Burying the blue revolution.Hailed as the blue revolution, the marine aquaculture aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasing share of world fisheries production. industry promises us a supply of seafood that will remove our dependence on wild fish populations. But as Darryl Luscombe reports, every revolution has its price. In May 1996 the tuna farming industry of Boston and Proper bays in Port Lincoln, South Australia Port Lincoln (postcode 5606) is a city in the Australian state of South Australia. It is a coastal city situated on the Boston Bay at the southern extremity of the Eyre Peninsula. , was counting its dead -- 75,000 southern bluefin tuna The southern bluefin tuna, Thunnus maccoyii, is a tuna of the family Scombridae found in open southern hemisphere waters of all the worlds oceans mainly between 30°S and 50°S, to nearly 60°S. At up to 2.5 m (8. . Less than five years earlier the idea of fattening fat·ten v. fat·tened, fat·ten·ing, fat·tens v.tr. 1. To make plump or fat. 2. To fertilize (land). 3. schools of wild tuna, caught with massive purse-seine nets during their eastern migration through the Great Australian Bight Great Australian Bight, wide bay of the Indian Ocean, indenting the southern coast of Australia. An unbroken line of cliffs c.200 ft (60 m) high runs along the coast and extends inland as the arid and desolate Nullarbor Plain. , was considered both an experiment and a gamble. But quickly the tuna farming industry established 60 floating sea cages, and made public commitments to environmental responsibility and ecological sustainability. Yet as more and more dead tuna were dumped into landfill, rumours of the industry's more unsavoury aspects began to spread. Had development been fast-tracked at the expense of environmental considerations? South Australian bureaucrats, politicians and the industry repeatedly said no. Each argued that the farming ventures had been thoughtfully considered, with environmental concerns thoroughly assessed during the development of the industry management plan. The tuna deaths were, they said, the result of a freak phenomenon -- suffocation suffocation: see asphyxia. . The gills of the tuna had become clogged by silt and excrete excrete /ex·crete/ (eks-kret´) to throw off or eliminate by a normal discharge, such as waste matter. ex·crete v. To eliminate waste material from the body. churned up from the seafloor by persistent, unseasonal winds. The oceanic fish had been unable to escape their floating prisons. End of story. But it was not, as internal government memorandums released to the Australian Democrats have since shown. Sent by senior government scientists to high-ranking bureaucrats three years before the deaths, the memorandums heavily criticised the tuna farming industry draft management plan. Comments ranged between the diplomatic, `selectively biased in favour of tuna farms developing', to the blunt, `a recipe for environmental vandalism'. Another noted how independent environmental impact assessments of tuna farming had been `rejected at the request of industry'. Data was instead prepared by tuna industry consultants, with the endorsement of the management plan steering committee comprising representatives of several state government departments, the Port Lincoln Shire Council and, of course, the industry. Estimates of the pollution generated by tuna cages was central to the concerns of government scientists. The slow currents within Boston Bay would allow faeces and undigested food to fall through the cages and build up as putrefying silt on the sea floor, devoid of oxygen and capable of asphyxiating as·phyx·i·ate v. as·phyx·i·at·ed, as·phyx·i·at·ing, as·phyx·i·ates v.tr. To cause asphyxia in; smother. v.intr. To undergo asphyxia; suffocate. seafloor life. If, as estimated, a cage containing 100 tonnes of fish produces the equivalent amount of waste discharged by 7,000 people, then 60 cages would generate waste-water nutrient levels equivalent to that of a city of 420,000 people each year. With nutrient levels in Boston Bay having already been increased due to Port Lincoln's sewage outfall out·fall n. The place where a sewer, drain, or stream discharges. outfall Noun Brit, Austral & NZ the mouth of a river, drain, or pipe: , a staged development of the farms was urged, subject to independent monitoring of environmental checkpoints. But these precautionary measures were overlooked in the final industry management plan. Few restrictions were suggested, the steering committee even prefacing the final document with the statement that `it appears to have the safeguards to ensure that ecologically sustainable development Ecologically sustainable development is the environmental component of sustainable development. It can be achieved partially through the use of the precautionary principle, namely that if there are threats of serious or irreversible environmental damage, lack of full scientific occurs'. Behind the blue curtain The marine aquaculture (mariculture mariculture marine aquaculture. ) industry claims that it provides a more reliable seafood supply for all, but most of its product targets the luxury market. The industry also claims that its efforts decrease pressure on overexploited wild fish populations. However, the feeding of caged fish, or the growing of species without adding food in `natural' environments, does not reduce the pressure on marine ecosystems, it merely shifts the burden and may substantially increase it. Fish that are intensively farmed, such as salmon, require a high-protein diet. This usually comprises so-called `low value' wild fish. For every kilogram of Tasmanian Atlantic salmon farmed, about seven kilograms of minced jack mackerel mackerel, common name for members of the family Scombridae, 60 species of open-sea fishes, including the albacore, bonito, and tuna. They are characterized by deeply forked tails that narrow greatly where they join the body; small finlets behind both the dorsal and , a Tasmanian coastal fish, are used as feed. For bluefin tuna, a hyperactive fish with a large appetite, the weight ratio of pilchard pilchard Local name in Britain and elsewhere for the European sardine (Sardina pilchardus). It is found in the Mediterranean and off the Atlantic coasts of Spain, Portugal, France, and Britain. feed to tuna product is around 17:1. Although plant substitutes for fishmeal fish·meal n. A nutritive mealy substance produced from fish or fish parts and used as animal feed and fertilizer. fishmeal Noun ground dried fish used as feed for farm animals or as a fertilizer are being researched, there are very few being used in Australian farms. The extensive mariculture of oysters and mussels can also create problems. As filtering organisms, oysters have the potential to strip away the planktonic food source of marine animals. This can occur to the point where the oysters are themselves starved, as has occurred at Murat Bay near Ceduna in South Australia. Although oyster leases make up more than 90 per cent of all mariculture operations in Australia, and continue to proliferate in bays and inlets, little is known of their cumulative long-term impacts on local environments. Some sections of the mariculture industry are contributing to the continued use of the introduced Pacific oyster, a species notorious for establishing feral populations beyond farm boundaries. The oysters alter intertidal in·ter·tid·al adj. Of or being the region between the high tide mark and the low tide mark. in habitats and crowd out native species, and their razor-sharp shells cause serious cuts to people fossicking Fossicking is a term found in Cornwall and Australia referring to prospecting. This can be for gold, precious stones, fossils, etc. by sifting through a prospective area. In Australian English, the term has an extended use meaning to "rummage". in intertidal areas. Although Tasmania and South Australia continue to advocate farming of this species in open coastal waters, the Victorian government recently banned the Pacific oyster's release on environmental grounds. A growing concern Mariculture is now big business in Australia, worth around $450 million per year. With most politicians eager for regional employment and economic growth, it is being heavily promoted in most states. Community vigilance will be the only protection for locations with significant environmental values. Sheltered bays will be most under pressure. Favoured by the industry, they are also the breeding and replenishment grounds for many marine species, including those valued by commercial and recreational fishers. The reclamation of coastal land for ponds, such as that carried out by the prawn prawn: see shrimp. farming industry in New South Wales New South Wales, state (1991 pop. 5,164,549), 309,443 sq mi (801,457 sq km), SE Australia. It is bounded on the E by the Pacific Ocean. Sydney is the capital. The other principal urban centers are Newcastle, Wagga Wagga, Lismore, Wollongong, and Broken Hill. and Queensland, is hardly the answer. It has seen the removal of large swathes of native vegetation, the modification of wetlands, the contamination of local water tables and the demand for infrastructure services such as roads and electricity. These can all cause significant impacts to the coastal environment. Questions out of the blue Public agencies and the mariculture industry repeatedly claim that the industry's environmental impacts can be mitigated by careful farm siting and stocking. However, most mariculture research concentrates on improving product output and quality, with government infrastructure to control and monitor the industry generally limited. A number of questions must therefore be raised about the planning and management of individual mariculture projects, including: * Have the mariculture farms been strategically considered and sited away from areas of environmental significance with adequate buffers? * Are the chosen species appropriate' * Are stocking densities and pollution loadings within the capacity of the environment? * Have thorough and independent environmental impact and risk assessments been undertaken? * Are farm expansions subject to independent monitoring of the venture's environmental impacts? * Is the venture economically viable, or could the reclaimed land and the industry infrastructure eventually be abandoned? If these and many other questions are not adequately dealt with, the mariculture industry may simply be seen as revolting rather than revolutionary. RELATED ARTICLE: THE UNSAVOURY SIDE OF MARINE FARMING Destruction of terrestrial habitat by clearing and excavation Prawn farming adjacent to Hinchinbrook Channel, Queensland. Antibiotic use leading to resistant bacterial strains It is believed that no research has been carried out in Australia. Reduction in genetic variability of wild fish populations Uncontrolled hatchery hatchery a commercial establishment dedicated to the hatching of bird eggs to provide day old chicks and poults to the poultry industry. hatchery liquid the contents of unfertilized eggs. Used in petfood manufacture. releases, such as barramundi barramundi see lates calcarifer. in Queensland. Effluent pollution Prawn farms in northern NSW NSW New South Wales Noun 1. NSW - the agency that provides units to conduct unconventional and counter-guerilla warfare Naval Special Warfare and Queensland. Tasmanian Atlantic salmon farms in Tasmania. Tuna farms in Port Lincoln. Escape of introduced species Feral Pacific oyster populations from farms in Port Stephens (NSW), off Ceduna (SA). Ten invertebrates introduced to Tasmania in live oysters from New Zealand. Exploitation of wild fish populations for stock food, which decreases food available for other marine species Jack mackerel for Tasmanian Atlantic salmon farms. Pilchards for southern bluefin tuna in Port Lincoln. Loss of visual amenity Many coastal estuaries in NSW, including Wallis Lakes and Port Stephens. Increased risk of disease transmission to wild stocks Imported pilchards used as tuna feed implicated im·pli·cate tr.v. im·pli·cat·ed, im·pli·cat·ing, im·pli·cates 1. To involve or connect intimately or incriminatingly: evidence that implicates others in the plot. 2. in recent disease outbreak that killed millions of wild pilchards across southern Australia. Conflicts over access to publicly owned land and water Commercial fishers displaced by oyster farms in Bay of Shoals (SA). * Darryl Luscombe is Wetlands Campaign Officer with the Victorian National Parks Association The Victorian National Parks Association is a nature conservation organisation based in Victoria, Australia. It is an independent, non-profit, membership-based group, which exists to protect Victoria's unique natural environment and biodiversity through the establishment and . |
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