Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards
Analytical stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea from 1975 to 1999 was performed taking into account the occurrence of discarding at sea of sardine caught by the Italian fleet. We have attempted to model the fishermen’s behaviour using data collected by an obser...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Consejo Superior de Investigaciones Científicas
2005-12-01
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| Series: | Scientia Marina |
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| Online Access: | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/288 |
| _version_ | 1819297157371396096 |
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| author | Alberto Santojanni Nando Cingolani Enrico Arneri Geoff Kirkwood Andrea Belardinelli Gianfranco Giannetti Sabrina Colella Fortunata Donato Catherine Barry |
| author_facet | Alberto Santojanni Nando Cingolani Enrico Arneri Geoff Kirkwood Andrea Belardinelli Gianfranco Giannetti Sabrina Colella Fortunata Donato Catherine Barry |
| author_sort | Alberto Santojanni |
| collection | DOAJ |
| description | Analytical stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea from 1975 to 1999 was performed taking into account the occurrence of discarding at sea of sardine caught by the Italian fleet. We have attempted to model the fishermen’s behaviour using data collected by an observer on board fishing vessels. This enabled us to estimate the amounts of discards, which were added to the catches landed, collected by ISMAR-CNR Ancona. Discards were calculated for the period 1987-1999, as their values were negligible before 1987. Stock assessment on the entire data series from 1975-1999 was carried out by means of Virtual Population Analysis (VPA). Discarding behaviour differs among ports due to different local customs and market conditions. The quantity added to the annual total catch ranged from 900 tonnes to 4000 tonnes, corresponding to between 2% and 15% of the total corrected catch. VPAs indicated that mid-year sardine stock biomass rose steadily from 400,000 tonnes in 1975 to a peak of 950,000 tonnes in 1984. Subsequently, biomass declined steadily to the more recent values, around 300,000 tonnes. Although discarded quantities were relatively high, their influence on stock assessment was not strong because of the high level of both catch and, in particular, estimated biomass at sea. |
| first_indexed | 2024-12-24T05:09:32Z |
| format | Article |
| id | doaj.art-b595dbfbc7de4c9d99e4516135da70cf |
| institution | Directory Open Access Journal |
| issn | 0214-8358 1886-8134 |
| language | English |
| last_indexed | 2024-12-24T05:09:32Z |
| publishDate | 2005-12-01 |
| publisher | Consejo Superior de Investigaciones Científicas |
| record_format | Article |
| series | Scientia Marina |
| spelling | doaj.art-b595dbfbc7de4c9d99e4516135da70cf2022-12-21T17:13:44ZengConsejo Superior de Investigaciones CientíficasScientia Marina0214-83581886-81342005-12-0169460361710.3989/scimar.2005.69n4603284Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discardsAlberto Santojanni0Nando Cingolani1Enrico Arneri2Geoff Kirkwood3Andrea Belardinelli4Gianfranco Giannetti5Sabrina Colella6Fortunata Donato7Catherine Barry8ISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaRenewable Resources Assessment Group (RRAG), Department of Environmental Science and TechnologyISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaISMAR - CNR, Sezione Pesca Marittima, Largo Fiera della PescaMarine Resources Assessment Group (MRAG)Analytical stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea from 1975 to 1999 was performed taking into account the occurrence of discarding at sea of sardine caught by the Italian fleet. We have attempted to model the fishermen’s behaviour using data collected by an observer on board fishing vessels. This enabled us to estimate the amounts of discards, which were added to the catches landed, collected by ISMAR-CNR Ancona. Discards were calculated for the period 1987-1999, as their values were negligible before 1987. Stock assessment on the entire data series from 1975-1999 was carried out by means of Virtual Population Analysis (VPA). Discarding behaviour differs among ports due to different local customs and market conditions. The quantity added to the annual total catch ranged from 900 tonnes to 4000 tonnes, corresponding to between 2% and 15% of the total corrected catch. VPAs indicated that mid-year sardine stock biomass rose steadily from 400,000 tonnes in 1975 to a peak of 950,000 tonnes in 1984. Subsequently, biomass declined steadily to the more recent values, around 300,000 tonnes. Although discarded quantities were relatively high, their influence on stock assessment was not strong because of the high level of both catch and, in particular, estimated biomass at sea.http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/288sardineadriatic seadiscardsobserver dataregression tree modelsstock assessmentpopulation dynamics methodsvirtual population analysis (vpa) |
| spellingShingle | Alberto Santojanni Nando Cingolani Enrico Arneri Geoff Kirkwood Andrea Belardinelli Gianfranco Giannetti Sabrina Colella Fortunata Donato Catherine Barry Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards Scientia Marina sardine adriatic sea discards observer data regression tree models stock assessment population dynamics methods virtual population analysis (vpa) |
| title | Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards |
| title_full | Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards |
| title_fullStr | Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards |
| title_full_unstemmed | Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards |
| title_short | Stock assessment of sardine (Sardina pilchardus, Walb.) in the Adriatic Sea with an estimate of discards |
| title_sort | stock assessment of sardine sardina pilchardus walb in the adriatic sea with an estimate of discards |
| topic | sardine adriatic sea discards observer data regression tree models stock assessment population dynamics methods virtual population analysis (vpa) |
| url | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/288 |
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