The waters of Port Phillip Bay

More on Tanker Collisions The closure of the Suez Canal in 1967 coinciding, as it did, with the conversion of the oil transport industry to the use of large tankers which were too big to negotiate it had little impact on the industry. The future pattern of oil tanker movements was already determined and southern Africa has seen an enormous increase in traffic around its coast, particularly of tankers carrying oil from the Persian Gulf to Europe and the eastern United States, to say nothing of supplying South African needs. Inevitably there has been a dramatic increase in accidents and since the economics of oil transport dictate that supertankers should be employed on this extended sea route, some of them have been spectacular. In February the Wafra ran aground near Cape Agulhas on the southern coast of South Africa causing extensive shore pollution, and a post mortem on the effects of that and the clean-up measures that followed the oil spill is reported elsewhere in this issue. In August, Cape Agulhas was the scene of another spectacular disaster. The tankers Oswego Guardian and Texanita, both Liberian registered, were in collision in thick fog in the early morning of 21 August 80 km east of Cape Agulhas. Oswego Guardian was fully laden with crude oil and bound for Cape Town, Texanita was in ballast en route for the Persian Gulf. Lessons from the loss of the supertankers Marpessa, Mactra and King Haakon in December 1969 (see Marine Pollution Bulletin, 1 (2), 20, 1970) also around the coast of southern Africa, have evidently not been learned. These were all travelling in ballast and were cleaning their tanks which contained an explosive mixture of air and oil vapour. It was suspected then that electrostatic sparks produced when high pressure sprays were used to clean the tanks ignited the gas and blew up the ships. The same thing happened to the Texanita in the collision. Some of the earlier accidents had caused loss of life but none on the present scale. Forty-seven of the 50 man crew were killed, the other three, and one member of the crew of the Oswego Guardian were injured. The solution to the problem of explosive gas mixtures building up in empty oil tanks when a ship is travelling in ballast has been to blanket the tanks with inert gas such as nitrogen or simply exhaust gases from the ship's engines. A good many tankers already employ this system with success and the question must be asked why not all? A seaman's life is hazardous enough without unnecessary risks being added to it. It is well known that the reason why countries such as Liberia and Panama have the world's largest tanker fleets is because of the laxity of their controls. They are not called 'flags of convenience' for nothing. To be fair, it must be admitted that it is not yet known if the Texanita had been equipped to flush her tanks with inert gas, but the fact that she exploded with the almost complete loss of her crew suggests that the precautions were inadequate. In these circumstances, biological damage resulting from the oil spill seems almost irrelevant. Oswego

Guardian was holed forward and the captain emptied the forward tanks to raise the bow. The resulting oil slick covered a large area about 15 km off Cape Agulhas, extending seawards. Preliminary reports suggested that there was no contamination of the shoreline, but since this area is fairly isolated and not much visited in winter, minor beach pollution could have gone undetected. The chief casualties appear to have been penguins. 450 were recovered for treatment, but many more may have been killed at sea. Particular concern has been expressed for the welfare of the Jackass penguin (Spheniscus demersus) which concentrates on the South African coast in the winter and has an estimated population of only 103,000 (see Marine Pollution Bulletin, (14), 2, 1969). Treatment of this bird in captivity is notoriously difficult and previous rescue attempts after oil spills have not been very successful.

The Waters of Port Phillip Bay The Environment Protection Authority of Victoria, Australia, has aired its first environment protection policy for three months of public comment. The policy concerns the waters of Port Phillip Bay and divides the 2,000 km 2 area into ten segments, each of which has certain differences in respect of topography, beneficial uses, waste discharges or hydraulic characteristics. For each segment, beneficial uses to be protected are listed, together with the water quality standards needed to protect those uses. The ten water quality parameters include dissolved oxygen, bacteria counts, pH, temperature and bottom deposits. More than 2.6 million people live in the region, the built-up area extends 65 km around the shoreline, and 90,000 homes are not connected to main sewers. Inevitably industrial and domestic waste eventually enters the waters of the bay. The EPA intends to control this source of pollution by licensing discharging industries, and encouraging outer suburban homeowners to connect to main sewers. Now that the public has been given an invitation to participate in the government of the environment the complexities of the 'pragmatic approach' (Marine Pollution Bulletin, 3 (8), 113, 1972) are becoming apparent. Some of the most experienced biologists and chemists are unwilling to venture from their academic towers, pleading ignorance and subsequent loss of credibility in the open fields of draft legislative policy. Lawyers are unsure of the science on which the policy is founded. By good luck or good management, a small team headed by Dr R. J. Birrell of the Sociology Department, Monash University, released a short report on the problems of bacterial pollution along the nearshore waters of Port Phillip Bay, one day before the release of the official EPA statement of planning policy. This report claimed high E. coli counts off many of the most popular bathing beaches, reaching a maximum of 110,000/100 ml off the Patterson Creek. This creek drains a large area of unsewered residential development much favoured by people wanting to escape the gloomy unhealthiness of the city. DAVID HUGHES 163