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The distributions of migratory species in the ocean span local, national and international jurisdictions. Across these ecologically interconnected regions, migratory marine species interact with anthropogenic stressors throughout their lives. Migratory connectivity, the geographical linking of individuals and populations throughout their migratory cycles, influences how spatial and temporal dynamics of stressors affect migratory animals and scale up to influence population abundance, distribution and species persistence. Population declines of many migratory marine species have led to calls for connectivity knowledge, especially insights from animal tracking studies, to be more systematically and synthetically incorporated into decision-making. Inclusion of migratory connectivity in the design of conservation and management measures is critical to ensure they are appropriate for the level of risk associated with various degrees of connectivity. Three mechanisms exist to incorporate migratory connectivity into international marine policy which guides conservation implementation: site-selection criteria, network design criteria and policy recommendations. Here, we review the concept of migratory connectivity and its use in international policy, and describe the Migratory Connectivity in the Ocean system, a migratory connectivity evidence-base for the ocean. We propose that without such collaboration focused on migratory connectivity, efforts to effectively conserve these critical species across jurisdictions will have limited effect.

Predictive models are central to many scientific disciplines and vital for informing management in a rapidly changing world. However, limited understanding of the accuracy and precision of models transferred to novel conditions (their 'transferability') undermines confidence in their predictions. Here, 50 experts identified priority knowledge gaps which, if filled, will most improve model transfers. These are summarized into six technical and six fundamental challenges, which underlie the combined need to intensify research on the determinants of ecological predictability, including species traits and data quality, and develop best practices for transferring models. Of high importance is the identification of a widely applicable set of transferability metrics, with appropriate tools to quantify the sources and impacts of prediction uncertainty under novel conditions.

Purse‐seine tropical tuna fishing in the eastern tropical Pacific Ocean (EPO) results in the bycatch of several sensitive species groups, including elasmobranchs. Effective ecosystem management balances conservation and resource use and requires considering trade‐offs and synergies. Seasonal and adaptive spatial measures can reduce fisheries impacts on nontarget species while maintaining or increasing target catches. Identifying persistently high‐risk areas in the open ocean, where dynamic environmental conditions drive changes in species' distributions, is essential for exploring the impact of fisheries closures. We used fisheries observer data collected from 1995 to 2021 to explore the spatiotemporal persistence of areas of high bycatch risk for 2 species of oceanic sharks, silky shark (Carcharhinus falciformis) and oceanic whitetip shark (Carcharhinus longimanus), and of low tuna catch rates. We analyzed data collected by fisheries scientific observers onboard approximately 200 large purse‐seine vessels operating in the EPO under 10 different flags. Fishing effort, catch, and bycatch data were aggregated spatially and temporally at 1° × 1° cells and monthly, respectively. When areas of high fishing inefficiency were closed the entire study period and effort was reallocated proportionally to reflect historical effort patterns, yearly tuna catch appeared to increase by 1–11%, whereas bycatch of silky and oceanic whitetip sharks decreased by 10–19% and 9%, respectively. Prior to fishing effort redistribution, bycatch reductions accrued to 21–41% and 14% for silky and oceanic whitetip sharks, respectively. Our results are consistent with previous findings and demonstrate the high potential for reducing elasmobranch bycatch in the EPO without compromising catch rates of target tuna species. They also highlight the need to consider new dynamic and adaptive management measures to more efficiently fulfill conservation and sustainability objectives for exploited resources in the EPO. [ABSTRACT FROM AUTHOR]

Open-ocean fisheries expanded rapidly from the 1960s through the 1980s, when global fish catches peaked, plateaued and possibly began to decline. While catches remain at best stagnant, fishing effort globally continues to increase. The likelihood of ecosystem impacts occurring due to fishing is related to fishing effort and is thus also expected to be increasing. Despite this rapid growth, ecological research into the impacts of fisheries on open-ocean environments has lagged behind coastal and deep-sea environments. This review addresses this knowledge gap by considering the roles fisheries play in controlling the open-ocean at three ecological scales: (i) species (population or stock); (ii) biological community; and (iii) ecosystem. We find significant evidence for top-down control at the species and community scales. While evidence of ecosystem-level impacts in the open-ocean were not explicit in the literature, we provide examples of these impacts in several marine pelagic systems and encourage further research at this ecological scale. At the species level, fishing can reduce abundance, and alter physiology and life history traits, which, in turn, affect the functional role of the species within the biological community. Fishing may also induce changes to open-ocean community trophodynamics, and reduce biodiversity and resilience in open-ocean ecosystems. Our ability to manage open-ocean ecosystems has significant implications for provisioning of ecosystem services and food security. However, we posit that the monitoring required to assure the sustainability of open-ocean ecosystems is not being undertaken, and will require coordination with the Global Ocean Observing System, industry, and academia. [ABSTRACT FROM AUTHOR]

The pelagic stingray Pteroplatytrygon violacea is known to be a frequent by-catch in longline fisheries worldwide. This study analysed the eco-geographic, technical and temporal parameters that affect pelagic stingray by-catch by the Spanish surface drifting longline fleet that operates in the Mediterranean Sea. Between 2000 and 2013, 3007 longline fishing operations were monitored. Over this period, we recorded 57 574 pelagic stingray by-catches by this fleet. Two gear types were involved in 96.05% of the pelagic stingray by-catch observed: traditional surface longliners targeting swordfish (LLHB) and surface drifting longliners targeting albacore (LLALB). We obtained two statistically significant explanatory models for the two types of gear. In both cases, two of the most important variables were fisheries being sited over the continental shelf and fishing during the summer season. The LLHB explanatory model included the following variables: number of hooks, latitude where setting started, distance between the ends of the longline, and the spring season. Regarding the LLHB, we found an association between the Capture per Unit Effort of pelagic stingray from favourable sets per year and the North Atlantic Oscillation in the previous year. [ABSTRACT FROM PUBLISHER]

The article discuses the role of various authorities to improve the global scope of potential Illegal, unreported & unregulated (IUU) fishing. It is reported that the Global Record of Fishing Vessels, Refrigerated Transport Vessels & Supply Vessels is an initiative that aims to provide a single access point for information on vessels used for fishing related activities. It is further reported that an important element for abating IUU activity is to track the activity of all vessels at sea.