989 research outputs found

    Long-finned squid (Loligo vulgaris) fishery landings of the spanish fishing fleet operating in the northern Atlantic of the Iberian Peninsula

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    This study is based on the Loligo spp. commercial landing records of the Spanish fishery operating in the Galician and Cantabrian waters for the period 2000 to 2007. The fishery for long-finned squid in the Northern Iberian Peninsula waters during the study period took almost exclusively Loligo vulgaris (Lamarck, 1798), appearing only a few a few specimens of L. forbesi (Steenstrup, 1856) mixed with the L. vulgaris landings. This scarcity on L. forbesi was investigated by Chen et al. (2006), who noted the dramatic decline of L. forbesi abundance in the Iberian Peninsula in the 1990s and suggested that environmental changes could have been responsible. The long-finned squid represents only the 3% of cephalopod weight landings in the Northern Spain, but it constitutes the second cephalopod species in gastronomic and economic importance for this region, after the common octopus

    Patterns and Trends in Cetacean Occurrence Revealed by Shorewatch, a Land-Based Citizen Science Program in Scotland (United Kingdom)

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    Shorewatch is a citizen science project, managed by Whale and Dolphin Conservation (WDC), that records the occurrence of cetaceans during regular, standardized watches from a series of locations along the coast of Scotland (United Kingdom). Observer training and a clearly defined protocol help deliver a valuable source of information about cetacean occurrence and activity along the coast. Between 2005–2018, over 52000 watches generated over 11000 sightings of at least 18 cetacean species. Generalized Additive Models based on sightings for the five most commonly sighted species (bottlenose dolphin, harbor porpoise, minke whale, Risso’s dolphin, and common dolphin), at those sites with the longest time series, demonstrated seasonal, geographical and year-to-year differences in their local occurrence and relative abundance. Bottlenose dolphins are mainly present at observation sites located on the east coast of Scotland, being uncommon on the west coast, while harbor porpoise and minke whale are principally present at sites located on the west coast. The seasonality observed in cetacean occurrence is consistent with peak abundance in summer months described by previous studies in the area. Mean depth around the observation sites is the static variable that apparently has the greatest influence on species presence and number of sightings, except for Risso’s dolphin. All the species except bottlenose dolphin showed upward trends in occurrence and number of sightings over the period 2012–2018. Evidence of temporal autocorrelation was found between results from consecutive watches at the same site on the same day as well as between results from consecutive days at the same site. The power to detect declines in local abundance over a 6-year period depends on the underlying sighting rate of each cetacean species, the number of watches performed and the rate of decline. Simulations performed to determine the power to detect a decline suggest that the current intensity of observation effort in some observation sites, of about 2500 watches per year, may offer good prospects of detecting a 30% decline of the most frequently sighted species (95% of the time) over a 6-year period, although a more even distribution of observation effort in space and time is desirable. The data could potentially be used for monitoring and 6-yearly reporting of the status of cetacean populations.En prens

    Vocal foragers and silent crowds: context-dependent vocal variation in Northeast Atlantic long-finned pilot whales

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    13 pages, 6 figures, 3 tables.-- Fleur Visser ... et al.-- This article is an open access publicationVocalisations form a key component of the social interactions and foraging behaviour of toothed whales. We investigated changes in calling and echolocation behaviour of long-finned pilot whales between foraging and non-foraging periods, by combining acoustic recordings and diving depth data from tagged individuals with concurrent surface observations on social behaviour of their group. The pilot whales showed marked vocal variation, specific to foraging and social context. During periods of foraging, pilot whales showed more vocal activity than during non-foraging periods (rest, travel). In addition to the expected increase in echolocation activity, call rates also increased, suggesting that pilot whales communicate more during foraging. Furthermore, calls with multiple inflections occurred more often immediately before and after foraging dives and during the early descent and late ascent phases of foraging dives. However, these calls were almost never detected at diving depths of the tagged whale beyond 350 m. Calls with no or few inflections were produced at all times, irrespective of diving depth of the tagged whale. We discuss possible explanations for the distinct vocal variation associated with foraging periods. In addition, during non-foraging periods, the pilot whales were found to be more silent (no calling or echolocation) in larger, more closely spaced groups. This indicates that increased levels of social cohesion may release the need to stay in touch acoustically.This study was financially supported by the US Office of Naval Research, The Netherlands Ministry of Defence, the Norwegian Research Council and the Norwegian Ministry of DefencePeer reviewe

    Effects of Aesthetics and Playfulness on Web Usability – An empirical investigation

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    Limited empirical research exists on the explicit relevance of hedonic dimensions (aesthetics and playfulness) of humancomputer interaction design to usability. This research aims to determine the effects of color temperature on the perceptions of websites aesthetics, playfulness, and in turn usability. A Partial Least Squares (PLS) analysis of data collected from 328 participants in a four-group between-subject research design involving the use of a mock hotel website offered support for all nine hypotheses proposed. ‘Cooler’ colors (e.g. blue) were found to favorably impact perceptions of classical aesthetics, which in turn influenced perceptions of efficiency positively, while also correlating with perceptions of expressive aesthetics. The latter, on the other hand, were affected favorably by warmer colors (e.g. red), and had a positive effect on perceptions of playfulness. In line with prior usability studies, positive relationships between efficiency and effectiveness respectively and satisfaction with the Website were supported, and by considering the shown positive relationship between playfulness and satisfaction 60% of the variance in satisfaction was explained. Implications for theory and practice are also discussed

    Assessing the risk of an emerging zoonosis of worldwide concern : anisakiasis

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    The authors sincerely thank the Biobanking platform at the PARASITE project (EU FP7 PARASITE project (GA no. 312068)) for providing host-parasite data. We thank Rosa Fernández and Cristina Martínez from CETMAR for their help during creation and divulgation of the questionnaires. We also thank Arturo del Rey Moreno (“Antequera” hospital) for his helpful comments. We are also grateful to “Subdirección General de Economía Pesquera” of “Ministerio de Agricultura, Alimentación y Medio Ambiente” (MAGRAMA) of the Spanish government for providing anchovy trade statistics for 2013. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068).Peer reviewedPublisher PD

    Size-at-maturity of Brown Crab (Cancer pagurus) in Scottish waters based on gonadal and morphometric traits

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    CRediT authorship contribution statement Carlos Mesquita: Conceptualization, Methodology, Formal analysis, Writing - original draft. Helen Dobby: Conceptualization, Writing - review & editing, Supervision. Stephanie Sweeting: Methodology, Data curation, Formal analysis. Catherine S. Jones: Supervision, Writing - review & editing. Graham J. Pierce: Conceptualization, Writing - review & editing, Supervision.Peer reviewedPostprin

    Population genetic structure of the parasite Anisakis simplex (s. s.) collected in Clupea harengus L. from North East Atlantic fishing grounds

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    The Atlantic herring is a schooling, pelagic species that inhabits both sides of the North Atlantic Ocean. Herring stock identification is usually based on several approaches, including fish meristic characters, population genetic analysis and the use of parasite species composition. A total of 654 Anisakis spp. larvae collected from herring of four fishing grounds in the Norwegian Sea, Baltic Sea, North Sea, and the English Channel off the French coast, was identified to species level using diagnostic allozymes and sequence analysis of EF1 α−1 nDNA and the mtDNA cox2 genes. Population genetic differentiation of Anisakis simplex (s. s.) among the different fishing areas was estimated, at the intraspecific level, on the basis of mtDNA cox2 sequences analysis. Spatial comparison based on molecular variance analysis and Fst values was performed for the collected specimens (among regions). Haplotype network construction showed relevant differences in haplotype frequencies between samples of A. simplex (s. s.) from the different geographical areas. Results indicate a genetic sub-structuring of A. simplex (s. s.) obtained from herring in different areas, with the population from the Norwegian Sea being the most differentiated one, and with North Sea and Baltic Sea populations being most similar. The population genetic structure of A. simplex (s. s.) was in accordance with the herring population genetic structure throughout the host’s geographical range in the NE Atlantic. Results suggest that mtDNA cox2 is a suitable genetic marker for A. simplex (s. s.) population genetic structure analysis and a valuable tool to elucidate the herring stock structure in the NE Atlantic Ocean
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