Metal in the Sea 81

News Havoc Caused by Kinky Pipelines 82 Lack of Progress on Saving Whales 83 Going by the Board 83 Sakhalin Offshore Prospecting 83 Sounds Interesting 83 Change of Tune on the Seabed 84 Life Found under Antarctic Ice 84 Plymouth Oil Bibliography Supplement 84 Little Pollution on Thai Coast 84

Reports Diagenesis, Metals and Pollution in Estuaries 85

H. Elderfield and A. Hepworth Arsenic in Marine Organisms from West

Greenland 87 A. Bohn

Heavy Metals in Organisms of the Atlantic Coast of S.W. Spain and Portugal 89

R. D. Stenner and G. Nickless Trace Elements in Sediments from the

Lower Severn Estuary and Bristol Channel 92 R. Chester and J. 14. Stoner

Book Review Economics and the Environment 96

Correction 96

Angeles is a prime example. Examination of cores from the Greenland icecap shows that at deep levels, ice which fell as snow 2000 years ago contains little lead, and so the picture remains up to levels corresponding with the second half of the eighteenth century when the industrial revolution in Europe followed later by industrialization in North America caused a rapid increase in lead rained out over Greenland. The most massive increase, still climbing, is from ice levels representing the period since 1940, with the enormous growth of the automobile population and use in the northern hemisphere in the last three decades.

Diffuse inputs of pollutants are notoriously hard to control, but equally, since the rain-out is also widely distributed, there is an enormous dilution factor once the contaminant reaches the sea. It is certainly true that at present there is far more to worry about over local industrial inputs which may cause great elevations of concentration over a short distance than from the general raising of background levels over large parts of the land and sea in the northern hemisphere. This cannot be an excuse for ignoring the problem; nor is it. Heavy metals and other persistent pollutants are now monitored in seafood in a good many countries and there are several monitoring programmes of metal levels in seawater and organisms.

Metal pollution is a complicated business, however, and we are still far from knowing enough about the behaviour of metals in the. sea to be able to know just what happens to all these inputs. Two of the papers in this issue of the Bulletin expose the problems of deciding how much metal

82

Marine Pollution Bulletin

in marine sediments has a natural source and how much is due to human activities, how much is free, and how it may be transferred between the sediment column and the overlying water. Much depends too on the form in which the metal exists in the environment. It is well known that methyl mercury is much more dangerous to humans than free mercury, but it is less well known that the toxicity of many metals depends on the molecular species they exist in. Since the proportions of the molecular species are in equilibrium which may be changed by the physico-chemical conditions, crude measurements of particular metallic elements in water or in organisms may be misleading or have little practical value.

Nevertheless it is a matter for some concern to discover from two other papers in this issue of the existence of arsenic in marine organisms far from likely inputs, even if the news that much of it is in the form of organoarsenics and less toxic than inorganic arsenic compounds, is welcome.

Less in the news that some other forms of pollution, metals in the sea are a cause for concern. They and untreated sewage are the only known direct hazards to human health in the sea that result from effluent discharges and pollution. Constant attention to this problem is a vital need if we are to continue or even expand out exploitation of the marine food resource.

Havoc Caused by Kinky Pipelines The buckling produced during the laying of an undersea

oil pipeline, or by a relatively innocent accident, such as the dropping of an anchor, could have disastrous consequences for a considerable length of the line, possibly causing widespread pollution as opposed to pollution at a restricted zone. British Petroleum (BP) has, however, fortunately taken this into account, but nevertheless the possible dangers arising from this discovery should be borne in mind, especially with the rush to have North Sea oil production in full swing as quickly as possible.

Dents produced during the construction of a pipeline in deep water could be propagated along its entire length, according to Dr A. C. Palmer and Mr J. H. Martin of Cambridge, who have carried out extensive tests on model pipes, exposing pipes with a kink to high external pressures. If the latter was sufficiently high, the kink would travel along the pipe, damaging parts not originally affected. If an unprotected pipe is accidentally buckled as it is laid, great lengths of it could eventually be wrecked.

In their recent paper in Nature the authors draw analogy with a tube of toothpaste. If a tube is held between thumb and forefinger, which are then moved along its length, we have a rough model of kink propagation in a real pipe, with the tube distorted into a dumb-bell shape. At depths of more than 300 m a kink would travel at about 400 km/h. although at the depths usually encountered in North Sea operations (200 m) the speeds would not be so alarming. The variation in speed with depth arises from the fact that it is the external water pressure which propagates the kinks, and pressure increases with depth.

Volume 6/Number 6/June 1975

The cost of repairs and the difficulty in carrying them out require that undersea installations of any sort -- such as telecommunications cables or pipelines - must never wear out or be susceptible to damage. The cost of buckling in oil pipelines could amount to more than $1 million (£430,000) per km. An anchor accidentally dropped on a pipe could trigger the process and cause considerable damage.

BP are protecting their pipelines from extensive wrecking by encasing them in a sort of strait-jacket. Pipelines typically consist of a steel tube surrounded by a concrete shell, the chief function of which is to add weight to the pipe and keep it on the sea floor. These pipelines, susceptible to damage and kink propagation can be protected by adding a number of extra sleeves of steel pipe in metre lengths and with walls 2 - 3 cm thick. These would prevent external damage by interfering with the propagation of kinks, the pressure needed for the latter being greater than the external pressure of the sea at a particular depth. Another possibility would be to design buckle arresters which would stop kinks which had begun to propagate.

Lack of Progress on Saving Whales Environmental organizations are expected to continue

their boycott of Japanese products as a continuing protest to the lack of progress on saving whales. Reports of the December meeting of the Scientific Committee at La Jolla, California indicate only limited progress was achieved. On the last days, the group finally agreed on a formula for managing whale stocks based on a sliding scale for each species. The scientists agreed that the maximum sustainable yield (MSY) would differ for each species but they have not yet agreed on what the MSY is for a n y species. When a stock goes below 10% of the MSY they have agreed that the stock cannot be taken. This formula will have to be accepted by the International Whaling Commission at its next meeting in London in June 1975.

Since Japan did not agree to the formula at the La Jolla meeting, it can be expected to run into difficulties in the IWC. The Scientific Committee reached agreement on three categories of protection: (1) a category termed 'protected' which will include those already protected; (2) those whales almost untouched (at 'initial stock level'); and (3) those stocks at or near sustained yield level. Each category will be harvested differently. This is a protective arrangement by population rather than by species. For example, it is anticipated that the North Pacific Sei whale will be protected but some South Pacific Sei populations will be exploited.

Concern has been expressed that the move towards national control over the coastal area out to 200 miles - almost certain to be accepted at the Law of the Sea Conference - could seriously affect international regulation of whaling. According to a NOAA spokesman about 50-60% Of whale stocks are found in this 200 mile area. So far the proposals at the Law of the Sea Conference on migratory species provide for coastal state control over the species when they are in coastal waters. The NOAA spokesman also indicated that there will be efforts on the part of certain countries to remove the grey whale and the Pigmy blue whale from the protected list. Environmental groups will oppose this.

Going by the Board In their annual report published in March, the

Conservation Society warn that exploitation of North Sea oil will lead to heavy sacrifices of the social and physical environment of Scotland. "In the haste to get as much energy as possible, environmental standards go by the board, and heavy sacrifices will be made not merely to extract the oil eventually, but to use it up as fast as possible." Energy policy seems to assume a steady increase in energy consumption, mitigated only by those con- servation measures that could be put into effect without prejudicing economic growth.

Sakhalin Offshore Prospecting Soviet organizations will start offshore geological

prospecting for oil and gas in June in the north-east and south-west of Sakhalin Island (Soviet Far East). Under a Soviet-Japanese agreement on cooperation in prospecting the Japanese side is financing the survey operations over 10 years by granting a commercial credit to be repaid by oil and gas deliveries. Under the terms of bank credits, the Japanese will supply machines, equipment and materials needed for mining operations.

After the credits have been paid off the Japanese can be supplied for 10 years with 50% of the oil and gas annually extracted at the jointly discovered deposits at world market prices.

This major agreement is assessed by Japan and the Soviet Union as an important new step in the fulf'tlrnent of a number of large-scal.e programmes of Soviet-Japanese cooperation in the development of mineral resources of Siberia and the Far East, a considerable part of which is already being carried out.

Sounds Interesting The very latest in devices for detecting pollution - an

echo-sounding system similar to that used for detecting submarines from ships - has been put forward by a group of scientists working at the National Oceanic and Atmos- pheric Administration. They claim to have detected oceanic suspended particulate matter acoustically at concentrations lower than any previously recorded case. Clouds of such matter have previously been observed by satellite, sampled by water bottles and sensed by a nephelometer, an instrument which calculates particle size by measuring the amount of light which a given volume absorbs.

Initial visual sightings of particle clouds would lead to more detailed acoustic analysis by this sophisticated sonar technique. The feasibility of using such a system has been determined with sediments disturbed by tidal movements, and the researchers aim to continue their theoretical and field work to develop what they consider "may prove to be a valuable survey tool, with immediate applications for the sedimentologist, geologist, ecologist and pollution monitoring agencies". This will involve the determination of those factors, such as small biota and pollutants, which are likely to cause acoustic patterns. The behaviour and properties of acoustic clouds - the way their movements

83