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| Registros recuperados: 160 | |
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| Fromentin, Jean-marc. |
| In 1963, the leading fisheries targeting Atlantic bluefin tuna (Thunnus thynnus) in the Norwegian Sea and North Sea suddenly collapsed without any warning. Little is known about this collapse and several hypotheses have been put forward, such as changes in migratory routes, recruitment failure or eradication of a sub-population: all of these hypotheses could result from natural causes and/or from overfishing. To help explain this mysterious event, an original data set of the main bluefin tuna fisheries of the 20th century, including total catch and size composition of the catch, has been compiled and analysed. The results reveal a strong and unambiguous link between the Nordic purse seine and Spanish trap fisheries during the 1950s and 1960s. However, this... |
| Tipo: Text |
Palavras-chave: Thunnus thynnus; Retrospective analysis; Population structure; Migration patterns; Fisheries collapse. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6425.pdf |
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| Brophy, Deirdre; Haynes, Paula; Arrizabalaga, Haritz; Fraile, Igaratza; Fromentin, Jean-marc; Garibaldi, Fulvio; Katavic, Ivan; Tinti, Fausto; Karakulak, F. Saadet; Macias, David; Busawon, Dheeraj; Hanke, Alex; Kimoto, Ai; Sakai, Osamu; Deguara, Simeon; Abid, Nouredinne; Santos, Miguel Neves. |
| Two stocks of bluefin tuna (Thunnus thynnus) inhabit the north Atlantic; the western and eastern stocks spawn in the Gulf of Mexico and the Mediterranean Sea respectively. Trans-Atlantic movements occur outside spawning time whereas natal homing maintains stock structure. Commercial fisheries may exploit a mixed assemblage of both stocks. The incorporation of mixing rates into stock assessment is precluded by uncertainties surrounding stock discrimination. Otolith shape descriptors were used to characterise western and eastern stocks of Atlantic bluefin tuna in the present study and to estimate stock composition in catches of unknown origin. Otolith shape varied with length and between locations and years. Within a restricted size range (200-297-cm fork... |
| Tipo: Text |
Palavras-chave: Elliptical Fourier analysis; Population structure; Stock mixture analysis. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00346/45745/45381.pdf |
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| Cowart, Dominique; Halanych, Kenneth M.; Schaeffer, Stephen W.; Fisher, Charles R.. |
| Lamellibrachia vestimentiferan tubeworms form aggregations at hydrocarbon cold seeps in the deep Gulf of Mexico (GoM), creating structures that provide living space for other fauna. In the GoM, three Lamellibrachia taxa vary in morphology and depth ranges: Lamellibrachia luymesi (300–950 m), Lamellibrachia sp. 1 (950–2,604 m), and Lamellibrachia sp. 2 (1,175–3,304 m). While Lamellibrachia sp. 2 is consistently identified as a separate species, L. luymesi and sp. 1 cannot be discriminated using barcoding markers cytochrome oxidase subunit 1 (COI) and large ribosomal subunit rDNA (16S). To determine if limited gene flow was a factor in the formation of these taxa, we employed more quickly evolving markers, including mitochondrial cytochrome B (CYTB),... |
| Tipo: Text |
Palavras-chave: Deep sea; Hydrocarbon seep; Microsatellite; Population structure; Siboglinid; Vestimentiferan tubeworm. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00194/30494/29935.pdf |
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| Cowart, Dominique; Huang, Chunya; Arnaud-haond, Sophie; Carney, Susan L.; Fisher, Charles R.; Schaeffer, Stephen W.. |
| The history of colonization and dispersal in fauna distributed among deep-sea chemosynthetic ecosystems remains enigmatic and poorly understood because of an inability to mark and track individuals. A combination of molecular, morphological and environmental data improves understanding of spatial and temporal scales at which panmixia, disruption of gene flow or even speciation may occur. Vestimentiferan tubeworms of the genus Escarpia are important components of deep -sea cold seep ecosystems, as they provide long-term habitat for many other taxa. Three species of Escarpia, Escarpia spicata [Gulf of California (GoC)], Escarpia laminata [Gulf of Mexico (GoM)] and Escarpia southwardae (West African Cold Seeps), have been described based on morphology, but... |
| Tipo: Text |
Palavras-chave: Deep sea; Hydrocarbon seep; Microsatellite; Population structure; Siboglinid; Vestimentiferan tubeworm. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00152/26354/24515.pdf |
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| Moura, Teresa; Jones, Emma; Clarke, Maurice W.; Cotton, Charles F.; Crozier, Paul; Daley, Ross K.; Diez, Guzman; Dobby, Helen; Dyb, Jan E.; Fossen, Inge; Irvine, Sarah B.; Jakobsdottir, Klara; Lopez-abellan, Luis J.; Lorance, Pascal; Pascual-alayon, Pedro; Severino, Ricardo B.; Figueiredo, Ivone. |
| Deep-water sharks exhibit species-specific reproductive strategies, which include segregation by sex, size and reproductive stage. However, due to the wide spatial distribution of most species, available information, usually collected at a regional scale, is usually not adequate to infer species reproductive spatial dynamics. This study draws together information on the distribution of reproductive stages of three species of squaliform sharks: Portuguese dogfish Centroscymnus coelolepis (Somniosidae), leafscale gulper shark Centrophorus squamosus (Centrophoridae) and birdbeak dogfish Deania calcea (Centrophoridae), gathering data from several geographical areas from the Atlantic, Indian and Pacific Oceans. For each species we analysed the sex ratio and the... |
| Tipo: Text |
Palavras-chave: Commercial fishery data; Deep-sea; Life stage; Population structure; Survey data. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00188/29902/29420.pdf |
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| De Cubber, Lola; Lefebvre, Sebastien; Fisseau, Charline; Cornille, Vincent; Gaudron, Sylvie Marylene. |
| Arenicola spp. are marine benthic polychaetes dug for bait by anglers. Without regulation, this activity can lead to the decrease of lugworms' population meanwhile affecting the physical characteristics of the beach and the biodiversity. Here, we identified through morphology and genetics two species of lugworms, Arenicola marina and A. defodiens, within a Marine Protected Area of the Eastern English Channel (France). For each species, abundance and spatial distribution were assessed using a stratified random sampling and interpolation at four studied sites, as well as some life-history traits. These data were compared to lugworms' collection data to estimate its sustainability and to provide potential management measures. At one site, A. marina was... |
| Tipo: Text |
Palavras-chave: Arenicola marina; Arenicola defodiens; Spawning; Population structure; Size at first maturity; Recreational fisheries; Conservation; English channel. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00451/56284/60474.pdf |
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| Aemero, Mulugeta; Boissier, Jerome; Climent, Deborah; Mone, Helene; Mouahid, Gabriel; Berhe, Nega; Erko, Berhanu. |
| Background: Human intestinal schistosomiasis caused by Schistosoma mansoni and urinary schistosomiasis caused by Schistosoma haematobium are endemic in Ethiopia. Although schistosomes look morphologically uniform, there is variation in infectivity, egg productivity and virulence due to variation in their genetic make. Knowing the genetic diversity and population structure of S. mansoni isolates will enable to understand and consider the possible variability in terms of infectivity, egg productivity and virulence. Methods: Between 2010 and 2011, genetic diversity and population structure of Schistosoma mansoni isolates from four endemic areas of Ethiopia was assessed using previously published 11 polymorphic microsatellite loci. Miracidia were hatched from... |
| Tipo: Text |
Palavras-chave: Schistosoma mansoni; Microsatellite; Genetic diversity; Population structure; Ethiopia. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00302/41369/71868.pdf |
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| Bertignac, Michel; Fernandez, Carmen; Methot, Richard. |
| European hake (Merluccius merluccius) is widely distributed over the north-east Atlantic shelf, from Norway to Mauritania. Despite its large distribution (covering ICES Division IIIa, Subareas IV, VI and VII and Divisions VIIIa,b,d, from Norway to the Bay of Biscay) and a complex population structure, the so-called northern stock of hake is currently assessed as a single unit, using a spatially aggregated implementation of the Stock Synthesis assessment model. In this study, a preliminary spatially explicit implementation of Stock Synthesis is developed, which accounts for the distribution of the hake population during its life cycle (nurseries and spawning areas) and the distribution of the fleets (trawlers, gillnetters and long-liners) exploiting the... |
| Tipo: Text |
Palavras-chave: Northern hake; Spatial dynamics; Population structure; Spatial stock assessment.. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00126/23764/21657.pdf |
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| Registros recuperados: 160 | |
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