Interdisciplinary approaches to shark and ray conservation

Human actions are causing pervasive declines in biodiversity and ecosystem services. Sharks, rays and their cartilaginous relatives (Class Chondrichthyes, herein ‘sharks’) are amongst the most threatened taxa on earth, primarily due to overfishing. Oceanic shark populations have declined by more 70% in the past 50 years, and over one third of shark species and threatened with extinction. Technologies and practices that reduce impacts of fisheries on sharks are relatively well documented, yet little is known about how to incentivise adoption across different types of fisheries while also managing trade-offs between conservation objectives and the important socio-economic functions of fisheries. This thesis seeks to fill this knowledge gap, by exploring approaches which can simultaneously deliver conservation outcomes for sharks and well-being outcomes for people. I begin by critically assessing current approaches for understanding and managing threats to sharks, and highlight gaps relating to socio-economic issues. I then develop a general decision-making framework, based on the mitigation hierarchy, which can integrate socio-economic issues to support least-cost shark conservation. The remainder of the thesis then focuses on research methods and conservation approaches for understanding and addressing socio-economic implementation gaps in shark conservation. I take a dual approach, exploring: 1) fisher behaviour and behavioural interventions in small-scale fisheries (SSFs) in Indonesia, and 2) broader structural interventions, with a focus on market-based approaches. In the SSFs, I empirically investigate the socio-economic drivers of shark fishing, and barriers to pro-conservation behaviour; assess the impact of an existing intervention for manta ray conservation, and document lessons learned; and use predictive methods to explore the cost-effectiveness of hypothetical incentive-based interventions. I find that a range of micro- and macro-level drivers influence shark fishing mortality in SSFs, including: basic needs for food and livelihoods, socio-cultural values, incidental catches, and profit motivations. These drivers interact and vary across fisheries. I also find that incentive-based approaches could tackle these drivers, whilst also maintaining the well-being of coastal communities, provided they are well-designed and implemented as part of an intervention mix. In terms of structural interventions, I explore financing mechanisms for shark conservation, based on operationalising the beneficiary-pays and polluter-pays principles. I demonstrate that bycatch levies could offer a market-based approach for incentivising bycatch reduction in commercial fisheries, and generating revenue for compensatory conservation which could support delivery of no net loss or net gain for marine biodiversity. I also find that marine tourists who benefit from healthy shark populations are willing to pro-actively pay for shark conservation outcomes. Together, these two income streams could generate billions of dollars in ocean finance, and fund direct investments or performance-based payments for marine conservation in SSFs. I conclude by demonstrating how these behavioural and structural interventions could be drawn together as part of an integrated strategy, and offer some recommendations for future research and practice. Overall, my findings highlight the importance of a more holistic and interdisciplinary approach to shark conservation, and illustrate some feasible strategies and next steps for achieving better outcomes for sharks and people. If well implemented, these findings could contribute towards delivering the post-2020 global biodiversity strategy, the sustainable development goals, and a sustainable and equitable ocean economy.

Keywords: social sciences
marine megafauna
equity
economic valuation
elasmobranchs
fisheries
law enforcement
marine conservation
endangered species
behaviour change
wildlife trade
incentives
Advisor: Milner-Gulland, EJ