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Puerto Serrano, Spain

The use of commercial catch statistics to estimate overfishing consequences has been criticised, but alternative long-term data sets are rare. Long time-series data sets from recreational fisheries competitions have been used to infer trends in coastal fish communities. Here an historic archive (1953-2007) of recreational spear fisheries in Galicia (NW Spain) was employed to estimate long-term changes in coastal ecosystems. Using generalised additive regression models, decreases in the abundances of coastal rocky reef fishes of up to 76% over the last 50 years were found. In the same period, the mean body weight also decreased by 76%. In addition, relative catch frequency has decreased for the most valuable commercial species. Overfishing, amongst other human impacts, has brought these ecosystems so close to collapse that it is urgent to implement measures to ensure their recovery. © 2014 John Wiley & Sons Ltd. Source

Juan-Jorda M.J.,University of La Coruna | Juan-Jorda M.J.,Simon Fraser University | Juan-Jorda M.J.,Tecnalia | Mosqueira I.,European Commission - Joint Research Center Ispra | And 2 more authors.
PLoS ONE | Year: 2013

Scombrids (tunas, bonitos, Spanish mackerels and mackerels) support important fisheries in tropical, subtropical and temperate waters around the world, being one of the most economically- and socially-important marine species globally. Their sustainable exploitation, management and conservation depend on accurate life history information for the development of quantitative fisheries stock assessments, and in the fishery data-poor situations for the identification of vulnerable species. Here, we assemble life history traits (maximum size, growth, longevity, maturity, fecundity, spawning duration and spawning interval) for the 51 species of scombrids globally. We identify major biological gaps in knowledge and prioritize life history research needs in scombrids based on their biological gaps in knowledge, the importance of their fisheries and their current conservation status according to the International Union for Conservation of Nature Red List. We find that the growth and reproductive biology of tunas and mackerel species have been more extensively studied than for Spanish mackerels and bonitos, although there are notable exceptions in all groups. We also reveal that reproductive biology of species, particular fecundity, is the least studied biological aspect in scombrids. We identify two priority groups, including 32 species of scombrids, and several populations of principal market tunas, for which life history research should be prioritized following the species-specific life history gaps identified in this study in the coming decades. By highlighting the important gaps in biological knowledge and providing a priority setting for life history research in scombrid species this study provides guidance for management and conservation and serves as a guide for biologists and resource managers interested in the biology, ecology, and management of scombrid species. © 2013 Juan-Jordá et al. Source

Juan-Jorda M.J.,University of La Coruna | Juan-Jorda M.J.,Simon Fraser University | Juan-Jorda M.J.,Tecnalia | Mosqueira I.,European Commission - Joint Research Center Ispra | And 2 more authors.
Reviews in Fish Biology and Fisheries | Year: 2013

The scombrids (tunas, bonitos, Spanish mackerels and mackerels) sustain some of the most important fisheries in the world and their sustainable management depends on better understanding of their life history strategies. Here, we first assemble life history information on maximum size, growth, longevity, maturity, fecundity and spawning duration and interval for all scombrid species. Second we characterize their life history patterns and trait co-variation and evaluate how many principal axes of trait variation underlie scombrid life history strategies. Most of their life history variation can be explained along three axes or dimensions: size, speed, and reproductive schedule. Body size governs the first axis ranking species along a small-large continuum. The second axis was mostly influenced by time-related traits, such as longevity, growth rates, spawning duration, time between spawning events, ranking species along a slow-fast continuum of life histories. Scombrid species with the slowest life histories such as Atlantic bluefin tuna Thunnus thynnus and Atlantic mackerel Scomber scombrus tend to inhabit more temperate waters while species with faster life histories such as yellowfin tuna Thunnus albacares and short mackerel Rastrelliger brachysoma are typically found in more tropical waters. The third axis comprises the negative relationship between number of eggs produced at length of maturity and rate in gain of fecundity with size describing the schedule of reproductive allocation which reflects a fundamental trade-off between reproduction and growth. Finally, in addition we show that the life history strategies of scombrids conform more closely to the Periodic and Opportunistic strategists within the triangular model of fish life histories. © 2012 Springer Science+Business Media B.V. Source

Fernandez-Boan M.,University of La Coruna | Freire J.,Barrabes Next | Parma A.M.,CONICET | Fernandez L.,University of La Coruna | Orensanz J.M.,CONICET
ICES Journal of Marine Science | Year: 2013

The assessment and management of small-scale benthic fisheries requires attention to the spatial structure of stocks and patterns of effort allocation. Spatial information helps in the interpretation of fisheries data, and is required for designing spatially explicit management strategies, often prescribed in the case of benthic fisheries. Monitoring of boats with GPS, combined with port interviews, was evaluated as an approach to investigate the spatial pattern of fishing intensity and catch per unit of effort (CPUE) in the sea urchin (Paracentrotus lividus) diving fishery from Galicia, Spain. Fishing opportunities (FOs), relatively small regions of high fishing intensity, were identified and mapped at a fine scale. New FOs were first visited at an approximately constant rate. Concentration analysis shows that effort intensity was not uniformly distributed within FOs. CPUE did not exhibit a significant trend throughout the season, either at the scale of the aggregated fishery or within individual FOs. Catch per area and area covered per unit of diving time were inversely related, indicating that fishers stay longer in high-density patches. While abundance is the primary driver of effort allocation, other factors contributing to suitability were identified. Based on these results, we discuss realistic options for the monitoring of this and comparable fisheries. © 2013 © 2013 International Council for the Exploration of the Sea. Published by Oxford University Press. All rights reserved. Source

The term remote sensing is related to the action of obtaining information about an object, area or phenomenon without a direct contact. Over time this term has become increasingly important due to technological advances until becoming a technique of obtaining information, key in many and different fields. However, especially in Spain, the information about these issues is scarce and distribute in several sources. For this reason, this text attempts to bring together the main historical milestones in remote sensing at a national level. It is not expected to be an exhaustive review; however it reflects its evolution over time from what its beginnings were to what we know today. Source

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