RESUMO
A specimen of tripletail Lobotes surinamensis (total length: 402 mm, total mass: 1262 g) was caught in the shallow waters of the inner Bristol Channel on September 2, 2019, with this only the second known capture of this species from the British Isles. Given the cosmopolitan distribution of this species, the potential origin of this specimen is uncertain.
Assuntos
Perciformes , Animais , Reino Unido , Fatores de TempoRESUMO
Morphological similarities between skates of the genus Dipturus in the north-eastern Atlantic and Mediterranean have resulted in longstanding confusion, misidentification and misreporting. Current evidence indicates that the common skate is best explained as two species, the flapper skate (Dipturus intermedius) and the common blue skate (D. batis). However, some management and conservation initiatives developed prior to the separation continue to refer to common skate (as 'D. batis'). This taxonomic uncertainty can lead to errors in estimating population viability, distribution range, and impact on fisheries management and conservation status. Here, we demonstrate how a concerted taxonomic approach, using molecular data and a combination of survey, angler and fisheries data, in addition to expert witness statements, can be used to build a higher resolution picture of the current distribution of D. intermedius. Collated data indicate that flapper skate has a more constrained distribution compared to the perceived distribution of the 'common skate', with most observations recorded from Norway and the western and northern seaboards of Ireland and Scotland, with occasional specimens from Portugal and the Azores. Overall, the revised spatial distribution of D. intermedius has significantly reduced the extant range of the species, indicating a possibly fragmented distribution range.
Assuntos
Rajidae , Animais , Rajidae/anatomia & histologia , Irlanda , Portugal , Escócia , PesqueirosRESUMO
Anarhichas lupus is a boreo-Arctic species with biological characteristics often associated with vulnerability to overexploitation. Although not commercially targeted in the North Sea, A. lupus is a bycatch species in mixed demersal fisheries. Here we provide an overview of the status of A. lupus in the North Sea, as observed from commercial landings and fishery-independent trawl survey data. A. lupus was once common across much of the central and northern North Sea but, since the 1980s, have declined in abundance, demographic characteristics (reduced size) and geographical range, with the shallower and more southerly parts of its range most impacted. A. lupus is still relatively frequent in the northern North Sea, where fishing intensity, though decreasing, is high. Bycatch through fishing remains a potential threat and, considering the likely impacts of predicted climate change on cold-water species, risks of further regional depletion and/or range contraction remain. Whether or not A. lupus is able to re-establish viable populations in former habitat in UK coastal waters is unknown. Given the lack of data, the precautionary principle would suggest that manageable pressures be minimized where the species and its habitat are at risk of further impacts, and more regular assessments of population status be undertaken.
Assuntos
Mudança Climática , Caça , Animais , Ecossistema , Pesqueiros , Mar do NorteRESUMO
Saxitoxins (STXs) are a family of potent neurotoxins produced naturally by certain species of phytoplankton and cyanobacteria which are extremely toxic to mammalian nervous systems. The accumulation of STXs in bivalve molluscs can significantly impact animal and human health. Recent work conducted in the North Sea highlighted the widespread presence of various saxitoxins in a range of benthic organisms, with the common sunstar (Crossaster papposus) demonstrating high concentrations of saxitoxins. In this study, an extensive sampling program was undertaken across multiple seas surrounding the UK, with 146 starfish and 5 brittlestars of multiple species analysed for STXs. All the common sunstars analysed (n > 70) contained quantifiable levels of STXs, with the total concentrations ranging from 99 to 11,245 µg STX eq/kg. The common sunstars were statistically different in terms of toxin loading to all the other starfish species tested. Two distinct toxic profiles were observed in sunstars, a decarbomylsaxitoxin (dcSTX)-dominant profile which encompassed samples from most of the UK coast and an STX and gonyautoxin2 (GTX2) profile from the North Yorkshire coast of England. Compartmentalisation studies demonstrated that the female gonads exhibited the highest toxin concentrations of all the individual organs tested, with concentrations >40,000 µg STX eq/kg in one sample. All the sunstars, male or female, exhibited the presence of STXs in the skin, digestive glands and gonads. This study highlights that the common sunstar ubiquitously contains STXs, independent of the geographical location around the UK and often at concentrations many times higher than the current regulatory limits for STXs in molluscs; therefore, the common sunstar should be considered toxic hereafter.
Assuntos
Toxinas Marinhas/análise , Neurotoxinas/análise , Saxitoxina/análise , Estrelas-do-Mar , Animais , Organismos Aquáticos , Intoxicação por Frutos do MarRESUMO
Angel sharks (Squatina spp.) are distributed in warm temperate to tropical waters around the world. Many species occur in shelf seas and exhibit seasonal inshore-offshore migrations, moving inshore to give birth. Consequently, there can be high spatial overlap of angel shark populations with fisheries and other human activities. Their dorso-ventrally flattened body shape, large size (most species attain >100 cm total length, LT ) and demersal nature means that they may be taken in a variety of demersal fishing gears from birth. Available data indicate that angel sharks typically have a biennial reproductive cycle, with litter sizes generally <20 and the young born at c. 20-30 cm. The biological characteristics of angel sharks render them susceptible to overexploitation, as exemplified by the decline of Squatina squatina from many parts of its former range in the north-east Atlantic and Mediterranean Sea. Currently, half of the 22 recognized extant species of angel shark are classed as Threatened on the International Union for Conservation of Nature (IUCN) Red List (with a further three classified as Data Deficient). Given the biological vulnerability of angel sharks, and that many species are data-limited, the current paper provides a review of available biological information and fisheries data pertaining to this family.
Assuntos
Conservação dos Recursos Naturais , Tubarões/fisiologia , Distribuição Animal , Animais , Conservação dos Recursos Naturais/tendências , Pesqueiros , Atividades Humanas , Mar Mediterrâneo , Reprodução/fisiologiaRESUMO
In early 2018, a large easterly storm hit the East Anglian coast of the UK, colloquially known as the 'Beast from the East', which also resulted in mass strandings of benthic organisms. There were subsequent instances of dogs consuming such organisms, leading to illness and, in some cases, fatalities. Epidemiological investigations identified paralytic shellfish toxins (PSTs) as the cause, with toxins present in a range of species and concentrations exceeding 14,000 µg STX eq./kg in the sunstar Crossaster papposus. This study sought to better elucidate the geographic spread of any toxicity and identify any key organisms of concern. During the summers of 2018 and 2019, various species of benthic invertebrates were collected from demersal trawl surveys conducted across a variety of locations in the North Sea. An analysis of the benthic epifauna using two independent PST testing methods identified a 'hot spot' of toxic organisms in the Southern Bight, with a mean toxicity of 449 µg STX eq./kg. PSTs were quantified in sea chervil (Alcyonidium diaphanum), the first known detection in the phylum bryozoan, as well as eleven other new vectors (>50 µg STX eq./kg), namely the opisthobranch Scaphander lignarius, the starfish Anseropoda placenta, Asterias rubens, Luidia ciliaris, Astropecten irregularis and Stichastrella rosea, the brittlestar Ophiura ophiura, the crustaceans Atelecyclus rotundatus and Munida rugosa, the sea mouse Aphrodita aculeata, and the sea urchin Psammechinus miliaris. The two species that showed consistently high PST concentrations were C. papposus and A. diaphanum. Two toxic profiles were identified, with one dominated by dcSTX (decarbamoylsaxitoxin) associated with the majority of samples across the whole sampling region. The second profile occurred only in North-Eastern England and consisted of mostly STX (Saxitoxin) and GTX2 (gonyautoxin 2). Consequently, this study highlights widespread and variable levels of PSTs in the marine benthos, together with the first evidence for toxicity in a large number of new species. These findings highlight impacts to 'One Health', with the unexpected sources of toxins potentially creating risks to animal, human and environmental health, with further work required to assess the severity and geographical/temporal extent of these impacts.
Assuntos
Organismos Aquáticos/química , Saxitoxina/análogos & derivados , Intoxicação por Frutos do Mar , Animais , Crustáceos/química , Monitoramento Ambiental , Mar do Norte , Saxitoxina/análise , Ouriços-do-Mar/química , Estrelas-do-Mar/químicaRESUMO
The stomach contents of 640 starry smooth-hound Mustelus asterias from the north-east Atlantic were examined. The diet was dominated by crustaceans (98.8% percentage of index of relative importance, %IRI), with the two main prey species being hermit crab Pagurus bernhardus (34% IRI) and flying crab Liocarcinus holsatus (15% IRI). Ontogenetic dietary preferences showed that smaller individuals [20-69 cm total length (LT ) n = 283] had a significantly lower diversity of prey than larger individuals (70-124 cm LT , n = 348); however, 18 prey species were found exclusively in smaller individuals and eight prey taxa were found exclusively in larger individuals. Larger commercially important brachyurans such as edible crab Cancer pagurus and velvet swimming crab Necora puber were more prevalent in the diet of larger individuals. Specimens from the North Sea ecoregion had a lower diversity of prey types for a given sample size than fish from the Celtic Seas ecoregion. Whilst cumulative prey curves did not reach an asymptote, this was primarily due to the high taxonomic resolution utilized and 95% of the diet was described by just seven crustacean taxa. The trophic level (TL) was calculated as 4.34 when species-level prey categories were used. This fine-scale taxonomic resolution resulted in a TL estimate close to a whole level above that estimated using wider taxonomic groupings. This large bias has important methodological implications for TL studies based on categorized prey data, particularly those of predatory fish.
Assuntos
Dieta , Elasmobrânquios/fisiologia , Cadeia Alimentar , Animais , Crustáceos , Comportamento Alimentar/fisiologia , Conteúdo Gastrointestinal , Mar do Norte , Estado Nutricional , Oceanos e Mares , Comportamento Predatório/fisiologiaRESUMO
At-sea observer programmes can provide spatio-temporal data on the sizes and quantities of fish being either discarded or retained, including for species and size categories that may not be sampled effectively during scientific surveys. Such data were analysed for English and Welsh fisheries operating on the continental shelf of the North Sea ecoregion (ICES Divisions 4a-c and 7d) and Celtic Seas ecoregion (ICES Divisions 6a, 7a-c, e-k) for the period (2002-2016). These data were collated for four main gear types: beamtrawl, nephrops and otter trawls, and nets (including gillnets, tangle nets and trammel nets). Beamtrawlers caught proportionally more smaller individuals than otter trawlers, whilst nets were the most size-selective gear for larger sharks. Size-related discarding was observed, with smaller spurdog Squalus acanthias and starry smooth-hound Mustelus asterias (< 60 cm total length, LT ) usually being discarded. Such size-based selection was not evident for lesser-spotted dogfish Scyliorhinus canicula, which was generally landed as bait. Temporal changes in the discard-retention patterns were evident for S. acanthias and porbeagle Lamna nasus, with increased regulatory discarding as management measures became restrictive. A corresponding increase in the proportion of the non-quota M. asterias retained was also observed over the study period. Knowledge of the size-based discard-retention patterns by métier can also help inform on where future studies on discard survival could usefully be undertaken.
Assuntos
Pesqueiros/estatística & dados numéricos , Tubarões , Animais , Oceano Atlântico , Cação (Peixe) , Inglaterra , Mar do Norte , Squalus , País de GalesRESUMO
How have North Sea skate and shark assemblages changed since the early 20th century when bottom trawling became widespread, whilst their environment became increasingly impacted by fishing, climate change, habitat degradation and other anthropogenic pressures? This article examines long-term changes in the distribution and occurrence of the elasmobranch assemblage of the southern North Sea, based on extensive historical time series (1902-2013) of fishery-independent survey data. In general, larger species (thornback ray, tope, spurdog) exhibited long-term declines, and the largest (common skate complex) became locally extirpated (as did angelshark). Smaller species increased (spotted and starry ray, lesser-spotted dogfish) as did smooth-hound, likely benefiting from greater resilience to fishing and/or climate change. This indicates a fundamental shift from historical dominance of larger, commercially valuable species to current prevalence of smaller, more productive species often of low commercial value. In recent years, however, some trends have reversed, with the (cold-water associated) starry ray now declining and thornback ray increasing. This shift may be attributed to (i) fishing, including mechanised beam trawling introduced in the 1960s-1970s, and historical target fisheries for elasmobranchs; (ii) climate change, currently favouring warm-water above cold-water species; and (iii) habitat loss, including potential degradation of coastal and outer estuarine nursery habitats. The same anthropogenic pressures, here documented to have impacted North Sea elasmobranchs over the past century, are likewise impacting shelf seas worldwide and may increase in the future; therefore, parallel changes in elasmobranch communities in other regions are to be expected.
Assuntos
Mudança Climática , Oceanos e Mares , Tubarões/crescimento & desenvolvimento , Rajidae/crescimento & desenvolvimento , Animais , Pesqueiros , Mar do NorteRESUMO
Sports participation is a leading cause of catastrophic cervical spine injury (CSI) in the United States. Appropriate prehospital care for athletes with suspected CSIs should be available at all levels of sport. Planning the process of transport for home venues before the start of the season and ensuring that a medical time out occurs at home and away games can reduce complications of transport decisions on the field of play and expedite transport of the spine-injured athlete.
Assuntos
Traumatismos em Atletas , Traumatismos da Coluna Vertebral , Humanos , Estados Unidos/epidemiologia , Traumatismos em Atletas/diagnóstico , Traumatismos em Atletas/terapia , Traumatismos da Coluna Vertebral/diagnóstico , Traumatismos da Coluna Vertebral/terapia , Transporte de Pacientes , Vértebras Cervicais/lesões , Exame FísicoRESUMO
Mercury (Hg) is a non-essential metal that can have toxic effects on the fitness of organisms and tends to bioaccumulate with age and to biomagnify in higher trophic levels. Few studies have assessed oxidative stress and neurotoxicity in deep-water sharks. This study evaluated early ontogenetic changes and physiological effects (antioxidant defences, oxidative damage, aerobic metabolism and neurotransmission functions) of Hg accumulation in the white muscle and brain tissues of the velvet belly lantern shark Etmopterus spinax from the southern Iberian coast (NE Atlantic). Results suggested that the low mercury concentrations observed may induce acute effects in E. spinax before they reach sexual maturity. We found different Hg concentrations in E. spinax: [Hg] males > [Hg] females; [Hg] muscle > [Hg] brain. Females appeared to have higher redox capability translated into higher activities and levels of antioxidant defences than males. However, higher levels of oxidative damage were also observed in females. Whilst the mechanisms underlying these effects remain unknown, these results suggest differences in mercury accumulation between tissues and sex, and potentially deleterious effects on oxidative stress status and neurophysiology of E. spinax, potentially impairing swimming performance and reproduction, which could subsequently impact on the health of both individuals and population.
Assuntos
Mercúrio , Tubarões , Poluentes Químicos da Água , Animais , Bioacumulação , Feminino , Masculino , Mercúrio/análise , Mercúrio/toxicidade , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Many sharks and skates are particularly vulnerable to overfishing because of their large size, slow growth, late maturity and low fecundity. In Europe dramatic population declines have taken place in common skate (Dipturus batis L.), one of the largest demersal fish in regional shelf seas, leading to extirpations from substantial parts of its former range. Here we report the discovery of cryptic species in common skate collected from the northeast Atlantic continental shelf. Data from nuclear microsatellite markers indicated two clearly distinct clades and phylogenetic analysis of mitochondrial DNA sequences demonstrated monophyly of each one of them. Capture locations showed evidence of strong spatial segregation, with one taxon occurring mainly in waters off the southern British Isles and around Rockall, while the other was restricted to more northerly shelf waters. These apparently cryptic species showed overlapping substrate and depth preferences, but distributional limits were closely related to temperature gradients, potentially indicating thermal limits to their distributions. This discovery of hidden diversity within a large, critically endangered marine vertebrate demonstrates how marine biodiversity can be underestimated, even in such a relatively well-studied and heavily exploited region.
Assuntos
Espécies em Perigo de Extinção , Repetições de Microssatélites/genética , Rajidae , Animais , Biodiversidade , Núcleo Celular/genética , DNA Mitocondrial/genética , Europa (Continente) , Genética Populacional , Oceanos e Mares , Filogenia , Análise de Sequência de DNA , Rajidae/classificação , Rajidae/genética , Especificidade da EspécieRESUMO
Many people in the Abbeyfield survey (Nursing Older People. 22, 6, 4) associated holding hands exclusively with romance. Perhaps few of them had experienced any kind of relationship with people with dementia. Holding hands is a vital mode of communication and more eloquent than words for many people in the moderate and advanced stages of the disease.
RESUMO
Commercial landings of starry smooth-hound Mustelus asterias in northern European seas are increasing, whilst our knowledge of their ecology, behaviour and population structure remains limited. M. asterias is a widely distributed demersal shark, occupying the waters of the southern North Sea and Irish Sea in the north, to at least the southern Bay of Biscay in the south, and is seasonally abundant in UK waters. There are no species-specific management measures for the northeast Atlantic stock, and the complexity of its population structure is not yet fully understood. To address this issue, we deployed both mark-recapture and electronic tags on M. asterias to gain novel insights into its horizontal and vertical movements. Our data suggest that the habitat use of M. asterias changes on a seasonal basis, with associated changes in geographical distribution, depth utilisation and experienced temperature. We report the first direct evidence of philopatry for this species, and also provide initial evidence of sex-biased dispersal and potential metapopulation-like stock structuring either side of the UK continental shelf. Investigations of finer-scale vertical movements revealed clear diel variation in vertical activity. The illustrated patterns of seasonal space-use and behaviour will provide important information to support the stock assessment process and will help inform any future management options.
Assuntos
Movimento , Tubarões , Migração Animal , Animais , Oceano Atlântico , Conservação dos Recursos Naturais , TemperaturaRESUMO
Reliable descriptions of the status of offshore seabed habitats usually require substantial investment in field data collection and sample analysis. While assessment of, for example, biogenic reef habitat can often include simple physical parameters (e.g. spatial extent), comparative measures for soft sediment habitats generally rely on the distribution and relative abundance of species, with a description of the associated sedimentary environment. To investigate the power of surveys to detect significant trends in assemblage structure, samples of meiofauna, macroinfauna and megafauna (i.e. representing ecological components from nematodes to demersal fish), were collected from four offshore mud and sand habitat sites in western UK shelf seas during July 2004 and 2005. Spatial arrays of samples within these sites, up to 23 km apart, were designed to optimise descriptions of assemblage structure and the patterns of spatial distribution at a local scale. Analyses of species abundance, biomass and taxonomic relatedness of the species complement at each site suggested that most assemblages represented relatively unimpacted regional conditions. The power of the sampling programme to detect a significant change in univariate community attributes was assessed. The variability in many of the community attributes indicated that intensive replicate sampling would be required to detect ecologically important changes. Improving the power of such benthic surveys to detect trends would therefore require substantial additional time and effort to be invested in sample collection and analysis. Resource analysis showed that the time from gear deployment to complete sample identification was gear-dependent, lowest per sample for meiofauna (10h) and megafauna (6-12h), and highest for macroinfauna (12-22 h). These results have implications for the development of meaningful indicators of habitat status for offshore soft sediment habitats, and the resources required for effective monitoring of change.
Assuntos
Biodiversidade , Monitoramento Ambiental/métodos , Peixes , Sedimentos Geológicos , Invertebrados , Animais , Oceanos e Mares , Densidade Demográfica , Dióxido de SilícioRESUMO
The pilot project described here took the form of action research, focusing on dementia awareness education for nurses on acute wards and in accident and emergency departments. An essential feature of the educational package was the involvement of four carers, each of whom described specific experiences. Their accounts were recorded on DVD and presented in the education sessions, which the carers also attended to add comments and answer questions. Feedback from the nurses was positive with all of them claiming new awareness and understanding of patient and carer needs. The education sessions are to be continued with other nurses.
Assuntos
Atitude do Pessoal de Saúde , Demência/enfermagem , Educação Continuada em Enfermagem/organização & administração , Avaliação das Necessidades/organização & administração , Recursos Humanos de Enfermagem Hospitalar , Idoso , Atitude Frente a Saúde , Enfermagem Geriátrica/educação , Conhecimentos, Atitudes e Prática em Saúde , Pesquisa sobre Serviços de Saúde , Humanos , Pesquisa em Educação em Enfermagem , Pesquisa Metodológica em Enfermagem , Recursos Humanos de Enfermagem Hospitalar/educação , Recursos Humanos de Enfermagem Hospitalar/psicologia , Projetos Piloto , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Inquéritos e QuestionáriosRESUMO
Trace metal concentrations in muscle and liver tissues from two offshore species of skate were examined. Concentrations of mercury in muscle of Leucoraja circularis (n=20; 23-110.5cm total length, 157-490m water depth) and L. fullonica (n=24; 28.5-100cm total length, 130-426m water depth) were 0.02-1.8 and 0.04-0.61mgkg-1, respectively. Concentrations of both As and Hg increased with total length. Only the largest specimen had a concentration of Hg in muscle >1.0mgkg-1. Data were limited for specimens>90cm long, and further studies on contaminants in larger-bodied skates could usefully be undertaken.
Assuntos
Mercúrio/análise , Metais/análise , Rajidae/metabolismo , Poluentes Químicos da Água/análise , Animais , Arsênio/análise , Fígado/química , Músculos/química , Oceanos e Mares , Oligoelementos/análiseRESUMO
Updated descriptions and measurements for the eggcases of 10 rajiform and three scyliorhinid species occurring in the shelf seas around the British Isles are given, based on museum material, specimens collected during the 'Great Eggcase Hunt' (a Shark Trust recording project), and specimens obtained from fishery surveys. Quantitative data are given for Amblyraja radiata (n = 94), Dipturus batis (n = 24), D. cf. intermedia (n = 33), Leucoraja naevus (n = 94), Raja brachyura (n = 53), R. clavata (n = 52), R. microocellata (n = 57), R. montagui (n = 52), R. undulata (n = 52), Rostroraja alba (n = 5), Galeus melastomus (n = 7), Scyliorhinus canicula (n = 52) and S. stellaris (n = 58). An updated key for the identification of elasmobranch eggcases is provided, incorporating recent changes in skate taxonomy.
Assuntos
Elasmobrânquios/anatomia & histologia , Elasmobrânquios/classificação , Embrião não Mamífero/anatomia & histologia , Animais , Oceano Atlântico , Feminino , Rajidae/anatomia & histologia , Rajidae/classificação , Reino UnidoRESUMO
Concentrations of 11 trace elements in three tissues of porbeagle shark Lamna nasus (n=33) were determined. The maximum observed concentrations of Cd and Pb in muscle were 0.04 and 0.01mgkg-1, respectively, and all muscle samples were below European seafood limits for these metals. Hg concentrations in either the red or white muscle that exceeded European regulations for seafood were observed in one-third of specimens. Hg concentration, however, increased with length, and all fish >195cm had concentrations >1.0mgkg-1, with a maximum observed value of 2.0mgkg-1. Concentrations of Fe and Cu were, on average, 9.7 and 10 times higher in red muscle than in nearby white muscle, respectively. Mn, Zn, As and Se were also found in significantly higher concentrations in red muscle than in white muscle.