Abstract

Encircling gillnets are known in the Gulf of Salamanca as "boliche", are active fishing gears which originally operated in the Ciénaga Grande de Santa Marta and from the 80s began to be used at sea for the purpose to capture medium pelagic fish. Despite operating as a purse seine, the principle of capture is gillnet. This work identified the main historical changes in constructive parameters of encircling gillnets and their effect on the magnitude and spatial distribution of catches. To get to know about current technical details of the gear in-situ measurements were performed, while historical were determined with semi-structured surveys to fishermen. To establish historical changes in CPUE and fishing sites the databases fishery landings were used. The results indicate that the main change in gear was the net height, which increased from 1 to 3 mesh (7 to 19 m), this adaptation was aimed of put nets at greater depths, and consequently the sinker in footrope was also amended. The border of this fishery expanded, reaching a maximum depth of 19 m in fishing hauls. CPUE increased 3.1 times between the start and end of the period evaluated (1994-2008). This study demonstrates the ability of fishermen to make technological changes to fishing gear and increase their catches. However, to determine the increase in profitability the cost should be studied because fishing is done currently ever further.

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