Promising emulsifier

Plight of the Baltic Details of the various industrial and domestic wastes commonly discharged into the Baltic, and the countries responsible for their discharge, are set out in a recent report by the International Council for the Exploration of the Sea Working Group on Pollution of the Baltic. (ICES Cooperative Research Report Series A, February 1970) The report comes 9 months after the group's second meeting, held in Helsinki in J u n e 1969 (the first was held in Copenhagen, 4 months earlier) and contains information provided by representatives from Denmark, the Federal Republic of Germany, Finland, Poland, Sweden and the USSR, as well as from the Food and Agricultural Organization and the Conference of Baltic Oceanographers - information being given by the latter on the situation in The German Democratic Republic. Dr Brent I. Dybern of Havsfiskelaboratoriet, Lysekil, Sweden, was chairman of the group. The Baltic areas that come under scrutiny include the Baltic proper, stretching eastwards from the sill of Darss, the Bights of Mecklenburg and Kiel, the Gulf of Finland, the Bothnian Bay and Bothnian Sea, the Oresund, the Danish Belt Sea and the Kattegat. A characteristic feature of the deep basins in these areas is the brackish, more or less stagnant water (see 'Marine Pollution Bulletin' (1970) 1 ( 1 ) : 8 ) . In the deepest layers of the Baltic proper the marked decrease, since the beginning of the century, in oxygen content has been accompanied by an increase in the amount of phosphorus -- estimated at 2.5 x 109 kg and 3 x 108 - 4 x 108 kg. respectively (totals). According to the report all the countries represented have laws against water pollution ((the controlling power being exercised by national or regional authorities), but inland waters are better protected than coastal waters. With the exception of the USSR and the German Democratic Republic all have signed the London Oil Pollution Convention. As regards other types of pollutant, however, Finland alone exercises legal control of dumping outside territorial waters, though in the German Federal Republic such discharges are subject to voluntary control. Pollution research is carried out in all the countries, and international collaboration in hydrography and marine biology is developing. Considerable quantities of sewage are discharged into Baltic coastal waters and most of it is untreated or undergoes only primary (mechanical) treatment. Particularly heavily polluted are the semi-enclosed bays and archipelagos where exchange of water with the open sea is restricted. According to the report the increasing discharge of phosphorus in sewage (estimated at 11 x 106 - 14 x 106 kg annually) probably contributes to the high phosphorus values in the deep basins of the open sea. The working group considers there is an urgent need for further studies on the phosphorus balance of the Baltic. Pollution by industrial effluents is most severe in Sweden and Finland, due chiefly to the wood processing industries. In both countries the industries are under heavy pressure to reduce pollution from this source by effective treatment arrangements, and it is optimistically thought that the pollution will decrease in future. Though heavy metals, phenols, cyanides and so on are currently discharged into the Baltic in very small quantities, the report suggests that these may be dangerous in the long run. Accumulations of mercury have been reported in fish around the Baltic coasts of Sweden, Finland and Denmark, as a result of which its use, particularly in the pulp and paper industries, is now largely forbidden. In all the countries, dumping of industrial wastes is generally avoided inside territorial waters. Most dumping in the open sea seems to have been done by Sweden; (7.6 x 10 6 kg of raw arsenic mixed with concrete were 50

dumped into the Bothnian Bay in 1930-1). The overall trend is towards the strengthening of control of industrial pollution, first of all in coastal areas and eventually in the open sea. In spite of the paucity of figures on the content of pesticides (other than DDT) in Baltic coastal waters, the influence of pesticides on the marine environment is nevertheless thought to be small in the German Federal Republic, Finland, The German Democratic Republic, Poland and the USSR. Organisms along the Baltic coast of Sweden, however, have been shown to contain several times as much DDT as organisms along the west coast. More significantly, concentrations of DDT in seals along the Baltic are up to ten times as high as in seals from the North Sea and along the Canadian coast. The report says that the use of DDT is now partly or wholly forbidden in the USSR, Sweden and Denmark; in the German Democratic Republic the use of aldrin, dieldrin and endrin is not permitted; in the German Federal Republic the use of aldrin, chlordane, dieldrin, endrin and heptachlor is forbidden; similarly in Sweden, several accidents have brought about prohibition of the use of aldrin, dieldrin and, to a certain extent, lindane and in the USSR several organochlorine compounds are no longer used. Oil pollution is increasing in most Baltic countries. Denmark, Finland and Sweden have refineries along the coast to which oil is delivered, but the problem is most serious in Sweden where considerable damage has been done to beaches, fishing gear and marine life - especially birds. Some Baltic harbours are equipped to deal with spills but the report says the equipment is insufficient and often too expensive to be used by many ships. Warm water 'pollution' is not a problem at present, the report says, but may become so when the large nuclear power stations planned for Sweden, the German Democratic Republic and Finland are built. Warm water could have a beneficial effect, but it could also eliminate some components of the present flora and fauna. The effects of sand sucking operations in some parts of the Oresund are causing concern for it is said that they make the water turbid, deplete the b o t t o m water of oxygen and destroy spawning grounds for fish.

Promising Emulsifier A new oil spill remover for use on beaches has been developed by the Centre National d'Etudes pour la Protection des Etres Vivants in Paris. The product has very low toxity and since it is composed largely of carbohydrates (glucose and sucrose) and p h o s p h o r i c acid, it provides a substrate for microorganisms and encourages the degradation of the emusified hydrocarbons. A preliminary description of the product which is marketed under the trade name 'Sefoil', appeared in 'C.R. Acad. Sci. Paris', (269, : 2435-8) on December 15, 1969. It will be relatively expensive and is not well suited for use on a massive scale, but if it lives up to the promise of the tests and field trials, it may well find favour. 'Sefoil' is applied in the form of a fluid paste. It has a density of 1.596, it is readily miscible with oil when agitated, and the emulsion can be diluted with fresh, brackish or seawater. In field trims it has been used in a proportion of sixty parts 'Sefoil' to 100 parts crude oil and it seems to be equally effective when used on rocky or sandy beaches where removal of the oil is total and permanent after hosing down. In laboratory tests 0.5 ml. of crude oil emulsified with 60 per cent 'Sefoil' in 100 ml. of seawater retained only traces of the heavier fractions after 3 months at room temperature. An equal quantity of unemulsified crude oil in water under the same conditions had lost only some parts of the lightest fractions.

Various toxicity tests have been carried out using 60:100 emulsions of 'Sefoil' and crude oil. Growth of cultures of Phaeodactylum tricornatum was reduced 50 per cent at concentrations of 0.35 ml./l. Photosynthetic activity in algal cultures was not appreciably reduced at concentrations up to 0.05 ml./l., and no significant changes could be detected in experimental marine ecosystems containing 0.04 ml./l, of the emulsion. Five species of fish, Labrus, Mugil, Gobius, Cattus and Pleuronectes, survived well for 6 days in a solution containin~ 0.12 ml./l, of 'Sefoil' in seawater and the shrimp Palaemon serratus can live for a similar period in a solution containing 0.30 ml./1. Mytilus is more sensitive and cannot tolerate concentrations greater than 0.12 ml./1. In all these tests the concentrations used were greater than those likely in any practical use of 'Sefoil' and the toxic concentrations are much higher than those for other oil spill removers in general use. Topical or internal application of 'Sefoil' to mice has proved harmless, and 'Sefoil' has evidently been used with some success in cleaning oiled seabirds, although details of these investigations are not yet available.

Protecting the Great Barrier Reef The discovery of important offshore oil and gas fields in Bass Strait between Tasmania and Victoria, in addition to other smaller fields, has given strong impetus to oil exploration in Australia. Much interest has been focussed on the Great Barrier Reef area (see 'Marine Pollution Bulletin' 1 (3) : 35), a large section of which has been leased for exploration activities. Fig. 1 shows the lease areas held by Australian and overseas exploration companies for periods up to 1975.

Foam for absorbing Oil A non-toxic polyurethane foam aggregate that can absorb up to one hundred times its own weight of oil has been developed by Baxter-Oleogon Ltd, a firm in Carlisle, Cumberland. The foam, 'Oleogon', has two essential components: liquid polyurethane oleochemicals and a fatty polyester, production of the latter being protected by patents owned by Harburger Fettchemie Brinckman and Margell GmbH of Hamburg. Like other polyurethane foams 'Oleogon' has a very low water absorption rate. It is produced by a special process (patents owned by BaxterOleogon Ltd) in long 'sausages' which are then shredded. The foam can be used loose, in which case it is simply scattered onto floating oil, or in the form of a 30.5 cm diameter boom, the foam being packed into yellow, proofed nylon sleeve netting. The ends of the booms are fitted with woven nylon ropes for towing. For absorption of oil in confined areas the foam-filled nets are available in the form of a mattress. Baxter-Oleogon has-also designed and produced a mobile, self-contained, foam-making unit which can operate at the site of an oil spill producing up to 70.75 m 3 of foam per day. According to Mr W. Baxter, director of the firm, the foam will absorb oils of widely differing type and viscosity, though with very thick oils some agitation may be necessary. Practical trials carried out on behalf of the British Docks Board at Doncaster and Birmingham have proved the efficiency of the foam, but one trial at Hull showed that the rate of absorption is lowered b y the presence of detergent. Trials in the open sea have not yet been conducted. Baxter added that weathered, congealed oil at low temperatures is not readily absorbed. By passing the oil-saturated foam through a suitable press the oil can be recovered and the foam re-used, though the absorption rate of such re-used foam is not as high as unused foam. At £1 per 2.83 cm 3 in boom form or 15s 0d loose, 'Oleogon' is considerably cheaper than detergents, says Baxter. Foam-packed booms are being sent to river authorities, power stations and helicopter pads all over Britain and the firm has so far received seventy-two enquiries from the United States. Rather than sell pre-made foam to interested parties overseas, Baxter hopes that large corporations will buy the rights to build and operate the units under their own names.

Fig. 1 Queensland offshore lease areas for petroleum (as announced by the Queensland Government on 4 September, 1969).

Several blowouts have occured during offshore exploration in Australian waters; since the Santa Barbara incident in January 1969 there has been much public concern about the conservation of the Great Barrier Reef with regard to present offshore drilling technology. Together with biologists and conservationists, the Australian public has opposed plans by Japex (a Japanese oil exploration company) to commence exploratory drilling operations under a farmout agreement with Ampol Pty. Ltd (an Australian oil company). The company's first well was to have been placed near Mackay. The area within 160km of this bay contains many tourist resorts and is probably the most important recreational area on the reef. Resort owners have demanded that the Queensland Government provide them with adequate insurance to cover possible damage caused by oil pollution. After transport of the Japex drilling rig from Texas to the drilling site had commenced, Australian unions combined in refusing to supply materials to the drilling platform if it arrived. Ampol quickly withdrew from the operation and requested that the Queensland State and the Australian Commonwealth Governments institute an enquiry into the safety of oil drilling on the reef. The Queensland Government, anxious for the establishment of an offshore oil industry, insisted that exploration activities 51