Flexibility of joint production in mixed fisheries and implications for management

Florence Briton,Olivier Thébaud,Claire Macher,Lorne Richard Little,Caleb Gardner,Sarah Kraak

doi:10.1093/icesjms/fsab057

Abstract

Abstract Over the past decade, efforts have been made to factor technical interactions into management recommendations for mixed fisheries. Yet, the dynamics underlying joint production in mixed fisheries are generally poorly captured in operational mixed fisheries models supporting total allowable catch advice. Using an integrated ecological–economic simulation model, we explore the extent to which fishers are likely to alter the species composition of their landings in a mixed fishery managed with individual transferable quotas, the Australian Southern and Eastern Scalefish and Shark Fishery. Our simulations capture three different types of joint production problems, highlighting the flexibility that exists in terms of achievable catch compositions when quota markets provide the economic incentives to adapt fishing practices to quota availability. These results highlight the importance of capturing the drivers of fishing choices when advising TAC decisions in mixed fisheries. We also identify a hierarchy of species in this fishery, with harvest targets set for primary commercial species determining most of its socio-economic performance.

Highlights

There is broad recognition that traditional single-species approaches, which still form the basis of most tactical management decisions in fisheries, fall short of addressing the complexities observed in mixed fisheries, where a variety of species are simultaneously caught in fishing operations, due to so-called technical interactions
Our simulations suggest that mixed fisheries are likely to feature an important latent flexibility in their catch composition, and that changes in fishing practices can broaden the space of achievable outcomes
We highlight that well-functioning Individual Transferable Quotas (ITQs) markets provide the economic incentive to adjust fishing practices to quota availability

Summary

Introduction

There is broad recognition that traditional single-species approaches, which still form the basis of most tactical management decisions in fisheries, fall short of addressing the complexities observed in mixed fisheries, where a variety of species are simultaneously caught in fishing operations, due to so-called technical interactions. Economists were among the first to argue that knowledge about the technological structure of a multi-output fishery is critical to its successful regulation The regulator of a mixed fishery may seldom encounter such a situation, since production in such a fishery has generally been shown to be non-separable in inputs (Jensen, 2002), catch limits in mixed fisheries are still mostly set using single-species approaches, i.e. as if their catch was the result of independent production processes

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Discussion

Conclusion