High mercury levels in Australian commercial fish
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but for genotypes that will thrive in a particular set of conditions to be selected on the spot, raises more issues. If this phenomenon proves to be widespread, as we suspect, it may explain the resilience of the marine environment to pollution. The discovery of different genotypes in places suspected of being exposed to pollution and the claim that this represents pollution 'damage' is obviously misguided. It is not damage; it is the marine environment rolling with the punch, and we should be grateful for it. While few studies of recovery processes in certainly damaged eco- systems have achieved the sophistication of studying the genetic constitution of the newly established populations, recovery in any useful sense of the word will not depend on restoring a population of the same genetic constitution as before. These are not academic quibbles. Governmental policy towards pollution of various kinds is determined in a vague and faltering way to what is perceived as the serious- hesS of the damage caused. In an even more vague and more faltering way, that depends on the assessment made by scientists engaged in studying pollution effects. Many of them were understandably impressed by the scale of Marine Polhjtion Bulletin initial losses in major accidents, most obviously big oil spills. But in the last 10 years we have learned a lot and there should, by now, be a more sophisticated approach to these problems. It is difficult to explain to non-marine biologists the vagueness of 'normality' in the sea and it is easy to take a dramatic, simple-minded viewpoint and get that across to politicians and the public at large. However, that serves nobody's interests in the end, and at some stage complicated concepts have to be explained. I do not know if the various French groups that were sueing for inflated damages arising from the wreck of the Amoco Cadiz were simply trying their luck with the insurers (a common enough event) or if they were simply misinformed about the likely outcome of the apparently catastrophic scale of the oil pollution. Biological advice, by now, could certainly be much improved if the latter is true. The insurers are well informed and, to judge from the experience in the American courts, are persuasive. Pollution biologists concerned with the public interests might give some thought to getting a more realistic view of what happens in the sea. R.B. CLARK More Tanker Disasters Disaster is a word that comes easily when describing oil tanker wrecks, but two accidents in November, both involving heavy loss of life certainly qualify. On 1 November, the Liberian registered 61 674 DWT tanker Burmah Agate was in collision with the Liberian Freighter Mimosa in the Gulf of Mexico, 8 km off the mouth of Galveston Bay, Texas. The Burmah Agate was fully laden with 390 000 barrels (46 500 tonnes) of light Nigerian crude and blended crude oil. Explosions and fire on the tanker followed the collision and 32 of the Burmah Agate crew and one of the Mimosa crew were killed. Firefighters were unable to cover the entire surface of the Burmah Agate fast enough to prevent petroleum vapours reigniting and the tanker continued on fire for over a month. It is estimated that 80% of the lost oil was burned off, the rest forming sticks, some of which came ashore on the Texas coast, particularly on Galveston Island beaches. The greatest escape was on 18 November when the Burmah Agate cracked amidships, releasing a large amount of oil which formed a slick 10 km long. The second disaster occurred in the Bosphorus on 15 November when the 147691 DWT Romanian tanker Independenta collided with the Greek freighter Eurialy, less than 2 km from the shores of Istanbul. Again there were explosions and fire, killing 52 of the 54 crew of the tanker. The Independenta was carrying 94 600 tonnes of Lybian crude to Black Sea ports. The tanker sank by the stern and by 23 November fire had consumed all the oil in the stern tanks, but also melted much of the mid-section of the tanker and spread to the bow tanks. Because of the fire and risk of further explosions, salvage and firefighting crews were unable to approach the vessel. The port of Istanbul was closed for a time and an area close to the harbour had to be evacuated. Burning oil on the water threatened houses on the shoreline of an Istanbul suburb, but these were controlled by the Turkish Navy and Istanbul fire department. The busy narrow straits of the Bosphorus have no traffic separation scheme and this disaster may lead to a renegotiation of international agreements to allow one to be introduced. High Mercury Levels in Australian Commercial Fish The CSIRO Division of Fisheries and Oceanography, Cronulla has found that some large specimens of both gemfish (Rexea solandrO and blue grenadier (Macruronus novaezelandiae) in south-eastern Australian waters contain up to 1.6 ppm mercury, the permitted maximum level for human consumption being 0.5 ppm in most States. The gemfish and blue grenadier which contained more than 0.5 ppm Hg had mean weights of 4.5 (range 2.4--6.3) kg and 4.6 (range 2.9-7.3) kg, respectively. Both species are relatively new to most consumers. Gemfish are a deep water trawl fish whose annual catch in New South Wales has increased, since 1969, by a factor of six to 4000 tonnes. It is now 30% of the total wet catch and is now worth more than $2 million dollars a year to N.S.W. fishermen. Blue grenadier or hoki, a valued resource in New Zealand, has yielded promising catches in exploratory surveys. CSIRO's Division of Food Research have reported that it can be processed into quality fish fingers. Meanwhile, N.S.W. State Fisheries are monitoring mercury levels in commercial fish, CSIRO Food Research Unit is looking into natural detoxification of mercury by vitamin E and selenium, and the Australian Fisheries Council's Working Group on mercury in fish have compiled a report that should be released early next year. DORIS GARDNER
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Transcript of High mercury levels in Australian commercial fish
but for genotypes that will thrive in a particular set of conditions to be selected on the spot, raises more issues. If this phenomenon proves to be widespread, as we suspect, it may explain the resilience of the marine environment to pollution. The discovery of different genotypes in places suspected of being exposed to pollution and the claim that this represents pollution 'damage' is obviously misguided. It is not damage; it is the marine environment rolling with the punch, and we should be grateful for it. While few studies of recovery processes in certainly damaged eco- systems have achieved the sophistication of studying the genetic constitution of the newly established populations, recovery in any useful sense of the word will not depend on restoring a population of the same genetic constitution as before.
These are not academic quibbles. Governmental policy towards pollution of various kinds is determined in a vague and faltering way to what is perceived as the serious- hesS of the damage caused. In an even more vague and more faltering way, that depends on the assessment made by scientists engaged in studying pollution effects. Many of them were understandably impressed by the scale of
Marine Polhjtion Bulletin
initial losses in major accidents, most obviously big oil spills. But in the last 10 years we have learned a lot and there should, by now, be a more sophisticated approach to these problems. It is difficult to explain to non-marine biologists the vagueness of 'normality' in the sea and it is easy to take a dramatic, simple-minded viewpoint and get that across to politicians and the public at large. However, that serves nobody's interests in the end, and at some stage complicated concepts have to be explained.
I do not know if the various French groups that were sueing for inflated damages arising from the wreck of the Amoco Cadiz were simply trying their luck with the insurers (a common enough event) or if they were simply misinformed about the likely outcome of the apparently catastrophic scale of the oil pollution. Biological advice, by now, could certainly be much improved if the latter is true. The insurers are well informed and, to judge from the experience in the American courts, are persuasive. Pollution biologists concerned with the public interests might give some thought to getting a more realistic view of what happens in the sea.
R.B. CLARK
More Tanker Disasters Disaster is a word that comes easily when describing oil tanker wrecks, but two accidents in November, both involving heavy loss of life certainly qualify.
On 1 November, the Liberian registered 61 674 DWT tanker Burmah Agate was in collision with the Liberian Freighter Mimosa in the Gulf of Mexico, 8 km off the mouth of Galveston Bay, Texas. The Burmah Agate was fully laden with 390 000 barrels (46 500 tonnes) of light Nigerian crude and blended crude oil. Explosions and fire on the tanker followed the collision and 32 of the Burmah Agate crew and one of the Mimosa crew were killed. Firefighters were unable to cover the entire surface of the Burmah Agate fast enough to prevent petroleum vapours reigniting and the tanker continued on fire for over a month. It is estimated that 80% of the lost oil was burned off, the rest forming sticks, some of which came ashore on the Texas coast, particularly on Galveston Island beaches. The greatest escape was on 18 November when the Burmah Agate cracked amidships, releasing a large amount of oil which formed a slick 10 km long.
The second disaster occurred in the Bosphorus on 15 November when the 147691 DWT Romanian tanker Independenta collided with the Greek freighter Eurialy, less than 2 km from the shores of Istanbul. Again there were explosions and fire, killing 52 of the 54 crew of the tanker. The Independenta was carrying 94 600 tonnes of Lybian crude to Black Sea ports. The tanker sank by the stern and by 23 November fire had consumed all the oil in the stern tanks, but also melted much of the mid-section of the tanker and spread to the bow tanks. Because of the fire and risk of further explosions, salvage and firefighting crews were unable to approach the vessel. The port of Istanbul was closed for a time and an area close to the harbour had to be
evacuated. Burning oil on the water threatened houses on the shoreline of an Istanbul suburb, but these were controlled by the Turkish Navy and Istanbul fire department. The busy narrow straits of the Bosphorus have no traffic separation scheme and this disaster may lead to a renegotiation of international agreements to allow one to be introduced.
High Mercury Levels in Australian Commercial Fish The CSIRO Division of Fisheries and Oceanography, Cronulla has found that some large specimens of both gemfish (Rexea solandrO and blue grenadier (Macruronus novaezelandiae) in south-eastern Australian waters contain up to 1.6 ppm mercury, the permitted maximum level for human consumption being 0.5 ppm in most States.
The gemfish and blue grenadier which contained more than 0.5 ppm Hg had mean weights of 4.5 (range 2.4--6.3) kg and 4.6 (range 2.9-7.3) kg, respectively. Both species are relatively new to most consumers. Gemfish are a deep water trawl fish whose annual catch in New South Wales has increased, since 1969, by a factor of six to 4000 tonnes. It is now 30% of the total wet catch and is now worth more than $2 million dollars a year to N.S.W. fishermen.
Blue grenadier or hoki, a valued resource in New Zealand, has yielded promising catches in exploratory surveys. CSIRO's Division of Food Research have reported that it can be processed into quality fish fingers.
Meanwhile, N.S.W. State Fisheries are monitoring mercury levels in commercial fish, CSIRO Food Research Unit is looking into natural detoxification of mercury by vitamin E and selenium, and the Australian Fisheries Council's Working Group on mercury in fish have compiled a report that should be released early next year.
DORIS GARDNER
