Another important consequence is the difficulty of obtaining clean water for processing fish. There are about 500 fish processing plants in three Atlantic provinces alone. Their output is valued at about $125 million annually, and most of it is exported. Many of the plants are very small and are located in the harbours of fishing communities, so the cheapest water would be from the harbour. Standards of cleanliness for processing water are extremely stringent, however, and any trace of harbour pollution forces the plant to develop freshwater supplies. The cost of locating clean water is seriously hampering development of the fish processing industry in Atlantic Canada (Sprague and Ruggles, 1967). Oil pollution After the sinking of the tanker Arrow in Chedabucto Bay, Nova Scotia, a powerful ad hoc research team has been formed under the chairmanship of Dr W. L. Ford, Director of the Atlantic Oceanographic Laboratory, Bedford Institute. This team represents many disciplines, including physical oceanography, marine geology, chemistry, ecology and engineering, and the members have many affiliations, including the Department of Energy, Mines and Resources, the Department of Fisheries and Forestry, the Defence Research Board and the universities and technical colleges of the area. In addition to advising on the operational aspects of retrieving as much as possible of the oil and cleaning the contaminated beaches, the team is taking the opportunity of gathering all possible information on the fate of the oil and its effects on the environment. Because the winter water temperature is below 0 deg. C, the accident gives some insight into the possible consequences of an oil spill in Arctic waters. Such information is of enormous importance to Canada which almost certainly has vast amounts of oil under its continental shelf, much of it in Arctic latitudes. Chemical identifications have also been made of oil isolated from water after several spills in the Miramichi estuary. A few oil dispersants have been studied: XZIT and Gamasol are quite toxic to freshwater fish. Corexit 7664 is not very toxic for herring or salmon. Its efficiency in dispersing bunker C oil in seawater, however, decreased with decreasing temperature (Zitko and Carson, 1969). The new dispersant Corexit 8666 is, b y itself, practically
non-toxic for salmon, flounders and lobsters. Mixed equally with bunker C oil there is still fairly low toxicity; 1,000 mg/l. of each killed salmon in 3 or 4 days b u t flounders and lobsters survived. Fisheries Research Board of Canada Marine Ecology Laboratory, Bedford Institute, Dartmouth, Nova Scotia, Canada. Fisheries Research Board of Canada Biological Station, St Andrews, New Brunswick, Canada.
K . H . Mann
J . B . Sprague
Elson, P . F . (1969) Threat of industrialization to Canada's Atlantic salmon, 'Fish. of Canada', 22 (5) : 3-9. Idler, D. R. (1969) Coexistence of a fishery and a major industry in Placentia Bay, 'Chem. in Canada', 21 ( I I ) : 16-21. Sprague, J. B., Elson, P. F. and Saunders, R. L. (1965) Sublethal copper-zinc pollution in a salmon river -- a field and laboratory study, 'Intern. J. Air Water Poll.', 9 : 531-543. Sprague, J. B. and McLeese, D.W. (1968) Toxicity of kraft pulp mill effluent for larval and adult lobsters and juvenile salmon, 'Water Res.', 2 : 753-760. Sprague, J. B. and Ruggles, C. P. (1967) Impact of water pollution on fisheries in the Atlantic provinces, Canada Dept. Fish. 'Canadian Fish. Rep.', No. 9 : 11-15. Trites, R. W. (in the press) Determination of the physical capacity of the marine environment to accept pollutants, In: 'Proc. Poll. Conf. sponsored by Atlantic Section of the Cherfu Inst. Canada, August 24-26, 1969'. Zitko, V. and Carsons, W.G. (1969) Bunker C oil. Dispersibility in water by Corexit and XZIT at different temperatures, 'Fish. Res. Bd. Canada, Ms Rep. Ser.' No. 1043. Zitko, V., Aiken, D. E., Tibbo, S. N., Besch, K. W. T. and Anderson, J . M . (in the press) Toxicity of yellow phosphorus to herring (Clupea harengus) Atlantic salmon (Salmo salar), lobster (Homarus americanus) and beach flea (Gammarus oceanicus), 'J. Fish. Res. Bd. Canada', 27.
Oiled Beaches successfully cleaned A 16 km stretch of the South Wales coastline between Barry Docks and Nash Point was polluted by oil on 8 April after a collision off Lavernock Point between the 15,895 ton Greek tanker Efthycosta II and the 1,500 ton Esso Ipswich. Both tankers were carrying refined products from Milford Haven to Cardiff, the cargo of the Greek tanker consisting of 14,000 tons of heavy fuel (bunker) oil. The cause of the collision, which occurred between 7.30 and 8 a.m. is not known, but the No. 1 tank of the Efthycosta II was holed, releasing 700-800 tons of oil: about 350 tons of this was, however, sucked back up into the tanker. A slick, 275 m long and 0.3 m thick, was brought in by the tide at Whitmore Point, Barry Island, soon after midday, causing serious pollution. Between 5 and 8 km west of this at Font-y-gary, a smaller slick was broken up by tidal currents as it came ashore. A large slick was reported south of Font-y-gary and slicks had reached the beach at Llantwit Major, 16 km down the coast, by the evening. Movements of the slicks -- apparently in a south-westerly direction - were followed by a Royal Navy Shackleton aircraft and by coastguards. For 2 days experts from the Ministry of Technology Warren Spring Laboratory sprayed about 50 km of sea with 3,500 gallens of BP 1002. Beach cleaning was carried out
by local authorities and by fire brigade teams. Initial burning of fresh oil was highly successful, as was subsequent mechanical removal of congealed oil. Small quantities of BP 1002 were applied from watering cans (the use of sprayers had been banned), but had little effect. Fortunately the flora and fauna of the affected area are not well developed, and the scouring action of the waves should quickly remove any detergent and remaining stranded oil. Nine observers sent out by the Nature Conservancy to report on the wildlife situation recorded only seven dead birds during the first 36h. Two hundred and six birds were slightly oiled, including 175 herring gulls, fifteen lesser black-backed gulls, twelve oyster catchers, two turnstones and two ringed plovers. None of the birds has been cleaned. Another survey was due to be carried out in the week beginning on 20 April. A spokesman from the Welsh Office in Cardiff said the question of liability had yet to be sorted out, but added that the captains of both tankers had been very cooperative. This report is based on information provided by Mr Geoffrey Crapp, Field Studies Research Council Oil Pollution Research Unit, Orielton Field Centre, Pembroke, S. Wales and Mr David Whyte, Nature Conservancy, Subregional Office, Cardiff, S. Wales. 77