THE

A review i t ~ a ~ornbat li

I n t h i s review an att.empt has been made to c o l l a t e the cen t r a l points i

, ,

of the most important of the multitudinous reports which have appeared in i i

connection vkth the Torrey Canyon o i l pollution. The content has been

l imited t o the biological aspects of a large-scale o i l spi l lage and i t s

subsequent treatment, although the importance of t o u r i s t amenitties also

receives consideration in the discussion. Consequently, several re la t46

topics which l i e outside &Ye scope of "dne b i o l o a s t have e i t he r been omittea

c r jus t mentioned i n passing: they Tnclude the tbchnical problems of the

salvage of o i l from a crippled tanker, the control o r col lect ion of f l o a t k g

o i l , and kle aad in i s t r a t i v$ org.anisationa1 requirements f o r effect ive action -

i n an emergency of "his kind.

There are four sections:

I The Problem

IS 3 e Treatnent

A. I n England

B. I n France

III Discussion

IV Conclusions

Brackated nunbers i n the t e x t r e f e r t o the l i s t of publications

The Problem

The Torrey Canyon was carrying 119,000 tons of Kuwait cfide o i l I 1) a t the time of ruraing aground on 18&& IIarch, 1967, on the Seven Stones Reef)

some 15 miles west of Land's End. The f a t e of tine cargo was astimated

(1) .- as follows . 30,000 tons released on grounding;

20,000 tons released during next 7 days;

50,000 tons released on breakup, 8 days a f t e r grounding;

19,000 tons destroyed by bombing, 12 days a f t e r grounding.

About 18,000 tons reached the Cornish beaches"), the f i r s t o i l

coming ashore on 25th March and continuing f o r four o r f i ve days although

it was vrithdrawn and redeposited with every t i d e f o r some time afterwards.

The oLl vhicicb reached the French coast(2) comprised about 15,000 tons

on the Cotes du Nora from the o i l released when the tanker grounded, and.

about 50,000 tons from the break-up on 26th March. This second batch

passed t o the west of Ushant, together with an unknovm, but probably sna l l ,

quantity of unburnt o i l released during o r a f t e r the bombing from 28th - -

30th March. Host of it was successfully sunk, and a small quanti ty

came ashore i n Finistere. .

I1 The Treatanent

A. I n Endand

1. A t Sea. It wQs found t h a t t he r a t e of movement of o i l patches ir.

t h e direct ion of the ivind could be predicted i u i t h a f a i r l y high degree of

accuracy. Then well away from land, the veloci ty can be calculated as

3.3% of wind speed''), ~uith subsequent vec tor ia l adding o r sub%racting of

res idual surface currents. Were the mind d r i f t flows closely p a r a l l e l

with a coast on the r i gh t the f a c t o r i s about 4.2% and when the coast i s

on i;he l e f t it f a l l s t o about 2.5% of wind velocity.

Treatment of the o i l a t sea was confined t o spraying wi th detergent,

followed by ag i ta t ion with the s h i p ' screxvs and high-pressure hosing.

Up to 6 t h Apr i l? 592,000 gallons of &etergen$,(mostly BP 1002 and ~ a s i c )

had been issued f o r use in this way(11. *,By the end of April, the crude

o i l content of surface water samples(') in the Western Channel mas s t i l l

appreciable, even though the sampling was carr ied out well away from

v i s ib l e sl icks. I n the T o m y Canyon ~ e c k area the surface contamination 9 iras 11-20 pa r t s o i l in 10 , and in other p a r t s of the Western Channel

9 the range was 3-l.4 pa r t s o i l in 10 . SruSrZco water taken a t a point

off Portland B i l l and not contaminated by Torrey Canyon o i l contained 9 3 par t s crude o i l in 10 . These figures are m8xima. l and were obtained

I by spectrofluorimetry.

On the beaches,. Attempts tc c o n t r a l ~ t h e o i l movements by means of . - 2 . ______- booxs m e t ~ r i t h l i - b t l e or no success. Of the des ims given a f a i r p rac t ica l

t o s t , t l ~ e bbrst v:zs the Rar!?e design''), a 16" diameter f oam-fflled neoprene

flotat2011 c:~lindes with a 222n s k i r t and weighted lower cylinder. This boom

excz-uded o i l f ron Forthleven harbour in sp i t e of a 7' swell, but it was

defeated b ~ r ws.va : - z.&~r:s gro- a t e r than about 18" o r 2", and by t i d a l currents

ir: excess of 2 l=lots,

Treataent i-.n the beaches was generally by detergent application o r

7< i : , - - - z *..-- : a T:le f - k s t mas perhaps the most widely use&, and up t o - .,

6-L;i 4.7~i.l. l,lb&9C00 gaLlons (again mostly 2B 1002 and ijasio) had been -!\

~ . , S ~ C . - d L B p 17th April. a fur ther 500,000 gallons of detergent had been

Iss-led fsr sh,-rc use and it is estimated t h a t a t o t a l of 2; millior? gallons

.;as issueG dt -dng the vilole operation, a t sea and nn t,\e shore. The

?ecokmsn<.e?t ~p~l?.r;ab,;loi r a t e was 1 par-; detergent t o 4 pa r t s o i l , timed

if possl;ol.? so t:~c'; the inco;aing t i d e ag5tated the mixture short ly aftemiards, %~.L wi- okl?e:~r~se it, was -Lo be hosed =dowi.

-

A t Seme, Co-~e She h c 8 1 Authority cleaned the rooks by what has been

c ! . a h ~ & - ~ ) J;3 be the !nosi: e f ~ i c l e n t inethod seen i n Com%all. ' .. special - . vehxc1.e ~ 2 s e)j;ll::;?p~!?. w i t h a largo Ze-kergent tank, a pump and three high-

n3ssu re i p ~ ~ c ~ e : i s i;ik?.i? pis501 grip o d o f f controls. The hoses viere on

,cm:.3L i?r:cis, IEen -the rocks ha& been sprayed the Setergent was washed

or.r . WZ.;~. . .,.. . . r ter 1:o:;es. m~ ~ n i s s:s;tcm \vas no t so successful on the sand,

v$.:eler:. s h i s ~s-,coitpz,ied by furmwing and ploughing with bulldozers so

as i;s le'; Cle r',s-iag tLde m 5 x the o-il and detergent f o r b e t t e r dispersal;

b:r thz cs:~.cei-.":?akio.n of oi7. 18' below the surface, ivas s t i l l ve-ry h i& I

i!.:p t 3 30,y fLs J Z E ~ ~ per cue f.t. sand), ~ u l l d o z k g was continued up to

ea?:-:ly :-a&, By Baq~.lst the beach appetired tc have boon cleaned sa t i s f ac to r i l y

b ~ t t h r e was c 12"-13" layor of blue-black sand covered by 3 ' 4 ' or' new sand,

This h d a v e q bad appearsnce kt in view of i t s low o i l oontent(9.5 - 0.7 fL. z z s , pe-c. cu, f*,) it d5d not aFpear t o inconvenience v i s i to rs . It was

la'cer confirzed tha-5 t h i s Slue-black zon,e das a ha,-mless sulphide l aye r c--. 4

uvllich i s r z . - : r r ~ d l y pz-eswnL on many beaches, and in this case was probably A k a b4.Y ~TO&.I.C t of b2.odeg-cada.tLon of the oil.)

A.nct%ez !~-.av:ll;r poll:lted beach a t Portlherras was t rea ted only p s r t i a x y

s?cczssfuX~y n2C: detergent. By August there was no pollution, but the

n a b r a l s i t c . a t i o ~ o f the beach mas such t h a t 3' - 4' of sand, together x i t h

%he o i l =?a dekrgen t , had been removed by t i d a l action.

Physii:al removal of contaminated sand mas somewhat more successful.

A t I1>rkhmeor Beach, St , Ives, the pollution mas very heavy, and although

e a r l i e r a t t z o ~ t s to get r i a of the w a t e r i n - o i l emulsion (% - 5% oi l )

bp c ' e t e rgn t had only made matters worse ( s ee page 7) the top 6" - 9" l ayer

of s a ~ d was b u l l b z e d t o low water l e v e l ahd there t rea ted with detergent,

Within 8 days the o i l concentration i n the sand was only s l i gh t ly above (5) acceptable l imi t s - 0.2 t o 2.5 f l , ozs. o i l per cu. f t . sand . Initial

concentrations of o i l , before a n y decontanination exercises, had been

up t o 33 f l , 02s. per cu. f t . By August 6" of nerr sand covered the beach,

and the slight o i l iness of t he black underlay was eas i ly removed from

human skin by r ins ing w i t h water.

A t Trevaunance Cove, 4-5 acres in s ize , the owner refused to

allor-i detergents t o be used and instead scraped off the top layer of

pollutcd sand which he dumped down an old mine shaft. The o i l content ( 5) of the beach afterwards was l e s s than 0.2 f l . 02s. per cu, ft. .

I n Guernsey, sewage tanker l o r r i e s sucked up 3,000 tons(2) of o i l

and o i l emulsion f o r discharge in to a quarry. Up t o seventeen tankers

of 800-1,000 gallon capacity were used t o pump the o i l from the sea surface,

where a f resh wind a t h i & water b u i l t up the o i l to a layer thicker than

thd minimum 2" required by the pups . \'hen the wind dropped or changed, - pumping had t o stop. -

B. I N mCE

1. A t sea. I n i t i a l attempts t o sir& the o i l with sawdust and

powdered chalkwere unsuccessful(6), but Crais de Champagne was used tc good

e f f ec t a f t e r a trial on 18th April. This i s f i n e l y ground calcium

carbonate containing I$ sodium s teara te t o rendBr the chalk hydrophobic and

oleophilic. Although the only effective way t o apply it was to s l i t the

bags and pour it over the s ide of the boat, followed by steaming through

the o i v c h a l k mass, the Prcnch were able t o sink between 20,000 and 30,000

tons of uvaterin-oil emulsion with 3,000 tons of is treated ch &2,3) ,

No oil/chalk r k t u r e came ashore subsequently, nor did t h i s treatment ( 7 ) in te r fe re w i t h f i sh ing . By May a system of pumping the o i l aboard an

aaapted pe t ro l coaster had been worked out but by t h a t time most of the o i l

had been sunk o r dispersed. I n the two days tha t t h i s system was ( 2 ) func t iona l i tpumped up1,200 tons of o5.l . ,

, a - --I

2. On the beaches. Roscoff harbour was successfully protected (2961 by

two kinds of boom, The f irst , which i-ias the more sat isfactory was made fro^

straw and jute f i b r e s buoyed up with t r ac to r inner tubes, while the second,

which -#as heavier, had an expanded polyurethane core sumunded with straw

and covered w i t h jute f ibres. Other booms protected the oyster beds in

tho Morlaix and ~ e n z d r ivers t o the east . To the west in Finis tere the

types in use were a p l a s t i c apron 1 m. deep ~veighted with shinglc i n pockets

along the bottom edge and another (be t te r ) one of canvas w e w t e d with lead

and supported with rods of hm.lumin; both T.vere kept up by f i sh ing ne t f loa t s ,

It i s calculated") t ha t 300 tons of emulsified o i l came ashora i n

F in is te re in west Bri t tany and 15,000 tons in the Cotes du Nord. Sandy

beaches were s u c c e s s f ~ l l y cleaned by repe t i t ive ly placing a l i n e of straw

o r gorse along the shore a t low t ide , and as the t i d e rose the o i ly sand was

c o U c t e d by tho straw o r gorse rn l l i ng up towards high watcr mark. It

was then collected and burned.

Detergents were sprayed on polluted holiday beaches in north Brittany,

but only on those well away from estuarine oyster bcds. Oxane and

Fina-sol were used. A t other places the top layers of sand were bulldozed

off , s ince the o i l had sunk in t o a depth of 6". A t Locquirec, on the

north coast, steam was used t o clean oi led rocks on 20th June. The

machines roquircd a large supply of f resh watcr, and delivered steam a t

140 '~ and 8k$sq.cm. pressure (114 lbs/sq.in.) through spray nozzles.

This was followed by r ins ing the mcks with 0 ,% Teepol solution, the whole

operation cleaning about 30 sq, metres of rock surface per hour per nachinz.

By mid-July only insignif icant t r aces of o i l pol lut ion were apparent

on t rea ted beachos(6) and holiday a c t i v i t i e s were not interrupted. Onc

rocky beach ( a t ~ l o m a n a c ' h ) which had no t been t rea ted had black laycrs

on the rocks, a d i s t i n c t smell of o i l and th in o i l y layers on the rock

pools. Detergent spraying, if properly carr ied out, can remove o i l t h a t

has been on rocks f o r up t o two months('), but o i l , if l e f t indef in i te ly

mithout any attempts t o remove it, m i l l remain as a hard black f i lm around ( 7 ) high water mark fo r a t l e a s t one and probably f o r several years .

Bfhon one examines the methods used t o combat an o i l s p i l l of the s ize

of the Tormy Canyon disaster , i t becomes c l ea r t h a t no single method i s

perfoct - nor can it be f a i r l y expected t o be, especially i n s i tuat ions

whore there i s a conf l ic t between the in t e r e s t s of tourism and those of

f i sher ies . A t best one must be adaptable i n taking steps t o remove o i l

pollutinn, e i t he r on the sea o r on the shore, and be aware of the drawbacks

as wel l as the advantages inherent i n each methoa.

Detergents were reasonably successful i n dispersing f loa t ing o i l from

the Torrey Cmyon, bearing in mind thc'vast quan.tities involved. ( H ~ E J

it i s worth pointing out t h a t a deter&& does not destrox o i l - it merely

disperses it i n t o very f i n e pa r t i c l e s which f a c i l i t a t e bac t e r i a l breakdown.)

However, there mere three main disadvantages associated with attempts t o

disperse o i l on the beaches. They were (i) inefficiency i n achieving the

object of the exercise, (ii) tho toxic e f f ec t s of the detergents on a large

number of marine animals, (iii) i n s t a b i l i t y of the sand on t rea ted beaches.

The f i r s t disadvantage resul ted pa r t l y from over-zealous application

of the detergent - i n some places it was jus t poured out3of the drums

ias tead of being sprayed - and par t ly from the nature of the o i l coming

ashore. Where the o i l arrived as a r e l a t i ve ly t h in f l u i d , detergent

treatmm-bwas-reasonably successfulf&tbough-difficdty of access by

spraying machinery to mky coves resul ted in inef f ic ien t application in

those s i tuat ions) , but in many places the o i l was i n the form of a sticky

brown mass, a water-in-oil emulsion rqhioh becme known as "chocolate mousse"

f r o m i t s appearance, ( l i f ter 24 liours, a f resh o i l s p i l l has l o s t 2% by

weight; of vo la t i l e matter, and 3% a f t e r 3 days. Because of the increased

viscosi ty which r c s c l t s from t h i s evaporation, weathered c i l i s formcd

into an emulsion by wave action much more easi ly than f resh o i l and the

"chocolate mousse" was jn f a c t a water-in-oil emulsion containing up t o

8@ water. Xiere the em~ls ion coming ashore contained l e s s than 4% viator it mas cclowed black,) Tmatmciit of tho "chocolate mousse"

mi+& dotergent was l a r p z y unsatisfactory; it had t o be worked in to the

crnulsion wit.! groat agitation; the normal spraying and hosing was not

very effective. 4-n.n3thcr source of ineff ic iency (on sandy beaches, e.g.

Porthmccr) was the u r ~ i n which the detergent reduced the viscosi ty of tho ( 5) o i l and caused it t3 soak decply in-to the - sand . This made fu r the r

attempts k remove It very d i f f i cu l t . -

Tho sccorS disak~antagc - the toxic ef fbc ts of detcrgents - m s

obscrved on the shorcs of C~rnwall '~ ' and investigated i n laboratory

t e s t s ( 2 y 9), b a a during and a f t c r mopping up operations. A t Scnncn covc,

which had becn spraycd -&th dotergent, the rocky p a r t of the shore held

dcad o r ?Lying ind5~idual.s of many species - f i s h i n tho rock pools, worms,

crustacc+rs, mcUuscs - but a t Porthgwarra, a s m a l l mcky crcek whare

o i l had come ashorc as an emKLsion and had not bccn treatcd, animal l i f e

appcarcd t o be quftc hoalthy w i t h gastropod sna i l s crawling on oil-covered

seawced. T:lc Aay a f t e r Porthgwarra had becn sprayed with detergent the

con&itions of 'dm L!tcrtidal species were s imilar t o those secn a t

Senncn Cove. Laboratory investigations showed t h a t the concentration of

BP 1002 mqulmd t o kill the majority of cxperimcntal shrimps (Crangon

vulgaris) i n 24 h o ~ r s was 2 pa r t s per million. FOP t he limpet ( R t e l l a --- vulgaris) t h e figurn mas 5 ~.p.m., f o r the sea ancmcnn ( ~ c t i n i a e ? )

*

25 p.p,n., f o r thc shore crab (careinus mae%s)-&5 p.p.m. and f o r the

pcriwinklk (;.it;erina Zit%oma) 100 p.p.m, Meat from lobs tc rs taken up ( 9) t o 800 yards offshorc from a t rca tcd bcach was found t o bc ta in tcd .

The t 2 ~ i r Z ?Lsadvantagc - tho production of temporary quicksands - ( 5) was very prono.?'~czd Lr cleaned arcas of Porthmcor beach . Those

conditions wcrc rspr~duocd in the where i t was found t h a t

10 p.p.m. of d c t e r ~ n t was suf f ic ien t t o markcdly reducc the cohesiveness

of the sand particles, tha t it required nunomus t i d a l cyclcs t o f lush J

out the solvcnt par+ of tho dotergent which becomes adsorbcd on to the sand

grains,

Since the t h e of 'chc T o m y Canyon grounding several detergents 1

L - 8 - have come on the rnarket which a r e said t o be e i t he r more effect ive or l e s s

toxic than BP 1002. The I . C . I . product Ci rmsol was much be t t e r a t

emulsifying o i l under laboratory t e s t , and Esso's Corexit has been shown t o be (I' )but the f orrner i s s t i l l r e l a t i ve ly much l e s s harmful t o marine l i f e ,

toxic and the l a t t e r i s not such an effect ive emulsifier a s e i t he r Ci:rasol or

BP 1002 when subjected t o the same laboratory test!I2) Until such t i ~ e a s t he

perfect o i l dispersant i s produced - an effect ive 5ut non-toxic eau ls i f ie r - the large scale w e of these materials should be confined t o s p i l l s on the

open sea, using the most e f f ic ien t emulsifier available. If a s p i l l i s t o be

deal t with close inshore and i n circumstances where the use of detergents i s

unavoidable, then the detergent chosen should be the l e a s t toxic avcilable.

Two fur ther methods a r e available f o r use a t sea - absozbing and sinking.

Straw i s adequate f o r absorbing small quant i t i es ; depending on the type

. =

(1 3) of o i l the amount absorbed varies f r o a 8-30 times the weight of the straw.

An expensive method, but one which might be worth while i n valuable shallow

waters i s t o coat and absorb the o i l with-a .cob-web l i k e r a f t of sprayed

plastic/acetone solution; Polyurethane fwL hits a l s o been t r i e d success full^*,

although not on Torrey Cayon of.1. . This i s a hydrophobic material which can be

used a s a r o l l e r mounted on the b m s of a col lect ing barge or cut up i n t o chips

and broadcast over the f loa t ing o i l . . However, there a r e trio drawbacks t o the

use of absorbing agents. F i r s t l y it i s d i f f i c u l t t o spply the material t o the

o i l s l i c k under rough sea conditions without a l o t of waste, and secondly the I

recovery of the oil-soaked agent presents considerable prac+.ical problems. F i t h

straw, f o r example, one of the d i f f i c u l t i e s i s t ha t about 40% of the o i l runs off

when l i f t e d a t sea, although it can be used t o absorb o i l on beaches (see page <)

where these conditions do not apply.

Several sinking agents a r e available; apar t , h o ~ e v e r , from i t s physical

properties, a sinking agent must be both cheap and readi ly available i f i t s use

i s t o be a prac t ica l proposition. The Frencfi used blackboard chalk - Cr:ir: de , *

Champagne - with 1% sodium stearate-td, r&.'er it hydrophobic and oleophilic.

The chalk i t s e l f was powdered calcium carbonate of the kind which i n t h i s

country i s found only i n Co. Antrim under the basa l t (our blackboard chalk i s

made from gypsum). Powdered limestone (another form of calcium carbonate),

which occurs widely throughout Ireland, i s a l so s a t i s f a c t q when t rea ted mith

s tearate , but it i s not a s absorbent a s c h a l ~ . Pulverised f u e l ash from

e l e c t r i c i t y generating s ta t ions has the same hydrophobic and oleophilic

properties when it has been t reated with chloro-silane vapour a t t he r a t e of 0 . ~ )

by weight.(I3) 1 ° C I, w r k e t a gypsum residue cal led Stuc'co which i s simiiar t o

P l a s t e r of Par is , and when it i s applied t o an o i l s l i c k it sinks, taking the

o i l with it, anti s e t s t o a f a i r l y hard cake on the sea bed, !I 3 )

The principal d i f f i cu l ty with a sinking agent i s t o get the material on to

the sea surface without most of it blowing away. The French found t h a t it was

- 9 -

impossible t o work from naval vessels because the f i n e powder clogged up the

radar and armaments and they were reduced t o s l i t t i n g the bags of Craie de

Champagne and pouring the contents over the side of f i sh ing vessels. Even

under these circumstances it sank the o i l very well, although it must be

pointed out t ha t

a t sea f o r several weeks, The Warren Spring Laboratory i n England are working

on a system of in jec t ing the powder i n to a boat ' s f i r e pump and pumping it

out a s a s l u r r y the water spray then seems t o form a curtain and allows the

powder t o reach the sea surface, (14) They have a l so found, however, tha t it

requires an equal weight of sinking agent t o s ink a given quantity of f resh o i l

( i n France the r a t i o was I part chalk t o 7 or 8 par t s emulsified o i l ) and t h i s

brings us t o the problem of bulk

If one thinks i n terms of a f resh o i l s p i l l of 100,000 tons (which was the

quanti ty l o s t fcom the Torrey Canyon) it w i l l be seen tha t the l o g i s t i c s of

moving 200,000 tons of powdered sinking agent t o the d i sas te r area would be

enough t o monopolise, if not over2rhela, most national transport systems since

it would involve approximately 10,000 railway wagons Even i f a stockpile of

the m t e r i a l was available the problem of bulk s t i l l applies when it comes t o

actual ly using it. As mentioned above, e f f ic ien t scat ter ing from boats i s

dif'ficult; the use of hel icopters o r crop-dusthg a i r c r a f t would appear t o be

the solution but t h e i r l imited carrying capacity would hinder the necessary

high r a t e of application of the sinking agent.

Finally, it i s not cer ta in tha t a sinking agent w i l l ac tua l ly bring the

o i l a l l the way down t o the bottom, Because the water density increases with

depth the o i ly pa r t i c l e s of sinking agent might only t rave l par t of the way dam

f ro r l t he surface, but i t i s not d i f f i c u l t t o envisage s i tua t ions where t h i s

would be more favourable than complete sinking.

Booms had l imited success i n controll ing the movement of o i l s l icks ,

and then only i n harbours or es tuar ies where the wave height was lower than

18" or where the surface flow mas l e s s than 2 knots.

Burning of weathered o r emulsified+.s&l id t k f f i c u l t i f not impossible, and

t h i s method of t r ea t ing o i l pol lut ion did not get beyond the experimental sthge,

The most successful r e su l t s were obtained when the emulsion mas f i r s t

broken down with detergent t o re lease the o i l , and burning was a l so ass i s ted

by the addit ion of f i n e l y divided sol ids suoh a s powdered pumice.") Attempts

t o burn off black o i l on a sea wall using oxy-acetylene eq~ipment (~)caused

considerable flaking of t he rock surface and sprayed the o p e r ~ t o r with carbon-

coated s p l i n t e r s it i s a slow method - about 150 sq. f t , per hour per mn. (~5)

If the pol lut ion i s r e l a t i ve ly l i g h t and i n the form of sem&solid masses, the

lumps can be collected by hand and burned i n a drum supplied with compressed

a i r a t t h e base. But taken by and large, burning i s an expensive and laborious

process.

CONCLUSIONS

Bearing i n mind the inherent drawbacks a s well a s the advantages of

t he methods used t o combat t he Torrey Canyon d i sa s t e r and a l so the problem

already referred t o concerning the often confl ic t ing in t e r e s t s of tourism a d

f i she r i e s , one can firam up a preferent ia l l i s t of actions which can be taken

t o deal with o i l pol lut ion i n dif ferent si tuations.

Away from land, the f i r s t and possibly the most important s tep i s t o

keep the o i l s p i l l under observatior. Since the r a t e of movemnt of a patch

of o i l before the wind can be predicted 171th reasonable accurary, i t s extent

and posi t ion m y be observed from the a i r without expensive and time wasting

searching. Samples of the o i l should a l so be taken periodicaily t 3 deternine

the progress of i t s weathering and consequent increase i n density, since t h i s

i s one of the fac tors on rrhich w i l l depend the decision t o use detergent,

which i s expensive, or a sinking agent, chich i s general1.y cheaper.

As long as the o i l stays well away from land it should be just ke2t mder

observation, but if it s t a r t s t o drift tovards coastal waters vhi le s t i l l fresh

i t should be sprayed n i t h the most efficient detergents availalile, On the 0 t h ~ ' -

hand if the o i l i s old and has increased i n density t o tTe stage where tine use

of a sinking agent becomes prac t ica l , then t h i s method shoulcl be used i n

preference The poss ib i l i t i e s of sucking up the o i i should not be overloo?'sd.

Detergents should not be used where there a r e comerzial '_y .raluable

she l l f i sh beds. If, however, a holiday b ~ f ~ c h of grea te r im2orta~ce i s

ehreatened, and if there are she l l f i sh nearby, then l m t o ~ i o i t 3 ; should 2,e '-1,;:

c r i t e r i o n when select ing a detergent if i t s use i s considered upavoi&able, I?

such treatment i s not imperative in the amenity i n t e ~ e s t the o i l shou.?.d e i t h t r

be sunk or allowed t o come ashore, e i ther of which ni3.l cause l e s s bis logical

damage. Estuarine she l l f i sh beds may be protected by bos^msl and t h i s i s a b u t

the only s i tua t ion where conditions w i l l permit t h e i r effect ive use.

If it has been impossible t o prevedt the o i l coming ashore the course of

a.ction i s largely determined by the t ~ e - o f beach t o be des l t x i t h and also,

as before, by i t s importance a s a holidaPam&ity. Secluded and !.naccessible

roclqy coves should be l e f t alone - they w i l l be cleaned natura.ll,v i n t i ne and 2.c

not (contrary t o popular bel ief i n Cornwall a t the time of the Torrey Ca Ly) const i tute a source of pollution during t h i s period of natural cleansin . -Roc* beaches frequented by t o u r i s t s may be cleaned e i the r by physical emo oval

of the o i l , or by the caref'ul use of detergents. These must be scrubbed i n nr!.?;h

heavy brushes, par t icu la r ly if t he o i l has s t a r t ed t o harden, or i f pollutri.on 1.;-

by "chocolate rn~usse'~ emulsion, Action should be delayed (also contrary t o

e a r l i e r ideas, t h i s i s possible) u n t i l conditions OF wind a i d t i d e a r e

f avourable.

Detergents should not be used on a sandy beach, since a t best they a r e

inef fec t ive and sometimes even make matters worse. Instead, an absorbing

agent - straw, gorse, proprietary polyurethene foam - should be spread along

the beach a t la; t i d e t o absorb the o i l and be ro l led up the beach by the

r i s ing t ide . As the t i d e s t a r t s t o f a l l again the oil-soaked absorbing agent

i s col lected f o r burning or dumping and the process repeated a s of ten a s

necessary. Alternatively, the top layers of sand should be physically

removed with earth-moving equipment,

Finally, it should be pointed out t h a t , whatever the merits and demerits

of the methods tha t have been mentioned, there a r e two things which a r e a t

bes t guaranteed t o hinder and a t worst t o defeat the most comprehensive plans

t o combat large-soale o i l pollution of the marine environment, One i s lack of

preparation, the, other i s panic.

Se?m.?al of the reports quoted i n t h i s review a r e r e s t r i c t ed Br i t i sh

Admiralty documents and special permission was obtained f o r t h e i r publication.

I should thank the Director, Admiralty Materials Laboratory, Poole and the

Superintendent of t he Admiralty O i l Laboratory, Cobham, f o r permission t o quote

from A .Ef.L, Report No, A / ~ O (M), A.O.L. Report No. 52 and Technical Note

No. 31. I am a l s o grateful f o r permission t o quote some unpublisked r e su l t s of

work car r ied out a t t he Ninistry of Technology Warren Spring Laborztory,

Stevenage, by Dr. P.G. Jeffery (Head, Physioal and Chemical Services ~ i v i s i o n )

and M r F. Shuttleworth ( ~ n ~ i n e e r i n g services). Considerable assistance was

also received from the s taff of the Naval Sc ien t i f ic and Technical Information

Centre, Orpington, i n obtaining r ep r in t s of many relevant reports and

publications.

1, The Torre:? Canyon: Report of the Comm,it%be of Sc ien t i s t s on the 7 - 0 -.i

Scien t i f ic and Technological Aspects of t he

Torrey Canyon disaster.

H I Stationery Office, London, 1967.

2. Smith, J.E. (ed.)1968 '9- A report by the Plymouth Laboratory of the

Marine Biological Association of t he United

Kingdom.

Cambridge Univ, Press, London

Cooper, L.H.N. , 1 968

Parker, C.A. e t . a1. ,1967

Sc ien t i f ic consequences of the wreck of the

Torrey Canyon.

Helgolander wiss. Meeresunters. 17 : 340-355.

O i l Contents of the Sea following the Torreg

Canyon Incident.

Report No, A/~O(IN) , Admiralty Materials

Laboratory, Poole, Dorset.

5. Taylor, W.E.L, , 1968 'Torreg Canyon' exercise 'Mop-UE'.

Report No. 52 Admiralty O i l Laboratory,

Cobham, Surrey.

6. Wyllie, D., & Taylor, France and the 'Torrey Canyon'. Technical

m.E.L,, 1967 Note No, 31, Admiralty O i l Laboratory, Cobnam,

Surrey. ,

7. Bone, Q., & Holme,N. ,I 968 Lessons from the 'Torrey Canyon'

New Scient is t 2: 613. pp. 492-3. - -

8. OiSullivan, A . J , , and The Torrey Canyon Disaster and In t e r t i da l

Richardson, A. J., 1967 Marine Life.

Nature 214 : 5087, pp. 448, 5W, 54.2. - 9. Simpson, A.C, 1968

Laboratory Leaflet (Nee. Series) No, 18,

Ministry of Agriculture, Fisher ies & Food,

Fisheries Laboratory, Burnham-on-Crouch, Essex.

10. Spooner, M.F,, 1968 (Personal communication)

11. Gr i f f i th , D. de G. 1969 Investigations i n to the t ox ic i ty of Corexit. Fishery l e a f l e t No.6, Dept. of Agriculture and Pisher ies , b b l i n .

12. Jeffery,P.G.1968 ( ~ a r r e n Spring Laboratory,Stevenage,Herts. )- Personal Communication.

13. Wardley Smith, J. 1968 9* Warren Spring Laboratory, Stevenage, Herts,

(Paper g h n -6 Symposium on t h e Biological

Effects of O i l Pollution, Field Studies

Council, Orielton.)

14. Shuttleworth, F. 1968 (Warren Spring Laboratory, St evenage, ~ e r t s . ) - Personal communication.

15. Recommended Nethods f o r Dealing with O i l Pollution.

Engineering and Information Services Leaflet

LR 79. Warren Spring Laboratbry, Stevenage,

Hert s.