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Auteur Hoffle, H.; Van Damme, C.J.G.; Fox, C.; Lelievre, S.; Loots, C.; Nash, R.D.M.; Vaz, S.; Wright, P.J.; Munk, P.
Titre Linking spawning ground extent to environmental factors – patterns and dispersal during the egg phase of four North Sea fishes Type Article scientifique
Année 2018 Publication Revue Abrégée Can. J. Fish. Aquat. Sci.
Volume 75 Numéro 3 Pages 357-374
Mots-Clés climate-change; spatial distributions; cod gadus-morhua; neighbor matrices; offshore oil; generalized additive-models; dependent development rates; haddock melanogrammus-aeglefinus; pleuronectes-platessa l; whiting merlangius-merlangus
Résumé Previous studies have shown that four commercially important demersal species, namely Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and European plaice (Pleuronectes platessa), spawn in distinct areas across the North Sea. Based on two comprehensive ichthyoplankton surveys in 2004 and 2009, the present study uses generalized additive mixed models to delimit these spawning grounds using the distribution of recently spawned eggs, investigates their relationship to specific environmental conditions, and examines egg dispersal during their development. Results indicate that presence-absence of early stage eggs is more related to temporal and topographic variables, while egg densities are closely linked with hydrography. Egg distribution patterns were relatively consistent during development and only changed near hatching. Compared with historic observations, the location of the spawning grounds appeared stable on the broad scale but centres of egg abundance varied between the surveyed years. Potential effects of long-term climate change and anthropogenic short-term disturbances, such as seismic surveys, on fish reproduction are discussed, pointing out the demand for multispecies studies on these issues.
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Langue English Langue du Résumé Titre Original
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ISSN 0706-652x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2316
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Auteur Dalongeville, A.; Andrello, M.; Mouillot, D.; Lobreaux, S.; Fortin, M.-J.; Lasram, F.; Belmaker, J.; Rocklin, D.; Manel, S.
Titre Geographic isolation and larval dispersal shape seascape genetic patterns differently according to spatial scale Type Article scientifique
Année 2018 Publication Revue Abrégée Evol. Appl.
Volume 11 Numéro 8 Pages 1437-1447
Mots-Clés caribbean reef fish; connectivity; divergent selection; ecological data; ecological genetics; landscape genetics; marine connectivity; marine fish; Mediterranean Sea; Mullus surmuletus; neighbor matrices; oceanography; population-structure; sea; seascape genetics; single nucleotide polymorphism; surmuletus
Résumé Genetic variation, as a basis of evolutionary change, allows species to adapt and persist in different climates and environments. Yet, a comprehensive assessment of the drivers of genetic variation at different spatial scales is still missing in marine ecosystems. Here, we investigated the influence of environment, geographic isolation, and larval dispersal on the variation in allele frequencies, using an extensive spatial sampling (47 locations) of the striped red mullet (Mullus surmuletus) in the Mediterranean Sea. Univariate multiple regressions were used to test the influence of environment (salinity and temperature), geographic isolation, and larval dispersal on single nucleotide polymorphism (SNP) allele frequencies. We used Moran's eigenvector maps (db-MEMs) and asymmetric eigenvector maps (AEMs) to decompose geographic and dispersal distances in predictors representing different spatial scales. We found that salinity and temperature had only a weak effect on the variation in allele frequencies. Our results revealed the predominance of geographic isolation to explain variation in allele frequencies at large spatial scale (>1,000km), while larval dispersal was the major predictor at smaller spatial scale (<1,000km). Our findings stress the importance of including spatial scales to understand the drivers of spatial genetic variation. We suggest that larval dispersal allows to maintain gene flows at small to intermediate scale, while at broad scale, genetic variation may be mostly shaped by adult mobility, demographic history, or multigenerational stepping-stone dispersal. These findings bring out important spatial scale considerations to account for in the design of a protected area network that would efficiently enhance protection and persistence capacity of marine species.
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Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection (up) Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1752-4571 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2422
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