely confined to intcstinal tracts of animals, where the enriched nutrient milieu will enable microorganisms to decompose refrac tory materials (chitin. cellulose, and so forth) in an cn Josymbiotic fashion. This notion is supported by the finding of an enlarged gut in deep-sea irmiiusks (10). Accor ding to this hypothesis, .the role played bv microorganisms in the II MAY 197} sea sediments appears to be funda.mentally different from that in shallowwater sediments, or. for that matter, in soil. Experiments on incubations of solidified organic materials (agar, starch, gelatin) on the deep-sea floor in open containers (II) show that after 1 year of exposure, marks of animal feeding appeared to be almost the only sign of disintegration. No work on the intestinal flora of deep-sea invertebrates has yet been done. Complementing our earlier work (/), the data reported in this study confirm the conclusion that the deep sea must be considered extremely inefficient with respect to recycling of organic wastes. Holgi-r W. Jannasch Carl O. Wirsen Woods Hole Oceanographic liislitnlion. Woods Hole, Massachusetts 02543 L If. W, Jniitijwh. K. FinilijclUu, C\ O. Wirsen, A. Jf/Vmr HI, 672 (IV72>. 2. O. II. l.owry, N. J. Rosebrouj'h, A. 1.. Farr, R. J. Randall. J. Mol. Chan. 19.1. 2<A (1951). 3. IdcnlihcU by U. Turner (Museum of Compara . tive Zoolopv, Harvard University). 4 K. L. Smith and J. M. Teal, Science 179, 2S2 0973). 5. C. Ii. ZoLlell, Bull. Misc.U Mar. Biol. InM. Kyoto Vniv. 12, 77 (19CS). 6. --------- ant*. L. L. IJitUc, Can. J. Mic/obiol. 13, 1311 (1967). 7. J. F. Grasslc and H. L. Sanders, Deep-Sea Res., in press. 8. T. J. Smayda, Occuttogr. Mar. Mol. Anna. Rev. C, 353 (1970). 9. D. V/. Mcn/cl and J. H. Rytber, Inu. 3/Vir. Sci. Vniv. Alaska Buhl. So. 1 (1970), p. 31. 10. J. A. Allen and II. L. Sanders, Deep-Sea Res. 13. 1175 (1966). 11. H. \V. Jannasch aud C. O. Wirsen, in prepara tion. 12. We thank R. Holmes for assistance ip one of the Alvin dives; and J. M. Teal, J. l-\ Grassle, and K. L. Smith for a critical discussion of the manuscript. Research supported by NSF f.rant GA 33-t05. This is contribution No. 2987 of the Woods Hole Oceanographic In stitution. fc December 1972 n Polychlorobiphcnyls in North Atlantic Ocean Water Abstract. Concentrations of polychlorobiphcnyls (PCB's) have been measured at the surface and at various depths in the water of the North Atlantic Ocean between 26N and 63N. The concentrations average about 20 parts per trillion and amount to an estimated 2 X 70* metric tons of PCB's in the upper 200 meters of water. The average concentrations of PCB's in the surface water of the Sargasso Sea are lower than those in the northern North Atlantic. Seawater is the most abundant solvent available for trapping hydrocarbons, such as the polychlorobiphcnyls (I'CE's), released into the environment. The volume of the oceans (1021 liters) is sufficient to dissolve all the PCB's that have been manufactured (1). Relatively few measurements have been made of PCB concentrations in open-ocean water to- determine the extent to which it functions as a solvent trap (2). Most analyses have been confined to orga nisms (.?), which comprise less than 1 part per million of the total volume. During the summer of 1972 we analyzed the PCB concentrations of open-ocean water in the eastern and western North Atlantic between 26N and 63 N. The stations and analyses are tabulated in Table 1 (4). For samples 1 to 9 and 13 we extracted 19 liters of sea water (5) with 2 liters of a hexane-ether mixture (94 : 6), concentrated the extract, and then analyzed it by electron-cupturc gas chromatography (ECGC). For the other samples we pumped 19 to SO liters of water through a brass or glass column 116 by 2 cm (inside diameter)] packed with Ambeilitc XAD-2 resin (I'.ohm & Haas) to a height of 12 cm (6) at 250 ml/miu. The PCB's were eluted from the column with 300 ml of boiling acetonitrile at full gravity flow. The acetonitrile was then diluted with 1 liter of water (distilled or seawater) and extracted with hexane. The con centrated hexane extract was analysed by ECGC. No cleanup of the extract was required prior to ECGC. Unfiltered seawater samples collected and analyzed simultaneously with water filtered through a 0.3-pm glass fiber filter or a glass wool plug contained a maximum of 10 percent more PCB than the filtered seawater samples. All analyses were completed on shipboard within 4 hours of sampling (7). Three observations can be made from the data: 1) Although the range is very broad, the concentrations of PCB's in the northern North Atlantic average 35 ng/kg [35 parts per trillion (ppt)] in surface waters, and 10 ppt at 200 m. 2) The PCB concentrations decrease with depth. 3) The surface waters of the Sar gasso Sea (stations 25-41) have slightly lower surface concentrations of PCB's (27 ppt) than surface waters in other parts of the North Atlantic. The widespread distribution of PCB's DSW 346176 60 STLCOPCB4084467 in llic open North Atlantic supports previous observations that the atmo sphere must be the predominant mode of transport (.?). The wide range of concentrations observed I to 150 ppt), in some eases at points only SO Km apart (stations 29 and 33), may be due to scaslicks (2), localized rainfall, or discharges from ships. No relation ship between PCB concentration and proximity to land was observed. The presence of measurable PCB concen trations, even to depths of 3000 m, suggests that animals which migrate vertically, plus sinking shells, feces, and dead organisms, transport PCB's out of the mixed layer (about 150 m) and prevent even higher concentrations from accumulating in the productive zone. The Sargasso Sea is an area of high evaporation and low rainfall. We sug gest (hat I'CH's, adsorbed on particu late's falling into this region, arc par tially solubilized by equilibrating with the surface water, livaporativc codistil lation then transports some of this material to areas of higher precipitation. The volume of the upper 200 m of the North Atlantic is I O'* liters. If we as sume an average PCB concentration of 2 X 10~8 g/liter in that volume (S), then there may be about 2 X 10' g (2 X 10' metric tons) of l'CB's in the water (/, 9). The total amount of PCB's produced in the United States in 1971 was l.S X 101 metric tons (/). On the basis of quantitative estimates of rates of production and rates of loss to the environment, a 2sDDT/ PCB ratio [iiDDT refers to DDT, 1,1,1,trich!oro-2,2-bis(/>-ch!orophenyl) eth ane, and its major metabolites] of 10 is expected in the North Atlantic, if Table 1. Concentrations of PCB's in North Atlantic ocean water. The limit of detection was 1 X 10"* g/litcr for a 19-liter sample. Sta Position tion North West Dale (1972) Depth (m) PGR conccnlration^ (x lO" e/liter) 1 2 3 4 5 6 7 8 9 10 11 12 n 14 15 16 17 18 19 20 21 . 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 52 55' 44 00' 40 33' 36" 11' 34" 02' 35" 00' 34" 47' 38" 20' 38" 23' 38" 19' 41" 09' 43" 57' 43" 20' 43" 16' 46" 31' 52" 31' 52" 35' 55" 41' 57" 22' 60" 04' 60" 09' 60" 29' 63" 03' 41" 32' 39" 40' 37" 12' 34" 32' 35" 22' 35" 17' 35" 56' 36" 05' 36" 24' 35" 37' 34* 26' 33" 41' 28" 42' 26" 50' 25" 56' 26" 58' 28" 26' 31" 13' 35" 08' 30" 36' 29" 16' 25" 33' 22 50' 18" 59' 14" ST 11" 23' 11" IT 19" 28' 20" 46' 22" 13' 21" 57' 21" 34' 21" 43' 19' 52' 19" 53' 15" 02' 12" or 06" 02' 05" 36' 04" 43' 02' 22' 70" 40' 70" 03' 68" 54' 67" or 67" 36' 68" 28' 66" 34' 67" 27' 68" 24' 67" 49' 66" 22` 65" 44' 58 39' 55" 38' 54" 15' 53 57' 53" 55' 52 49' 6/30 7/3 1/S 1/1 1/9 7/11 7/13 7/15 7/22 7/23 7/24 7/25 7/27 1/29 7/30 8/1 8/2 8/4 8/5 8/6 8/7 8/7 8/8 10/2 9/21 9/22 9/23 9/24 9/24 9/25 9/26 9/27 9/27 <t/2S 9/28 10/3 10/5 10/6 10/7 10/8 10/9 ' 0 0; 200 0; 200 0; 200 0; 200 0; 200 0; 200 0; 200 0; 200 0 0 0 0 100; 3000 O 0; 100 1500 0 200 200 0 0 0; 200 0 0 0 0 1000 0 0 0 0 0 0 0 0 0 0 0 0 0 150 35; 10 4; 7 11; 3 30; 6 14; 5 67; 39 19; 2 - 41; 13 77 <1 52 47 45; > If 10 45; 8 >lt 3 97 42 82 23 21; 7 30 29 36 12 1 2 5 11 22 9 12 ' 15 26 30 27 42 88 68 The closest matching commercial mixture In all cases was that containing 54 percent chlorine. Thus the commercially available Arodor 1254 (Monsanto) was Used as the standard. Procedural blanks ranged limn (Mo 3 ny'liter ami were subtracted tjom the tabulated caunvutrations; DDT and its metabolites, if present, were present at concentrations less than I nm'liier. 1 Root match for Arodor. we assume that the half-lives arc simi lar (9). The observed ratio from our data (and from (2)] must be less than 0.05 [that is, < 1 ppt/20 ppt (see first footnote. Table 1)]. Thus the environ mental half-life of the PCB's appears considerably greater than that of DDT and its metabolites. Groncr. R. IlAnyry WillumjCj. Sttinualtr John M. Tl~al Woods Hole Oceanographic Institution, ' Woods Hole, Massachusetts 02543 References pnd Notes 1. The total U.S. production of ECU'S since 1957 is about 3.6 X 10u g [C/icm. 7;rip. New* (6 Dec. 1971), p, 15) Vrhiwh is estimated to be about one-half of the total world pro duction. 2. C. K. OIney and J. G, Quinn, paper pre sented as port of the deliberations of the International Decade of Ocean Exploration Baseline Conference, E. D. Goldberg, chair man, Brookhaven National Laboratory, Upton, N.Y., 24-26 May 1972 (these workers mea sured the ECU concentrations in the su.incc mierolaycr and 20 cm below the surface in the North Atlantic; their subsurface con centrations agree with our surface measure ments, although iheir sample size was much smaller). 3. G. K. Harvey, V. T. Bowen, R. H, Backus, G. D. Grice, in Nobel Symposium 70: The Changing Chemistry of the Oceans, D. Dyrssen and D. Jagner, Eds. (Almqvist & Wikscll, Stockholm, 1972), p. 177; deliberations of the International Decade of Ocean Exploration Baseline Conference, E. D. Goldberg, chair man, Brookhavea National Laboratory, Upton, N.Y., 24-26 May 1972. 4. Stations 1 to 23 were occupied on cruise tCf of R.V. Chain; stations 25 to 41 were occupied on cruise 71 of R.V. Atlantis-IJ. Station 24 is the Woods Hole dock. 5. Surface samples were collected in a stainlcs? steel bucket from the bow of the- ship while it was under way. Deep samples were collected in a 160-liter Bodman bottle lined with Kel-F; R. H. Bodman, V. T. Bowen, L. W. Slabaugh /. Mar. Res. 19, 141 (1961). ' 6. The parameters for the use of this resin given in the text were developed by the authors in this laboratory. The efficiency of the adsorptive extraction, when compared with solvent extraction, is >95 percent. 7. A Packard gas-liquid chromatograph, model 407, equipped with a ^Ni electron-capture detector was used. No motion sensitivity was observed in the instrument's response. A shipboard analysis revealed that the ship's paints, greases, and oils did not contain any PCB's. 8. These data and (2). In.contrast, PCB con centrations in coastal northeastern Pacific waters average 1 ppt (I. Barrett, paper pre sented as part of the deliberations of the International Decade of Ocean Exploration Baseline Conference, E. D. Goldberg, chair man, Brookhaven National Laboiatory, Upion, N.Y., 24-26 May 1972). 9. This quantity is remarkably similar to a recently calculated estimate of 1.5 X lb1 metric tons of PCB's in the North Atlantic; no water data wcjo available at the time of the calculation |I. C. T. Nishet and A. F. Sarofun, Rnviron. Health Rerspect. 1, 21 (1972)1. 10. We thank Dr. R. H. Backus, chief scientist on cruise 105 of R.V. Chain, for allowing i:s the opportunity to collect those samples and Dr. V. T, -rtowen for making the deep samples nvaikblc. Supported by grant GX 35212 from the Oflice of lire International Decade of Ocean Exploration, National Sci ence Foundation and grant GQ luu'O from tho Environmental Protection Agency. Woods Hole Oceanographic Institution contribution No. 2798. 10 November 1972 ' 644 SCIENCE* VO!.. 180 DSW 346177 STLCOPCB4084468