The effect of sea surface temperature on the structure and connectivity of species landings interaction networks in a multispecies recreational fishery

Kayla M Blincow,Brice X Semmens

doi:10.1139/cjfas-2021-0085

Abstract

Multispecies fisheries, particularly those that routinely adapt the timing, location, and methods of fishing to prioritize fishery targets, present a challenge to traditional single-species management approaches. Efforts to develop robust management for multispecies fisheries require an understanding of how priorities drive the network of interactions between catch of different species, especially given the added challenges presented by climate change. Using 35 years of landings data from a southern California recreational fishery, we leveraged empirical dynamic modelling methods to construct causal interaction networks among the main species targeted by the fishery. We found strong evidence for dependencies among species landings time series driven by apparent hierarchical catch preference within the fishery. In addition, by parsing the landings time series into anomalously cool, normal, and anomalously warm regimes (the last reflecting ocean temperatures anticipated by 2040), we found that network complexity was highest during warm periods. Our findings suggest that as ocean temperatures continue to rise, so too will the risk of unintended consequences from single-species management in this multispecies fishery.

Highlights

IntroductionA multispecies fishery is a single fishery that targets multiple species
As the name suggests, a multispecies fishery is a single fishery that targets multiple species.Such fisheries, especially those that readily adapt their fishing strategy to prioritize different species targets, can create complex interactions between species landings that are difficult to account for using traditional single species assessments (Murawski, 1991; Thorpe et al, 2016; Vinther et al, 2004)
Multispecies fisheries constitute complex social-ecological systems that can be difficult to manage, especially given the added challenges associated with climate change

Summary

Introduction

A multispecies fishery is a single fishery that targets multiple species Such fisheries, especially those that readily adapt their fishing strategy to prioritize different species targets, can create complex interactions between species landings that are difficult to account for using traditional single species assessments (Murawski, 1991; Thorpe et al, 2016; Vinther et al, 2004). Vinther et al 2004, Ulrich et al 2011, Plagányi et al 2014, Thorpe et al 2016, Nielsen et al.2018) Despite these advances, many challenges remain when it comes to multispecies fisheries. Many challenges remain when it comes to multispecies fisheries One such challenge is the ability to quantify and describe the complex dependencies that can be created between species landings. Given the influence of climate change on ocean ecosystems, efforts to understand how future ocean conditions will mediate such dependencies is an important part of planning for resilient fisheries

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Conclusion