Protecting Marine Biodiversity
The ocean is home to the majority of the world’s biodiversity, but global environmental changes and local and regional stressors threaten the health of marine ecosystems, as well as food security and economic opportunity. Through various research initiatives, SFG is demonstrating that the productivity of fisheries and the security of human livelihoods are inextricably linked to effective marine conservation and biodiversity protection.
Analysis of Bycatch in Global Fisheries
Two key objectives of marine conservation are rebuilding target fisheries to produce more food and income, and protecting threatened bycatch species. These goals often appear to be in competition with one another, therefore it is important that we understand the degree to which the decline in bycatch populations is merely a symptom of target stock overfishing, and the degree to which these declines actually represent real tradeoffs between food, income, and conservation.
To answer this question, we calculated the reduction in bycatch mortality that would be necessary to ensure the recovery of 20 different sea turtle, marine mammal, and seabird populations that are currently threatened by bycatch. We then compared this reduction to the estimated change in fishing pressure needed for target stocks to produce their maximum sustainable yield or profit. When we compared these two estimates, we found that some bycatch populations would need greater reductions in mortality than the target stocks in order to recover. For these populations, we calculated the minimum catch and profit that would need to be foregone by target fisheries to ensure the recovery of bycatch populations.
Some of the world’s most intense overfishing and many of the species most severely impacted by bycatch are found in the same places--in coastal fisheries of the developing world. Because of this overlap, we project little to no tradeoff between maximizing fishery yields or profits and recovering the majority of the bycatch populations included in our analysis. Though we do project a severe tradeoff for some bycatch populations, our results suggest that rebuilding global target fisheries could have significant co-benefits for sea turtle, marine mammal, and seabird conservation.
Tracking Illegal Fishing of Protected Shark Populations
Illegal fishing is a high-risk activity, so to make it worth the risk, fishers commonly target high-value species, such as sharks, whose fins alone can sell for hundreds of US dollars per kilogram. In an effort to reduce the number of sharks caught illegally each year, SFG is analyzing Global Fishing Watch data to improve our understanding of illegal shark fishing activity around the world. We have a unique opportunity to compare vessel activity with data from a shark movement study in the Republic of the Marshall Islands (RMI), where 8 of 15 satellite-tagged sharks in the RMI Shark Sanctuary were illegally fished. By attempting to match shark satellite tracking data with Global Fishing Watch data, we can create a system to identify suspicious fishing activity on protected shark populations and classify vessels with a high probability of engaging in illegal shark fishing.
Comparing the Cost Effectiveness of Electronic Monitoring Systems and Human Observer Programs
Electronic monitoring (EM), which leverages technologies such as cameras and other sensors, has the potential to significantly enhance fisheries data collection and monitoring. Compared to traditional onboard human observer programs, EM is often cheaper to implement, and many pilot studies suggest that the data these systems collect is of comparable accuracy. Yet many factors related to both the fishery and its specific management objectives influence the relative costs and accuracies of EM and human observer programs. In collaboration with our partners at The Nature Conservancy, we are building a tool that will enable fishery managers to better explore the tradeoffs between EM and human observer programs. We are also conducting two case studies on the potential costs of implementing EM programs in the domestic longline fisheries of French Polynesia and the Federated States of Micronesia.