Assessing Vulnerability of Fish in the U.S. Marine Aquarium Trade

The trade in coral reef fishes for aquariums encompasses over 1,800 species from over 40 exporting countries, yet the population status for most traded species is unknown and unevaluated. At the same time, these coral reef fishes face a growing number of threats and often occur in jurisdictions with limited management capacity and data. In response, we assess vulnerability to overfishing for 72 coral reef fishes popular in the aquarium trade for the United States – the top importer – from the top exporting countries (Indonesia and the Philippines). We use a data-limited assessment approach: productivity susceptibility analysis (PSA). PSA estimates relative vulnerability of species by assessing their biological productivity and susceptibility to overfishing. The most and least vulnerable stocks were differentiated by attributes related to the reproductive biology (e.g., breeding strategy, recruitment pattern, and fecundity), appropriateness, for an average home aquarium, ease of capture (e.g., schooling and aggregation), and rates of natural mortality. Our analysis identifies several of the most and least vulnerable species popular in the aquarium fish trade. The species that ranked as least vulnerable to overcollection were Gobiodon okinawae, Nemateleotris magnifica, Gobiodon acicularis, Salarias fasciatus, Ptereleotris zebra, Gobiodon citrinus, Pseudocheilinus hexataenia, Chaetodon lunula, Nemateleotris decora, and Halichoeres chrysus. In contrast, the ten most vulnerable species were Chromileptes altivelis, Plectorhinchus chaetodonoides, Pterapogon kauderni, Premnas biaculeatus, Echidna nebulosa, Centropyge bicolor, Zebrasoma veliferum, Pomacanthus semicirculatus, Zebrasoma scopas, and Thalassoma lunare. In a data-limited context, we suggest how these vulnerability rankings can help guide future efforts for reducing vulnerability risk. In particular, species that are relatively high-vulnerability are prime targets for research and aquaculture efforts, increased monitoring of collection and exports, species-specific stock assessments, and voluntary reductions by retailers and consumers to avoid overexploitation

Situación actual y proyecciones futuras de las pesquerías multiespecíficas de peces en la región suroriental de Cuba: Situação atual e projecções futuras da pesca de peixes multiespecíficos na região sudeste de Cuba

Las pesquerías multiespecíficas de peces en Cuba incluyen alrededor de 150 especies, diferentes artes de pesca que se utilizan simultáneamente y un número elevado de puertos de desembarques, lo que dificulta el monitoreo y la evaluación de estos recursos, por lo cual el manejo ha sido limitado. Por ello nos propusimos evaluar el estado actual, así como las compensaciones futuras en biomasa, captura y ganancias de las especies más vulnerables bajo diferentes estrategias de manejo. Mediante el método Catch-MSY se estimó el estado actual, y un modelo bioeconómico se empleó para realizar las proyecciones a largo plazo de las salidas. Los stocks estudiados se encuentran agotados, y la mayoría con valores que implican un alto riesgo para la sustentabilidad de sus poblaciones. Además, la mayoría están sobreexplotados y sufren pesca ilegal. Sin embargo, a largo plazo bajo estrategias de manejo sustentable, muestran oportunidades de recuperación y de tener pesquerías económicamente rentables siempre que se elimine la pesca ilegal y se apliquen incentivos económicos

Combining fish and benthic communities into multiple regimes reveals complex reef dynamics

Abstract Coral reefs worldwide face an uncertain future with many reefs reported to transition from being dominated by corals to macroalgae. However, given the complexity and diversity of the ecosystem, research on how regimes vary spatially and temporally is needed. Reef regimes are most often characterised by their benthic components; however, complex dynamics are associated with losses and gains in both fish and benthic assemblages. To capture this complexity, we synthesised 3,345 surveys from Hawai‘i to define reef regimes in terms of both fish and benthic assemblages. Model-based clustering revealed five distinct regimes that varied ecologically, and were spatially heterogeneous by island, depth and exposure. We identified a regime characteristic of a degraded state with low coral cover and fish biomass, one that had low coral but high fish biomass, as well as three other regimes that varied significantly in their ecology but were previously considered a single coral dominated regime. Analyses of time series data reflected complex system dynamics, with multiple transitions among regimes that were a function of both local and global stressors. Coupling fish and benthic communities into reef regimes to capture complex dynamics holds promise for monitoring reef change and guiding ecosystem-based management of coral reefs

Patterns, mechanisms and community consequences of variation in kelp forest canopies

Structurally complex vegetative habitat can have strong influences on the patterns, mechanisms and consequences of species interactions and the structure of a community. How spatial and temporal variation of biogenic habitat influences species interactions that determine spatial and temporal patterns of community structure and functions is not well understood. I investigated how environmental gradients and anthropogenic perturbations influence the physical structure of the canopy of giant kelp, Macrocystis pyrifera , forests and the consequences for community structure and functions. Examination of kelp forest canopies along an environmental gradient of oceanic swell revealed that kelp forests more exposed to swell support greater total abundance, species richness, and markedly different invertebrate assemblages than did more protected kelp forests. Additionally, abundance of an epibiont, Membranipora spp., was positively correlated with increased swell exposure, which contributed to the variation in community structure. I also experimentally assessed the effects of biogenic habitat and the epibiont on prey assemblages, predator-prey interactions and the foraging success of predators (juvenile rockfishes of the genus Sebastes). The cumulative effects of Macrocystis and Membranipora caused a shift in the species composition of the prey assemblage and increased growth rates of juvenile rockfishes by 100%, reflecting an increase in biomass and size of the substrate-associated prey. The results demonstrate how epibionts can modify predator-prey interactions and enhance the functional role of vegetation (i.e. nursery habitat for juvenile fishes). I also investigated how the reduction of canopy habitat by kelp harvesting influences the invertebrate assemblage. I found that when habitat reduction occurs later in the summer when the growth of Macrocystis is minimal, the canopy and associated assemblage did not recover. In contrast, reduction of habitat earlier in the summer, when Macrocystis is still growing, enables the canopy and invertebrate assemblage to recover. Additionally, I determined that partial reduction of the canopy habitat maintains partial functioning of the canopy. By understanding the patterns, mechanisms and consequences of variability in a biogenic habitat on its associated community, we can better understand, predict and manage how natural and anthropogenic impacts to kelp forest canopies alter ecosystem structure, functions and the services they provide humans

A participatory climate vulnerability assessment for recreational tidal flats fisheries in Belize and The Bahamas

Recreational fishing is a pillar of the multibillion-dollar tourism sector in the Caribbean, supporting economic development and community livelihoods. However, as climate change drives increased habitat degradation, key recreational target species may experience declines. To effectively prioritize adaptation and mitigation efforts it is critical to project climate change impacts on recreational species and the communities that depend on them. We conducted a comprehensive climate vulnerability assessment (CVA) for three recreationally important tidal flats species in Belize and The Bahamas: bonefish (Albula vulpes), tarpon (Megalops atlanticus), and permit (Trachinotus falcatus). Species vulnerability was assessed by coupling 1) a research-based CVA to evaluate the sensitivity and exposure of species to climate impacts with 2) a participatory workshop involving 17 fishing guides, resource managers, and science and policy experts working in fisheries systems in Belize and/or The Bahamas. The workshop elicited local expert knowledge to resolve and contextualize CVA scoring and to identify strategies to increase climate resilience. According to the research-based CVA, key climate factors in the Caribbean are expected to see a ‘very high’ magnitude of change by 2050. All three species exhibit ‘very high’ vulnerability to these changes based on life history traits and reliance on nearshore habitats that are exposed to rapid temperature increases and storm damage. The expert stakeholder group confirmed a ‘very high’ magnitude of expected climate impacts in the Caribbean region, to which bonefish, the most valuable species, is likely to have a ‘very high’ vulnerability. However, stakeholders perceived tarpon and permit to be less vulnerable to these impacts than the CVA predicted, based on “on the water” observations of their habitat flexibility and resilience to disturbance. The group identified strategies at the individual, community, national, and international levels to enhance climate resilience in the recreational fishing sector. Our work highlights how participatory CVA processes can support a stronger understanding of species’ vulnerability while building capacity and collaboration to increase climate change readiness

An indicator-based adaptive management framework and its development for data-limited fisheries in Belize

Decisions regarding the selection and implementation of management strategies that constrain fishing pressure can be among the most difficult choices that fisheries managers and stakeholders must make. These types of decisions often need to be confronted in a data-limited context, where few if any management measures are currently in place or fisheries are managed independent of adequate scientific advice. This situation can sometimes create a high risk of overfishing and potential loss of economic and social benefits. To address this situation, simple model-free indicator-based frameworks have the potential to be effective decision-making platforms for fisheries where quantitative estimates of biomass and fishing mortality based reference points are lacking. In this paper, a multi-indicator framework is developed that enables decision-makers to proceed with management decisions in data-limited situations. Model-free indicators are calculated using trends in observed data, rather than stock assessment derived estimates of biomass and fishing mortality. The framework developed is adaptive so that adjustments to catch or effort are recursive and can respond to changing environments, socioeconomic conditions, and fishing practices. Using stakeholder-defined objectives as a foundation, indicators and reference points of fishery performance are chosen that can be evaluated easily by undertaking analyses of available data. Indicators from multiple data streams are used so that uncertainty in one indicator can be hedged through careful interpretation and corroboration of information from alternative indicators. During the adaptive management cycle, managers and stakeholders evaluate each indicator against the associated reference points to determine performance measures, interpret the results using scientific and local knowledge, and adjust fishery management tactics accordingly using pre-defined harvest control rules. The framework facilitates the interpretation of situations in which performance measures suggest divergent stock abundance or productivity levels. A case study is presented on this framework's development for conch and lobster fisheries of Belize. •Multiple indicators are used to corroborate interpretation of fishery performance.•Design and implementation of the framework centers around stakeholder engagement.•The framework is flexible to accommodate different data types and capacity for data analysis.•An adaptive management framework was designed for Belize's conch and lobster fisheries

Drivers of conflict and resilience in shifting transboundary fisheries

Climate change is causing fish stocks to shift, upending the social-ecological systems that rely on the historic distributions of these stocks and creating or exacerbating fisheries conflicts. The movements of internationally shared stocks between Exclusive Economic Zones (EEZs) or between EEZs and the high seas are especially concerning because they bring into play a variety of geopolitical factors and equity issues surrounding missing or conflicting regulations of jurisdictional boundary zones. Though many studies have explored the responses to and repercussions of shifting stocks on fisheries management, there is a dearth of interdisciplinary case studies that provide insight into the complexity of conflict formation in shifting transboundary fisheries, and that highlight the initial response stages where inclusion of proactive and cooperative measures can greatly improve a system's resilience to conflict. Our study helps to fill this gap by drawing on the knowledge of a diverse group of experts to analyze four case studies where transboundary stock shifts, geopolitical or governance tensions, and uncertainty regarding the future of the marine environment collide. Through synthesis of case study findings, we create a causal model of fishery conflict, within which we highlight factors that may heighten or mitigate the risk of conflict over shifting resources such as complex histories of power imbalance, unequal access to resources, or a lack of consistent and transparent data collection. Cooperation and equitable decision-making processes are recognized as vital components of internationally shared stock management which can promote lasting, effective, and conflict-resilient fisheries

Drivers of conflict and resilience in shifting transboundary fisheries

Climate change is causing fish stocks to shift, upending the social-ecological systems that rely on the historic distributions of these stocks and creating or exacerbating fisheries conflicts. The movements of internationally shared stocks between Exclusive Economic Zones (EEZs) or between EEZs and the high seas are especially concerning because they bring into play a variety of geopolitical factors and equity issues surrounding missing or conflicting regulations of jurisdictional boundary zones. Though many studies have explored the responses to and repercussions of shifting stocks on fisheries management, there is a dearth of interdisciplinary case studies that provide insight into the complexity of conflict formation in shifting transboundary fisheries, and that highlight the initial response stages where inclusion of proactive and cooperative measures can greatly improve a system's resilience to conflict. Our study helps to fill this gap by drawing on the knowledge of a diverse group of experts to analyze four case studies where transboundary stock shifts, geopolitical or governance tensions, and uncertainty regarding the future of the marine environment collide. Through synthesis of case study findings, we create a causal model of fishery conflict, within which we highlight factors that may heighten or mitigate the risk of conflict over shifting resources such as complex histories of power imbalance, unequal access to resources, or a lack of consistent and transparent data collection. Cooperation and equitable decision-making processes are recognized as vital components of internationally shared stock management which can promote lasting, effective, and conflict-resilient fisheries