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Deep-water sharks are highly diverse, vulnerable, and understudied as a group, despite the increasing pressures on their populations. Twenty-five species of deep-water sharks have been recorded in the Azores, an oceanic archipelago in the mid-North Atlantic, that are regularly caught as bycatch in hook-and-line fisheries. Avoiding the bycatch of deep-water sharks presents multiple challenges due to their high catchability, difficulties in correctly identifying species, and the general lack of data on these species. This review summarizes the findings of recent studies from the region, providing an up-to-date science-based framework for mitigating bycatch effects of Azorean hook-and-line fisheries. Several depth-based, area-based, and gear-based measures have been studied that demonstrate the potential to either avoid or increase the survival of deep-water shark bycatch. However, these measures may have limited efficacy for some species (e.g. highly mobile species) and thus, limited widespread applicability. Convincing fishers to avoid deep-water shark bycatch is also a challenge given the antagonistic interactions with sharks damaging the catch and fishing gear, while simultaneously a market incentive for shark liver oil remains. It highlights the need to proactively engage fishers and incentivize the mitigation of bycatch of deep-water sharks in Azorean waters. [ABSTRACT FROM AUTHOR]

The pencil cardinal Epigonus denticulatus is a small deep‐water fish inhabiting continental slopes usually between 300 and 600 m depth. We report the first record of E. denticulatus in the Azores archipelago, where one specimen was found floating by fisherman off Faial island. Meristic and morphometric characters are in accordance with those reported for the species and molecular analyses further supported species identity. The record of E. denticulatus as a native species in the Azores increases the number of Epigonus species in the region to a total of three. [ABSTRACT FROM AUTHOR]

The presence of the opal chimaera, Chimaera opalescens, is reported for the first time in the deep waters of the Azores, with the capture of four specimens by fishermen and the video recording of an additional five individuals. Species identification was supported by the 646 bp sequenced fragment of the mitochondrial gene cytochrome oxidase subunit I. Because C. opalescens is a recently recognised species that had been recurrently misidentified as rabbitfish, Chimaera monstrosa, the historical data of C. monstrosa in the Azores were reviewed to assess the possible presence of both Chimaera species in the region. Although several authors have reported the occurrence of C. monstrosa in the Azorean waters since the 1800s, the majority of these are based on only three specimens caught during the late 1800s. The investigation performed using literature and examination of the museum specimens still available concluded that the most likely scenario is that C. monstrosa is absent from the Azores and past records of that species in the region are most likely misidentifications of C. opalescens. [ABSTRACT FROM AUTHOR]

The long-term provision of ecosystem goods and services depends on the operationalisation of ecosystem-based management approaches that ensure effective conservation and sustainable use of marine resources. This management challenge is addressed internationally through two United Nations instruments: Sustainable Development Goal (SDG) 14 - Life Below Water, and the Convention on the Law of the Sea (UNCLOS) for the Conservation and Sustainable Use of Marine Biological Diversity in Areas Beyond National Jurisdiction (BBNJ Agreement). To achieve sustainability and conservation goals as described in SDG 14 and the BBNJ Agreement, a combination of management tools, including area-based management tools (ABMTs), is necessary. Spatially explicit ecosystem models can inform policy frameworks by enabling ecosystem-wide assessments of ABMTs with indicators that track their management performance. However, the operational use of these complex models depends on the confidence and uncertainty of their predictions. Here, we present a framework to systematically evaluate the performance of a spatially explicit ecosystem model for deep-sea and open-ocean environments, using the ecosystem model for the EEZ of the Azores (NE Atlantic, Portugal) as a case study. The systematic approach aimed to determine the model's suitability as a tool to inform area-based management in the deep-sea. The framework was applied to Ecospace, the spatial-temporal module of the ecological modelling suite Ecopath with Ecosim. It consisted of a stepwise approach for model development and assessment through key parameterisation steps. The steps served for calibration of model parameter values and formal evaluation of temporal and spatial results against the best available reference data. Overall, this approach proved useful in identifying key model sensitivities and sources of uncertainty that arise when considering spatial variability in trophodynamics in the ecosystem model. Moreover, we concluded the model i) effectively predicted the observed inter-annual variability of benthic fish stocks in response to fisheries, trophic interactions, and environmental factors and ii) showed good and moderate spatial goodness-of-fit in replicating reference spatial distribution patterns of stocks and fishing activities. Despite its strengths, the spatial model has limitations related to uncertainties in model parameterisation and the spatial variability of trophodynamics. The systematic assessments presented in this study provide a framework for future model applications to predict the ecosystem-wide impacts of alternative spatial management measures in the deep-sea. • We systematically evaluate a spatially explicit ecosystem model for the Azores EEZ. • The approach identified key sensitivities and sources of model uncertainty. • The model has an adequate goodness-of-fit to temporal and spatial reference data. • The model is an important tool to inform area-based management for the deep-sea. [ABSTRACT FROM AUTHOR]

Marine ecotourism is a pivotal sector in the blue economy strategies of many nations and is a vital economic activity for peripheral coastal regions and islands; yet a comprehensive understanding of its socioeconomic importance remains poorly quantified due to a lack of systematic evidence collation. This is even more pronounced when compared with other traditional marine activities (i.e. commercial fisheries), which are the target of monitoring programs that span several decades. The paucity of information on marine ecotourism and the disproportionate influence of traditional activities in decision-making arenas represent a practical impediment to promoting the broader agenda of blue growth and ecosystem-based management for Europe's regional seas. This study presents an assessment of the socioeconomic impact of non-extractive recreational activities closely associated with marine biodiversity (i.e. whale watching, diving and big game fishing) in one of Europe's outermost regions: the Azores archipelago (northeast Atlantic). Data were collected through a series of questionnaire surveys of the clients (n = 1740) and managers of marine-tourism businesses (n = 49). Our results suggest that in 2014 approximately 17% of total visitors to the Azores engaged in marine ecotourism activities generating approximately 80€ million in total expenditures to the regional economy (2.2% of regional Gross Domestic Product). Results also indicate that on average a typical marine ecotourist has longer stay and higher expenditure pattern compared to other visitors. These values add a new dimension to arguments in support of marine conservation and call attention to the comprehensive integration of marine ecotourism activities in management plans. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Arquipélago. Life & Marine Sciences / Ciencias Biológicas e Marinhas is the property of Universidade dos Acores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Arquipélago. Life & Marine Sciences / Ciencias Biológicas e Marinhas is the property of Universidade dos Acores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The recognition that deep-water sharks are among the most vulnerable marine species to fisheries exploitation led to the implementation of fishing prohibition regulations in European waters. Reducing unwanted bycatch and mortality are key fisheries mitigation measure for the conservation of these species. Yet, few studies have investigated how to mitigate the common bycatch of these sharks on deep-water longline fisheries. Specifically, the potential of hook type as such a measure has never been investigated. Here, we conducted fishing experiments to test how circle hooks affect the catchability, the hooking position, and the overall condition of deep-water sharks, in comparison to the commonly used J-hooks in the Azores bottom longline fishery. We found that circle hooks did not significantly reduce deep hooking (throat or gut hooked), nor improve the overall condition of captured sharks, while the catchability of deep-water sharks on circle hooks was greater than on the J-hooks currently used in the local fishery. As such, circle hooks do not appear as a suitable measure to reduce deep-water shark bycatch and increase survival potential in deep-water longlining. Despite deep hooking being rare for the deep-water sharks caught with both hook types in the experiments, at-vessel mortality was still substantial (around 40%). Post-release survival remains mostly unquantified but preliminary results suggest it could also be high. This study highlights the urgent need for continued research addressing bycatch mitigation measures for deep-water sharks and identifying efficient strategies to reduce bycatch and increase survival. • We tested circle hook as potential bycatch mitigation measure for deep-water sharks. • Circle hooks resulted in higher catch of deep-water sharks than J-hooks. • Circle hooks did not reduce deep hooking nor improve deep-water shark condition. • Circle hooks did not appear suited to mitigate deep-water shark bycatch in longlines. • Alternative measures to reduce bycatch and improve survival are still much needed. [ABSTRACT FROM AUTHOR]

Elasmobranchs inhabiting depths beyond 200 m are extremely susceptible to overexploitation but are extracted by fisheries around the world either as target species or as bycatch. There is little information available to formulate management strategies to reduce elasmobranch-fishery interactions in the deep sea. In European Union waters, prohibiting the catches of deep-sea elasmobranchs has provided the necessary impetus to study by-catch avoidance of these threatened species. We used over 20 years of fisheries-independent and fisheries-dependent data to model the spatial distribution of 15 species of deep-sea elasmobranchs (12 sharks and 3 rays) captured frequently in the Exclusive Economic Zone of the Azores Archipelago (Mid-Atlantic Ridge) to explore spatial management to reduce unwanted catches of these species. We applied Generalised Additive Models to predict the probability of presence of 15 species, as well as the abundance of 6 of those species, within the Azores EEZ and neighbouring seamounts (up to 2000 m depth), using environmental and operational variables as predictors. Our results identified that depth is most influential in determining the distribution of these sharks and rays, in addition to seafloor topography. Distinctive bathymetric features such as seamounts and ridges were highlighted as areas where the probability of presence of the greatest number of species overlapped. Although not related to habitat, gear type influenced the capture probability of certain species, with the artisanal handline, gorazeira , having lower captures than bottom longline. Our results support using depth-based, area-based, and gear-based tactics to design management measures to reduce elasmobranch bycatch, for more sustainable deep-sea fisheries. [Display omitted] • Most frequently captured deep-sea elasmobranchs modelled in the Azores using delta GAMs. • Spatial distribution predictions can be used to reduce bycatch of 15 sharks and rays. • Depth and seafloor topography important predictors. Lower catch on handline than longline. • Maximum species richness predicted around seamounts and ridges. • Inform area and gear-based management that can balance species conservation and fisheries. [ABSTRACT FROM AUTHOR]