Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps
Obtaining data to study fish biology can be a challenge if a stock is fished by a variety of gears with different effort units and different selectivity, particularly if these gears only partially overlap in space and time. In this work, we attempted to study the biology of the spotted flounder Cith...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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EDP Sciences
2017-01-01
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| Series: | Aquatic Living Resources |
| Subjects: | |
| Online Access: | https://www.alr-journal.org/articles/alr/full_html/2017/01/alr170063/alr170063.html |
| _version_ | 1797698210831007744 |
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| author | Pappa Marianna Chychykalo Anastasiia Koutsidi Martha Mavraki Ninon Lefkaditou Evgenia Koutsikopoulos Constantin Tzanatos Evangelos |
| author_facet | Pappa Marianna Chychykalo Anastasiia Koutsidi Martha Mavraki Ninon Lefkaditou Evgenia Koutsikopoulos Constantin Tzanatos Evangelos |
| author_sort | Pappa Marianna |
| collection | DOAJ |
| description | Obtaining data to study fish biology can be a challenge if a stock is fished by a variety of gears with different effort units and different selectivity, particularly if these gears only partially overlap in space and time. In this work, we attempted to study the biology of the spotted flounder Citharus linguatula in the Patraikos Gulf and the adjacent central Ionian Sea (eastern Mediterranean) and to evaluate the current fisheries management. We characterized age composition and growth, length-at-maturity, and catch-per-unit-effort (CPUE) of spotted flounder from the catches of bottom trawls, gillnets and trammel nets for the period autumn 2013–2014. Variation of fish total length, gonadosomatic index, hepatosomatic index and condition factor was analyzed using generalized additive models (GAMs) with regard to sex, date, fishing gear and depth. We also modeled CPUE fluctuations of each gear by date, depth, longitude and latitude using GAMs. Fish age ranged from 1 to 5 years. A slightly allometric growth was documented with females attaining larger sizes than males. Length-at-maturity was 163 mm for females and 169 mm for males. The seasonal change of gonad maturity stages and the gonadosomatic index indicated spawning in late summer-autumn. Changes in length frequencies indicated that recruitment to the fisheries occurred in late spring-early winter in shallow depth (<40 m). The catch composition of trawls and the CPUE model results suggested that the selectivity of this gear should be regulated to reduce catching immature individuals of spotted flounder. The results further indicated that the seasonal trawl closure of the Patraikos Gulf contributes to reduce catching juveniles. |
| first_indexed | 2024-03-12T03:50:58Z |
| format | Article |
| id | doaj.art-cd2e9061f62b4c79af7512256e033e0b |
| institution | Directory Open Access Journal |
| issn | 1765-2952 |
| language | English |
| last_indexed | 2024-03-12T03:50:58Z |
| publishDate | 2017-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | Aquatic Living Resources |
| spelling | doaj.art-cd2e9061f62b4c79af7512256e033e0b2023-09-03T12:21:19ZengEDP SciencesAquatic Living Resources1765-29522017-01-01303210.1051/alr/2017032alr170063Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlapsPappa Marianna0Chychykalo Anastasiia1Koutsidi Martha2Mavraki Ninon3Lefkaditou Evgenia4Koutsikopoulos Constantin5Tzanatos Evangelos6https://orcid.org/0000-0001-9972-9632Section of Animal Biology, Department of Biology, University of PatrasSection of Animal Biology, Department of Biology, University of PatrasSection of Animal Biology, Department of Biology, University of PatrasSection of Animal Biology, Department of Biology, University of PatrasInstitute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine ResearchSection of Animal Biology, Department of Biology, University of PatrasSection of Animal Biology, Department of Biology, University of PatrasObtaining data to study fish biology can be a challenge if a stock is fished by a variety of gears with different effort units and different selectivity, particularly if these gears only partially overlap in space and time. In this work, we attempted to study the biology of the spotted flounder Citharus linguatula in the Patraikos Gulf and the adjacent central Ionian Sea (eastern Mediterranean) and to evaluate the current fisheries management. We characterized age composition and growth, length-at-maturity, and catch-per-unit-effort (CPUE) of spotted flounder from the catches of bottom trawls, gillnets and trammel nets for the period autumn 2013–2014. Variation of fish total length, gonadosomatic index, hepatosomatic index and condition factor was analyzed using generalized additive models (GAMs) with regard to sex, date, fishing gear and depth. We also modeled CPUE fluctuations of each gear by date, depth, longitude and latitude using GAMs. Fish age ranged from 1 to 5 years. A slightly allometric growth was documented with females attaining larger sizes than males. Length-at-maturity was 163 mm for females and 169 mm for males. The seasonal change of gonad maturity stages and the gonadosomatic index indicated spawning in late summer-autumn. Changes in length frequencies indicated that recruitment to the fisheries occurred in late spring-early winter in shallow depth (<40 m). The catch composition of trawls and the CPUE model results suggested that the selectivity of this gear should be regulated to reduce catching immature individuals of spotted flounder. The results further indicated that the seasonal trawl closure of the Patraikos Gulf contributes to reduce catching juveniles.https://www.alr-journal.org/articles/alr/full_html/2017/01/alr170063/alr170063.htmlcitharidaeflatfishmulti-gear fisheriesfisheries managementdynamicsgrowth |
| spellingShingle | Pappa Marianna Chychykalo Anastasiia Koutsidi Martha Mavraki Ninon Lefkaditou Evgenia Koutsikopoulos Constantin Tzanatos Evangelos Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps Aquatic Living Resources citharidae flatfish multi-gear fisheries fisheries management dynamics growth |
| title | Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps |
| title_full | Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps |
| title_fullStr | Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps |
| title_full_unstemmed | Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps |
| title_short | Biology and fisheries of the spotted flounder (Citharus linguatula) caught by multiple gears with partial spatiotemporal overlaps |
| title_sort | biology and fisheries of the spotted flounder citharus linguatula caught by multiple gears with partial spatiotemporal overlaps |
| topic | citharidae flatfish multi-gear fisheries fisheries management dynamics growth |
| url | https://www.alr-journal.org/articles/alr/full_html/2017/01/alr170063/alr170063.html |
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