The Effect of Seasons on Gill Net Selectivity

Year 2019, Volume: 34 Issue: 4, 116 - 121, 16.09.2019

Adnan Ayaz , Uğur Altınağaç Alkan Öztekin , Uğur Özekinci

https://doi.org/10.26650/ASE2019575395

Abstract

In this study, the aim was to investigate the seasonal variations in the selectivity of striped red mullet (Mullus surmuletus L., 1758) captured by gill nets during the year in the north Aegean Sea. Fisheries’ operations were carried out between August 2008 and August 2009. Gill nets with 18, 20, and 22 mm mesh sizes were used in the trials. These nets are widely used in the region. Gill nets were deployed three hours before sunset and were removed from the sea at sunset. Similarly, the nets were set up two hours before sunrise and hauled from the sea an hour after sunrise. The SELECT method was used to determine the selectivity of gill nets. The deviances from the SELECT method revealed that lognormal models gave the best fits for all seasons. As a result of the calculations made according to the lognormal model, the modal lengths of the gill nets were calculated as the shortest in the spring season and the longest in the summer. The spread values of the selectivity curves of the experimental gill nets were determined the lowest in the winter season and the highest in the summer season. As a result of selectivity analysis, the differences between the spring and summer season modal lengths of the nets were calculated as 1.5 cm, 1.65 cm, and 1.82 cm for the nets with 18 mm, 20 mm, and 22 mm mesh sizes, respectively. The study results showed that the fishing season was important in gill nets selectivity.

Keywords

Seasons, gill net, selectivity, SELECT method, Aegean Sea

Supporting Institution

TÜBİTAK

Project Number

106Y021

Thanks

The present study was supported by TUBITAK project 106Y021

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