Bycatch of marine megafauna by small-scale fisheries is of growing global concern. The southeastern Pacific sustains extensive fisheries that are important sources of food and employment for millions of people. Mismanagement, however, jeopardizes the sustainability of ecosystems and vulnerable species. We used survey questionnaires to assess the impact of small-scale gillnet fisheries on sea turtles across 3 nations (Ecuador, Peru and Chile), designed to fill data gaps and identify priority areas for future conservation work. A total of 765 surveys from 43 small-scale fishing ports were obtained (Ecuador: n = 379 fishers, 7 ports; Peru: n = 342 fishers, 30 ports; Chile: n = 44 fishers, 6 ports). The survey coverage in study harbors was 28% for Ecuador, 37.0% for Peru, and 62.7% for Chile. When these survey data are scaled up across the fleets within surveyed ports, the resulting estimate of total annual bycatch across the study harbors is 46 478 turtles; where Ecuador is 40 480, Peru 5 828 and Chile 170 turtles. Estimated mortality rates vary markedly between countries (Ecuador: 32.5%; Peru 50.8%; Chile 3.2%), leading to estimated lethal takes of 13 225, 2 927, and 6 turtles for Ecuador, Peru, and Chile, respectively. These estimates are remarkably large given that the ports surveyed constitute only 16.4, 41, and 22% of the national gillnet fleets in Ecuador, Peru, and Chile, respectively. Limited data from observer-based surveys in Peru suggest that information from surveys are reliable and still informative. Information from surveys clearly highlight Ecuador and Peru as priority areas for future work to reduce turtle bycatch, particularly given the status of regional populations such as leatherback and hawksbill turtles.
In terrestrial and coastal systems, the mitigation hierarchy is widely and increasingly used to guide actions to ensure that no net loss of biodiversity ensues from development. We develop a conceptual model which applies this approach to the mitigation of marine megafauna by‐catch in fisheries, going from defining an overarching goal with an associated quantitative target, through avoidance, minimization, remediation to offsetting. We demonstrate the framework's utility as a tool for structuring thinking and exposing uncertainties. We draw comparisons between debates ongoing in terrestrial situations and in by‐catch mitigation, to show how insights from each could inform the other; these are the hierarchical nature of mitigation, out‐of‐kind offsets, research as an offset, incentivizing implementation of mitigation measures, societal limits and uncertainty. We explore how economic incentives could be used throughout the hierarchy to improve the achievement of by‐catch goals. We conclude by highlighting the importance of clear agreed goals, of thinking beyond single species and individual jurisdictions to account for complex interactions and policy leakage, of taking uncertainty explicitly into account and of thinking creatively about approaches to by‐catch mitigation in order to improve outcomes for conservation and fishers. We suggest that the framework set out here could be helpful in supporting efforts to improve by‐catch mitigation efforts and highlight the need for a full empirical application to substantiate this.
Ecosystem‐based management and conservation approaches such as marine protected areas (MPAs) require large amounts of ecological data to be implemented and adaptively managed. Recently, many citizen science programs have endeavored to help provide these much‐needed data. Implementation of MPAs under the Marine Life Protection Act (MLPA) Initiative in Southern California was followed by a monitoring program to establish a comprehensive baseline of the ecological conditions of several marine ecosystems at the time of MPA implementation. This baseline monitoring consortium involved several citizen science monitoring programs alongside more traditional academic monitoring programs, creating an opportunity to evaluate the potential for citizen scientists to become more involved in future long‐term monitoring efforts. We investigated different citizen science models, their program goals, and contributions to MPA baseline monitoring, including their respective monitoring protocols and data quality assurance measures, in the context of the goals of the MLPA baseline monitoring program. We focused on three very different case studies: (i) commercial fishermen and other volunteers collaborating with researchers to study the California spiny lobster, (ii) volunteer divers monitoring rocky reefs with the Reef Check California (RCCA) program and (iii) middle and high school students monitoring the inter‐tidal life of rocky shore and sandy beach ecosystems with the National Marine Sanctuaries’ Long‐term Monitoring Program and Experiential Training for Students (LiMPETS) program. We elucidate capacities and potential of citizen science approaches for MPA baseline monitoring and for building capacity towards sustainable long‐term monitoring of MPAs. Results from this study will be relevant and timely as the monitoring of California's MPAs transitions from baseline to long‐term monitoring, and as citizen science continues to become more prevalent in California and elsewhere.
Bigeye tuna (Thunnus obesus, Scombridae) are a globally important commercial fish. About 60% of the world's bigeye is caught in the Pacific Ocean, where stocks have been subject to overfishing and longline fleets are governed by increased conservation measures. One conservation measure entails multilateral bigeye quota reductions. Since 2010, quota reductions have resulted in four extended closures for Hawai`i longliners. Previous research indicated that regulatory closures may result in differential socioeconomic impacts, but little is known about how four extended closures may affect fishers and fishing trips in a diverse longline fleet with 142 active vessels. The purpose of this research is to assess the trip-level impacts of closures on Hawai`i longliners and determine whether impacts could be lessened while sill meeting conservation measures. To do this, economic data and longline logbooks for Hawai`i longliners were analyzed from 2010 to 2015, and 28 longline fishers were interviewed in Fall 2015. Vessels allowed to fish during closures spent nearly two more days at sea not fishing compared to the same month in years without a closure, with no significant difference in trip length. Vessels with special permits are allowed to fish closer to port during closures, while the larger vessels (25% of the fleet) were restricted from retaining bigeye between 32 and 61 days a year, raising equity concerns across the fleet. Our findings also suggest that two levels of collective action may be needed to meet Pacific-wide economic and conservation goals for an economically and ecologically important pelagic common-pool marine resource.
Seafood is an essential source of protein for more than 3 billion people worldwide, yet bycatch of threatened species in capture fisheries remains a major impediment to fisheries sustainability. Management measures designed to reduce bycatch often result in significant economic losses and even fisheries closures. Static spatial management approaches can also be rendered ineffective by environmental variability and climate change, as productive habitats shift and introduce new interactions between human activities and protected species. We introduce a new multispecies and dynamic approach that uses daily satellite data to track ocean features and aligns scales of management, species movement, and fisheries. To accomplish this, we create species distribution models for one target species and three bycatch-sensitive species using both satellite telemetry and fisheries observer data. We then integrate species-specific probabilities of occurrence into a single predictive surface, weighing the contribution of each species by management concern. We find that dynamic closures could be 2 to 10 times smaller than existing static closures while still providing adequate protection of endangered nontarget species. Our results highlight the opportunity to implement near realtime management strategies that would both support economically viable fisheries and meet mandated conservation objectives in the face of changing ocean conditions. With recent advances in eco-informatics, dynamic management provides a new climate-ready approach to support sustainable fisheries
Fishery landings of coral reef fish from a nearshore commercial spear fishery from 2011 to 2014 were analyzed and summarized. Results showed that the fishery comprised two effort components—shore‐ and boat‐based fishing—with shore‐based fishing dominating fishery effort. These two components yielded differing fishery characteristics, including landings, CPUE, seasonality, fishing locations, and targeted species. Time series of select species’ sizes (family Acanthuridae and subfamily Scarinae) showed relatively consistent trends over the sampling period, with the sizes of most harvested species exceeding the life history milestones of length at maturity and length at sex change. Sizes of harvested species were influenced by fishing effort type. Brief comparisons with prior spear fishery analyses focusing on the Northern Mariana Islands indicated that effectively evaluating the nighttime commercial coral reef spear fishery requires an understanding of fishery dynamics and implementation of a long‐term monitoring program.
Marine Spatial Planning (MSP) has evolved over many years and since its early beginnings there has been a growing urgency to develop transboundary planning. This is because the borders of marine ecosystems and the dynamics of some maritime activities, such as navigation, are not restricted to or bound by specific political and administrative borders. Cooperation across borders has been promoted by higher political levels for decades, and the implementation of cross-border consultation procedures is regulated by law. However, literature suggests that transboundary interaction is not an obvious step in the process of MSP and that today's practices have various weaknesses. This paper examines current practices and procedures of transboundary MSP interactions in the Baltic Sea Region to date. It brings together results from MSP process observations and interviews with marine planners in two recent research projects (Baltic SCOPE and BONUS BALTSPACE). Our results confirm the need for transboundary interaction and integration. The research also shows that there are differences in how MSP agencies interact with domestic and foreign stakeholders. Furthermore, formal transboundary consultations often seem to be limited to topics of the environment and health, and to the stakeholders responsible in these realms. The results include a variety of ways to overcome these challenges.
Refugia are one means of species survivorship during a global crisis. As the Earth is facing a major crisis in the marine biosphere, the study of refugia through past extinctions and other global crises is relevant to creating and maintaining effective marine reserves (including marine protected areas and other formally established havens for conservation). A synthesis of previous studies identifies the following properties common to most definitions of a refugium: (1) During a global crisis, a species can persist in a refugium, which can include a range shift, habitat shift, or migration or contraction to an isolated geographic area. Subsets of isolated geographic refugia include life history refugia (areas necessary for breeding), cryptic refugia (small areas, must remain connected for populations to remain viable), and harvest refugia (defined from the modern literature to escape overfishing pressure). (2) In the refugium, the habitat may remain stressed but is sufficiently habitable for the species to maintain sufficient albeit small populations (relative to pre-crisis population size) over many generations. (3) After the crisis ends, the species emerges from the refugium and expands during the recovery interval. Otherwise, the refugium will become a refugial trap in which the species remains a relict population or ultimately becomes extinct.
The present understanding of refugia from the geologic past comes from three sources, namely fossil data, phylogeographic reconstructions, and species distribution models, the latter two being more common for studies across the last glacial maximum. The synthesis herein suggests several important factors when considering the future of marine reserves. Because climate change is an ongoing process, the present refugia of marine reserves may not be sufficient for the future survival of marine species. Short-term refugia of some present marine reserves may deteriorate because of further climate change and have to be abandoned for new long-term options as new habitats become available. Cryptic refugia of small reserves must remain connected in terms of species’ dispersal and exchange, but must also be flexible, in that cryptic refugia naturally are sometimes ephemeral because of habitat heterogeneity through time. Finally, habitats in marine reserves must be of sufficiently low stress to maintain viable populations, but should frequently be re-evaluated to avoid becoming refugial traps in the future.
The contributions of all the chapters in this book are integrated to give a perspective on the requirements for realizing the sustainable fisheries of dynamic resources. A comprehensive overview of the whole process of data gathering, analyzing, and decision-making for fisheries assessment and management is presented in a sequential adaptive way as a plan-do-check-act (PDCA) cycle and illustrated in a schematic diagram. The process is a loop of sequential information updates and adaptive decision-making in the actual world parallel with the corresponding virtual world. Some points along the panoramic diagram are discussed with reference to discussions in previous chapters. Issues discussed are (1) diversity of management objectives and performance measures: multidisciplinary approach; (2) development of harvest control rules (HCRs); (3) revealing dynamics of stocks, communities, and ecosystems: mechanistic approach; (4) value of monitoring for adaptive management: empirical approach; (5) assessment models vs. operating models: to what extent should they be complex?; and (6) social institution and organization for fisheries management. The ocean is eternal in its existence; however, its components are never static but dynamic. Since fish communities dynamically change with climate-induced ocean regime shifts, we humans have no choice but to adapt to the nature of ecosystems. The benefits of the ocean will be eternal for us only if we successfully achieve such an adaptation.
There is an urgent need for an improved empirical understanding of the relationship among biodiverse marine resources, human health and development outcomes. Coral reefs are often at this intersection for developing nations in the tropics—an ecosystem targeted for biodiversity conservation and one that provides sustenance and livelihoods for many coastal communities. To explore these relationships, we use the comparative development contexts of Haiti and the Dominican Republic on the island of Hispaniola. We combine child nutrition data from the Demographic Health Survey with coastal proximity and coral reef habitat diversity, and condition to empirically test human benefits of marine natural resources in differing development contexts. Our results indicate that coastal children have a reduced likelihood of severe stunting in Haiti but have increased likelihoods of stunting and reduced dietary diversity in the Dominican Republic. These contrasting results are likely due to the differential in developed infrastructure and market access. Our analyses did not demonstrate an association between more diverse and less degraded coral reefs and better childhood nutrition. The results highlight the complexities of modelling interactions between the health of humans and natural systems, and indicate the next steps needed to support integrated development programming.