Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal)
Although the bivalve dredge used on the Algarve coast (southern Portugal) is highly selective for the target species, in some periods of the year the bycatch can exceed the catch of the commercial species. The present study aimed to quantify the bycatch and discards, estimate damage and mortality, a...
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| Format: | Article |
| Language: | English |
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Consejo Superior de Investigaciones Científicas
2018-12-01
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| Series: | Scientia Marina |
| Subjects: | |
| Online Access: | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1760 |
| _version_ | 1818669880522571776 |
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| author | Mariana Anjos Fábio Pereira Paulo Vasconcelos Sandra Joaquim Domitília Matias Karim Erzini Miguel Gaspar |
| author_facet | Mariana Anjos Fábio Pereira Paulo Vasconcelos Sandra Joaquim Domitília Matias Karim Erzini Miguel Gaspar |
| author_sort | Mariana Anjos |
| collection | DOAJ |
| description | Although the bivalve dredge used on the Algarve coast (southern Portugal) is highly selective for the target species, in some periods of the year the bycatch can exceed the catch of the commercial species. The present study aimed to quantify the bycatch and discards, estimate damage and mortality, and propose management measures to minimize discards and mortality. A total of 15 fishing surveys (60 tows) were performed using two types of dredges (“DDredge” targeting Donax trunculus and “SDredge” targeting Spisula solida and Chamelea gallina). Of the 85257 individuals (392.4 kg) of 52 taxa that were caught, 73.4% belonged to the target species, 22.1% to commercially undersized target species and 4.5% to bycatch species. Bycatch rates were lower for SDredge (13.5% in number and 6.3% in weight) than for DDredge (46.0% in number and 32.9% in weight). Damage and mortality rates were also lower using SDredge (1.3% and 1.0% of the total catches, respectively) than using DDredge (4.0% and 2.8% of the total catches). Survival experiments revealed the diverse vulnerability of the taxa and confirmed the influence of the damage score on the mortality rate. The results gathered in the present study encourage the adoption of a bycatch reduction device to reduce both direct and indirect mortality. |
| first_indexed | 2024-12-17T06:59:15Z |
| format | Article |
| id | doaj.art-d2565b043a3c487bb07cf95f34590122 |
| institution | Directory Open Access Journal |
| issn | 0214-8358 1886-8134 |
| language | English |
| last_indexed | 2024-12-17T06:59:15Z |
| publishDate | 2018-12-01 |
| publisher | Consejo Superior de Investigaciones Científicas |
| record_format | Article |
| series | Scientia Marina |
| spelling | doaj.art-d2565b043a3c487bb07cf95f345901222022-12-21T21:59:20ZengConsejo Superior de Investigaciones CientíficasScientia Marina0214-83581886-81342018-12-0182S1759010.3989/scimar.04742.08A1725Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal)Mariana Anjos0https://orcid.org/0000-0001-5518-2110Fábio Pereira1https://orcid.org/0000-0002-1806-0189Paulo Vasconcelos2https://orcid.org/0000-0002-2119-2297Sandra Joaquim3https://orcid.org/0000-0002-6324-5908Domitília Matias4https://orcid.org/0000-0002-2191-7497Karim Erzini5https://orcid.org/0000-0002-1411-0126Miguel Gaspar6https://orcid.org/0000-0001-9245-8518Centro de Ciências do Mar (CCMAR), Universidade do AlgarveCentro de Ciências do Mar (CCMAR), Universidade do Algarve - Instituto Português do Mar e da Atmosfera (IPMA)Instituto Português do Mar e da Atmosfera (IPMA) - Centro de Estudos do Ambiente e do Mar (CESAM), Departamento de Biologia, Universidade de AveiroInstituto Português do Mar e da Atmosfera (IPMA) - Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do PortoInstituto Português do Mar e da Atmosfera (IPMA) - Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR), Universidade do PortoCentro de Ciências do Mar (CCMAR), Universidade do AlgarveCentro de Ciências do Mar (CCMAR), Universidade do Algarve - Instituto Português do Mar e da Atmosfera (IPMA)Although the bivalve dredge used on the Algarve coast (southern Portugal) is highly selective for the target species, in some periods of the year the bycatch can exceed the catch of the commercial species. The present study aimed to quantify the bycatch and discards, estimate damage and mortality, and propose management measures to minimize discards and mortality. A total of 15 fishing surveys (60 tows) were performed using two types of dredges (“DDredge” targeting Donax trunculus and “SDredge” targeting Spisula solida and Chamelea gallina). Of the 85257 individuals (392.4 kg) of 52 taxa that were caught, 73.4% belonged to the target species, 22.1% to commercially undersized target species and 4.5% to bycatch species. Bycatch rates were lower for SDredge (13.5% in number and 6.3% in weight) than for DDredge (46.0% in number and 32.9% in weight). Damage and mortality rates were also lower using SDredge (1.3% and 1.0% of the total catches, respectively) than using DDredge (4.0% and 2.8% of the total catches). Survival experiments revealed the diverse vulnerability of the taxa and confirmed the influence of the damage score on the mortality rate. The results gathered in the present study encourage the adoption of a bycatch reduction device to reduce both direct and indirect mortality.http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1760bivalve dredgingbycatchdiscardsdamage scoresurvival ratemetallic grid dredgefishing gear technical designbycatch reduction device |
| spellingShingle | Mariana Anjos Fábio Pereira Paulo Vasconcelos Sandra Joaquim Domitília Matias Karim Erzini Miguel Gaspar Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal) Scientia Marina bivalve dredging bycatch discards damage score survival rate metallic grid dredge fishing gear technical design bycatch reduction device |
| title | Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal) |
| title_full | Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal) |
| title_fullStr | Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal) |
| title_full_unstemmed | Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal) |
| title_short | Bycatch and discard survival rate in a small-scale bivalve dredge fishery along the Algarve coast (southern Portugal) |
| title_sort | bycatch and discard survival rate in a small scale bivalve dredge fishery along the algarve coast southern portugal |
| topic | bivalve dredging bycatch discards damage score survival rate metallic grid dredge fishing gear technical design bycatch reduction device |
| url | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/1760 |
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