Publications

Climate change poses unprecedented challenges for fisheries management systems. Increased environmental variability and uncertainty due to climate change are creating shifts in productivity and distribution of fished species, and subsequent social-ecological impacts that require timely implementation of adaptive management strategies. Yet many proposed “climate-ready” fisheries actions – such as integrating climate factors into stock assessments and increasing flexibility in decision-making – either complicate or add to existing responsibilities of fishery managers and strain existing institutions. In the United States, many fisheries management agencies have explicitly acknowledged certain capacity shortfalls and institutional limitations to addressing current and projected impacts of climate change on marine fisheries. Many resource and capacity gaps across the adaptive fisheries management cycle could be filled through more effective fishery partnerships among management agencies, fishing industries, private sector, and academia. Partnership approaches are key to unlocking capacity for achieving climate-ready fisheries yet expanded implementation may require a shift towards a model that empowers and obligates fishery stakeholders to take on expanded roles with appropriate guidelines and oversight, while establishing increased roles for agencies as facilitators and auditors for certain tasks. Building and institutionalizing more effective fishery partnerships to achieve climate-ready fisheries will require clear guidance and enabling conditions.

Rural economies in many developing countries are characterized by a lean season in the months preceding harvest, when farmers have depleted their cash and grain savings from the previous year. To identify the impacts of liquidity during the lean season, we offered subsidized loans in randomly selected villages in rural Zambia. Ninety-eight percent of households took up the loan. Loan eligibility led to increases in on-farm labor and agricultural output, driving up wages in local labor markets. Larger effects for poorer households suggest that liquidity constraints contribute to inequality in rural economies.

Contrary to most terrestrial organisms, which release their carbon into the atmosphere after death, carcasses of large marine fish sink and sequester carbon in the deep ocean. Yet, fisheries have extracted a massive amount of this “blue carbon,” contributing to additional atmospheric CO2 emissions. Here, we used historical catches and fuel consumption to show that ocean fisheries have released a minimum of 0.73 billion metric tons of CO2 (GtCO2) in the atmosphere since 1950. Globally, 43.5% of the blue carbon extracted by fisheries in the high seas comes from areas that would be economically unprofitable without subsidies. Limiting blue carbon extraction by fisheries, particularly on unprofitable areas, would reduce CO2 emissions by burning less fuel and reactivating a natural carbon pump through the rebuilding of fish stocks and the increase of carcasses deadfall.

Marine protected areas (MPAs) are conservation tools that are increasingly implemented, with growing national commitments for MPA expansion. Perhaps the greatest challenge to expanded use of MPAs is the perceived trade-off between protection and food production. Since MPAs can benefit both conservation and fisheries in areas experiencing overfishing and since overfishing is common in many coastal nations, we ask how MPAs can be designed specifically to improve fisheries yields. We assembled distribution, life history, and fisheries exploitation data for 1,338 commercially important stocks to derive an optimized network of MPAs globally. We show that strategically expanding the existing global MPA network to protect an additional 5% of the ocean could increase future catch by at least 20% via spillover, generating 9 to 12 million metric tons more food annually than in a business-as-usual world with no additional protection. Our results demonstrate how food provisioning can be a central driver of MPA design, offering a pathway to strategically conserve ocean areas while securing seafood for the future.

Overfishing and other anthropogenic impacts to ocean ecosystems have motivated widespread implementation of no-take marine reserves to protect biodiversity and fished resources. Fully protected marine reserves now comprise approximately 2.5% of the ocean and calls for enhanced protections abound. The benefits to marine biodiversity within reserve borders are clear, yet the contributions beyond borders remain the subject of continued scholarship. In this article, six co-benefits of marine reserves for fisheries are explored. Broadly, the six co-benefits fall within two categories 1) use of reserves as tools to adaptively learn, promote resiliency, and manage marine resources, especially in the face of a changing climate and 2) use of reserves to provide credit against uncertainty in management and sustainability criteria. Broader understanding and consideration of the benefits of marine reserves can further policy discussions and deepen conversations regarding social, ecological, and economic tradeoffs of implementing marine reserves.

The World Trade Organization (WTO) is in a unique position to deliver on Sustainable Development Goal (SDG) 14.6 by reforming global fisheries subsidies in 2020. Yet, a number of unanswered questions threaten to inhibit WTO delegates from crafting a smart agreement that improves global fisheries health. We combine global data on industrial fishing activity, subsidies, and stock assessments to show that: (1) subsidies prop up fishing effort all across the world’s ocean and (2) larger subsidies tend to occur in fisheries that are poorly managed. When combined, this evidence suggests that subsidy reform could have geographically-extensive consequences for many of the world’s largest fisheries. While much work remains to establish causality and make quantitative predictions, this evidence informs the rapidly-evolving policy debate and we conclude with actionable policy suggestions.

Bigeye tuna in the Western and Central Pacific Ocean were perceived as overfished for nearly 20 years, in large part due to incidental catch in the much larger skipjack tuna fishery. Efforts to halt the overfishing of bigeye stalled due to disagreements over the distribution of costs and benefits from reform. An alternative Coasean-style approach to setting both harvesting levels and the allocation of costs and benefits might offer a path forward. We calculate the costs and benefits of achieving bigeye conservation goals and describe an exchange through which benefits could be realized via removal of Fish Aggregating Devices (FADs). Through trade, aggregate benefits and costs are more apt to be in balance relative to mandated protection controls. The realities of bargaining costs in a multilateral setting are not underappreciated, but in light of existing stalemates in this and other fisheries, consideration of Coasean-style approaches is warranted.

Moored fish aggregating devices (MFADs) are promoted throughout global small-scale fisheries as tools to enhance livelihoods and shift fishing pressure onto offshore resources. A particularly large number of projects initiating and encouraging MFAD development have occurred in the Caribbean region. Despite ongoing promotion of MFAD fisheries in the region, there is limited understanding of their current extent, distribution, and management across Caribbean states. Here we integrate key informant surveys with a supporting literature review to generate the first comprehensive overview of MFAD fishery status and trends in the insular Caribbean and Bermuda. While regional growth has been substantial, we find wide diversity among states in terms of the number of MFADs deployed, MFAD ownership (private or public), fleet engagement, and the existence and enforcement of MFAD regulations. Our results suggest that despite the presence of regulations in some states, management limitations and private MFAD ownership may be associated with a rapid proliferation of deployed MFADs across the Caribbean. We discuss the critical role of management and monitoring in attaining the anticipated benefits of MFAD fisheries and reducing social and environmental risks. By documenting the diverse paths that MFAD fisheries have taken in different states, this study provides an opportunity for prospective and existing MFAD programs to better evaluate the risks and rewards associated with MFADs and to design appropriate management.

Natural resources are often subject to state uncertainty: resource abundance is not known with certainty, but can be measured. Measurements are typically imperfect and costly to obtain. The decision of whether to invest in resource measurement may be influenced by other state variables, for example a resource commodity price. We introduce a mixed-observability model of optimal forest management featuring a partially-observable forest resource and perfectly-observable stochastic price. The decision maker optimizes the expected net present value of forest returns by choosing when to measure current forest volume (conduct an inventory), harvest and replant, or delay action. Parameter values are obtained from numerous forestry data sources. Optimal investment in inventory reduces the cost of uncertainty about timber volume and increases the predictability of returns. Moreover, price stochasticity interacts with inventory decisions to produce asymmetric effects of high and low prices on inventory timing. We also produce the first graphical Faustmann rule analogues for jointly-optimal inventory and harvest.

Technology adoption often requires multiple stages of investment. As new information emerges, agents may abandon a technology that was profitable in expectation. We use a field experiment to vary the payoffs at two stages of investment in a new technology: a tree species that provides on-farm fertilizer benefits. Farmer decisions identify the information about profitability that arrives between the take-up and follow-through stages. Results show that this form of uncertainty increases take-up but lowers average tree survival, decreasing the cost-effectiveness of take-up subsidies. Thus, uncertainty offers another explanation for why even costly technologies may go unused or be abandoned.

In California, record-breaking fires in 2017 and 2018 destroyed communities and dominated headlines across the country. The Thomas fire in Ventura and Santa Barbara Counties, and the Tubbs fire in Napa, Sonoma, and Lake Counties damaged or destroyed over 7,200 structures, burning over 318,000 acres in
2017. In 2018, the Woolsey fire in Los Angeles and Ventura Counties damaged 1,990 structures, burning almost 97,000 acres. The Camp fire in Paradise damaged 19,531 structures, becoming the most destructive fire in California history. In this report, we put these recent events into broader historical perspective, using a newly developed dataset that catalogues wildfire damages dating back to 1979. This report presents this novel data set, which illustrates that these recent severe fires are part of a broader trend of increasing fire burn area and damages over the last 40 years.

One of the aims of the United Nations (UN) negotiations on the conservation and sustainable use of marine biodiversity in areas beyond national jurisdiction (ABNJ) is to develop a legal process for the establishment of area-based management tools, including marine protected areas, in ABNJ. Here we use a conservation planning algorithm to integrate 55 global data layers on ABNJ species diversity, habitat heterogeneity, benthic features, productivity, and fishing as a means for highlighting priority regions in ABNJ to be considered for spatial protection. We also include information on forecasted species distributions under climate change. We found that parameterizing the planning algorithm to protect at least 30% of these key ABNJ conservation features, while avoiding areas of high fishing effort, yielded a solution that highlights 52,545,634 km² (23.7%) of ABNJ as high priority regions for protection. Instructing the planning model to avoid ABNJ areas with high fishing effort resulted in relatively minor shifts in the planning solution, when compared to a separate model that did not consider fishing effort. Integrating information on climate change had a similarly minor influence on the planning solution, suggesting that climate-informed ABNJ protected areas may be able to protect biodiversity now and in the future. This globally standardized, data-driven process for identifying priority ABNJ regions for protection serves as a valuable complement to other expert-driven processes underway to highlight ecologically or biologically significant ABNJ regions. Both the outputs and methods exhibited in this analysis can additively inform UN decision-making concerning establishment of ABNJ protected areas.

As human use of the oceans increases, marine spatial planning (MSP) is being more widely adopted to achieve improved environmental, economic, and social outcomes. However, there is a lack of practical guidance for stakeholder driven, scientifically informed MSP processes in small island and data-limited contexts. Here, we present an overview of MSP on the Caribbean island of Montserrat, with a focus on the scientific and technical input that helped inform the process. Montserrat presents an interesting case study of MSP in the small island context as it has ocean uses that are common to many islands, namely small-scale fisheries and tourism, but the marine environment has been heavily impacted due to volcanic activity. We detail the methods for data collection and analysis and the decision-making process that contributed to a marine spatial plan. We highlight aspects of the process that may be useful for other small islands embarking on MSP, and lessons learned regarding scientific support, including the need for on-site scientific support and guidance throughout MSP, the importance of setting clear objectives, working within data limitations and making data accessible, and choosing and using appropriate decision support tools.

Although climate change is altering the productivity and distribution of marine fisheries, climate-adaptive fisheries management could mitigate many of the negative impacts on human society. We forecast global fisheries biomass, catch, and profits to 2100 under three climate scenarios (RCPs 4.5, 6.0, 8.5) and five levels of management reform to (1) determine the impact of climate change on national fisheries and (2) quantify the national-scale benefits of implementing climate-adaptive fisheries reforms. Management reforms accounting for shifting productivity and shifting distributions would yield higher catch and profits in the future relative to today for 60–65% of countries under the two least severe climate scenarios but for only 35% of countries under the most severe scenario. Furthermore, these management reforms would yield higher cumulative catch and profits than business-as-usual management for nearly all countries under the two least severe climate scenarios but would yield lower cumulative catch for 40% of countries under the most severe scenario. Fortunately, perfect fisheries management is not necessary to achieve these benefits: transboundary cooperation with 5-year intervals between adaptive interventions would result in comparable outcomes. However, the ability for realistic management reforms to offset the negative impacts of climate change is bounded by changes in underlying biological productivity. Although realistic reforms could generate higher catch and profits for 23–50% of countries experiencing reductions in productivity, the remaining countries would need to develop, expand, and reform aquaculture and other food production sectors to offset losses in capture fisheries. Still, climate-adaptive management is more profitable than business-as-usual management in all countries and we provide guidance on implementing–and achieving the benefits of–climate-adaptive fisheries reform along a gradient of scientific, management, and enforcement capacities.

Models of human dimensions of fisheries are important to understanding and predicting how fishing industries respond to changes in marine ecosystems and management institutions. Advances in computation have made it possible to construct agent-based models (ABMs)—which explicitly describe the behaviour of individual people, firms or vessels in order to understand and predict their aggregate behaviours. ABMs are widely used for both academic and applied purposes in many settings including finance, urban planning and the military, but are not yet mainstream in fisheries science and management, despite a growing literature. ABMs are well suited to understanding emergent consequences of fisher interactions, heterogeneity and bounded rationality, especially in complex ecological, social and institutional contexts. For these reasons, we argue that ABMs of human behaviour can contribute significantly to human dimensions of fisheries in three areas: (a) understanding interactions between multiple management institutions; (b) incorporating cognitive and behavioural sciences into fisheries science and practice; and (c) understanding and projecting the social consequences of management institutions. We provide simple examples illustrating the potential for ABMs in each of these areas, using conceptual (“toy”) versions of the POSEIDON model. We argue that salient strategic advances in these areas could pave the way for increased tactical use of ABMs in fishery management settings. We review common ABM development and application challenges, with the aim of providing guidance to beginning ABM developers and users studying human dimensions of fisheries.

Climate change is driving fishery stocks out of their historical ranges. Along with the management challenge of species entering new jurisdictions, the exit of species from countries’ waters poses distinct threats to those resources and the economies that depend on them. We show that this risk is particularly acute in the tropics, where projected exits are highest and entries are fewest. We find that existing policy frameworks are poorly equipped for this challenge, and we suggest a way forward that draws on climate policy.

Two of the largest protected areas on earth are U.S. National Monuments in the Pacific Ocean. Numerous claims have been made about the impacts of these protected areas on the fishing industry, but there has been no ex post empirical evaluation of their effects. We use administrative data documenting individual fishing events to evaluate the economic impact of the expansion of these two monuments on the Hawaii longline fishing fleet. Surprisingly, catch and catch-per-unit-effort are higher since the expansions began. To disentangle the causal effect of the expansions from confounding factors, we use unaffected control fisheries to perform a difference-in-differences analysis. We find that the monument expansions had little, if any, negative impacts on the fishing industry, corroborating ecological models that have predicted minimal impacts from closing large parts of the Pacific Ocean to fishing.

Small-scale fisheries are an important livelihood and primary protein source for coastal communities in many of the poorest regions in the world, yet many are overfished and thus require effective and scalable management solutions. Positive ecological and socioeconomic responses to management typically lag behind immediate costs borne by fishers from fishing pressure reductions necessary for fisheries recovery. These short-term costs challenge the long-term success of these interventions. However, social marketing may increase perceptions of management benefits before ecological and socioeconomic benefits are fully realized, driving new social norms and ultimately long-term sustainable behavior change. By conducting underwater visual surveys to quantify ecological conditions and by conducting household surveys with community members to quantify their perceptions of management support and socioeconomic conditions, we assessed the impact of a standardized small-scale fisheries management intervention that was implemented across 41 sites in Brazil, Indonesia, and the Philippines. The intervention combines TURF reserves (community-based territorial use rights for fishing coupled with no-take marine reserves) with locally tailored social-marketing behavior change campaigns. Leveraging data across 22 indicators and 4 survey types, along with data from 3 control sites, we found that ecological and socioeconomic impacts varied and that communities supported the intervention and were already changing their fishing practices. These results suggest that communities were developing new social norms and fishing more sustainably before long-term ecological and socioeconomic benefits of fisheries management materialized.

Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported global marine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.