Examining ecosystem functioning through the lens of trait diversity serves as a valuable proxy. It offers crucial insights into how exploitation affects the specific ecological roles played by fisheries targeted species. The present study investigates the potential impacts of exploitation on the ecological roles of fish species targeted by fisheries through an examination of trait diversity.
View Article and Find Full Text PDFThe trait-based approach provides a powerful perspective for analyzing fisheries and their potential impact on marine ecological processes, offering crucial insights into sustainability and ecosystem functioning. This approach was applied to investigate trends in fish assemblages landed by both local and coastal fishing fleets in the Azores archipelago over the past four decades (1980s, 1990s, 2000s, and 2010s). A matrix of ten traits was built to assess functional redundancy (Fred), functional over-redundancy (FOve), and functional vulnerability (FVul) for the fish assemblages caught by every fishing fleet in each decade.
View Article and Find Full Text PDFThe brown macroalgae of the species has reached European waters and the Strait of Gibraltar as an invasive species. The proliferation and colonization of the species in subtidal and intertidal zones of these regions imposes significant threats to local ecosystems and additionally represents a significant socioeconomic burden related to the large amounts of biomass accumulated as waste. As a way to minimize the effects caused by the accumulation of algae biomass, investigations have been made to employ this biomass as a raw material in value-added products or technologies.
View Article and Find Full Text PDFMesopelagic organisms play a crucial role in marine food webs, channelling energy across the predator-prey network and connecting depth strata through their diel vertical migrations. The information available to assess mesopelagic feeding interactions and energy transfer has increased substantially in recent years, owing to the growing interest and research activity in the mesopelagic realm. However, such data have not been systematically collated and are difficult to access, hampering estimation of the contribution of mesopelagic organisms to marine ecosystems.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2020
The correct Table 2 is presented in this paper.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2020
It has been emphasized that seafood consumers may have a higher risk of mercury (Hg) exposure. Nevertheless, the co-occurrence of selenium (Se) in organisms may affect the toxicity and bioavailability of Hg. In this work, we aim to demonstrate the possible role of Se as a potential protective element against Hg in muscle and liver tissues of three demersal deep-sea fish species: common mora Mora moro, birdbeak dogfish Deania calcea, and smooth lanternshark Etmopterus pusillus.
View Article and Find Full Text PDFSounds produced by teleost fishes are an important component of marine soundscapes, making passive acoustic monitoring (PAM) an effective way to map the presence of vocal fishes with a minimal impact on ecosystems. Based on a literature review, we list the known soniferous fish species occurring in Azorean waters and compile their sounds. We also describe new fish sounds recorded in Azores seamounts.
View Article and Find Full Text PDFZoological nomenclature revisions are essential for biodiversity studies and indispensable to avoid naming and description of already described species and should be valued in all subsequent studies considering biology, molecular biology, ecology or habitat mapping of deep-sea species. Herein, a thorough revision of the taxonomic literature on Octocorallia since the beginning of deep-sea exploration in the Azores is provided. Since 1870, when the first octocoral, Virgularia mirabilis (Müller, 1776), was recorded in the Azores a cyclic pattern on the taxonomical study of octocorals reveals the deep-sea investigation efforts made on the region at different periods: Prince Albert I of Monaco, Biaçores and recent expeditions.
View Article and Find Full Text PDFSmall-scale artisanal fisheries can have a significant negative impact in cetacean populations. Cetacean bycatch has been documented in the pole-and-line tuna fishery in the Azores with common dolphins being the species more frequently taken. Based on data collected by observers on ∼50% of vessels operating from 1998 to 2012, we investigate the influence of various environmental and fisheries-related factors in common dolphin bycatch and calculate fleet-wide estimates of total bycatch using design-based and model-based methods.
View Article and Find Full Text PDFSharks are a diverse group of mobile predators that forage across varied spatial scales and have the potential to influence food web dynamics. The ecological consequences of recent declines in shark biomass may extend across broader geographic ranges if shark taxa display common behavioural traits. By tracking the original site of photosynthetic fixation of carbon atoms that were ultimately assimilated into muscle tissues of 5,394 sharks from 114 species, we identify globally consistent biogeographic traits in trophic interactions between sharks found in different habitats.
View Article and Find Full Text PDFPopulation genetic studies of species inhabiting the deepest parts of the oceans are still scarce and only until recently we started to understand how oceanographic processes and topography affect dispersal and gene flow patterns. The aim of this study was to investigate the spatial population genetic structure of the bathyal bony fish Coryphaenoides mediterraneus, with a focus on the Atlantic-Mediterranean transition. We used nine nuclear microsatellites and the mitochondrial cytochrome c oxidase I gene from 6 different sampling areas.
View Article and Find Full Text PDFCommon dolphins (Delphinus delphis) are responsible for the large majority of interactions with the pole-and-line tuna fishery in the Azores but the underlying drivers remain poorly understood. In this study we investigate the influence of various environmental and fisheries-related factors in promoting the interaction of common dolphins with this fishery and estimate the resultant catch losses. We analysed 15 years of fishery and cetacean interaction data (1998-2012) collected by observers placed aboard tuna fishing vessels.
View Article and Find Full Text PDFKnowledge of the mechanisms limiting connectivity and gene flow in deep-sea ecosystems is scarce, especially for deep-sea sharks. The Portuguese dogfish (Centroscymnus coelolepis) is a globally distributed and near threatened deep-sea shark. C.
View Article and Find Full Text PDFIt has been speculated that some deep-sea fishes can display large vertical migrations and likely doing so to explore the full suite of benthopelagic food resources, especially the pelagic organisms of the deep scattering layer (DSL). This would help explain the success of fishes residing at seamounts and the increased biodiversity found in these features of the open ocean. We combined active plus passive acoustic telemetry of blackspot seabream with in situ environmental and biological (backscattering) data collection at a seamount to verify if its behaviour is dominated by vertical movements as a response to temporal changes in environmental conditions and pelagic prey availability.
View Article and Find Full Text PDFBottom trawl fishing threatens deep-sea ecosystems, modifying the seafloor morphology and its physical properties, with dramatic consequences on benthic communities. Therefore, the future of deep-sea fishing relies on alternative techniques that maintain the health of deep-sea ecosystems and tolerate appropriate human uses of the marine environment. In this study, we demonstrate that deep-sea bottom longline fishing has little impact on vulnerable marine ecosystems, reducing bycatch of cold-water corals and limiting additional damage to benthic communities.
View Article and Find Full Text PDFIn contrast to generally sparse biological communities in open-ocean settings, seamounts and ridges are perceived as areas of elevated productivity and biodiversity capable of supporting commercial fisheries. We investigated the origin of this apparent biological enhancement over a segment of the North Mid-Atlantic Ridge (MAR) using sonar, corers, trawls, traps, and a remotely operated vehicle to survey habitat, biomass, and biodiversity. Satellite remote sensing provided information on flow patterns, thermal fronts, and primary production, while sediment traps measured export flux during 2007-2010.
View Article and Find Full Text PDFThe present investigation provides an efficient diagnostic method based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis to discriminate between two cryptic species of scabbardfish, Aphanopus carbo and A. intermedius, with commercial relevance in several European fish markets. Two DNA fragments from the mtDNA, including control region and partial cytochrome oxidase subunit I genes of about 1100 bp and 700 bp, respectively, were isolated by PCR amplification.
View Article and Find Full Text PDFWe relate fish biological and ecological characteristics to total and organic mercury concentrations to determine whether accumulation is influenced by trophic level, Hg concentration in the diet, and vertical distribution. Levels of total mercury and methylmercury were determined in the muscle tissue of eight species of fish: Pagellus acarne, Trachurus picturatus, Phycis phycis, P. blennoides, Polyprion americanus, Conger conger, Lepidopus caudatus and Mora moro, caught in the Azores.
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