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This article explores the presence of site fidelity, or philopatry, in blue sharks. While blue sharks are typically known for their wide-ranging movements, this study documents the repeated sightings of two blue sharks at a specific location in the Azores archipelago. The sharks were attracted to the area by local dive operators who regularly provide food. These findings challenge the belief that blue sharks are strictly oceanic wanderers and suggest that they may exhibit some form of site fidelity to predictable feeding areas. The study emphasizes the importance of citizen science and collaboration between scientists and the diving industry in gathering valuable information for the management and conservation of marine migratory species. However, further research using longer-term satellite telemetry is necessary to gain a better understanding of the behavioral ecology of these sharks and its implications for their management and conservation. [Extracted from the article]

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]

Formulae for sediment thresholds of motion are commonly based on flume experiments on rounded quartz particles and it is unclear how well they predict thresholds in natural settings. Here, sediment threshold shear stresses were calculated from one such formula using surface grain‐size data from 112 sites around Santa Maria Island, Azores. To compare with those stresses, a Simulating Waves Nearshore model was run for three typical winter months to predict shelf stress maxima due to waves. As wind‐driven and other circulations also increase stresses, the model predictions are under‐estimates. Comparison of the two stress estimates suggests that the whole shelf of the island was mobile during extreme conditions. However, three forms of evidence contradict this. First, 129 rollovers of sandy clinoforms lying in 30 to 200 m water depths around the island were identified from boomer seismic data. It has been suggested that such rollovers mark depths at which hydrodynamic stresses fall beneath the sediment threshold of motion. Second, differences in grain‐size diversity between carbonate‐free and whole sediment indicate where carbonate particle fragmentation occurs. Third, seabed images reveal variations in ripple character and presence. The combined data suggest that deposition has occurred in the middle and outer shelf, overlapping where the model predicts sediment mobilization. However, by decreasing the model bottom shear stress or increasing the shear stress at threshold of motion by a factor of two to three, deposition is predicted to have occurred immediately deeper than the shallow active rollovers. Therefore, in practice, the ratio of wave‐imposed shear stress to stress at threshold of motion is two to three times smaller than predicted. This is speculated to be due to the presence of widespread hard substrates and other features shielding particles between them from wave stresses. Alternatively, the threshold of motion is higher than expected from the formulae for these sediments dominated by bioclastic particles. [ABSTRACT FROM AUTHOR]

Aggressive behaviour in fishes, particularly in territorial species, is a common trait used to defend resources such as food or mates. Territorial males of the Mediterranean parrotfish Sparisoma cretense have been described to chase away conspecifics yet other aggressive behaviour repertoire has not been reported for this species. We describe, for the first time, an extreme aggressive behaviour between two male Mediterranean parrotfish which includes biting and prolonged mouth locking. [ABSTRACT FROM AUTHOR]

Kelp was first recorded for the remote warm‐temperate Azores archipelago (central North Atlantic) in 1971, when a few Laminaria specimens were collected on the Formigas Bank at depths beyond conventional SCUBA diving reach. A shortage of technical means and projects targeting mesophotic environments has since kept this offshore marine protected area as the single known kelp occurrence site. Here, we present new kelp records collected on previously unexplored mesophotic reefs using remote imaging systems, open‐ and closed‐circuit SCUBA diving, and fisheries bycatch information. The new data extend the known distribution range of kelp in the Azores 350 km to the west and 25 km to the southwest, henceforth including several island shelves in the eastern and central Azores. In addition to the previously recorded Laminaria ochroleuca, kelp specimens with a morphology akin to Phyllariopsis brevipes subsp. brevipes are also reported. For the first time, seabed imagery is used to document the depth‐wise diversity of the Azores kelp beds and their associated biota. Our findings emphasize the poor knowledge that persists in regard to Macaronesia's mesophotic environments located beyond conventional SCUBA diving limits. The new on‐shelf kelp occurrences add conservation value to coastal areas and should facilitate island‐based research. However, their greater proximity to land‐based impacts and exposure to climate change also raise management needs. [ABSTRACT FROM AUTHOR]

The macroalgal flora of the Island of São Miguel (eastern group of the Azores Archipelago) has attracted the interest of many researchers in the past, the first publications going back to the nineteenth century. Initial studies were mainly taxonomic, resulting in the publication of a checklist of the Azorean benthic marine algae. Later, the establishment of the University of the Azores on the Island permitted the logistic conditions to develop both temporal studies and long-term research and this resulted in a significant increase on research directed at the benthic marine algae and littoral communities of the Island and consequent publications. Prior to the present paper, the known macroalgal flora of São Miguel Island comprised around 260 species. Despite this richness, a significant amount of the research was never made public, notably Masters and PhD theses encompassing information regarding presence data recorded at littoral and sublittoral levels down to a depth of approximately 40 m around the Island and the many collections made, which resulted in vouchers deposited in the AZB Herbarium Ruy Telles Palhinha and the LSM-Molecular Systematics Laboratory at the Faculty of Sciences and Technology of the University of the Azores. The present publication lists the macroalgal taxonomic records, together with information on their ecology and occurrence around São Miguel Island, improving the knowledge of the Azorean macroalgal flora at local and regional scales. A total of 12,781 specimens (including some identified only to genus) belonging to 431 taxa of macroalgae are registered, comprising 284 Rhodophyta, 59 Chlorophyta and 88 Ochrophyta (Phaeophyceae). Of these, 323 were identified to species level (212 Rhodophyta, 48 Chlorophyta and 63 Ochrophyta), of which 61 are new records for the Island (42 Rhodophyta, 9 Chlorophyta and 10 Ochrophyta), one an Azorean endemic (Predaea feldmannii subsp. azorica Gabriel), five are Macaronesian endemisms (the red algae Botryocladia macaronesica Afonso-Carrillo, Sobrino, Tittley & Neto, Laurencia viridis Gil-Rodríguez & Haroun, Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico, Phyllophora gelidioides P.Crouan & H.Crouan ex Karsakoff and the green alga Codium elisabethiae O.C.Schmidt), 19 are introduced species (15 Rhodophyta, two Chlorophyta and two Ochrophyta) and 32 are of uncertain status (21 Rhodophyta, five Chlorophyta and six Ochrophyta). [ABSTRACT FROM AUTHOR]

Background: The algal flora of the western group of the Azores archipelago (Islands of Flores and Corvo) has attracted the interest of many researchers on numerous past occasions (such as Drouet 1866, Trelease 1897, Gain 1914, Schmidt 1929, Schmidt 1931, Azevedo et al. 1990, Fralick and Hehre 1990, Neto and Azevedo 1990, Neto and Baldwin 1990, Neto 1996, Neto 1997, Neto 1999, Tittley and Neto 1996, Tittley and Neto 2000, Tittley and Neto 2005, Tittley and Neto 2006, Azevedo 1998, Azevedo 1999, Tittley et al. 1998, Dionísio et al. 2008, Neto et al. 2008). Despite this interest, the macroalgal flora of the Islands cannot be described as well-known with the published information reflecting limited collections preformed in short-term visits by scientists. To overcome this, a thorough investigation, encompassing collections and presence data recording, has been undertaken for both the littoral and sublittoral regions, down to a depth of approximately 40 m, covering a relatively large area on both Islands (approximately 143 km for Flores and 17 km for Corvo). This paper lists the resultant taxonomic records and provides information on species ecology and occurrence around both these Islands, thereby improving the knowledge of the Azorean macroalgal flora at both local and regional scales. New information: For the Island of Flores, a total of 1687 specimens (including some taxa identified only to genus level) belonging to 196 taxa of macroalgae are registered, comprising 120 Rhodophyta, 35 Chlorophyta and 41 Ochrophyta (Phaeophyceae). Of these taxa, 128 were identified to species level (80 Rhodophyta, 22 Chlorophyta and 26 Ochrophyta), encompassing 37 new records for the Island (20 Rhodophyta, 6 Chlorophyta and 11 Ochrophyta); two Macaronesian endemics (Laurencia viridis Gil-Rodríguez & Haroun and Millerella tinerfensis (Seoane-Camba) S.M.Boo & J.M.Rico); six introduced (the Rhodophyta Asparagopsis armata Harvey, Neoizziella divaricata (C.K.Tseng) S.-M.Lin, S.- Y.Yang & Huisman and Symphyocladia marchantioides (Harvey) Falkenberg; the Chlorophyta Codium fragile subsp. fragile (Suringar) Hariot; and the Ochrophyta Hydroclathrus tilesii (Endlicher) Santiañez & M.J. Wynne and Papenfussiella kuromo (Yendo) Inagaki); and 14 species of uncertain status (10 Rhodophyta, two Chlorophyta and two Ochrophyta). For the Island of Corvo, a total of 390 specimens distributed in 56 taxa of macroalgae are registered, comprising 30 Rhodophyta, nine Chlorophyta and 17 Ochrophyta (Phaeophyceae). Whilst a number of taxa were identified only to the genus level, 43 were identified to species level (22 Rhodophyta, eight Chlorophyta and 13 Ochrophyta), comprising 22 new records for the Island (nine Rhodophyta, four Chlorophyta and nine Ochrophyta), two introduced species (the Rhodophyta Asparagopsis armata and the Chlorophyta Codium fragile subsp. fragile and seven species of uncertain status (five Rhodophyta and two Ochrophyta). [ABSTRACT FROM AUTHOR]

Marine ecosystem-based management requires good spatial information on the distribution of marine species and habitats. Often, such information is limited to a few sampled locations, but modelling techniques can be applied to produce predictive distribution maps. A harmonized broad-scale seabed habitat map was recently produced for the archipelagos of Macaronesia under the EMODnet Seabed Habitats Programme. We use this new information to produce an extent-based evaluation of the representativeness and level of protection conferred by the current set of marine protected areas (MPAs) in the Azores to the variety of benthic marine habitats found in this oceanic region. A more objective assessment of the protection effectively provided to the habitats is obtained by applying a scoring system to the MPAs based on the number of allowed extractive and non-extractive human activities and their potential impact on marine biodiversity and habitats. Results show that Azorean habitats within the MPAs are nearly entirely classified as highly protected. In total, 26 habitats (7 of which are endangered and 2 are rare) have at least 10% of their extent in the Azores EEZ protected by MPAs, but another 29 fail to meet this target (4 on-shelf habitats and 25 deep-sea habitats), highlighting the need to extend current protection of bathyal and abyssal habitats and applying adequate ecological coherence criteria. This approach sets a standard that can be used wherever similar information is available, be it in other European regions or beyond. [ABSTRACT FROM AUTHOR]

Broadbill swordfish (Xiphias gladius) is a key species in commercial fisheries, but management efforts continue to be hindered by data gaps in their basic biology, including ongoing debate over stock boundaries and movement between management zones. We deployed 20 pop-up satellite archival transmitting (PSAT) tags on juvenile swordfish in the Azores and adults in the northwest Atlantic (NWA). We applied a recently developed geolocation approach that synthesizes tag data with a global observation-assimilating ocean model to improve geolocation accuracy. Resulting tracks from 16 individuals averaged 3751 km (range 345–7247 km) over 93 days (range 17–181 days). Juveniles tagged in the Azores made regional movements while adults tagged in the NWA moved between summer foraging grounds near the Grand Banks to winter habitats near the Antillean Arc. All individuals spent considerable time in the mesopelagic zone during the day, and this behaviour increased with fish size. We integrate results from our PSAT-based movements with conventional tag and catch-per-unit effort data, which indicates complex stock structure within the North Atlantic that largely supports current stock boundaries. Our work demonstrates the utility in synthesizing fishery-independent electronic tag data and fisheries datasets to improve our understanding of large pelagic fish ecology. [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.)

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]

The Azores (mid-north Atlantic) has a long history of artisanal multispecific fishery exploiting marine resources around the islands slopes and seamounts. Due to the archipelago´s oceanic character, demersal-deep-sea and pelagic-offshore species are central to local economy. However, a coastal subsistence fishery is also economically and culturally important, as well as understudied, underregulated and, up to the present, lacking independent monitoring. A Productivity and Susceptibility Analysis (PSA) was applied to determine stock vulnerability of 38, criteriously selected, coastal species. The PSA identified 20 stocks of concern (3 of which at major risk), thus considered of (high) priority to benefit from a precautionary management approach, at least until more quantitative stock assessments are developed in the future. All of these species generally share (1) a considerable basic knowledge gap (e.g., demography, trophic links, reproduction, habitat use, fisheries); and (2) the absence of previous formal stock assessments, resulting in unknown current population status. Such gaps become graver considering that most of these coastal resources show patterns consistent with progressive signs of intensive or even overexploitation, due to the intensification of combined pressure from the commercial and recreational coastal fishing dating back as early as the 1980's. As such, we propose an ecosystem-based framework for the regular monitoring, assessment and guidelines for general management of these data-poor coastal resources and fisheries in the region. [ABSTRACT FROM AUTHOR]

The archipelago of the Azores (mid-north Atlantic Ocean) is an outermost region of the European Union (EU) in which small-scale fisheries are a strong component of the local economy. Bottom longlining and handlining are the most important Azorean fisheries in landing values, fishing vessels and fishers. Despite their high selectivity and low discards, these fisheries can be highly impacted by the implementation of the Landing Obligation (LO). Semi-structured interviews were conducted with Azorean small-scale fishers to document their perceptions about discards and the LO, and to ascertain the mitigation measures they already implement or could further implement to avoid unwanted catch. Results suggest that most fishers strongly oppose the LO, perceiving it as inadequate to their fisheries. Several discard avoidance measures are already commonly used by most fishers, of which hook size and changing areas where there are too many undersized or over-quota individuals, are believed to be the most efficient. Additional measures to further improve selectivity and avoid unwanted catch appear limited. The recent conversion of many bottom longliners to handlining and the exemptions foreseen as part of the LO for the region might help Azorean fishers to mitigate the potential impacts of the LO. • Fishers' perceptions about the LO and potential mitigation measures were appraised. • Most fishers strongly opposed the LO, perceived as inappropriate to their fisheries. • Hook size and changing areas are already commonly used to avoid unwanted catch. • Conversion of longliners to handliners might help mitigate the impacts of the LO. • Options to further improve selectivity and avoid unwanted catch seem limited. [ABSTRACT FROM AUTHOR]