Standardization of small purse seiner fishing effort and its relation to fishing grounds in the eastern tropical sector of the Eastern Pacific Ocean

Abstract

Considering that fishing grounds could be locations where repetitive fishing efforts are carried out to guarantee economic gain, we analyzed the spatial distribution of the standardized effort associated with the foreign purse seine tuna fleet that operated in eastern tropical sector of the Eastern Pacific Ocean between 2009 and 2015, monitored by the Colombian Fisheries Observer Program. The standardization of the fishing power and fishing effort of 17 tuna vessels began with a principal component analysis applied to a correlation matrix calculated for purse seine length, height, and area, carrying capacity, vessel length, tonnage, and beam. The first principal component explained 72.58% of the variance and was used to develop a multiple linear regression model from which the mathematical expression to standardize fishing power (FP) was derived: FPvessel=1+1.84⋅12.10−1⋅C1. Fishing effort was standardized by multiplying the fishing power by the nominal effort of each vessel. Maps of the spatial distribution of these efforts as indicators of fishing grounds were then created. The highest concentration of fishing effort occurred between 2° and 4° N, and from the coastline to 82° W, coinciding with fishing grounds known as “Banco Tumaco”, “Pasacaballos”, and “Banco Colombia” in the southeastern part of the colombian Exclusive Economic Zone.