Assessment of the socio-economic value of aquaculture and sport angling for wild salmonids in northwestern Europe: Implications for treatments for sea lice infestation

This report presents the overall results achieved in the socioeconomic workpackage in the EU financed project SUMBAWS; Sustainable Management of Interactions Between Aquaculture and Wild Salmonid Fish.

The specific objectives of the work package, as stated in the project proposal, were to:

• quantify the socio-economic importance of the aquaculture and game angling sectors to the individual national economies.

• determine the economic effects (benefits and costs) of mutually acceptable sea lice treatments in the aquaculture sector, including the inter-industry effects.

• provide an overall cost-benefit analysis of sea lice, including both financial and socioeconomic elements.

The second chapter examines the economic significance the Atlantic salmon (Salmo salar L.) in three countries: Ireland, Norway and Scotland. These countries are among the most important countries for conservation and use of Atlantic salmon. The chapter begins by considering the various approaches which can be used in economic evaluation of fisheries and aquaculture, and opts in this instance to focus on the “economic impact” method. It derives broad-brush estimates for output, employment and overall economic impact for the three main sectors based on Atlantic salmon (recreational angling, commercial fishing and aquaculture) in each country. It goes on to show how these can be used to characterise the manner in which the salmon stocks are utilised in each country and concludes that the economic impact of recreational exploitation, compared to aquaculture, measured either in terms of output, employment or net impact, is more significant than is sometimes thought. Commercial fishing for salmon is insignificant compared to the two other sectors. In the final section, it enumerates a number of considerations which need to be borne in mind when using the data presented to make decisions and plans about the management, conservation and enhancement of salmon stocks, and identifies further research needs. Despite a general recognition of the huge social and economic values associated with Atlantic salmon, and the development of a substantial literature on individual regions and countries, few studies have reported and estimated the overall economic value of Atlantic salmon across a number of countries and compared the value of different types of use. There are probably a number of reasons for this dearth of work. First, as will be shown below, the term “economic value” can be defined in many ways, and therefore the studies use a wide variety of approaches and conceptual frameworks, making accurate comparison very difficult (See, for instance, Radford et al. 2001). There have also been wide variations in the methodology and data used. Furthermore, most studies are focused on elucidating policy decisions in a single country, region or locality.

The aim of the third chapter is to provide estimates of the costs associated with more effective sea lice treatment in Irish, Scottish and Norwegian salmon farms. To operationalise this concept in our models, we have chosen to estimate the costs of one additional, or marginal, prophylactic treatment. It is assumed for illustrative purposes that this additional treatment would reduce the infection level on wild fish significantly. Moreover, the reported cost estimates are compared with the overall value of salmonid production in Ireland, Scotland and Norway. The total estimated costs of one additional or marginal treatment across all salmonid fish farms correlated closely to the production volume in the three countries, with Ireland having by far the lowest cost (€0.38m.) and Norway having the highest (€11.65m.). The total cost estimate for Scotland was €3.28m. The estimated treatment costs as a proportion of the production value (Norway: 0.46%, Scotland: 0.44% and Ireland 0.36%) and the cost per kg produced fish (Norway and Scotland: €0.013 and Ireland: €0.011) were nevertheless relatively similar. The cost 3 NINA Report 126 4 estimates presented in this report are most likely maximum estimates of the cost of additional treatment against salmon lice. If an additional treatment were carried out as a mitigative action in a realistic situation it would be possible to reduce the costs since not all farming areas interact with important areas for wild salmonid migration. Furthermore, detailed knowledge on migration patterns and habitat use might enable a pinpointed treatment in cases where the areas overlap and it might be unnecessary to intensify the treatment in areas with a naturally low infestation level. Finally, optimization of the current treatment schedules might also reduce the need of increased treatment.

Chapter four focuses on what can be learned for the purposes of the present project from the collapse in sea trout populations in the West of Ireland since the late 1980s. It documents and quantifies the resulting decline in angler numbers and estimates the consequential drop in tourist expenditure in the region. By utilising some of the results and experience gained in Workpackage 7 of the SUMBAWS project, which is also based in the West of Ireland region, cost estimates for the preventative treatment of wild smolts are produced. The paper shows that the feasibility of widespread use of preventative treatment is questionable and that, even if feasible, very substantial costs would be involved.

The fifth chapter develops a theoretical model of the key stages in the assumed causal chain between enhanced lice treatment, through better smolt survival and improved returns to the coast to economic and social benefits in the form of greater income and employment in the commercial and angling sectors. The model incorporates data from the earlier chapters on economic impact and the marginal costs of an extra nationwide treatment in each country. The main output from the model is a series of Cost/Benefit ratios aimed at summarising the economic impacts from treatments with varying levels of effectiveness. A number of plausible scenarios are simulated to illustrate how these ratios vary with changes in the assumptions.