- Email: [email protected]
Attack on spear-fishing
Japanese Whaling In the light of the annum conference of the International Whaling Commission (IWC), held in London recently, it is interesting to reflect on the role of Japan in whaling, an important part of this country's food industry. Japan is a mountainous country, not likely to be able to sustain a major stock-rearing pattern of agriculture, which has traditionally obtained most of her animal protein from the sea. Given the limitations of cattlerearing, etc., a significant proportion of the supply of protein will continue to come from whales. The principle whaling nations are Norway, United Kingdom, Japan and Soviet Union. The total world catch in 1972 (for example) was 31,821 for all species. For Japan, the total catch in 1973 was 13,346 (5,082 sperm, 4,745 sei, and the rest from fin and Menke whales) from the Antarctic and the North Pacific. In contrast to the principal interest of Western nations in obtaining whale oil and a supply of meat for pet food, the Japanese make more use of their catch, thus making the industry more commercially viable and constructive. Their main objective is to provide whale meat as animal protein, the entire output going for human consumption. This accounts for 75% by value of the industry's production (about £45 million annually) and represents about 8% of the annual total meat consumption. A conservation policy has been established by the IWC, which provides an international control system dependent on information from member states about the estimated size of whale stocks, the extent of whaling, etc. The commission subjects countries to quotas for particular species, size limits, closed seasons and area closures. In adhering to the established marine biological principles of stock renewal, the commission also imposes a complete ban on the catching of threatened species, and of calves or suckling whales and their accompanying mothers. The industry's own livlihood requires that it observe this policy of encouraging growth of stocks. The world-wide shortage of animal protein food predicted by the FAO for the 1980s will certainly turn governments' eyes to the sea. Whaling may have a much greater part to play in the world food supply in future (leading to whale farms?). However, both the UN Environmental Conference in Stockholm in 1972, and the 1972 and 1973 meetings of the IWC, have proposed a severe curtailment in all whaling for the next 10 years.
Wetland Wildfowl Yet another link in the ever-increasing network of wetlands for palearctic waterfowl has been conserved by the establishment of the Wexford Wildfowl Reserve earlier this year. The reserve was officially inaugurated by the Irish Minister of Lands, thus setting an example for other nations to follow the Ramsar Convention on the conservation of wetlands of international importance. The reserve lies 90 miles south of Dublin on the north side of Wexford harbour (on the North Slobs), where a 1,000 hectares of land were reclaimed from the sea in
the mid-nineteenth century. The reserve proper is best known as the wintering grounds for some 5,000-6,000 Greenland White-fronted Geese (Anser albifrons flavirostris), which represent more than half the world population of this sub-species. At the same time, it provides food and shelter for many other species of wildfowl: all three species of swan are present, and the Barnacle Goose (Branta leucopsis) has been visiting the Slobs since 1920. The Canada Goose (B. canadensis), Brent Goose (B. bernicla) and the Pink-footed Goose (Anser brachyrhynchus) are also regular visitors. Twentythree species of duck have been recorded, together with thirty-five species of waders.
Red Mud The Council of Europe reports the increasing threat of pollution to the Venice lagoon. Every day 3,000 tons of red and white mud (1 minion tons per year) are being dumped into the sea 15 miles from the city. This would amount to creating an island 200 m long, 100 m wide and 25 m high each year. In spite of assurances that this waste is harmless, a judicial enquiry is under way to determine whether there is any threat to the biological balance of the upper Adriatic. (See also Mar. Poll. Bull., 4(2): 19; 4(3): 40; 4(11): 169-171; 5(4): 51; 5(7): 98).
Effect on Sewage Purification Inhibition of chemotaxis by chlorinated hydrocarbons may directly affect estuarine serf-purification rates, according to a recent report in Nature by Walsh and Mitchell of the Laboratory of Applied Microbiology at Harvard University. Some marine microbial predators are known to feed on the enteric bacteria contained in the municipal sewage which is discharged into tidal and estuarine regions. Rates of kill of E. eoli by marine predators (mainly Spirillum sp.) were examined in the presence of two chlorinated hydrocarbons, 2,4-dichlorophenoxyacetate (2,4-D) and o,o-dichlorobiphenyl. The concentration of the latter required to significantly decrease the percentage kill (also previously shown to inhibit chemotaxis in motile marine bacteria) is only 20 times greater than that observed for chlorinated hydrocarbons in natural estuarine ecosystems. Bacterial predators are chemotactic specifically to exudates of their prey. Consequently, even though recent increases in the concentrations of chlorinated hydrocarbons may not be sufficient to directly affect the viability of predators or pathogens, waste effluents may contain chlorinated hydrocarbons at concentrations 10-100 times greater than sea water residual levels. Such hydrocarbons may decrease the level of predator/ prey interactions responsible for self-purification in natural ecosystems in the vicinity of ouffalls.
Attack on Spear-Fishing Hunting under the sea is a relatively recent development compared with its counterpart on land. The dangling of a piece of bait on a line could not very well replace the thrill of the hunt, except in those circumstances requiring considerable strength and endurance to land a powerful struggling fish into the back of a 115
last-moving boat. The new excitement of hunters carrying spears and using diving techniques quickly began to attract enthusiasts. The hand-spear was replaced by the spear-gun, and sophisticated diving techniques enabled further exploration of the oceans. Dr Hans Hass (a man who perhaps did more than anyone else to create interest in the underwater world through his books and flms) has been alarmed by the devastation caused by large numbers of hunters in a relatively short space of time. Writing recently in Development Forum (published by the United Nations Centre for Economic and Social Information), he extoled the wonders he had discovered in the Mediterranean, the Red Sea, and in the West Indies before the war. 'I was shocked by what I saw. The fish were gone . . . underwater hunters had invaded the sea . . in Jamaica 1 thought 1 had landed on the moon." Dr Hass believes that the situation can only be alleviated by banning the use of spring-loaded spear guns
Toxicity of Oil-
and explosives, although he is prepared to be more accommodating when it comes to hand-spears. 'Tilis type of hunting requires considerable skill and is fair since it gives the fish a good chance to escape. Dr Hass mentions that the Seychelles and some West Indian islands have already banned spear-fishing, and efforts are continuing to secure bans elsewhere. He has appealed to the World Underwater Federation (the body sponsoring the world championships in spear-Iishing) to assist him in his quest l~r the banning ot" mechanical underwater weapons. The World Wildlife Fund approached the Federation and the problem is now being discussed in association with the International Union for Conservation of Nature and Natural Resources (IUCN). The French underwater expert, Jacques Cousteau (whose films did much to glamourize the underwater world) now strongly opposes the use of spear-guns and his American Company will no longer manufacture them.
iag Agents
It may be necessary to immobilize an oil spill of more than 10,000 tons in European waters by sinking with sand. The possibility of damage to marine organisms from the sinking agents used has been investigated and it is coneluded that toxic effects are unlikely to result. Despite recent major improvements in the efficiency of low-toxicity oil dispersants, the dispersing capacity of available vessels remains inadequate to deal with a spill of more than 10,000 tons in Europeans waters. In the event of an emergency on a larger scale, it may be necessary to immobilize the oil by sinking it, using sand. In this method, the oil is sunk by spraying it with a slurry of sand and sea water, into which a solution of wetting agent (tallow amine acetates) has been injected. The wetting agent renders the sand oleophitic and the specific gravity of the sand/oil mixture is sufficient to sink it. The mixture settles on the bottom as light, floccular masses which are easily moved by currents of 0.5 knot (927 m/h), and are therefore readily dispersed. Any excess of wetting agent carried down with the oil is likely either to be washed out as it settles, or to be released as sunken oil is moved over the bottom. Experiments to test the toxic effects of sunken oil masses on benthic animals have been reported previously (Blackman, 1972). This paper describes experiments to assess the possibility of damage to marine organisms from the sinking agents used.
Ethylene Glyca -(48h) Iso-propyl alcohol
103
,~E .~_ W2 I---
2-Butoxy Ethanol
10
Materials and Methods In the sand-sink method, the wetting agent is injected into the slurry as a solution in an organic solvent. The wetting agents to be tested were therefore presented in this form. Test solutions were prepared from stock solutions (0.75% weight/volume) of the wetting agent in an organic solvent. It is doubtful if any of the tests were carried out with true aqueous solutions, for the solution of wetting agent, when added to sea water, formed a fine, milky dispersion. The standard of static toxicity test of Portmann and Connor (1968) has been followed, using brown shrimps 116
1
102
I I 103 104 Concentration: parts per 106
.3 105
Fig. 1 Estimated time to reach 50% mortality against concentration for three solvents, with 95% confidence limits:
(Crangon erangon; 20 animals per tank), which were exposed to a range of solvent/wetting agent solutions in sea water for 48 to 120 h. Solutions were renewed every 6, 12 or 24 h, depending on an assessment of the vola-
Wetland Wildfowl Yet another link in the ever-increasing network of wetlands for palearctic waterfowl has been conserved by the establishment of the Wexford Wildfowl Reserve earlier this year. The reserve was officially inaugurated by the Irish Minister of Lands, thus setting an example for other nations to follow the Ramsar Convention on the conservation of wetlands of international importance. The reserve lies 90 miles south of Dublin on the north side of Wexford harbour (on the North Slobs), where a 1,000 hectares of land were reclaimed from the sea in
the mid-nineteenth century. The reserve proper is best known as the wintering grounds for some 5,000-6,000 Greenland White-fronted Geese (Anser albifrons flavirostris), which represent more than half the world population of this sub-species. At the same time, it provides food and shelter for many other species of wildfowl: all three species of swan are present, and the Barnacle Goose (Branta leucopsis) has been visiting the Slobs since 1920. The Canada Goose (B. canadensis), Brent Goose (B. bernicla) and the Pink-footed Goose (Anser brachyrhynchus) are also regular visitors. Twentythree species of duck have been recorded, together with thirty-five species of waders.
Red Mud The Council of Europe reports the increasing threat of pollution to the Venice lagoon. Every day 3,000 tons of red and white mud (1 minion tons per year) are being dumped into the sea 15 miles from the city. This would amount to creating an island 200 m long, 100 m wide and 25 m high each year. In spite of assurances that this waste is harmless, a judicial enquiry is under way to determine whether there is any threat to the biological balance of the upper Adriatic. (See also Mar. Poll. Bull., 4(2): 19; 4(3): 40; 4(11): 169-171; 5(4): 51; 5(7): 98).
Effect on Sewage Purification Inhibition of chemotaxis by chlorinated hydrocarbons may directly affect estuarine serf-purification rates, according to a recent report in Nature by Walsh and Mitchell of the Laboratory of Applied Microbiology at Harvard University. Some marine microbial predators are known to feed on the enteric bacteria contained in the municipal sewage which is discharged into tidal and estuarine regions. Rates of kill of E. eoli by marine predators (mainly Spirillum sp.) were examined in the presence of two chlorinated hydrocarbons, 2,4-dichlorophenoxyacetate (2,4-D) and o,o-dichlorobiphenyl. The concentration of the latter required to significantly decrease the percentage kill (also previously shown to inhibit chemotaxis in motile marine bacteria) is only 20 times greater than that observed for chlorinated hydrocarbons in natural estuarine ecosystems. Bacterial predators are chemotactic specifically to exudates of their prey. Consequently, even though recent increases in the concentrations of chlorinated hydrocarbons may not be sufficient to directly affect the viability of predators or pathogens, waste effluents may contain chlorinated hydrocarbons at concentrations 10-100 times greater than sea water residual levels. Such hydrocarbons may decrease the level of predator/ prey interactions responsible for self-purification in natural ecosystems in the vicinity of ouffalls.
Attack on Spear-Fishing Hunting under the sea is a relatively recent development compared with its counterpart on land. The dangling of a piece of bait on a line could not very well replace the thrill of the hunt, except in those circumstances requiring considerable strength and endurance to land a powerful struggling fish into the back of a 115
last-moving boat. The new excitement of hunters carrying spears and using diving techniques quickly began to attract enthusiasts. The hand-spear was replaced by the spear-gun, and sophisticated diving techniques enabled further exploration of the oceans. Dr Hans Hass (a man who perhaps did more than anyone else to create interest in the underwater world through his books and flms) has been alarmed by the devastation caused by large numbers of hunters in a relatively short space of time. Writing recently in Development Forum (published by the United Nations Centre for Economic and Social Information), he extoled the wonders he had discovered in the Mediterranean, the Red Sea, and in the West Indies before the war. 'I was shocked by what I saw. The fish were gone . . . underwater hunters had invaded the sea . . in Jamaica 1 thought 1 had landed on the moon." Dr Hass believes that the situation can only be alleviated by banning the use of spring-loaded spear guns
Toxicity of Oil-
and explosives, although he is prepared to be more accommodating when it comes to hand-spears. 'Tilis type of hunting requires considerable skill and is fair since it gives the fish a good chance to escape. Dr Hass mentions that the Seychelles and some West Indian islands have already banned spear-fishing, and efforts are continuing to secure bans elsewhere. He has appealed to the World Underwater Federation (the body sponsoring the world championships in spear-Iishing) to assist him in his quest l~r the banning ot" mechanical underwater weapons. The World Wildlife Fund approached the Federation and the problem is now being discussed in association with the International Union for Conservation of Nature and Natural Resources (IUCN). The French underwater expert, Jacques Cousteau (whose films did much to glamourize the underwater world) now strongly opposes the use of spear-guns and his American Company will no longer manufacture them.
iag Agents
It may be necessary to immobilize an oil spill of more than 10,000 tons in European waters by sinking with sand. The possibility of damage to marine organisms from the sinking agents used has been investigated and it is coneluded that toxic effects are unlikely to result. Despite recent major improvements in the efficiency of low-toxicity oil dispersants, the dispersing capacity of available vessels remains inadequate to deal with a spill of more than 10,000 tons in Europeans waters. In the event of an emergency on a larger scale, it may be necessary to immobilize the oil by sinking it, using sand. In this method, the oil is sunk by spraying it with a slurry of sand and sea water, into which a solution of wetting agent (tallow amine acetates) has been injected. The wetting agent renders the sand oleophitic and the specific gravity of the sand/oil mixture is sufficient to sink it. The mixture settles on the bottom as light, floccular masses which are easily moved by currents of 0.5 knot (927 m/h), and are therefore readily dispersed. Any excess of wetting agent carried down with the oil is likely either to be washed out as it settles, or to be released as sunken oil is moved over the bottom. Experiments to test the toxic effects of sunken oil masses on benthic animals have been reported previously (Blackman, 1972). This paper describes experiments to assess the possibility of damage to marine organisms from the sinking agents used.
Ethylene Glyca -(48h) Iso-propyl alcohol
103
,~E .~_ W2 I---
2-Butoxy Ethanol
10
Materials and Methods In the sand-sink method, the wetting agent is injected into the slurry as a solution in an organic solvent. The wetting agents to be tested were therefore presented in this form. Test solutions were prepared from stock solutions (0.75% weight/volume) of the wetting agent in an organic solvent. It is doubtful if any of the tests were carried out with true aqueous solutions, for the solution of wetting agent, when added to sea water, formed a fine, milky dispersion. The standard of static toxicity test of Portmann and Connor (1968) has been followed, using brown shrimps 116
1
102
I I 103 104 Concentration: parts per 106
.3 105
Fig. 1 Estimated time to reach 50% mortality against concentration for three solvents, with 95% confidence limits:
(Crangon erangon; 20 animals per tank), which were exposed to a range of solvent/wetting agent solutions in sea water for 48 to 120 h. Solutions were renewed every 6, 12 or 24 h, depending on an assessment of the vola-