Fishery externalities and biodiversity: Trade-offs between the viability of shrimp trawling and the conservation of Frigatebirds in French Guiana

Abstract

Sustainable management of natural resources, and in particular fisheries, must take into account several conflicting objectives. This is the case in the French Guiana shrimp fishery for which profitability objectives imply a reduction in the fishing activity. On the one hand, this fishery has negative externalities on marine biodiversity due to discards. On the other hand, this fishery has positive externalities on the economy of the local community and interestingly enough on a protected seabird species in the area (the Frigatebird that feeds on discards). In this paper, we examine the viability of that system considering two sustainability objectives: an economic objective in terms of the profitability of the fishing activity, and a conservation objective in terms of the Frigatebird population. For that purpose, we have developed a dynamic model of that bioeconomic system and study here the trade-offs between the two conflicting objectives. It provides a means to quantify the necessary give and takes involving the economic and ecological objectives that would ensure a viable management solution. Our study confirms the relevance of the viability approach to address natural resource management issues, which should lead to the development of new tools for the arbitration of conflicting sustainability objectives. In particular, such tools could be used as a quantitative basis for cost-benefit analysis taking into account environmental externalities.

Trophic ecology drives contaminant concentrations within a tropical seabird community

“…Conversely, this study found nestlings with a diet biased for lower trophic level prey to be in a better body condition than nestlings fed with higher trophic level prey (Morrison et al, 2014). In Frigatebirds, we would have expected depleted δ 13 C values in comparison to other species, given their attitude to feed far from the breeding colony and possibly in southern latitudes (Sebastiano et al, 2016), but they were not, possibly because Frigatebirds also feed on the shrimp fishery discards, a strategy commonly used in this colony (Martinet and Blanchard, 2009). …”

Regional trade-offs from multi-species maximum sustainable yield (MMSY) management options

“…Taking all ecosystem and economic feedbacks into account might also reveal unforeseen trade-offs and externalities, like in the case of French Guiana, where the (economically sub-optimal) oversized trawl fishery for shrimps positively impacts endangered frigatebirds Fregata spp. (Martinet & Blanchard 2009). In the case of the Baltic Sea, we envisage a broadening of the scope of future work to an eco system level.…”

Evaluating tradeoffs among ecosystem services to inform marine spatial planning

“…In parallel, there is a long history within decision theory, including multi-criteria and multi-objective analyses, of developing tools for decision-making where there are numerous and often competing objectives [33]. Multi-criteria analysis has been applied to numerous marine applications [34][35][36][37] and there has been recent progress applying these ideas to managing ecosystem services [20,[38][39][40][41]. However, there is not a synthesis of how tradeoff analysis can used in an EBM or MSP approach.…”