Evaluating socio-economic and conservation impacts of management: A case study of time-area closures on Georges Bank.

David M Keith,Christine A Ward-Paige,Jessica A Sameoto,Freya M Keyser,Ulrike Gertrud Munderloh

doi:10.1371/journal.pone.0240322

David M Keith, Christine A Ward-Paige + Show 3 more

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https://doi.org/10.1371/journal.pone.0240322

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Abstract

Globally, economies and marine ecosystems are increasingly dependent on sustainable fisheries management (SFM) to balance social, economic, and conservation needs. The overarching objectives of SFM are to maximize both conservation and socio-economic benefits, while minimizing short-term socio-economic costs. A number of tools have been developed to achieve SFM objectives, ranging from fishery specific to ecosystem-based strategies. Closures are a common SFM tool used to balance the trade-off between socio-economic and conservation considerations; they vary in scope from small-scale temporary closures to large-scale permanent networks. Unfortunately, closures are frequently implemented without a plan for monitoring or assessing whether SFM objectives are met. In situations in which a monitoring plan is not in place we propose that commonly available fishery data can often be used to evaluate whether management tools are effective in meeting SFM objectives. Here, we present a case study of closures on Georges Bank that shows how fishery data can be analyzed to perform such an assessment. Since 2006, on the Canadian side of Georges Bank, seasonal scallop fishery closures have been implemented with the aim of reducing by-catch of Atlantic cod (Gadus morhua) and yellowtail flounder (Pleuronectes ferruginea) during spawning. In lieu of data from a dedicated monitoring program, we analyzed data from Vessel Monitoring Systems (VMS), fishery logbooks, and a scallop survey to assess the impact of these closures on the scallop fishery, and use observer data (i.e. by-catch) to assess the effectiveness of these closures in meeting their conservation objective. While compliance for these time-area closures was high, the closures did not significantly displace fishing activity and overall there was limited evidence of an impact on the scallop fishery. Further, the discard rates for both cod and yellowtail were above average when their respective closures were active. These results suggest that improvements to the closures design and/or other measures may be required to achieve the desired SFM objectives.

Highlights

While humans have relied on fisheries for centuries, population increases and technological advances have resulted in increased pressures on both fisheries and marine ecosystems [1]
Despite the high scallop fishing effort when the yellowtail closures were in place, the location of the yellowtail closure cells in a region of relatively low scallop productivity on Georges Bank resulted in a low impact on the scallop fishery
The cumulative effect of, a) the voluntary move protocol, b) the significant overall decline in scallop fishery effort, and c) this effort being more concentrated in high scallop productivity zones, are likely to have contributed more to the observed reduction in discards of cod and yellowtail in recent years than the time-area closures. These results show how fishery dependent and fishery independent data can be used to assess the impacts of time-area closures on socio-economic and conservation objectives even without the establishment of a dedicated monitoring program

Summary

Introduction

While humans have relied on fisheries for centuries, population increases and technological advances have resulted in increased pressures on both fisheries and marine ecosystems [1]. Sustainability strategies primarily focus on fisheries, vulnerable species and ecosystems, and the protection of marine habitats (e.g. Aichi Biodiversity targets 6, 10, and 11). A suite of SFM tools have been developed in an effort to manage fisheries and marine ecosystems. These tools include fishery specific controls that limit the number of vessels, days at sea, by-catch, and the total allowable catch, as well as tools that focus more directly on the ecosystem [5, 6]. Ecosystem based SFM tools often involve limiting some forms of human use to protect vulnerable species, unique habitats, or ecosystems. Closures, which are a commonly employed management tool, are used to limit access to an area and can range in scope from small temporary area closures directed at limiting one specific activity to networks of large permanent marine reserves that prohibit a wide range of activities [7,8,9,10]

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