•• ID L \J'' MEMORANDUM EXTERNAL AFFAIRS February OEPARTMENl . f·~ . (".. . 13, 1979 FEB IJ ·197 9 Messrs. J, W. Flanagan V, Sirois W, J. Young P. Stauft W. A. West H. H. Clare Dr. C. G. Preece Attached for your interest is a copy of the latest Exxon Background Series pamphlet, "Fate and Effects of Oil in the Sea;" we have a limited number of pamphlets on hand if you should want additional copies. ~i~£~ Supervisor, c.c. P.A. J.C. Information Advisors Underhill, Centre Esso Resources Canada Limited /). ~ w - lo /, _, 1 T\ HLE OF l'ONTENTS fNTRODl 1 C'TION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 J;';Pl'TS OF OIL INTO THE SEA ............................... F,\TE OF OIL IN THE SE,\......... . ........ . 3 . .. .. 5 EFFECTS OF OIL I:'\ THE SEA ...... .. .......... 8 F'w,1 Chain .lla17111)icatio11............ . . . . . . . . . . . . . . . . . . . .. . . . 8 Oiling und Tarring ,!f'Brnches a 11dShorelines ... . ...................... 8 Ept('f,011 Bird Population......... .... .. .... .... . ............. 9 E.{fict.,011Brnlhic C'o1111111111itie.,..... . . . . . . . .. . . . . . .. . . . . . . . . . . 9 Efft ct., 011 Fi,IH ril'S. . . . . . . . . . . . . . . .. .. . . . . . . . . . . . .. . .. . . . . . . .. 9 E,,,rftrt,011Human Health ...... .. ......... ..... .. . . ......... .... .... ..... . . 10 ~DI.\L.\RY ............................................................... .. ... 11 CO. 'CLL"SIOXS ............................................................... \ ba('kgrounrl pap1•rprl'pan•d h\ th(' P11hlicAffair~ l)('partmPnt of Exxon Corporation rn coqpl•rat1on with othl•r Exxon rlPparlm!'nls anrl affiliate$ for Exxon anrl atfiliat<' us<' 11 rnnrll 1'Tm:-.: I hi ,•111,·,.,. t hl' scu as a rl'sull of natural pl1<•11ollh'llt1, it also l'fltl•l's the Sl'a as lhc 1,•s11ltni' nwn's aeti, ities. Whl'lher through 11:1!11rnl '<'<'PH,al'ridc11lal spills, or long--ll•rm, J.111l,•1,,1disd1arg-l'S. t lw prcs,,n,·c 01·oi I in tin• 1na1·i11,• ,•111·iron111cnt is lo some cxt,•11t. 1111m·nidahl,• . .l11stas nature and rnan l'ontriliut,• to pC'lroh•1tr11s appl'aranl'<' in llw Sl'a, so do they con! rihute lo its rl•mo1·,d.Natural processes, hnth d1,•111il'al and biological, degrade the pdml,•um h~·drncarbons. Man, in a more li111it,•dfashion. tries to contain and clean up nil i-pillcd into HtC' sea \\'lwn his efforts al pr,•q•ntmn han• failed. Too 111ud1petroleum at any one time or al any Oll<' plat'e can he detrimental lo marine !if,, nnd a,•sthc•tically unpleasant. IL is t.hercfon, important lo kno11·how much petroleum ,•nl,•rs the \\'Orld's ocean waters each year and what the consequences are. This paper attc>rnpts to p1'01·idesome answers. II I I 1'111 '111111 I 1111111 ii \, 1011111 1.J,,111\ ,d I\ 11 i, Ill I '" H I 111d11111I 111,h ,11 p, l1,d1·11111 p11ll1!111111 p11I, II Ii, ,I 111I 'I, ,, , I 1111 ii, ·,I 111111 .1111111 :iii\ I, I 1111111,1111111111, 1111111 11111 11,11,1)1•11!11 \l11111t111tl1 ·l 1111nl11 111,\\111111' 111 1111,111.1 1 1111111 1111111111! 1111pt'I 1111•111111111111 I 111111 Ill.Ill\ 1111111 Hid Ill d11J,11 IHJ' IIIIIHIIIII 1\11\, II 1111111, 1111!11\\IH• ' /lp11111 II , Ap1,10 ,,n11l1 lv1,11, ll1i1d ,,J 11111,,lill p• 1111 I, 111111·,il,it111,,1111 1 11 1 1nl 11,d1w1·d I l111,11J,h 11 1111 p111l 1ll11111w11 1111 (1,,111 11 ,d,vd,,d~ Hip , 11·1 llltll ld 11p1 I ;ti 11111 , 1·11· J '1'111· liar, Iii l1 i1111l11ld•· 111lo111I·•1 ,w,·1111·111 , 111111111 .I 1 IH ·\.\: \l'fl f I !iv 1111,('j'i I •111ly,I ,/ 1111/IJll1/'I 1111 H1v"' 1111d 111l, 111111111 1,/11w1•,,t1nl f'ot 1111111111 •1 11111,If '1111,l1 d 1'111·11111 .. , 1wl111 1,I ),'11:111,1,: I :IOIJIU:1,:n ()I<' 1•1,:• 1•1w1,i,;11M(l()IN(l IN'I'() 'l'lllo: oc1rnrm. MILi.iON Ml•:'l'ltlC:'J'CJNIIANNIJAl.1,Y (1111,fl) rot.if 01 "t b 11 rnt,1 .11 nn,d \, td, Ill nf /J, 1/i, , , f.11 ,,,, ,,,, , I \\,, hmglo11 municipal sewage plants, oil retineries, and industrial plants, contribute rn percent. Some petroleum hydrocarbons initially go into the atmosphere and then are earri( d own by precipitation into the Ol't',UUi. This ·ource accounts for about 10 pereent of he total. 1 Fl\dnH·arhons, th<· prin<'ipal <·ornp,HH·11tr-; • of' fH'l rol(•lllll, an• also J.:'<'IH•r:tlI'd by org:111 isrns Ii, ing in tlH' o<'<'HIIS,'l'lw tpmntity ((i million lll<"lri(' tons p(•r· y<·ar) of hiologwal hvdro1·nrho11s prodtH·1•d h_vt h<·s<·orvani:·,m, aiiproximatl's t II<'a11101111t ol' hydrcwarhott:-i 0 n'Hld Li11gf'rom l111•soiu·1·1·s pot-Lrayc•di t1 Figun' I. HottH' of' t IH biolog-i1·ally prodtw<•d hydroc·arl>ons an• id(•ntirnl in d1<·t11i<·al rnmpo:-lition to th<' pl'trol1•11111 hyclrcwarho11s, otlwrs arl' chC'mi<"allyquite• clifl'C'r<·nt. 1 ffshore production contributes less than 2 crcent of the total petroleum going into tlw ceam, . .About three-fourths of this small mount comes from spills of more than 0 barrels and about one-fourth from lesser ills and normal drilling and production eration discharg-es. etroleum is certainly not a substance reign to the marine em·ironment. Natural epg han been discharging petroleum to the marine environment for millions of ars. in amounts substantially greater an come. for instance. from off shore proction acti\·ities. Petroleum has also been ded continuously to the em·ironment by sion and by discharge from uplifted sedin tary rock::.. 1 Mm,l surJ°al'l' and 11(•ar-stirf'ac·(· 01·(•an wat<•rs contain hyclroC'arhons in the rang,• of' about t to JOparts per hill ion (ppb), a<·<·ordinglo a study 1wrf'onned by J1~xxon 1iescard1 and Eng-inet•ri11g Company and !•~xx.onl'roduetion l{e!-warehCompany with funding from tlw lf.S. Dt'partmcnt of Commprc·c•'s National (kt'ani(' and A tmosphene Administration. In dt•eper waters th<' c·orwentralions arP smalh•r, of'tc•n lpss than 1 ppb. Ont· parl pt'r hillion oroil 1•quals one.•drop of oil in about 2(1,000 gallons of \vater. Sonw eoastal waters, partiC'ulat'ly thm;e in industrialized areas whc.•re then• is greater probability for hydroC'arhon inputs, show higher hydrocarbon levels (up to 100-200 pph) than open ocean waters. Both pctrol(•umderived and biologically produced hydrocarbons are present in most samples of' ocean water, but there is a relatively higher percentage of the latter type of hydrocarbons in the open ocean. There h; little or no toxic cffcl'l of hydro(.'arbons on marine life at thcs<• levels. Most of the laborntory experiments dt•aling-with the toxicity of e1·ud<• oil or petrolc.•um produets are c.·or1elueted at eon<'Pntrations whil'h arc f'rnm one•hundrc.•dto 01w thousand tinws greater than Uw c.·on<·Pntrat ions m<•asurPdin the op •n o<·<•an. municipal sewage plants, oil refineries, and industrial plants, contribute 13 percent. Some petroleum hydrocarbons initially go into the atmosphere and then are carried down by precipitation into the oceans. This source accounts for about 10 percent of the total. Offshore production contributes less than 2 percent of the total petroleum going into the oceans. About three-fourths of this small amount comes from spills of more than 50 barrels and about one-fourth from lesser spills and normal drilling and production operation discharges. Petroleum is certainly not a substance foreign to the marine environment. Natural seeps have been discharging petroleum into the marine environment for millions of years, in amounts substantially greater than come, for instance, from offshore production activities. Petroleum has also been added continuously to the environment by erosion and by discharge from uplifted sedimentary rocks. Hydrocarbons, the principal components of petroleum, are also generated by organisms living in the oceans. The quantity (6 million metric tons per year) of biological hydrocarbons produced by these organisms approximates the amount of hydrocarbons resulting from the sources portrayed in Figure 1. Some of the biologically produced hydrocarbons are identical in chemical composition to the petroleum hydrocarbons, others are chemically quite different. Most surface and near-surface ocean waters contain hydrocarbons in the range of about 1 to 10 parts per billion (ppb), according to a study performed by Exxon Research and Engineering Company and Exxon Production Research Company with funding from the U.S. Department of Commerce's National Oceanic and Atmospheric Administration. In deeper waters the concentrations are smaller, often less than 1 ppb. One part per billion of oil equals one drop of oil in about 26,000 gallons of water. Some coastal waters, particularly those in industrialized areas where there is greater probability for hydrocarbon inputs, show higher hydrocarbon levels (up to 100-200 ppb) than open ocean waters. Both petroleumderived and biologically produced hydrocarbons are present in most samples of ocean water, but there is a relatively higher percentage of the latter type of hydrocarbons in the open ocean. There is little or no toxic effect of hydrocarbons on marine life at these levels. Most of the laboratory experiments dealing with the toxicity of crude oil or petroleum products are conducted at concentrations which are from one hundred to one thousand times greater than the concentrations measured in the open ocean. F\TF OF OlL I'-: THE Sl:<'.A What happens to oil once it enters the oceans? In order to develop reasonable contingency plans to control oil spills and longterm, low-level discharges, it is necessary to understand the processes acting on the oil at any given time following its release into the enYironment. When a spill occurs, many physical, chemical, and biological processes going on naturally in the ocean act on the spilled oil. Some of the processes are most important immediately after the spill occurs; other processes become increasingly important as time goes on. Figure 2 relates the time following discharge of a crude oil into the sea to various processes of movement and degradation. Line length represents the probable time span of any process while the line width indicates the intensity of the process through time and in relation to other concurrent processes. Spreading is a rapid and dominant process at the time of a spill, waning steadily until it more or less stops within a week to ten days. The preading process is controlled by the physical and chemical properties of the oil and the environment into which it is released. In rough seas, wind and wave action play an important role in the distribution of the oil slick. Oil spilled into very cold water may spread at a slower rate, especially if it is a high Yiscosity oil, such as heavy fuel oil. Other processes, such as evaporation, dissolu tion, dispersion, and emulsification, are enhanced by spreading. The drifting process results from the action of currents, winds, and tides upon slicks. The drifting process is always active, from the moment of a spill until the slick disappears from the surface of the sea. The significance of the drift is dependent upon the proximity of the slick with respect to beaches and fishing grounds or other biological resources. Modeling of drift trajectories is relatively new and involves very complex technology. It can be useful in contingency planning for control of possible spills and, perhaps someday, in assisting oil spill cleanup operations. However, the state of the art is not yet very advanced. Several techniques have been used to assist in monitoring the movement of oil spilled at sea. Drift buoys which travel with the slick and emit radio signals are now available. The combination of airborne infrared remote sensing techniques with surface samples permits determination of drift, as well as spreading, thickness, and volumes of the oil slick. 5 Evaporation is the primary initial process involved in the removal of oil from the sea. Evaporation is simply the process of transformation of oil components from the liquid phase to the vapor phase. Rates of evaporation of oil at sea are determined by wind velocity, water and air temperatures, intensity of the sun's rays, roughness of the sea, and the physical properties of the oil. Through evaporation, an oil slick composed of light, low-boiling components will be rapidly depleted. Some of these low-boiling components. such as benzene and toluene, are among the most toxic hydrocarbons in oil. Thus. their removal decreases the toxicity to marine life of that fraction of the oil remaining on the sea's surface. Di'solution is another initial process acting on any spilled oil. This process involves the dissolving in the sea water of certain components in the oil. Environmental factors, such as water turbulence, can significantly increase the rate of the dissolution process. The e\'idence, however, is that dissolution is less important than evaporation. The process of dispersion results in a mixture of oil with water. Extremely small droplets of oil are incorporated into water in the form of a dilute oil-in-,\·ater suspension. The process reaches a maximum rate only a few hours (4 to 10) following a spill but continues for some time. The condition of the sea is probably the .single most controlling factor but temperature, oil composition, viscosity, and spe<:ificgravity are also significant. Commercially available dispersants can help remove oil from the water surface by this means but, con. equently, result in eievated concentrations of hydrnearbons in the_•water. In open .seas these concentrations arc rapidly reduced.to very low levels. Most toxic eomponen ts will have already c\'aporate,l prior to di persion. Water-in-oil (as distinct from oil-in-water) emulsions also may form. As with clispersion, sea conditions arc probably the single most important factor in causing emulsions, but the chemical composition, viscosity, and 8pccific gravity of the oil and the water temperature are also important. The rougher the seas, the more active the process. Water-inoil emulsions form floating semisolid lumps, often described as "chocolate mousse." Most water-in-oil emulsification will occur from a few hours to several days after the spill. Depending on its stability, an emulsion may persist and age to form tar balls or lumps, or it may fragment and disperse as extremely small particles. Tar balls can persist for many years. Sedimentation occurs if the specific gravity of the oil becomes greater than that of water or if the churning action of the waves <>111'11 (s 111·1•tlq ; 1wl,•tl 1'11 sl 1•r 1111111 ·. l11gh 11111l1 •1·1tl:ir ", ·,,:hi 11111•,I 11 t h1· h,•n111•1 :-.,1lu1 J\lll, n1nhn ,. t ih' ,,,l:,t 1h• ,·,•01p111h'1tl x Pl gt'l\1•1•111, H1t,,k~1-.hl.,thHl 1~ ;111111qu1rt ;111tl:th11'pl'lll 1 1 'l '~t, ~. 1 th,• ,,II spill, l,•:1,1111: :11\•sidm• I'h1s n•,11'111• m.l\ ,·,1:-.1 at t lw :,1r ~,·;\ 1111,•rf;H·,·.i 111,n,,,,. ";\(, .,~ ,\1' 111 t h,1 u1ukrlying :4,•d1n1t•11t~. \\\ 1 n• it 111,t1-.,rpla11kt,1111,·\llt1:1tlllg i11\\111\'l'l :111dh,•11thll'(h1>tt<1111 d\\1•1l111g)111111'1111' mil'1,,lw:--,, hidt u:-.,•t lw ,)ii n~ :1 l\)11d~0 111·1·,·. th,•s,• ,>iir,•,1d111•s111ightp,•r,1st 11Hll'i'i1111<'l.1 . I \ •t 1'•11•11111 1'11 t 111g · 111 il'rt>lws ( h:11'1\'l'i:1,., , •11,t,. 111,•hbl:11·,,found in :111t ht• 11nt ,•1·s 1111d ,,•di 111\'lltS1>fth1• II 1\l'ld. lbt,•:; nf hi,11kgr:1d:1tit111:1n•1'\\lltrt1lil'd h.1 t lw :11,1ilahih t) ,,f p,•t l\>l1•11111-1•:1t ing 111il'n>h1• s. t 11n•.and 11111 ri1•11 t ,,ii ,·t1111p,isit ion. 11'111p1•r:1 snppli, •s. :<11d1 :Is nit rng,•11.phosphorn11,. lllJ~IWI ' 1t llllll'l 'll I llt'P H IIH'l'l •/Hil' dq i .. 1·11d11l1011 !tl'l l\'ll 111:-1nl' 11111·1·n lit1 :-1. 1 l'h11t11d11•11111·1i\ ll\id11( i1111 is lllll1(J11•1 ' pl'11011 1111 s 1l11111 :ind I h,• phy s 11·11l . l'l I 11dil'HIt111'1 ' Hllllll II I h11I th,' \\ :Ii I' I' Hlll'f111·1• :1, 1111u·h 11"ltl 11111·1 ·,·ls 111'oil s p1·1•ad 11,,•1·11 111ilt•ol' llt'l'llll s11rJ'a1·prn11ltl 111 • sq11111·1· tl1•grntkd i1111J',•wday s hy phot111'11<•111irnl o,id11t ion, gil't'll 1111 l'll't•<·tivt• l'ighl ho11rday I :II' h11nps · 111' s1111 lighl. 'l'ht• J'11rn1ali111111J' , il't 11111ly Jll'l'd11d,•s f11rll1<•rph11t11dw111i<'al o,idat ion ht·<·n11 s1•of I lwil' 1011 s 11l'fa1·p a l'l'a/ l'Oh111H'rat ins 1111dIH'l'HIIH<'light <·annol ill' t ra ns111i l t t•d h1•y111Hl t lw highly di'gradt•d, larr~ s11rf:11·1•. 1.000 MO NTH Evaporat,on 01ssolut1on D1spers1on Emuls1f1cation Sed1mentat1on 81odegradat1on Photo-ox1dat1on Line Length-Probable time span of any process line W1dth- Aelat1ve magnitude of the process both through time and in relation to other contemporary processes 10,000 YEAR 7 I I I' t\l till I I'll I· 'I·\ ·u Uh \ 1',HIS 11·~,·nr,·h :111d ;tc.1d,·1tl H' lll~l 1t II 111111 , tlm111•hn11lth,• ""rid. ha11•1·111tll'lh th,•1•11'1•1'I. t11'11il 111t'dtn"hnl I l,11t1111111h1111t 1-l••d('/,11111 M11y111Jil'llllll11 N111111•ro11~ st 11di1•sII ii h :i 1·ari1·t.1ol' 111ari1w oq,n11is111 ~ l:111 ·1·1111•a s111 ·1'd th,• 11ptai<1• and r,•li•:is,•or ltyd1·0,·arh1111 s wl11•11 tl1t• org-anisms 111·,•,•,pos1•d In 11ilnnd ll'h\'11n1m·l'd to ri,•an w:lii•r. 'l'l1t•irfindings show that liH' majonty l'h,• \nt11111al\, ·:id,•111. 1 111'~1·11•111·,·~ r,•porl. orn1nri1u• :111in1als,s11d1as woplankton, llh'lll HHh·d , :1rh,1·. \ \jH't•s:-;t•d t h, COIIM( 1l:-lll:-l fin fish, do :t<·1·1111111latl' hyclromrshl'llfish, 1111d ,1I' 1"q1t•l'I s OIi th,• 1•11'1 •cls II f nil i II I ill' ~I'l l. 'l'h1• honH;hul, wl11•n n•1111>1 ·t•d l'rnm t lw oil soun ·t•, prit11'1pal,·11111'111sio11s 111' Ihnl 1·,•p,11 ·1.g,•111•r ~1·lvt•s or i)l'(•ai1·,11·ho11H l hrnug-h 111\'l ahol ism. \\ ,•1,•.t:--r,,lltn\:,,:. Ill\ tl11 1 IH:ll'llh' 1 t 1 1\\ 1 ll'Otlll\\'UI 1 1 1 nrnri:w nrg-an1s111s dn nol t1•ncllo l'lh'I\' is no,., id,•111·,· for 1'011d rhai1111111g11ifka ll1•1·a11s1• n•tain th1•hydro\'arhons tht•y ac1·111111ilat1• 111111 ni' pl'tn1l,•11mh,Yd1·0,·111·ho11s in mari111• wlwn t•,posC'cl to oil, its1•1•rnsunlikel y Lhal tH).!,:\Ui$1HS . 111agnifiration or inl'rcasC' in hyclro\'arhon l1•1 •l'ls will ot·t·ur wlwn larg-N organisms l'c><•d Th,• nwst dnlll:l).\'111).! 1•ikl'tS or Jl\'t rol1•11111 an· lll'rorga11is111sin llw nalural food tlw ,,iling-nnd tarring or h1·al'h1•s.th,• 1•11du11- on s111a d1ain in the Ol'l'ans. This hiomagnifil'ation g-,•ring-,,r ~,·ahml sp,•,·i,•s. and tlw moclifirndo\'s O<'l'llrwith l'l'rtain other pollutanls, sul'h 1ion ,,fh,•nt hit' ,·nm m11nit i,•s along-poll11t1•d as m1•n·tll'~.and possibly insC'ctil'idl's, such l'O:tSliilll'S. as l>llT. Fish do not npp,•ar to s11f1'1•r front oil spills as Oili11,q,1111/'lhrri11y r!f'Nf'ac/11 •s and mud1 as s,•ahirds and h1•nthil' organisms. Shorr! i 111·s Oil on lwad1es is th1• form or oil pollution l)iff,•n•nt pl'lrok11m produrts hm1• difkrl'nt ,•ll't>l'ls.Toxil'ity is gn•at1•st for n•fi111•d clistilmost obl'ious to Lhe public and affects il dircl'tly. Mosl or the oil can be r moved by lat1•s high in aromatil' ,·ontt>nls. sm·h as dil'sl'I or h,•ating oib. Ho,n •n•r, ph~·sil'al smotlwring natural processes and modern deaning techis most s,•n•n• with ht'al') nucl •s or l'm•Ioils. niques, bul some oily rC>sidues,if buried, can persist for long periods of time. Although information is limitC'd, th1•l'fi'l'cl of oil \'Ontamination on human hC'alth doC'snot On rocky coasts, oil may be deposited on aprwar to ht• cause for alarm. rocks, usually in the upper part of the t idal zone, hut most of it will be removed by surf action. In the splas h zon , the oil will be gradua lly removed by weathering. The process of natural cleansing is slower with sandy beaehes beeause the oil tends to become buried in the sedimC>nts. In bays C'stuaries, and marshes, where fine sedin~cnls oecur, natural c·k•ansing by wavC' action is slower yet and any buried oil may remain for long periods of time. In proteeting coastlines from oil slicks, it would t herd ore appear that hays, estuaries, and marsh 'S should he proteetcd first. Since thes0 environments are rich in organic life , there is an additional inC'C'nli\'e to proteel them. E.ffi'c/.~011Bird Population Oil causes immediate and serious external harm to birds by destroying the waterproofing and insulation provided by their plumage. Harmful internal effects also emerge as the birds ingest oil in attempting to remove it from their feathers. Not all seabirds are exposed to the same extent, nor are the long-term consequences the same for each species. The greatest risk is to species that congregate in flocks, in both breeding and wintering areas, and especially to those species that frequent offshore waters or whose migration paths take them near busy shipping lanes. The northern hemisphere species most susceptible to oil pollution are auks, followed by sea ducks. Various strategies to protect seabirds have been proposed. Among these are reducing exposure to oil through scaring devices and dispersion of oil slicks, breeding in captivity, and research to discover ways of increasing reproductive success. E.ffects on Bent hie Communities One of the more adverse effects of oil in the sea is believed to be the harm done to organ ism living on bottom sediments along coastlines impacted by spilled oil. Those organ isms lidng in the tidal zone and just below seem to be the most susceptible. However, recent studies by a number of im·estigators show that these effects may not be as severe as was feared earlier. Studies in Louisiana bay waters near active oil drilling and production activities show that the distribution, density, and diversity of marine plants are a product of the natural environment and have not been significantly affected by 40 years of drilling and production activities. Offshore platforms in the area serve as artificial reefs and provide anchorage for more than 60 species of benthic plants. These plants are heavily grazed by fish living near the platforms. In the North Sea biological surveys were cond.ucted by Great Britain's Orielton Oil Pollut1.onResearch Unit in the vicinity of Ekofisk oII field m 1973, when it still was that new oil province's lar~est oil find. The surveys showed relatively uniform distribution of bottom-dwelling organisms throughout the area, near the center of the field and along transects up to 4 miles distant from the field. o evidence of significant ecological damage was detected. In August 1974, the supertanker Metula went aground in the Strait of Magellan off the ?oast of Chile. Approximately 54,000 tons of oil was released into the ea and much of it came ashore. Benthic plants and animals living in the intertidal zone suffered appreciable immediate damage. When University of Southern California scientists studied the area 111January 1975, they already noted signs of recovery. Subsequently, continuing gradual improvements have been observed by these and other scientists. Marsh plants had started growing through the oil residue. Mussels, however, were scarce in these oiled areas. E.ffects on Fisheries Fish are not affected by oil pollution as much as seabirds or bottom-dwelling organisms. They live and thrive in many offshore areas where oil is produced. Offshore Louisiana, where oil and gas wells have been producing since 1937, sport and commercial fisheries thrive. From 1950 to the early 1970s, when oil drilling and production activities increased significantly, the amount of fish and shellfish caught showed no decline. Similarly, in Lake Maracaibo (Venezuela), where oil production has been occurring for some 60 years, there is no evidence that fisheries resources are being depleted. or is there evidence of a detectable buildup of hydrocarbons in fish muscle tissue from the low, chronic concentrations of petroleum in Lake Maracaibo waters. JO In offshore California waters near two oil producing platforms, a fish sun·ey was conducted in 1976. A diverse (more than .JOspecies) and abundant (average of 20,000 fish under each platform) fish population abides there. Tissues from fish, mussels, and crabs showed no oil contamination. These platforms ha,·e been producing oil for more than 1.5years. During a fh·e-month wartime period in 1942, some 500,000 tons of crude oil and refined oil spilled into the Atlantic Ocean within 50 miles of the U.S. eastern coast through the sinking of some 100 ship . In\'estigations re,·ealed no e,·idence of oil-caused catastrophe to fish populations. In December 1976, the tanker Argo Merchant ran aground and spilled approximately 26,000 tons of fuel oil into U.S. eastern coa ·ta! waters some 30 miles off Nantucket Island. Rough seas and high winds tended to drive the oil southeastward away from the l' .. coast, off the continental shelf, and into the Atlantic Ocean circulation patterns. Biological studies showed some e\'idence of oil contamination in fish, shellfish, and plankton. Howe\'er, there was little adverse effect on fish trawling off the Rhode Island and Massachusett.· coast· during the period December 1976 to ;\larch 1977. Of 900 fishermen inter,·iewed, only 26 reported en\'ironmental damage, mostly to seabirds. Only two of the fishermen indicated problems associated with the fouling of fishing gear in the oil slick waters. In April 1977, the North Sea's first large oil spill occurred from the Ekofisk Bravo platform blowout and released between I2,000 and 20,000 tons of crude oil over a nine-day period. Chemical analyses by different • laboratories rc\'caled that hydrocarbon i(•,·els in the" atcr were not high enough to endanger marin(• life. No apparent serious damagP to fish or S(•abirds has been report('(l to date. In March 1978, the world's largest oil spill (226,000 tons of light crude oil) occurred near France when the supertanker A 11wcoCadiz went aground and broke up one mile ofTthe Brittany coast. The oil slick was extensive and affected more than 100 miles of coastline. Fish, as well as birds, were severely affected immediately after the spill. In a few months, the rocky coast and sandy beaches were mostly clean of' oil where the coast was exposed to high energy wave action. The shallow bays and estuaries showed oil contamination. A three-year study of the biological effects of this spill is planned by a joint French-US. team of scientists. The results of this study will shed much light on this important su bjecl. E.Dect.~nnHuman Health As to the effects of petroleum pollution on human health, the. AS report, Petroleum in the Marine Enriron men/, concluded there was no cause for alarm, although the amount of information on this subject was limited. Most of the concern arose from the introduction into the marine environment of polycyclic aromatic hydrocarbons (PAH), some of which are known to be carcinogenic. Howe,·er, these hydrocarbons, like the PAH introduced by nature, ultimately degrade, mostly by light-induced oxidation processes. The physical, chemical, biological, toxicological, and epidemiological studies on PAH in the marine environment, thus far carried out, support the belief that there is no cause for alarm for man's health. ,, \I \I \ I \ input of hydro. Bt•::;t t.)..:.timatllt•f tht' :..u1nu~ll l>:trh1m:-;inb> th1..• ~t a j:,,; ah(Hlt l:! million mttril•ton:-1 - .-\l~n,t half of th,• hydnx•:1rhons found 111 t ht· "',\ i, ~l'fwr:1t,·d b., natural hiolog1<·:iland ,h,•m,;·al rl',ll"tions. Th,• n•maindl'r is intr,>du,·,•d in to th,• s,•a m,,,t ly hy t lw ad ion of man. ~[o,1 surfw,· and n,•ar-surfan• 11at1•rs 111th,• "P<'ll lltt',1ns h:111•f11rn1I h• Ill parts p,•r billion (t,tal h.nlrt)(·arh,n1s. \\'at,•1-s 1war ports md indu,tri.ili ,•d ,lrt>a, ,·ontain high,•r I ·\lb. up to :!00 p.ms l"-'r hilli1u1 \\ h 1th ppen, to 1>11 r,·lt'a,ed into th,• marinl' Emin nn, nt ll'H>h,•s man~ physit-al. ,·h,•mi I. d hiolc ..:1• I prnce,:a,·s. ( "O'\t 'Ll SJ()\:-,: This pnp,·r has )ll"<'st'nt,•d infon11at1on whid1 ma., h,, us('ful in asst'ssing- tlw natun· and ,•,l<>nt of th,• prnhlt•111,T1•ntl'd hy th,• pn•s. <'ll<'<' of oil in tlw sl'a. Tlw fal'ls g-i\'t'rl sug-g-l'sl that tn Sclllll' ,·,t,•nt till' prohl,•m is hoth natural and s,•lf-rnrn•rt1ng-. But that drn•s not nwan that ,·on,•prn ahn11t i1lt-11tifiahl1•:ulq•rse (Ju1l,• lh1•\'0ntral'\'. All <'11',•,·tsis ill1•g-iti111at1•. whos,, adi1·iti,•s may <·ontriliuk to llw 1;ml,l,•111,induding-tlw pl'lrolpun1 industry, ll('<·d to do 1•,·1•r.1"lhingtlwy n•asonalilv l'an.do lo minimiZl' Sll<'h,•lkl'ls. · .\s far as lh1• pc>lroil'um industry is con<'enwd, pre\'ention of thp rPl(•as~,of oil into th,• Sl'a. as wpll as lll'rf,•1·tio11of rnnlainment and deanup lerhnolog-y, rnntinuc> to warrant a hig-h priority. Thl're is a spl'eial n1•ed lo idl'ntify high-rii"k shorclit1l's and lo den•lop 1·ornpn•lwnsi,·,• marinl' l'asually response plans to prnt,·,·t th,•m F'utur,• res,·arch shouhl bl' broadened beyond ()]I,pill, to 111d11d1• the Pffcl'ls of long-lc;·m, l,m-lt·,·l'I hydro,·arhon exposure on marine org-ani,nis. ~lll'h r,•seareh \\'ill be expensive and prohahly will rwPd lo he funded coopcra1i\t)l) hy g-ovprnment. 111dustry and other prn ate ~l'ctor groups. oth, rm nn !' Information I till hmttrri. h11l thf• eff ,, t on h11man h ·alth •Jfoil at 11rr1nt I,, I 111 th l3 app, ,m, not to 1.. nu for al trm II The following papers in the Exxon Background Series are available upon request from the Public Affairs Department, Exxon Corporation, 1251 Avenue of the Americas, New York, N.Y. 10020. Reducing Tanker Accidents Environmental Conservation-A Progress Report Very Large Crude Carriers (VLCCs) Middle East Oil World Energy Outlook The Offshore Search for Oil and Gas ,, Jl z-< m 0 z C Ul :,,