Past and recent demographic histories of western Mediterranean demersal chondrichthyans
Chondrichthyans (sharks, rays and chimaeras) play a key role in marine ecosystems, since they are top predators. Because of their life-history traits (slow growth, late maturity and low fecundity), they are especially vulnerable to fishing. In the Mediterranean, which hosts 7% of living chondrichthy...
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Universitat de les Illes Balears (UIB)
2017
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ftieo:oai:repositorio.ieo.es:10508/11363 2023-05-15T16:01:00+02:00 Past and recent demographic histories of western Mediterranean demersal chondrichthyans Ramírez-Amaro, S. (Sergio) Massutí, E. (Enric) Terrasa, B. (Bárbara)| Western Mediterranean Sea 2017 http://hdl.handle.net/10508/11363 eng eng Universitat de les Illes Balears (UIB) Centro Oceanográfico de Baleares http://hdl.handle.net/10508/11363 Universitat de les Illes Balears (UIB). Palma (Spain): 2017-237 Atribución-NoComercial-SinDerivadas 3.0 España http://creativecommons.org/licenses/by-nc-nd/3.0/es/ openAccess CC-BY-NC-ND Chondrichthyans batoids Scyliorhinus canicula Galeus melastomus Etmopterus spinax Raja clavata Raja spp Dasyatis cf. tortonesei Dipturus nidarosiensis vulnerable species demersal assemblages diversity population dynamics abundance biomass length at first maturity length frequency population genetic structure connectivity demographic history phylogeny speciation mtDNA STRs DNA barcoding temporal trends assessment conservation status management recovery fisheries bottom trawl research survey GFCM Mediterranean doctoralThesis 2017 ftieo 2022-09-27T23:46:47Z Chondrichthyans (sharks, rays and chimaeras) play a key role in marine ecosystems, since they are top predators. Because of their life-history traits (slow growth, late maturity and low fecundity), they are especially vulnerable to fishing. In the Mediterranean, which hosts 7% of living chondrichthyans, a notable change in marine ecosystems has occurred due to anthropogenic impacts, with overfishing as one of the most important. For this reason, and because these species can be an important by-catch of fisheries, the International Union for Conservation of Nature (IUCN) considers this region a key hotspot of extinction risk for chondrichthyans. This Thesis contributes to improve the scientific knowledge of chondrichthyans on the circalittoral and bathyal soft bottoms along the western Mediterranean. Methods traditionally used to study population dynamics and biological communities, jointly with molecular tools, were applied to assess the past and present status of these vulnerable species. Data and samples were obtained during the MEDITS bottom trawl research surveys, developed annually in spring-summer since 1994 throughout the four geographic sub-areas (GSAs) established by the General Fisheries Commission for the Mediterranean (GFCM) in the study area: Northern Alboran Sea (GSA01) and Alboran Island (GSA02) considered jointly as GSA01, Balearic Islands (GSA05) and Northern Spain (GSA06). A total of 33 species of demersal chondrichthyans, belonging to 13 families were identified, of which 26, 28, and 19 species were caught in GSA01, GSA05 and GSA06, respectively. Two different assemblages were detected in each GSA, corresponding to the continental shelf and slope. The highest values of diversity, abundance, and biomass were recorded on the continental shelf of GSA05 and the slope of GSA01, while GSA06 showed the lowest values at both depth strata. These results can be explained by differences in trawl fishing exploitation and types of bottom between GSAs. Biological parameters such as optimum depth, length at ... Doctoral or Postdoctoral Thesis Dipturus nidarosiensis Instituto Español de Oceanografía: e-IEO Canicula ENVELOPE(-58.515,-58.515,-63.717,-63.717) |
institution |
Open Polar |
collection |
Instituto Español de Oceanografía: e-IEO |
op_collection_id |
ftieo |
language |
English |
topic |
Chondrichthyans batoids Scyliorhinus canicula Galeus melastomus Etmopterus spinax Raja clavata Raja spp Dasyatis cf. tortonesei Dipturus nidarosiensis vulnerable species demersal assemblages diversity population dynamics abundance biomass length at first maturity length frequency population genetic structure connectivity demographic history phylogeny speciation mtDNA STRs DNA barcoding temporal trends assessment conservation status management recovery fisheries bottom trawl research survey GFCM Mediterranean |
spellingShingle |
Chondrichthyans batoids Scyliorhinus canicula Galeus melastomus Etmopterus spinax Raja clavata Raja spp Dasyatis cf. tortonesei Dipturus nidarosiensis vulnerable species demersal assemblages diversity population dynamics abundance biomass length at first maturity length frequency population genetic structure connectivity demographic history phylogeny speciation mtDNA STRs DNA barcoding temporal trends assessment conservation status management recovery fisheries bottom trawl research survey GFCM Mediterranean Ramírez-Amaro, S. (Sergio) Past and recent demographic histories of western Mediterranean demersal chondrichthyans |
topic_facet |
Chondrichthyans batoids Scyliorhinus canicula Galeus melastomus Etmopterus spinax Raja clavata Raja spp Dasyatis cf. tortonesei Dipturus nidarosiensis vulnerable species demersal assemblages diversity population dynamics abundance biomass length at first maturity length frequency population genetic structure connectivity demographic history phylogeny speciation mtDNA STRs DNA barcoding temporal trends assessment conservation status management recovery fisheries bottom trawl research survey GFCM Mediterranean |
description |
Chondrichthyans (sharks, rays and chimaeras) play a key role in marine ecosystems, since they are top predators. Because of their life-history traits (slow growth, late maturity and low fecundity), they are especially vulnerable to fishing. In the Mediterranean, which hosts 7% of living chondrichthyans, a notable change in marine ecosystems has occurred due to anthropogenic impacts, with overfishing as one of the most important. For this reason, and because these species can be an important by-catch of fisheries, the International Union for Conservation of Nature (IUCN) considers this region a key hotspot of extinction risk for chondrichthyans. This Thesis contributes to improve the scientific knowledge of chondrichthyans on the circalittoral and bathyal soft bottoms along the western Mediterranean. Methods traditionally used to study population dynamics and biological communities, jointly with molecular tools, were applied to assess the past and present status of these vulnerable species. Data and samples were obtained during the MEDITS bottom trawl research surveys, developed annually in spring-summer since 1994 throughout the four geographic sub-areas (GSAs) established by the General Fisheries Commission for the Mediterranean (GFCM) in the study area: Northern Alboran Sea (GSA01) and Alboran Island (GSA02) considered jointly as GSA01, Balearic Islands (GSA05) and Northern Spain (GSA06). A total of 33 species of demersal chondrichthyans, belonging to 13 families were identified, of which 26, 28, and 19 species were caught in GSA01, GSA05 and GSA06, respectively. Two different assemblages were detected in each GSA, corresponding to the continental shelf and slope. The highest values of diversity, abundance, and biomass were recorded on the continental shelf of GSA05 and the slope of GSA01, while GSA06 showed the lowest values at both depth strata. These results can be explained by differences in trawl fishing exploitation and types of bottom between GSAs. Biological parameters such as optimum depth, length at ... |
author2 |
Massutí, E. (Enric) Terrasa, B. (Bárbara)| |
format |
Doctoral or Postdoctoral Thesis |
author |
Ramírez-Amaro, S. (Sergio) |
author_facet |
Ramírez-Amaro, S. (Sergio) |
author_sort |
Ramírez-Amaro, S. (Sergio) |
title |
Past and recent demographic histories of western Mediterranean demersal chondrichthyans |
title_short |
Past and recent demographic histories of western Mediterranean demersal chondrichthyans |
title_full |
Past and recent demographic histories of western Mediterranean demersal chondrichthyans |
title_fullStr |
Past and recent demographic histories of western Mediterranean demersal chondrichthyans |
title_full_unstemmed |
Past and recent demographic histories of western Mediterranean demersal chondrichthyans |
title_sort |
past and recent demographic histories of western mediterranean demersal chondrichthyans |
publisher |
Universitat de les Illes Balears (UIB) |
publishDate |
2017 |
url |
http://hdl.handle.net/10508/11363 |
op_coverage |
Western Mediterranean Sea |
long_lat |
ENVELOPE(-58.515,-58.515,-63.717,-63.717) |
geographic |
Canicula |
geographic_facet |
Canicula |
genre |
Dipturus nidarosiensis |
genre_facet |
Dipturus nidarosiensis |
op_relation |
http://hdl.handle.net/10508/11363 Universitat de les Illes Balears (UIB). Palma (Spain): 2017-237 |
op_rights |
Atribución-NoComercial-SinDerivadas 3.0 España http://creativecommons.org/licenses/by-nc-nd/3.0/es/ openAccess |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766397011510165504 |