Effect of twine thickness on selectivity of gillnets for bogue, Boops boops,in Turkish waters

To investigate the effect of twine thickness on the selectivity of multifilament gillnet targeting bogue,Boops boops L., four different stations were sampled between March and November 2008 in the northern Aegean Sea. Gillnets with 22, 23, and 25 mm nominal mesh size (bar length) each having two different twine thicknesses (approximately 0.45 mm and 0.54 mm ∅) were applied for this purpose. The deviances from the SELECT method revealed that lognormal models provided the best fits for both of the twine thicknesses. Results from the two-way ANOVA analyses revealed that the mean total lengths increased with the mesh size (F = 87.36; df = 2; P < 0.0001) and decreased with the twine thickness (F = 46.12; df = 1; P < 0.0001). The 22 mm mesh size net (0.45 mm ∅) captured significantly larger fish than the 23 mm mesh size net (0.54 mm ∅) probably due to the higher elasticity and flexibility of the thinner twine. Thus, fisheries managers should take into consideration the twine thickness while advising mesh size regulations in gillnet fisheries

Fishing gear losses in the Gökova Special Environmental Protection Area (SEPA), eastern Mediterranean, Turkey

This two-stage study was designed to determine the types and quantities of lost fishing gear and their distribution in the Gökova Special Environmental Protection Area (SEPA), eastern Mediterranean Sea. The study was carried out in approx. 15% of the total Gökova SEPA (7000 hectares), where traditional fishing is intensive. In the first phase of the study, the owners of all fishing boats (about 67% of the local fishermen in Gökova SEPA, n = 56) were interviewed using a structured questionnaire. In the second phase, diving surveys were conducted at 14 locations to locate and identify lost fishing gear, estimate the extent of the loss, and deduce the coherence between the diving survey and the questionnaire data. The questionnaire results showed that 0.84% of gillnets, 3.41% of trammel nets, and 79.2% of longlines were lost during 2007 and that the major cause of gear loss was snagging on bottom structures. In the diving surveys, 22 600 m2 (2.26 hectares) of the bottom area were scanned, and an estimated 157 m of gill and trammel nets and 36 280 m of longline nets were located per hectare in the observed area. Moreover, at diving locations D1 and D2, lost trammel and gill nets were 'ghost fishing', suggesting that these lost gear should be removed from the ecosystem. A retrieval project coordinated by universities, fishery cooperatives, and NGOs might help accelerate efforts towards the removal of this lost gear. © 2010 Blackwell Verlag, Berlin

Comparison of fish aggregating devices (FADs) having different attractors

In this study three FAD types, which were being commonly used in small scale fisheries and had different attractors were tried. Attractors such as pyramid, rope and panel types were tied to static FADs. The fish species and densities attracted by them were examined. The samplings were made through visual census, trammel nets and line fishing before and after the deploying of FADs. Any significant difference was not able to be found statistically between the attractors tied to fish aggregating devices. In the result of observation and samplings before and after the deploying of FADs, while 10 fish species belong to 6 families were observed before deployment, 16 fish species belong to 11 families were determined after the deployment of the FADs. © Medwell Journals, 2010