EXPERIMENTAL ASSESSMENT OF THE EFFECT OF BYCATCH REDUCTION DEVICES IN AN ARTISANAL SHRIMP TRAWL FIHERY OF THE GULF OF SALAMANCA, COLOMBIAN CARIBBEAN

Abstract

In the Colombian Caribbean Sea the negative impacts on the bycatch cannot be only attributed to the industrial shrimp trawl flet, but also to the artisanal flet that exploits the shrimp resource by using beach seines and trawls locally called “changas”. These fihing gears capture a high proportion of juvenile fifih, which are generally discarded. Therefore, the objective of this work was to evaluate the effect of three types of bycatch reduction devices (BRD) Florida Fisheye (FF), Squared Mesh Panel (SMP), and Radial Escapement Section (RES) in the catch of this fihery. Two trials were carried out in two contrasting seasons, one in the rainy season and one in the dry one. Each test net was towed 28-30 times in parallel (one boat with a net equipped with a BRD and a control boat with a net of the same design and dimensions but no BRD), for a total of 90 paired samples in the rainy season and 84 in the dry season. Seasonal differences in the exclusion of both shrimp and bycatch were found, due to the high catch rates of jellyfih in the dry season, which affected the normal performance of all the three types of BRDs, especially of the RES. The rainy season trials showed that, opposite to the VMC and the SRE, the OP does not reduce signifiantly (p > 0.05) the discards, but only the incidental catch (p < 0.05). Although the exclusion power of the VMC and the SRE did not signifiantly differ (p > 0.05), we conclude that the VMC is a best choice for mitigating the discards of this fihery, due to its lower cost and conveniences of handling and assembly. However, some modifiations in the location and dimensions of this BRD in the codend should be tested so as to increase the retention of shrimp during the hauling of the gear by hand. Thus, adoption of this device by fihermen would be facilitated, with the consequent environmental and socioeconomic benefis.