University of Oxford
11a Mansfield Rd
The ocean provides 170 million tonnes of fisheries and aquaculture products for human use each year, accounting for 17% of animal protein consumed globally. Within this 17%, millions of small-scale fishers in developing nations are highly dependent on marine resources for food security and micro-nutrients. By 2050 we expect our planet will need to provide sufficient and nutritious food for approximately 10 billion people, which suggests the need for continued expansion of global fisheries to maintain or improve human well-being. Yet fish stocks and marine ecosystems already face depletion under current levels of fishing pressure.
The threat of overfishing is particularly acute for slow-growing, long-lived marine megafauna, such as sharks, rays and sea turtles. These species are caught as target, secondary or incidental catch throughout global fisheries, and their slow life history traits make them vulnerable to overexploitation. As a result, marine megafauna are some of the most threatened taxa in the world. Nearly 30% of all shark and ray species, for instance, are categorized as ‘Threatened’ based on IUCN Red List criteria.
These issues create one of the most intractable issues in marine conservation today: the need to balance conservation objectives for threatened marine megafauna with fisheries objectives for income, food security and human well-being. This trade-off is particularly challenging in small-scale fisheries in developing countries, where there is high dependency on marine resources.
Despite these challenges, there are bright spots of innovation and community engagement throughout tropical fisheries. We bring you examples from four tropical countries and five megafauna species, where interdisciplinary approaches are being used to:
- Better understand the severity and drivers of threats to marine megafauna
- Make management decisions, based on ecological and socio-economic factors
- Design innovative approaches for achieving conservation impact
- Scale-up action for the post-2020 new deal for nature and people
1. Understanding the severity and drivers of threats to marine megafauna
Thresher sharks in Indonesia – Muhammad Ichsan
Indonesia is the world’s largest shark and ray fishing nation. Amongst the most commonly caught species are the pelagic thresher sharks (Alopias pelagicus), which is an evolutionarily-distinct and globally-endangered (EDGE) species. Aceh is Indonesia’s largest shark-producing province, and a hotspot for thresher shark catches, though details on the drivers of these catches and potential management options are limited.
Ichsan’s research aims to characterize shark fisheries in Southwest Aceh District using an interdisciplinary approach, and identify management options for the thresher sharks. He found that more than 30 sharks and ray species are captured, including thresher sharks. Sharks are predominantly targeted for their fins, which are sold internationally. Other body parts are generally considered a ‘by-product’, although shark meat has importance as a local food source. Interestingly, thresher shark catches are insignificant compared to other sharks, and both fins and meat from threshers are generally of lower value than other targeted sharks. A technical assessment indicates that thresher shark catches could be reduced by effort limits or trip quotas with live release protocols. However, further information on the drivers of thresher shark capture and their socio-economic importance is required to understand the feasibility of implementing these measures.
2. Making management decisions
Mitigating impacts to sea turtles in Peru: William Arlidge
The biodiversity impact mitigation hierarchy has been proposed as an overarching framework for reducing marine megafauna bycatch, but empirical application across multiple case studies is still necessary. Focusing on a small-scale fishing community in northern Peru, Will explored how the mitigation hierarchy can support efforts to reduce captures of sea turtles in coastal fishers’ gillnets, and link these actions to broader goals for biodiversity. To do this, he adopted a mixed methods iterative approach to data collection. First, using a literature review to collate secondary data on the fishery and the species of sea turtles captured. He then collected primary data to fill identified knowledge gaps. Using a qualitative ecological Risk Assessment approach, Will identified and evaluated the potential risk that the fishery poses to each turtle species within regional management units. Finally, he evaluated potential management strategies to reduce turtle captures, incorporating stakeholder preference from questionnaire-based surveys and considering preliminary estimates of trends across a range of performance indicators. The results of the study support a holistic assessment of management strategies toward biodiversity goals standardized across fisheries and scales.
Bycatch mitigation of sharks and rays in India: Trisha Gupta
Trisha has been monitoring shark and ray fisheries on India’s west coast, as part of a Dakshin Foundation research project. Although sharks and rays are caught as bycatch in the trawl fisheries in this region, they support livelihoods and food needs of local communities. In collaboration with Oxford University, Trisha used the interdisciplinary mitigation hierarchy framework for sharks to assess measures to reduce bycatch, while having a minimal impact on fisher livelihoods. The study found that releasing live sharks and rays onboard would be the best option socio-economically, especially for species like the Critically Endangered guitarfish, which are relatively robust to capture and release. Fishers indicated that they would be willing to follow live release protocols as their earnings would not be greatly affected. Such findings form a small but positive step towards better conservation of sharks and rays in India.
3. Innovative approaches for conservation impact
Sawfishes are highly threatened and have been extirpated from most of their ranges. However, Bangladesh remains a potential stronghold, where critically endangered largetooth sawfish are still being landed. Alifa is working with local fishers to monitor sawfish catches and work towards threat mitigation solutions. Between October 2016 and December 2017, 25 sawfish landings were documented, of which at least 17 were largetooth sawfish (Pristis pristis) (which is a conservative account, as more were likely caught and landed throughout the coast). To halt local extinction of this species live release programs are essential. However, sawfish are also extremely valuable for marginalised fishers, and releasing sawfish catches is costly. To address this, Alifa has been conducting interviews and workshops with fisher communities throughout the coast of Bangladesh to design culturally-appropriate and socially-inclusive approaches to enable live release of sawfish in Bangladesh’s coastal fisheries.
Mantas in Indonesia: Jo Marlow
Indonesia a paradox: it is ranked in the top 3 worldwide destinations for manta watching, yet Indonesia is the world’s largest shark and ray fishing nation. Jo has worked on conservation projects in two manta ray hotspots in Indonesia over the past decade: Raja Ampat, a luxury dive tourism destination, and East Flores, a manta ray hunting hotspot. Both places are seeing manta conservation success, yet through highly contrasting approaches. Jo’s two case studies highlight the importance of adapting conservation approaches to local societal and cultural conditions.
4. Scaling-up conservation impact
Marine megafauna and the post-2020 framework: Hollie Booth
As we move towards a new strategic framework for global conservation over the next decade, and with a growing recognition of the need to rebalance humanity’s relationship with nature, it is important to connect the dots between these local bright spots of marine conservation, and scale-up action across the globe in a meaningful way. Hollie works on how to reconcile trade-offs between conservation and fisheries objectives at multiple scales, and how to empower all sectors of society to build a world in which nature and people can thrive together. A united framework for marine conservation action, which can be implemented by marine ministries, tourism companies, seafood consumers and fishing companies, will be needed to halt declines of marine megafauna populations, and move them on to a pathway to recovery.
For more information on these projects and people, join our symposium at IMCC6 on Wednesday 19th August: SSC-09 Sharks, turtles and small-scale fisheries: saving marine megafauna in an ocean-dependent world. Our symposium brings a diversity of voices from researchers and organisations working at the front-line of these fisheries management challenges.
You can also read more about each of the speakers here:
- Muhammad Ichsan is a ZSL EDGE fellow. Follow him on twitter: @Ichsan0001
- William Arlidge is an OXBER Post-doctoral research fellow. Follow him on twitter: @WilliamArlidge
- Trisha Gupta is an incoming DPhil Student at University of Oxford. Follow her on twitter: @Trisha_0405
- Alifa Haque is a DPhil Student at University of Oxford and NatGeo explorer. Her project is co-funded by Save Our Seas Foundation.
- Jo Marlow is Marketing and Communications manager for Misool Foundation
- Hollie Booth is a DPhil Student at University of Oxford and a technical advisor for the Wildlife Conservation Society. Follow her on twitter: @hollieboothie