826 resultados para South-west
Resumo:
The social dimensions of marine protected areas (MPAs) play an important role in MPA success, yet these social dimensions are little understood. We explore the social impacts arising from the establishment of an MPA using Lyme Bay (south west England) as a case study. Through a series of small group semi-structured interviews the social impacts experienced by fishermen (mobile and static gear), recreational users (divers and sea anglers) and recreation service providers (charter boat and dive businesses) were explored. The social impacts expressed varied according to activity in which the stakeholder group engaged. Negative themes included lengthening fishing trips, tension and conflict, fishermen identity, equity and uncertainty in the long-term. Positive themes included improved experiences for both commercial fishermen and recreational users, and expectations for long-term benefits. These impacts need to be understood because they influence stakeholder behaviour. Failure to interpret stakeholder responses may lead to poor decision-making and worsening stakeholder relations. These findings have implications for the success of the MPA in Lyme Bay, but also for the future network of marine conservation zones around the UK. Any assessment of MPA impacts must therefore identify social as well as economic and environmental change.
Disturbance to conserved bacterial communities in the cold water gorgonian coral Eunicella verrucosa
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The bacterial communities associated with healthy and diseased colonies of the cold-water gorgonian coral Eunicella verrucosa at three sites off the south-west coast of England were compared using denaturing gradient gel electrophoresis (DGGE) and clone libraries. Significant differences in community structure between healthy and diseased samples were discovered, as were differences in the level of disturbance to these communities at each site; this correlated with depth and sediment load. The majority of cloned sequences from healthy coral tissue affiliated with the Gammaproteobacteria. The stability of the bacterial community and dominance of specific genera found across visibly healthy colonies suggest the presence of a specific microbial community. Affiliations included a high proportion of Endozoicomonas sequences, which were most similar to sequences found in tropical corals. This genus has been found in a number of invertebrates and is suggested to have a role in coral health and in the metabolisation of dimethylsulfoniopropionate (DMSP) produced by zooxanthellae. However, screening of colonies for the presence of zooxanthellae produced a negative result. Diseased colonies showed a decrease in affiliated clones and an increase in clones related to potentially harmful/transient microorganisms but no increase in a particular pathogen. This study demonstrates that a better understanding of these bacterial communities, the factors that affect them and their role in coral health and disease will be of critical importance in predicting future threats to temperate gorgonian communities.
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The social and economic benefits of the coastal zone make it one of the most treasured environments on our planet. Yet it is vulnerable to increasing anthropogenic pressure and climate change. Coastal management aims to mitigate these pressures while augmenting the socio-economic benefits the coastal region has to offer. However, coastal management is challenged by inadequate sampling of key environmental indicators, partly due to issues relating to cost of data collection. Here, we investigate the use of recreational surfers as platforms to improve sampling coverage of environmental indicators in the coastal zone. We equipped a recreational surfer, based in the south west United Kingdom (UK), with a temperature sensor and Global Positioning System (GPS) device that they used when surfing for a period of one year (85 surfing sessions). The temperature sensor was used to derive estimates of sea-surface temperature (SST), an important environmental indicator, and the GPS device used to provide sample location and to extract information on surfer performance. SST data acquired by the surfer were compared with data from an oceanographic station in the south west UK and with satellite observations. Our results demonstrate: (i) high-quality SST data can be acquired by surfers using low cost sensors; and (ii) GPS data can provide information on surfing performance that may help motivate data collection by surfers. Using recent estimates of the UK surfing population, and frequency of surfer participation, we speculate around 40 million measurements on environmental indicators per year could be acquired at the UK coastline by surfers. This quantity of data is likely to enhance coastal monitoring and aid UK coastal management. Considering surfing is a world-wide sport, our results have global implications and the approach could be expanded to other popular marine recreational activities for coastal monitoring of environmental indicators.
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From mid December 2013 to the end of February 2014, the coast of south-west and southern England and Wales were battered by a succession of severe gales. This article gives an account of some of the impacts of those storms on inshore marine life.
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The acorn barnacle Chthamalus montagui can present strong variation in shell morphology, ranging from flat conic to a highly bent form, caused by a substantial overgrowth of the rostrum plate. Shell shape distribution was investigated between January and May 2004 from geographical to microhabitat spatial scales along the western coast of Britain. Populations studied in the north (Scotland and Isle of Man) showed a higher degree of shell variation compared to those in the south (Wales and south-west England). In the north, C. montagui living at lower tidal levels and in proximity to the predatory dogwhelk, Nucella lapillus, were more bent in profile. Laboratory experiments were conducted to examine behavioural responses, and vulnerability of bent and conic barnacles to predation by N. lapillus. Dogwhelks did not attack one morphotype more than the other, but only 15 % of attacks on bent forms were successful compared to 75 % in conic forms. Dogwhelk effluent reduced the time spent feeding by C. montagui (11 %), but there was no significant difference between conic and bent forms. Examination of barnacle morphology indicated a trade-off in investment in shell structure and feeding appendages associated with being bent, but none with egg or somatic tissue mass. These results are consistent with C. montagui showing an induced defence comparable to that found in its congeners Chthamalus anisopoma and Chthamalus fissus on the Pacific coast of North America, but further work to demonstrate inducibility is required.
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Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat ‘hotspots’ of high space use. Movement modelling showed sharks preferred habitats characterised by strong sea-surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge south-west of the Azores. In these main regions, and sub-areas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently ‘tracks’ oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.
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Potential explanatory variables often co-vary in studies of species richness. Where topography varies within a survey it is difficult to separate area and habitat-diversity effects. Topographically complex surfaces may contain more species due to increased habitat diversity or as a result of increased area per se. Fractal geometry can be used to adjust species richness estimates to control for increases in area on complex surfaces. Application of fractal techniques to a survey of rocky shores demonstrated an unambiguous area-independent effect of topography on species richness in the Isle of Man. In contrast, variation in species richness in south-west England reflected surface availability alone. Multivariate tests and variation in limpet abundances also demonstrated regional variation in the area-independent effects of topography. Community composition did not vary with increasing surface complexity in south-west England. These results suggest large-scale gradients in the effects of heterogeneity on community processes or demography.
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Results of the search of the periodic changes of the 530.3 nm line intensity emitted by selected structures of the solar corona in the frequency range 1-10 Hz are presented. A set of 12 728 images of the section of the solar corona extending from near the north pole to the south-west were taken simultaneously in the 530.3 nm ("green") line and white-light with the Solar Eclipse Coronal Imaging System (SECIS) during the 143-seconds- long totality of the 1999 August 11 solar eclipse observed in Shabla, Bulgaria. The time resolution of the collected data is better than 0.05 s and the pixel size is approximately 4 arcsec. Using classical Fourier spectral analysis tools, we investigated temporal changes of the local 530.3 nm coronal line brightness in the frequency range 1-10 Hz of thousands of points within the field of view. The various photometric and instrumental effects have been extensively considered. We did not find any indisputable, statistically significant evidence of periodicities in any of the investigated points (at significance level alpha = 0.05).
Resumo:
On rocky shores, the relative importance of abiotic and biotic processes that regulate community structure are thought to vary with levels of shore exposure. This can lead to characteristic features found on sheltered and exposed shores. This study identified differences in the population structure of mussels on exposed and sheltered rocky shores on Atlantic coasts of south-west Ireland. Direct interactions between epibiotic algae and their host mussels were also examined to test if potential effects varied with shore exposure. Mussel beds on sheltered shores were less dense and comprised larger mussels with greater rates of individual survival and growth than those on exposed shores. The results of a field experiment showed that algal epibionts had a negative effect on mussel survival on sheltered shores but not on exposed shores. Surprisingly, the presence of algal epibionts had no effect on mussel growth on either shore type. These findings contrast with those of previous studies. The effects of shore exposure and algal epibionts on Mussels may be species-specific and may interact with other factors across different regions. This study shows that predictions of effects of exposure on mussel populations and their epibionts should only be based on specific experimental evidence and cannot be generalised across regions. (C) 2009 Elsevier Ltd. All rights reserved.
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Background The attitudes members of the nursing profession hold towards survivors of brain injury may impact on the level of help, and degree of involvement they are willing to have. Given that the manner in which an individual receives their brain injury has been shown to impact on public prejudices, the importance of exploring nursing attitudes to this vulnerable group, and the subsequent impact this may have on the caring role, requires investigation. Objective To investigate the attitudes held by members of the nursing profession towards young male survivors of brain injury whose behaviour either contributed, or did not contribute, to their injury. Design Independent groups design. Setting and participants Ninety trainee and sixty-nine qualified nurses respectively drawn from a university in the south west of England and the emergency, orthopaedic and paediatric Departments of the Royal Devon and Exeter Hospital, UK. Methods Participants were randomly assigned to one of four fictional brain injury scenarios. A young male character was portrayed as sustaining a brain injury as a result of either an aneurysm, or through drug taking, with their behaviour being either a contributory or non-contributory factor. On reading these, participants were asked to complete the prejudicial evaluation scale, the social interaction scale and the helping behaviour scale. Results Analysis of variance showed that qualified nurses held more prejudicial attitudes than student nurses towards survivors of brain injury. Mean scores indicated that individuals seen as contributing towards their injury were likely to experience more prejudice (blame total = 42.35 vs. no blame total = 38.34), less social interaction (blame total = 37.54 vs. no blame total = 41.10), and less helping behaviour (blame total = 21.49 vs. no blame total = 22.34) by both groups. Conclusions Qualified nurses should be mindful of the impact their attitudes and judgements of survivors of brain injury may have on the subsequent care they provide. Greater emphasis on the effects of negative attitudes on patient interactions during training may provide nurses with the understanding to recognise and avoid challenges to their caring role in the future.
Resumo:
Lepidopleurida is the earliest diverged group of living polyplacophoran molluscs. They are found predominantly in the deep sea, including sunken wood, cold seeps, other abyssal habitats, and a few species are found in shallow water. The group is morphologically identified by anatomical features of their gills, sensory aesthetes, and gametes. Their shell features closely resemble the oldest fossils that can be identified as modern polyplacophorans. We present the first molecular phylogenetic study of this group, and also the first combined phylogenetic analysis for any chiton, including three gene regions and 69 morphological characters. The results show that Lepidopleurida is unambiguously monophyletic, and the nine genera fall into five distinct clades, which partly support the current view of polyplacophoran taxonomy. The genus Hanleyella Sirenko, 1973 is included in the family Protochitonidae, and Ferreiraellidae constitutes another distinct clade. The large cosmopolitan genus Leptochiton Gray, 1847 is not monophyletic; Leptochiton and Leptochitonidae sensu stricto are restricted to North Atlantic and Mediterranean taxa. Leptochitonidae s. str. is sister to Protochitonidae. The results also suggest two separate clades independently inhabiting sunken wood substrates in the south-west Pacific. Antarctic and other chemosynthetic-dwelling species may be derived from wood-living species. Substantial taxonomic revision remains to be done to resolve lepidopleuran classification, but the phylogeny presented here is a dramatic step forward in clarifying the relationships within this interesting group.
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Background: Many deep-sea benthic animals occur in patchy distributions separated by thousands of kilometres, yet because deep-sea habitats are remote, little is known about their larval dispersal. Our novel method simulates dispersal by combining data from the Argo array of autonomous oceanographic probes, deep-sea ecological surveys, and comparative invertebrate physiology. The predicted particle tracks allow quantitative, testable predictions about the dispersal of benthic invertebrate larvae in the south-west Pacific. Principal Findings: In a test case presented here, using non-feeding, non-swimming (lecithotrophic trochophore) larvae of polyplacophoran molluscs (chitons), we show that the likely dispersal pathways in a single generation are significantly shorter than the distances between the three known population centres in our study region. The large-scale density of chiton populations throughout our study region is potentially much greater than present survey data suggest, with intermediate ‘stepping stone’ populations yet to be discovered. Conclusions/Significance: We present a new method that is broadly applicable to studies of the dispersal of deep-sea organisms. This test case demonstrates the power and potential applications of our new method, in generating quantitative, testable hypotheses at multiple levels to solve the mismatch between observed and expected distributions: probabilistic predictions of locations of intermediate populations, potential alternative dispersal mechanisms, and expected population genetic structure. The global Argo data have never previously been used to address benthic biology, and our method can be applied to any non-swimming larvae of the deep-sea, giving information upon dispersal corridors and population densities in habitats that remain intrinsically difficult to assess.
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The late-glacial vegetation development in northern Norway in response to climate changes during the Allerod, Younger Dryas (YD), and the transition to the Holocene is poorly known. Here we present a high-resolution record of floral and vegetation changes at lake Lusvatnet, south-west Andoya, between 13500 and 8000 cal b.p. Plant macrofossil and pollen analyses were done on the same sediment core and the proxy records follow each other very closely. The core has also been analyzed using an ITRAX XRF scanner in order to check the sediment sequence for disturbances or hiatuses. The core has a good radiocarbon-based chronology. The Saksunarvatn tephra fits very well chronostratigraphically. During both the Allerod and the Younger Dryas time-periods arctic vegetation prevailed, dominated by Salix polaris associated with many typically arctic herbs such as Saxifraga cespitosa, Saxifraga rivularis and Oxyria digyna. Both periods were cold and dry. Between 12450 and 12250 cal b.p. during the Younger Dryas chronozone, the assemblage changed, particularly in the increased abundance of Papaver sect. Scapiflora and other high-Arctic herbs, suggesting the development of polar desert vegetation mainly as a response to increased aridity. After 11520 cal b.p. a gradually warmer and more oceanic climate initiated a succession to dwarf-shrub vegetation and the establishment of Betula woodland after 1,000 years at c. 10520 cal b.p. The overall late-glacial aridity contrasts with oceanic conditions in southern Norway and is probably related to sea-ice extent.