The effect of monofilament thickness on the catches of gillnets for common sole in the Mediterranean small-scale fishery

Published source details Grati F., Bolognini L., Domenichetti F., Fabi G., Polidori P., Santelli A., Scarcella G. & Spagnolo A. (2015) The effect of monofilament thickness on the catches of gillnets for common sole in the Mediterranean small-scale fishery. Fisheries Research, 164, 170-177.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Modify gillnet or entangling (trammel/tangle) net configuration Action Link

Modify gillnet or entangling (trammel/tangle) net configuration

A replicated study in 2010 of an area of sandy-mud seabed in the Adriatic Sea, Italy (Grati et al. 2015) found that modifying the configuration of a gillnet by increasing the twine diameter reduced the discards of non-commercial, but not commercial, species (fish and invertebrates). The percentage of discarded non-commercial species (fish and invertebrates) in catches decreased with increases in twine diameter (0.30 mm: 27%, 0.25 mm: 30%, 0.22 mm: 33%, 0.20 mm: 41%, 0.18: 39%), but there was no differences between diameters for discarded commercial species (5–7%). The average number of species caught was also lower for the thickest twine diameter compared to the three thinnest (0.30 mm: 7, 0.25 mm: 8, 0.18–0.22 mm: 9). In addition, catch rates of the target fish species, common sole Solea solea, were similar between twine diameters (data reported as statistical results). During July–October 2010, a total of 20 gillnet sets (deployments) were fished for 10–12 h. For each set, 50 single-twine gillnets (10 of each twine diameter: 0.18, 0.20, 0.22, 0.25 and 0.30 mm) were randomly arranged in one group, 1.5 m apart. All species caught were identified and separated into commercially valuable catch and unwanted catch.

(Summarised by: Khatija Alliji)