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ISA has recently affected the Faroes (Gardar: 2002b) and it was reported in an escapee rainbow trout in Clew Bay, Ireland in August 2002 (Charron: 2002b). Ireland has taken a precautionary approach “putting in place full disease control measures consistent with the Irish ISA Withdrawal Plan” (Fennelly: 2002). Consequently, Ireland’s only organic salmon farm at Clare Island has been closed to visitors and salmon sent off for ISA testing. In Scotland during 1998-9, for example, ISA led to the destruction of 4 million salmon, the setting up of a ‘National Crisis Centre’ and a quarter of the industry was placed in quarantine (Royal Society of Edinburgh: 2001). Supermarkets in the UK refused to sell farmed salmon from ISA affected farms (Edwards: 1999). In February 2000 the European Parliament’s Fisheries Committee reported that: “clearly the containment of ISA is of concern not only to Scotland, but to the Community as a whole. ISA poses a threat to the Community salmon industry at present, and potentially a greater threat if it were to spread to the other Member States” (European Parliament: 2000). IPN is now “ubiquitous” in Scotland affecting 60-70% of salmon farms (Cameron: 2002f, Macaskill: 2002). In Norway, where 11 million farmed salmon died last year, both ISA and IPN have caused significant mortalities (Intrafish: 1999a,b, Intrafish: 2002c, Solsletten: 2001, 2002b). So serious is the IPN problem that the EC is now “developing recombinant DNA vaccines” (EC: 2002f). In view of the fact that IPN can infect turbot and halibut (European Parliament: 1996b) and the number of escapes of IPN infected farmed salmon (Scottish Parliament: 2002b) the risk of fish farms spreading diseases to wild fish should not be underestimated.
The scientific evidence linking sea lice infestation on wild salmon and sea trout with proximity to salmon farms has now been proved beyond reasonable doubt (Edwards: 1998, Butler and Watt: 2002, Bjorn and Finstadt: 2002, Gargan and Tully: 2002, Holst et al: 2002). As the EC explains:
“These parasites proliferate on farmed salmon, and the young wild fish of migratory species (mainly of sea trout) could be heavily infected during their estuarine movements. The reduction of wild salmonids abundance is also linked to other factors but there is more and more scientific evidence establishing a direct link between the number of lice-infested wild fish and the presence of cages in the same estuary” (EC: 2002c, p9)
Locating salmon cages, for example, at the mouth of salmon rivers and in sea trout areas is the antithesis of the precautionary principle. Surely the only sensible solution is to relocate farms away from such sensitive areas (Butler et al: 2001, FoE: 2001b). In view of the endemic disease and parasite problems and the build up of antibiotic and chemical resistance (EC: 2001e), chemical controls have patently failed to address the parasite problem.
4) Chemicals:
Intensive finfish farmers, unlike shellfish farmers, are reliant upon a suite of chemicals to control diseases and parasites (Schnick et al: 1997, Alderman: 1999, Roth: 2000, Costello: 2001). Reports by the World Health Organisation and GESAMP have highlighted the environmental and public health threats of chemical use on fish farms (GESAMP: 1997, WHO: 1999). However, despite a reduction in the use of antibiotics and organophosphates in salmon farming (OSPAR: 1994) the use of synthetic pyrethroids, artificial colorants, antifoulants, antiparasitics and other ‘marine pollutants’ warrants serious concern (Staniford: 2002a). The cocktail of toxic chemicals used on salmon farms, in particular, jeopardises not only the marine environment but also the safety of workers (Douglas: 1995, GESAMP: 1997, Kelleher et al: 1998, Connolly: 2002). In Danish trout farms, for example, the abuse of antibiotics has raised consumer and environmental concerns (Lutzhoft et al: 1999). Chemicals used on salmon farms include carcinogens, mutagens and a myriad of marine pollutants (Staniford: 2002b). Since many chemical ‘treatments’ are designed to kill sea lice (which are crustacea) shellfish farmers have raised concerns in relation to the negative effects other shellfish such as lobsters, crabs, mussels, oysters and scallops (Blythman: 2001, Ross and Holme: 2001).
Ongoing research in Scotland is investigating the impacts of the sea lice chemicals teflubenzuron, cypermethrin and emamectin benzoate on zooplankton and copepods (Edwards: 2002a, SAMS: 2002a, 2002b, 2002c). Cypermethrin, for example, has been recently linked to reproductive effects in wild salmon and significant impacts on shellfish over several hectares (Ernst et al: 2001, Moore and Waring: 2001). The European Medicines Evaluation Agency openly concedes that “the proposed use of Azamethiphos in fish farming means that deliberate contamination of the environment will occur” (EMEA: 1999) yet in Scotland over 700 licences to use cypermethrin, azamethiphos, teflubenzuron and emamectin have been issued since 1998 (Merritt: 2002). The decision to licence them is based more on economic expediency than consumer or environmental safety and is tantamount to state-sponsored pollution (Merritt: 2002). The scale of chemical use in European salmon farming has now led the EC to fund research into sea lice resistance to chemicals used on salmon farms (EC: 2001e).
Such was the historical use of chemicals like dichlorvos (Ross: 1989, 1990, Ross and Horsman: 1988) - banned by the UK in April 2002 as it was deemed carcinogenic (: 2002) - that legal action from fish farm workers with cancers and other health issues is pending in the Scottish and Irish courts (Connolly: 2002, Staniford: 2002b). Significant clusters of testicular cancer in salmon farming areas have been reported in Ireland (Kelleher et al: 1998). Figures for the use of dichlorvos on Norwegian fish farms throughout the 1980s are also alarming (Grave et al: 1991, Horsberg: 2000). In Norway, the quantities of dichlorvos used were so high that fatal organophosphate poisoning of the farmed salmon took place (Salte et al: 1987, Horsberg et al: 1989) and residues were detected in the flesh of the salmon (Horsberg and Hoy: 1990). In the UK, the Government have estimated that up to 50 tonnes of dichlorvos (some four times more than all other household and agricultural uses combined) were used annually in the 1980s and early 1990s by Scottish salmon farmers (Davies: 1991, Department of the Environment: 1991, Scottish Office: 1992).
Chemicals such as DDT, dieldrin, chlordane, hexachloro-benzene, PCBs, toxaphene and dioxins, which all bioaccumulate via the fish feed, have been found both under salmon cages and in the flesh of farmed salmon (Hellou: 2002a, 2002b, Pirie: 2001, Cameron: 2002c, PRC: 2002). Anti-fouling paints containing TBT, copper and zinc have also been found under salmon cages (Davies et al: 1998, SEPA: 1998b). The World Health Organisation concedes that “veterinary drug residues or heavy metals may accumulate in aquaculture products at levels of concern for public health” (WHO: 1999). There is an alarming information gap:
“Information is needed on the transfer of feed contaminants to edible fish tissues and any implications of this for human health…As certain pesticides required in aquaculture can pose food safety hazards, more information is needed on the types of compounds used. Studies should be conducted to determine whether the use of pesticides can result in residue levels in fish tissue that are potentially harmful to human health” (WHO: 1999, pp 47-49)
Chemicals used illegally and detected in farmed salmon on sale in UK supermarkets include the recently banned carcinogen Malachite green (Department of Health: 1999, Cameron: 2002d, Scottish Executive: 2002a) and ivermectin (Cameron: 2001). So pervasive is the illegal use of toxic chemicals in Scotland that members of both Scottish Quality Salmon and the Shetland Salmon Farmers Association have both been caught using ivermectin and cypermethrin illegally (Intrafish: 1998, Barnett: 2000, BBC: 2000b, Cameron: 2002a) leading to calls by consumer groups for more testing of farmed salmon (Cameron: 2002b). Norwegian salmon farmers have also been caught using Malachite green illegally (Jensen: 2001) and in August this year Norway introduced new regulations allowing medicine residues in farmed salmon raising fears that there would be a negative impact on sales in the European market (Solsletten: 2002b). Elsewhere in sea bass and sea bream farming, reports of furazolidone, malachite green and ivermectin use in Malta
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