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Freire, Juan; Martí, Cristina Bernárdez; López-Prado, Antonio Corgos; Fernández, Luis; González-Gurriarán, Eduardo; Pastor, María Paz Sampedro; Amor, Patricia Verísimo

doi:10.1023/a:1013350723445

Cited by 52 publications

(10 citation statements)

References 14 publications

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“…In Galicia, as in the rest of the European seas (Froese and Proelß 2010), there is growing concern regarding the long-term sustainability of local fish stocks (Freire and García-Allut 2000, Freire et al 2002. In this regard, it must be noted that of the 29 species targeted by this recreational fishery only C. conger supports a large commercial fishing effort (Pita et al 2008).…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, the coastal fish communities of Galicia have also been traditionally exploited by a very heterogeneous multi-gear commercial fleet using mainly trawls, longlines, gillnets and purse seines (Freire and García-Allut 2000). Many of these coastal fisheries are currently mismanaged and overexploited (Freire and García-Allut 2000, Freire et al 2002. Therefore, it is important to obtain information on the effects of the spear fishery in order to manage the ecosystems comprehensively by developing integrated coastal management plans (Lloret and Font 2013).…”

Section: Introductionmentioning

confidence: 99%

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Assessing the impact of spear fishing by using competitions records and underwater visual censuses

Pita¹,

Freire²

2011

Sci. Mar.

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Summary:Recreational fishers are increasingly competing for space and resources with commercial fishers worldwide, but have been poorly studied. In particular, the impacts of spearfishing competitions on the temperate fish assemblages have seldom been analysed. In Galicia (NW Spain), there are currently 5000 spear fishers, and 500 of them participate in spearfishing competitions. An historic archive of spearfishing competitions was used to assess their influence on the subsequent competitions in the area and to analyse their effect on the fish abundances estimated by underwater visual censuses. The annual recreational catch of the spear fishers was also estimated and comparisons with the commercial landings were performed. The spear fishers targeted 29 species, although six accounted for 95% of the catch. Most of the species show low vulnerabilities to fishing pressure and only Dicentrarchus labrax, among frequently caught species, can be considered as moderately vulnerable. The overall impact of spearfishing competitions on fish populations was limited, although some competitions temporarily reduced the abundances of Labrus bergylta, the main target species, by up to 83%. Spear fishers caught a large proportion of the total catch of common species, with recreational catches of some species (e.g. L. bergylta) matching or exceeding the commercial catch. The inclusion of this fishery in the management models of the coastal ecosystems is strongly recommended.Keywords: underwater visual censuses; fish assemblages; recreational fisheries; spear fishing; fishing impacts; coastal ecosystems.Evaluación del impacto de la pesca submarina mediante el uso de registros de concursos y censos visuales subacuáticos Resumen: Los pescadores recreativos compiten cada vez más intensamente por el espacio y los recursos con los pescadores comerciales en todo el mundo, pero han sido poco estudiados. En particular, rara vez se han analizado los impactos de los concursos de pesca submarina sobre las comunidades de peces propias de las regiones templadas. En Galicia (noroeste de España), en la actualidad hay 5000 pescadores submarinos, y 500 de ellos participan en concursos. Se utilizó un archivo histórico de competiciones de pesca submarina para evaluar su influencia sobre los concursos celebrados posteriormente en la zona y para analizar su efecto sobre las abundancias de peces, estimadas mediante censos visuales subacuáticos (UVC). Además, se estimaron las capturas recreativas anuales de los pescadores submarinos y se realizaron comparaciones con los desembarques comerciales. Los pescadores submarinos capturaron 29 especies, aunque seis representaron el 95% de sus capturas. La mayor parte de las especies muestran bajas vulnerabilidades a la presión pesquera y sólo Dicentrarchus labrax, de entre las especies capturadas con frecuencia, puede ser considerada como moderadamente vulnerable. El impacto global de los concursos de pesca submarina sobre las poblaciones de peces fue limitado, aunque algunos concursos redujeron temporalmente las...

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Assessing the impact of spear fishing by using competitions records and underwater visual censuses

Pita¹,

Freire²

2011

Sci. Mar.

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“…Such diversity could, in principle, not be expected given the intensive fishing activity focussed on this crustacean. For instance, it has been estimated that 90% of Galician crabs are caught every season (Freire et al 2002). Nevertheless, an important counteracting factor could be the high fertility of the spiny spider crab, which would lead to large effective population sizes.…”

Section: Discussionmentioning

confidence: 99%

“…Inferred expansions were dated following the expression T = τ/2μk, where τ is the estimated number of generations since the expansion, μ is the mutation rate per site per generation and k is the sequence length. We assumed a mutation rate of 1% per lineage per million years (average estimate reported in Ketmaier et al 2003) and a mean generation time of 2 yr (see Freire et al 2002).…”

Section: Samplingmentioning

confidence: 99%

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Genetic variation of the spiny spider crab Maja brachydactyla in the northeastern Atlantic

Sotelo

Morán²,

Fernández³

et al. 2008

Mar. Ecol. Prog. Ser.

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The spiny spider crab Maja brachydactyla is a decapod crustacean that inhabits the northeastern Atlantic, from the British Isles to Senegal, and is the target of intense fishing activity. In the absence of previous genetic studies, we describe the genetic variability and structure of this species along Atlantic European coasts, paying special attention to the northwestern Iberian Peninsula (Galicia), where this species may be overexploited. Analysis of 2 mitochondrial fragments and 9 microsatellites indicates that these populations maintain appreciable levels of genetic diversity, most of which are found within localities. This scenario could be explained by quite large effective population sizes and noticeable levels of gene flow. M. brachydactyla in the northeastern Atlantic do not show any signs of a genetic bottleneck, and effectively conform to a diverse metapopulation with limited structure.

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Spermatogenesis of the spider crab Maja brachydactyla (Decapoda: Brachyura)

Simeó

Kurtz

Chiva

et al. 2009

Journal of Morphology

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This study describes spermatogenesis in a majid crab (Maja brachydactyla) using electron microscopy and reports the origin of the different organelles present in the spermatozoa. Spermatogenesis in M. brachydactyla follows the general pattern observed in other brachyuran species but with several peculiarities. Annulate lamellae have been reported in brachyuran spermatogenesis during the diplotene stage of first spermatocytes, the early and mid-spermatids. Unlike previous observations, a Golgi complex has been found in mid-spermatids and is involved in the development of the acrosome. The Golgi complex produces two types of vesicles: light vesicles and electron-dense vesicles. The light vesicles merge into the cytoplasm, giving rise to the proacrosomal vesicle. The electron-dense vesicles are implicated in the formation of an electron-dense granule, which later merges with the proacrosomal vesicle. In the late spermatid, the endoplasmic reticulum and the Golgi complex degenerate and form the structures-organelles complex found in the spermatozoa. At the end of spermatogenesis, the materials in the proacrosomal vesicle aggregate in a two-step process, forming the characteristic concentric three-layered structure of the spermatozoon acrosome. The newly formed spermatozoa from testis show the typical brachyuran morphology.

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Cited by 52 publications

References 14 publications

Assessing the impact of spear fishing by using competitions records and underwater visual censuses

Assessing the impact of spear fishing by using competitions records and underwater visual censuses

Genetic variation of the spiny spider crab Maja brachydactyla in the northeastern Atlantic

Spermatogenesis of the spider crab Maja brachydactyla (Decapoda: Brachyura)

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