Determination of Dyneema Net Material Selectivity in Demersal Trawl Fishing
Project no. 1048 · Status: Kapanmış · 2016
Summary
In this study, the effect of Dyneema codend net on length selectivity were studied for some commercially important species such as red mullet (Mullus barbatus), blotched picarel (Spicara smaris), kupes (Boops boops) in Mediterranean bottom trawl fishing. The studies were carried out in the east of the Aegean Sea with a traditional bottom trawler named “Efsane G”.during the period of February and March 2018. The data were analyzed using SELNET (Herrmann et al., 2012, 2013) software. Selectivity parameters were obtained by taking into account the variation between hauls. Four different models, namely Logit, Probit, Gompertz and Richard, were tested in order to define the rav (l, v) value for each species. As a result of the analysis, the model showing the lowest AIC value (Akaike, 1974) was selected for the selectivity data analysis of the particular species and the data analyzes were made according to this model selected for the species. Richard model was chosen as the most suitable model for red mullet and L50 value was determined as = 13 cm (13.03) (p-value = 0.0007, R2 = 0.9921). These results obtained from 40 mm square mesh Dyneema net codend were compared to previous results for other traditional codends used in Mediterranean fisheries. It has been observed that the 40 mm square mesh Dyneema codend gave a much higher L50 value than the other standard traditional 44 mm diamond mesh codends made of PE material. These results shows that the flexible Dyneema codend has higher selectivity potential compared to traditional codends.