How the Royal Navy combats oil pollution

will form an integral part of the activities of the research unit. At the same time it must be recognized that whatever conservation measures o f this kind are taken, large numbers of private organizations and amateur groups in several countries will a t t e m p t to rescue and rehabilitate oiled birds. A n y t h i n g that can be done to make their efforts more profitable will be worthwhile and may, in time, allow them to make a significant contribution to the preservation of

colonies of seabirds most at risk in areas where they are now declining. D e p a r t m e n t of Zoology, The University, Newcastle upon Tyne, NE1 7RU, England.

R. B. Clark

How the Royal Navy combats Oil Pollution An article in the S e p t e m b e r 1969 issue of the 'Marine Pollution Bulletin' (No. 15 : 15) outlined the part played by the Board of Trade in dealing with oil pollution offshore, and the general relationship b e t w e e n their principal officers, HM coastguards and the Maritime Headquarters of the Ministry of Defence. I should like to explain here the part that the Royal Navy plays as an agent of the Board of Trade in assisting to reconnoitre~ survey and disperse oil pollution offshore. Reconnaissance and surveillance Many reports of oil slicks are received by the principal officers of the Board of Trade and the Naval Maritime Headquarters from ships, aircraft and HM coastguards. Most reports contain the barest details and are rarely sufficiently comprehensive for full scale operations to begin. Sightings of slicks f r o m aircraft are frequently unreliable as to c o n t e n t ; m e r c h a n t ships with a tight schedule to maintain do not often have time to stop or investigate a slick more thoroughly. Maritime Headquarters and the principal officers require m u c h fuller information before they can decide whether to deploy sprayin~ vessels or to leave the slick to the natural degradative effects of the weather and the sea. HM ships and other Ministry of Defence vessels may well be in the vicinity of the slick, particularly in well-frequented waters such as the English Channel, and can provide quick and authoritative reports on the size, c o n t e n t and threat posed by the slick, and obtain a sample of the oil for analysis. If none o f HM ships is readily available, a general signal to m e r c h a n t shipping passing through the area often produces some of the i n f o r m a t i o n needed to make a correct assessment of the threat. In the event of a major disaster offshore, where the position of the source of pollution remains relatively static and defined a large surveillance effort is required to track the spread of oil, n o t only to confirm the predicted m o v e m e n t but to assess its future threat and the progress of measures against it. In this situation Royal Air Force and Royal Navy aircraft will be used to define the extent and size of the pollution and fast ships to define its position and content. In the event of a major spill of the size of that f r o m the Torrey Canyon this task needs to be carried out at least once a day and the c o m p l e t e d plots sent f r o m the controlling warships at sea to the Maritime Headquarters. These plots then form a basis for decision at headquarters on the d e p l o y m e n t of forces ashore and afloat to deal with the pollution.

Dispersal-command c o n t r o l The Royal Navy is unlikely to be called in by the Board of Trade to assist in dealing with m i n o r spills offshore. These may be m o r e economically left to natural degradation, dispersed by local effort, or dealt with w h e n the oil reaches the shore. When there are major disasters and 24

massive spillages, however, so m a n y government, scientific, legal and e c o n o m i c interests b e c o m e deeply involved that a large headquarters with comprehensive c o m m u n i c a t i o n facilities is essential to the c o m m a n d and control of the operation. Such headquarters exist at P l y m o u t h and Rosyth, with smaller offices elsewhere in the U n i t e d Kingdom. These provide the facilities needed by Ministers of State and officers f r o m the Board of Trade, Ministry of Housing and Local G o v e r n m e n t and Ministry of T e c h n o l o g y , as well as Area Oil Pollution Officers and Flag, General and Air Officers of the Services, to control all aspects of the clearing operation. These people are advised by representatives f r o m the oil companies, the Nature Conservancy, and fisheries, and can readily give advice on salvage, law and economics. This team controls all the varied aspects of such a large scale operation -- the ships at sea, the air space around the scene of the disaster, the logistic support of detergent and other supplies, the provision of devices such as b o o m s , operations ashore and on the beaches and the implementing of measures other than spraying. Dispersal at sea The vicinity of a massive source of pollution at sea caused by collision, fire or shipwreck soon becomes c r o w d e d with ships and aircraft drawn there by hopes of salvage, a desire to rescue or curiosity. The greater the disaster, the greater the scramble by the various news media to get their representatives on the spot. While the source and most of the pollution remains in the open sea spraying with detergent will be one of the m o s t c o m m o n m e t h o d s used to accelerate dispersal, because o t h e r more effective means such as transfer, burning or bulk removal may not be possible for physical, e c o n o m i c or legal reasons. These activities require close coordination and control that can only be carried out by an HM ship with good c o m m u n i c a t i o n and surveillance facilities. The spraying vessels, of all sizes and capabilities, m u s t be d e p l o y e d to the best advantage and the many requirements satisfied to keep them at sea and spraying. O t h e r means of disposal may involve as m a n y ships and resources. The airspace around the wreck must be w a t c h e d closely to maintain safety in mid-air and controlled to the advantage of the m a n y civilian and service aircraft that wish to use it. If the scene of the action is r e m o t e from the coast or sheltered harbours a considerable organization is required to maintain the fleet of vessels and to keep t h e m supplied. During the Torrey Canyon episode up to forty-five vessels were involved in spraying and support; there were as m a n y as eight aircraft in the vicinity at one time, and an average of 80,000 gallons of detergent were sprayed each day. The area of operations at sea e x t e n d e d over 150 square miles, and m a n y thousands of people were involved. It is

most unlikely that similar circumstances will occur again. It is, however, unfortunately true that it is only a question of time before another massive spillage occurs as a result of collision or some other disaster in the heavily congested waters around the British Isles. National and local plans now exist at most levels to meet such a situation. Local organizations are kept busy by the continual minor spillages that still occur, particularly around the busier shipping lanes. The same incidents serve to test the many lines of communications between the various authorities that are now actively involved in combating this problem.

The Royal Navy is closely involved in the national arrangements for dealing with oil pollution and is ready to respond to any threat that may arise. It also hopes that the need for its services will decrease as international agreement reduces the likelihood, and level, of oil pollution at sea. Office of the Flag Officer, Plymouth, Mount Wise, Devonport.

J. A. F. Lawson

Bacterial Degradation of Crude Oil Since November 1968 we have been concerned with (1) identifying the bacteria involved in the breakdown of oil and the optimum conditions for their growth; (2) observing the changes which occur in the bacterial populations during the course of oil degradation; (3) observing the changes induced by the bacteria in the composition of the oil and the time constants of these changes. Bacterial strains able to utilize crude oil or single hydrocarbons as sources of carbon and energy were isolated from estuarine mud after enrichment in a seawater medium containing crude oil (Kuwait, supplied by BP, Llandarcy), or a single hydrocarbon, as the only source of carbon. Octane, pentadecane and hexadecane were used as examples of straight chain paraffins with odd and even C-numbers; 2 methyl-hexane was used as an example of an isoparaffin and cyclohexane as an example of a cyclo-paraffin; heptene as an olefin; 1 phenyl-dodecane as a phenylalkane; and benzene and naphthalene were used as examples of aromatic hydrocarbons. TABLE 1 Growth of Isolates in Various Hydrocarbons

Approximately fifty strains of bacteria were collected and subjected to further examination. The majority were

Pseudomonas, Acinetobacter, Achromobacter/Alcaligenes, Flavobacterium and a few Gram positive organisms which are so far unidentified. Their ability to utilize various hydrocarbons as the sole source of carbon and energy is shown in Table 1. At present the action of these isolates, and also of mixed cultures, on mixtures of hydrocarbons is being determined. The results of gas-liquid-chromatography (GLC) indicate that in a mixture of C12 Cl s and C16 alkanes, the Cl2 is always attacked first and afterwards there is no preference between C1 s and C 16Growth of some of these strains and also of mixed cultures is not markedly inhibited in the presence of the following sinkers: siliconized pulverized fly ash, siliconized sand, Grangemouth 1 and 2 (BP), spent tannery lime, Crowsink, Oilsink, stearated chalk whiting, Nautex-H, untreated fly ash, and sand. In some tests bacteria in both pure and mixed culture were dried on to sinkers at 37 deg. C. The viability of the organisms was tested and was found to vary with different strains of bacteria as well as with different types of sinkers.

Growth o n s u n k e n oil Attempts to measure bacterial growth on oil sunk with any of the sinkers already mentioned were accompanied by practical difficulties. It was necessary to extract the bacteria from the oil and to ensure even distribution of the sample for counting. The most practical way was to emulsify the sample. Several agents were tested including Polycomplex-A, Nonidet P-40, Tween 80 and four other compounds; Corexit (Esso) was found to be the most suitable. Kuwait and Nigerian crude oils were mixed with siliconized fly ash and inoculated with a mixed culture of bacteria. Population changes were followed by counting the number of bacteria present in the inner and outer layers of oil (Fig. 1). The number of bacteria increased on both types of crude oil, and one organism eventually became dominant. The outer layer o f oil supported a greater population than the inner layer where it is assumed a deficiency of oxygen inhibited growth. A further experiment where oxygen was excluded as far as possible has verified this result. GLC analyses of the residual Nigerian and Kuwait crude oil are n o t complete and the results of this work will be given later. The results obtained so far, however, indicate that most n-alkanes have been almost completely metabolized in 2 months at 30 deg. C whereas the iso-alkanes 25