Report of the 2005 ICES/NASCO Symposium on Interactions ...

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NINA SPECIAL REPORT 34 3. Conclusions by <strong>the</strong> Conveners 3.1 Introduction It is clear that since <strong>the</strong> first symposium in Loen in 1990, scientific understanding <strong>of</strong> <strong>the</strong> interactions between cultured and wild salmon has increased considerably and <strong>the</strong> science confirms that cultured salmon can have significant negative impacts on <strong>the</strong> wild stocks. Real progress has been made in managing interactions but some significant challenges remain, particularly with regard to fur<strong>the</strong>r reducing <strong>the</strong> impacts <strong>of</strong> escapees and sea lice. These two topics dominated <strong>the</strong> symposium presentations, <strong>the</strong> discussions and <strong>the</strong> ‘take-home messages’ and are, in part, related to <strong>the</strong> large scale <strong>of</strong> <strong>the</strong> industry. A fur<strong>the</strong>r positive development since <strong>the</strong> last symposium relates to <strong>the</strong> extent <strong>of</strong> cooperation between wild and farmed salmon interests and it is clear that this process needs to be fur<strong>the</strong>r enhanced in future. Fur<strong>the</strong>rmore, <strong>the</strong> industry now acknowledges that its activities can have damaging impacts on <strong>the</strong> wild stocks and we believe that this acceptance provides a basis for making real progress in finding cooperative solutions to <strong>the</strong> remaining challenges. In developing our conclusions, we have considered <strong>the</strong> keynote speeches, <strong>the</strong> scientific and o<strong>the</strong>r information presented at <strong>the</strong> symposium, <strong>the</strong> summaries made by <strong>the</strong> Chairmen, <strong>the</strong> ‘take-home messages’ and <strong>the</strong> discussion sessions. We have also taken into account <strong>the</strong> findings from <strong>the</strong> recent Trondheim Workshop (Anon, 2006) and o<strong>the</strong>r relevant information. We have had to evaluate a great deal <strong>of</strong> material and to make judgements about it and about how much weight to give it in coming to conclusions. We want to make it clear that to do this inevitably involves a great deal <strong>of</strong> personal judgement. The reader will be aware that this is <strong>the</strong> case in coming to many pr<strong>of</strong>essional or o<strong>the</strong>r judgements. Just as two different juries might well have come to different verdicts after hearing evidence from <strong>the</strong> same trial, two different conveners might have come to somewhat different conclusions from this symposium. However, we are comforted that in coming to our conclusions, <strong>the</strong>re was a degree <strong>of</strong> unanimity at this meeting that was not present at <strong>the</strong> two earlier symposia, which helps us greatly. We want to reassure <strong>the</strong> readers <strong>of</strong> this report that we have tried hard to be objective. We also need to make it clear that although <strong>NASCO</strong> and <strong>ICES</strong> co-convened, and o<strong>the</strong>r organizations sponsored, and supported, <strong>the</strong> Bergen symposium, <strong>the</strong> views expressed 18 here are entirely those <strong>of</strong> <strong>the</strong> two Conveners. We have come to a number <strong>of</strong> conclusions. It should be noted, however, that while <strong>the</strong> title <strong>of</strong> <strong>the</strong> symposium referred to interactions between wild and cultured salmon and o<strong>the</strong>r diadromous fish species, <strong>the</strong> vast majority <strong>of</strong> papers concerned interactions between wild and farmed Atlantic salmon and our conclusions <strong>the</strong>refore relate principally to <strong>the</strong>se interactions and <strong>the</strong>ir management. 3.2 The Salmon Farming Industry A major change, and a most welcome one, since <strong>the</strong> last <strong>ICES</strong>/<strong>NASCO</strong> symposium in Bath in 1997, is that <strong>the</strong> salmon farming industry, certainly those representatives present in Bergen, now fully accept that <strong>the</strong>ir industry can have damaging impacts on <strong>the</strong> wild stocks. We very much welcome this because it is a prerequisite to cooperative action. We realize that, for various reasons, this has not been easy for <strong>the</strong>m to accept, but this acceptance can have major dividends for cooperation to mutual benefit in <strong>the</strong> future. In Bath and before, <strong>the</strong>re had been a climate <strong>of</strong> blame, public accusation and counter-accusation. Today, we feel that <strong>the</strong> climate has greatly improved, as was demonstrated at <strong>the</strong> symposium. As concrete evidence, we look not only at statements made by representatives <strong>of</strong> <strong>the</strong> industry at <strong>the</strong> Bergen symposium, but at <strong>the</strong> newly energized <strong>NASCO</strong>/North Atlantic salmon farming industry Liaison Group which, for <strong>the</strong> first time, held a joint meeting earlier in <strong>2005</strong>, <strong>the</strong> Trondheim Workshop, which not only discussed and debated some controversial issues (such as use <strong>of</strong> sterile fish in aquaculture) but sought new ways to cooperate (Anon, 2006). The goodwill and frankness that characterized both that meeting and <strong>the</strong> Bergen symposium should encourage us all to build on <strong>the</strong> cooperation that is developing. It will be evident from this report that we, <strong>the</strong> Conveners, believe that it is vital that actions be taken to protect and conserve <strong>the</strong> integrity <strong>of</strong> <strong>the</strong> wild stocks. But we would argue that it is clearly very much in <strong>the</strong> interests <strong>of</strong> our colleagues in industry, too. It protects <strong>the</strong>ir ‘seed corn’, <strong>the</strong>ir future, it protects <strong>the</strong>m from bad publicity and in today’s climate we expect that that aspect is vital for <strong>the</strong>ir future marketing, sales and economic success. Both Conveners have been involved in <strong>the</strong>se issues <strong>of</strong> interactions between farmed and wild salmon for many years but, for <strong>the</strong> first time, we feel encouraged by a new atmosphere <strong>of</strong> cooperation, frankness and <strong>the</strong> will to succeed. We hope that this will characterize <strong>the</strong>
NINA SPECIAL REPORT 34 consideration <strong>of</strong> our conclusions from <strong>the</strong> Bergen symposium. We do not underestimate <strong>the</strong> difficulties <strong>of</strong> implementing some <strong>of</strong> our conclusions, but we must emphasize <strong>the</strong> potentially severe damage to <strong>the</strong> wild stocks, and consequently <strong>the</strong> costs to society, <strong>of</strong> not doing so. 3.3 Disease and Parasite Interactions and <strong>the</strong>ir Management There has been considerable progress in addressing disease and parasite problems in aquaculture through, for example, improved husbandry and use <strong>of</strong> vaccines. There has also been progress in developing management strategies to reduce <strong>the</strong> levels <strong>of</strong> sea lice on farms and <strong>the</strong>reby reduce transmission to <strong>the</strong> wild. While sea trout appear to be particularly badly affected <strong>the</strong>re is evidence <strong>of</strong> impacts on wild salmon stocks as well. In some situations wild salmonid populations have suffered stock collapses that have been linked to sea lice infestations. Such stock collapses have implications for <strong>the</strong> diversity <strong>of</strong> <strong>the</strong> wild stocks (see section 3.4). It is clear that actions such as coordinated lice treatments, use <strong>of</strong> single generations and fallowing through area management initiatives are having benefits in protecting <strong>the</strong> wild stocks and that <strong>the</strong> cooperation between wild and farmed salmon interests on <strong>the</strong>se initiatives is a positive development. However, <strong>the</strong>re may still be problems for wild stocks from sea lice, perhaps more so during <strong>the</strong> second year <strong>of</strong> <strong>the</strong> farm production cycle. These management strategies may be voluntary but in some situations <strong>the</strong>y may need to be incorporated in regulations. Successful area management depends on commitment from all partners, open dialogue, transparency and input from all interested parties. Significant challenges remain in addressing sea lice issues, not least <strong>the</strong> need for <strong>the</strong> industry to be allocated additional sites to facilitate on-growing <strong>of</strong> single generations, and <strong>the</strong> limited number <strong>of</strong> treatments approved for sea lice control. While effective treatments are available, not all are licensed for use in aquaculture in all countries and we urge <strong>the</strong> regulatory authorities to make <strong>the</strong>se available as quickly as possible where environmentally acceptable. Development <strong>of</strong> resistance to <strong>the</strong> available treatments in <strong>the</strong> future would have serious implications for both wild and farmed salmon interests. Development <strong>of</strong> a vaccine against sea lice would be a major step forward. Alternative approaches, such as <strong>the</strong> use <strong>of</strong> wrasse in <strong>the</strong> cages to clean salmon <strong>of</strong> sea lice, might <strong>of</strong>fer benefits. The eradication <strong>of</strong> <strong>the</strong> parasite G. salaris from infected rivers and prevention <strong>of</strong> its fur<strong>the</strong>r spread are essential. In Norway, <strong>the</strong> parasite was spread by stocking following its introduction from <strong>the</strong> Baltic. Risk analysis suggests that movements <strong>of</strong> live fish, particularly rainbow trout, are <strong>the</strong> most likely source <strong>of</strong> spread among o<strong>the</strong>r countries. This is a difficult area since it raises issues associated with international trade agreements but it is essential that appropriate safeguards are in place to control such movements in a manner that does not jeopardize <strong>the</strong> wild stocks. It is also important that <strong>the</strong> two chemical treatments presently in use in Norway to eradicate <strong>the</strong> parasite, rotenone and acidified aluminium sulphate, are available for use in future. <strong>NASCO</strong>’s North-East Atlantic Commission has developed recommendations in relation to G. salaris (<strong>NASCO</strong>, 2004; 2006b) and we believe that it is important that <strong>the</strong>se recommendations are implemented urgently. 3.4 Genetic and Ecological Interactions and <strong>the</strong>ir Management Although <strong>the</strong>re has been progress in reducing <strong>the</strong> proportion <strong>of</strong> farmed fish that escape to <strong>the</strong> wild, <strong>the</strong> growth in production by <strong>the</strong> industry means that <strong>the</strong> number <strong>of</strong> fish escaping is still large relative to <strong>the</strong> wild stocks. There is no doubt that a proportion <strong>of</strong> escapees enter rivers and interbreed with <strong>the</strong> wild stocks. In some cases, <strong>the</strong>y make up very high percentages <strong>of</strong> spawning stocks and genetic changes in some wild populations have been detected. To put it bluntly, this means that in <strong>the</strong> last 30 years a large-scale, uncontrolled genetic experiment, which we believe poses <strong>the</strong> risk <strong>of</strong> irreversible changes to <strong>the</strong> wild stocks, has been undertaken. It is still continuing. In doing so, in <strong>the</strong> North Atlantic we are running <strong>the</strong> risk <strong>of</strong> changing local adaptations that have taken centuries or more to develop by allowing fertile farmed salmon, which have been selected for traits valuable to aquaculture, to interbreed with <strong>the</strong> wild stocks that have evolved <strong>the</strong>ir own characteristics over millennia. Since <strong>the</strong> symposium we are aware <strong>of</strong> recent advice from <strong>ICES</strong> to <strong>NASCO</strong> regarding <strong>the</strong> genetic impacts <strong>of</strong> farmed Atlantic salmon on <strong>the</strong> wild populations (<strong>ICES</strong>, 2006b). In this advice <strong>ICES</strong> indicates that very large numbers <strong>of</strong> farmed salmon escape annually relative to wild salmon abundance; a substantial body <strong>of</strong> useful quantitative data on genetic impacts <strong>of</strong> farmed salmon on wild stocks has been collected; gene flow from farmed to wild salmon will reduce <strong>the</strong> natural inter-population heterogeneity found in <strong>the</strong> wild Atlantic salmon, <strong>the</strong>refore reducing <strong>the</strong> adaptive 19
Page 1 and 2: NINA SPECIAL REPORT 34 Interactions
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Page 5 and 6: NINA SPECIAL REPORT 34 C O N T E N
Page 7 and 8: NINA SPECIAL REPORT 34 Executive Su
Page 9 and 10: NINA SPECIAL REPORT 34 1 INTRODUCTI
Page 11 and 12: NINA SPECIAL REPORT 34 internationa
Page 13 and 14: NINA SPECIAL REPORT 34 2 OVERVIEW O
Page 15 and 16: NINA SPECIAL REPORT 34 need for fur
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Page 25: NINA SPECIAL REPORT 34 3 CONCLUSION
Page 29 and 30: NINA SPECIAL REPORT 34 • monitori
Page 31 and 32: NINA SPECIAL REPORT 34 4REFERENCES
Page 33 and 34: NINA SPECIAL REPORT 34 ANNEX 1 Abst
Page 35 and 36: NINA SPECIAL REPORT 34 being framed
Page 37 and 38: NINA SPECIAL REPORT 34 in domestica
Page 39 and 40: NINA SPECIAL REPORT 34 The developm
Page 41 and 42: NINA SPECIAL REPORT 34 combined wit
Page 43 and 44: NINA SPECIAL REPORT 34 Lepeoph<stro
Page 45 and 46: NINA SPECIAL REPORT 34 Salmon lice
Page 47 and 48: NINA SPECIAL REPORT 34 Control and
Page 49 and 50: NINA SPECIAL REPORT 34 has been mad
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Page 53 and 54: NINA SPECIAL REPORT 34 ANNEX 2 Keyn
Page 55 and 56: NINA SPECIAL REPORT 34 Walter Crozi
Page 57 and 58: NINA SPECIAL REPORT 34 ANNEX 3 Gene
Page 59 and 60: NINA SPECIAL REPORT 34 escaped farm
Page 61 and 62: NINA SPECIAL REPORT 34 native speci
Page 63 and 64: NINA SPECIAL REPORT 34 ANNEX 4 Dise
Page 65 and 66: NINA SPECIAL REPORT 34 differences
Page 67 and 68: NINA SPECIAL REPORT 34 ANNEX 5 Post
Page 69 and 70: NINA SPECIAL REPORT 34 been some di
Page 71 and 72: NINA SPECIAL REPORT 34 ANNEX 6 Take
Page 73 and 74: NINA SPECIAL REPORT 34 principle. I
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NINA SPECIAL REPORT 34 encouraging.
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NINA SPECIAL REPORT 34 ANNEX 7 List
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NINA SPECIAL REPORT 34 Dr Sigurdur
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NINA SPECIAL REPORT 34 ISSN: 0804-4
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