Vitale, Sergio and Milisenda, Giacomo and Gristina, Michele and Baiata, Pasquale and Bonanomi, Sara and Colloca, Francesco and Gancitano, Vita and Scannela, Danilo and Fiorentino, Fabio and Sala, Antonello (2018) Towards more selective Mediterranean trawl fisheries: are juveniles and trash excluder devices effective tools for reducing undersized catches? Scientia Marina, 82 (S1215). pp. 215-223. ISSN 0214-8358
|
Text
sm82s1215.pdf - Published Version Download (1MB) | Preview |
Abstract
Mediterranean trawl fisheries are characterized by a critical combination of high fishing effort and low size at first capture for most commercial species. In this study we tested the use of sorting grids installed on bottom trawl nets to minimize the catch of undersized deep-water rose shrimp (Parapenaeus longirostris, DPS) and European hake (Merluccius merluccius, HKE). The catch of a traditional trawl net was compared with that obtained with the same net equipped with ad hoc designed juveniles and trash excluder devices (JTEDs) during an experimental survey. Three different JTEDs were tested: the first (G1-SM40) was built with a net of 40-mm square mesh; the second (G2-ST20) and third (G3-ST25) with vertical steel bars spaced 20 and 25 mm, respectively. The probability of retaining DPS and HKE by length class in trawl nets with and without JTED was analysed using generalized additive mixed models. With G1-SM40, the reduction of undersized individuals in the cod-end was about 60% and 44% for DPS and HKE, respectively. With G2-ST20, a 34% catch decrease of HKE individuals smaller than 20 cm total length was observed. A loss of marketable fractions of DPS was recorded with G1-SM40 (–25%) and G2-ST20 (30%). Finally, JTD G3-ST25 was efficient at reducing the catch of undersized specimens of DPS and HKE, but showed a higher loss of marketable fractions than the other JTEDs. Although further fishing trials would be required to maximize the sorting efficiency of the grids, the results obtained clearly indicated that grids can substantially reduce unwanted catches of undersized DPS and HKE in Mediterranean bottom trawl fisheries.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Sorting grids; JTED; Mediterranean trawl fisheries; Parapenaeus longirostris; Merluccius merluccius; trawl selectivity; Strait of Sicily |
| Subjects: | 500 Scienze naturali e Matematica > 510 Matematica > 511 Principi generali della Matematica > 511.8 Modelli matematici (Simulazione matematica) 500 Scienze naturali e Matematica > 570 Scienze della vita; Biologia > 577.7 Ecologia marina |
| Depositing User: | Dr Sergio Vitale |
| Date Deposited: | 14 Mar 2019 10:34 |
| Last Modified: | 14 Mar 2019 10:34 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/18868 |
Actions (login required)
 |
View Item |
