The Economics of Conflicting Interests: Northern Baltic Salmon Fishery Adaption to Gray Seal Abundance

Abstract

The successful conservation of gray seals has led to increased seal‐induced damage to the Atlantic salmon fisheries of the Baltic Sea. This paper addresses the conflict between the conservation of a formerly endangered species, the gray seal, and professional fishermen, whose livelihoods are affected by both seal‐induced damage and salmon fisheries management. We develop a bioeconomic model that incorporates the age structure of Atlantic salmon and gray seal populations. To determine the social optimum, we maximize the discounted net present value of the trap net fishery, taking into account the presence of seals in the form of seal‐induced losses, which we describe using a damage function. By choosing the optimal combination of fishing gear over time, we obtain the socially optimal fishing efforts, salmon stock size, and salmon catch. In addition, we study the private effects of introducing a technology subsidy aimed at mitigating the seal‐salmon conflict. The results suggest that technological adaptation would effectively reduce the cause of the conflict, while a technology subsidy encouraging such adaptation would shift the economic responsibility from individual fishermen to the broader public.

The Role of Food Web Interactions in Multispecies Fisheries Management: Bio-economic Analysis of Salmon, Herring and Grey Seal in the Northern Baltic Sea

“…Grey seals eat mature salmon from both salmon trap nets and the open sea (Lundström et al 2010;Suuronen and Lehtonen 2012). This implies that grey seals contribute both a natural mortality rate to the salmon population through mortality function and a fishery cost through the damage function at this spawning (Holma et al 2014;ICES 2016;Michielsens et al 2006). The damage function refers to the impact that salmon are eaten by seals from the fishery catch (in trap nets), which was adopted from Holma et al (2014).…”

“…Equations ( 1) and (2) (in Table 1) describe the population structure of the submodels for each species. The grey seal model and the salmon model were extended from Holma et al (2014), and the herring model was revised from ICES (2013b), Nieminen et al (2012) and Kulmala et al (2007). Depending on which species is referenced, the superscript species in the Eq.…”

“…The well-developed bio-economic models for Baltic salmon are mainly single species approaches (e.g., Kulmala et al (2008); Laukkanen (2001)). Moreover, the effects of grey seal on salmon are only included as impacts on salmon fishery harvests (Holma et al 2014;ICES 2016) or are embedded within all sources of natural mortality in the salmon stock assessment (ICES 2014;Michielsens et al 2006); they are not included as a direct prey-predation interaction between grey seal and salmon populations.…”

Quantitative criteria for choosing targets and indicators for sustainable use of ecosystems

“…As the seal population has increased, predation on valuable fish and damages caused by seals to fishing gear are increasingly seen as problems ( Holma et al, 2014 , Varjopuro, 2011 ). On the other hand, it has been proposed that abundant seal populations could boost tourism in coastal communities.…”

Optical and acoustic camera observations of the behavior of the Kuril harbor seal Phoca vitulina stejnegeri after invading a salmon setnet

“…Conflicts between fisheries and seals in terms of both bycatch and fishery damage have been reported recently (Lunneryd et al 2003;Jounela et al 2006;Lundström et al 2010;Hale et al 2011;Cronin et al 2014;Holma et al 2014 ) and are becoming more frequent due to an increase in seal populations as a result of conservation management and a resulting decrease in fish populations as a fisheries resource. However, strategies for managing seals have not yet been established (Butler et al 2011).…”