Naslov
Assessment of size selectivity in hydraulic clam dredge fisheries

Autori
Sala, Antonello ; Brčić, Jure ; Herrmann, Bent ; Lucchetti, Alessandro ; Virgili, Massimo

Izvornik
Canadian journal of fisheries and aquatic sciences (0706-652X) 74 (2017), 3; 339-348

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
hydraulic dredge ; clam fisheries ; selectivity

Sažetak
In hydraulic dredge clam fisheries, the onboard mechanical sorting can be considered as the main catch selection process. The catch is mechanically sorted by a sieve made up of a series of successive grids with holes of decreasing diameter. The effect of the grid hole diameter and sorting speed of the vibrating sieve of a hydraulic dredger was investigated in a field study to determine its clam selection properties and to formulate proposals aimed at improving fishery management. Data analysis demonstrates that it is technically impossible to achieve a knife- edge selection and that there is scope for improving the size selection process, for instance by increasing grid hole diameter, which, however, can be accompanied by a reduced catch of both undersized and commercial-sized individuals. An increase in the hole diameter to 21.71 mm, while ensuring less than 5% retention of undersized individuals, would entail a retention of 67% of the commercial sizes. The modelling approach applied can be extended to investigations of other dredge gear types and nonmobile benthic species.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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