INTERANNUAL VARIATION OF SIZE STRUCTURE AND REPRODUCTIVE ASPECTS OF THE PINK SHRIMP (FARFANTEPENAEUS BREVIROSTRIS) IN THE COLOMBIAN PACIFIC COAST

Abstract

The fishery of the deep water shrimp is a resource of great economic and social importance for the Colombian Pacific Coast. Farfantepenaeus brevirostris (pink shrimp) is the target resource supporting this fishery; however, reproductive information and the fishing effect on size structure with management implications, has not been documented in recent years. The aim of this study was to analyze the variation in size structure and reproductive aspects of F. brevirostris, therefore 45 hauls were sampled in three onboard fishery monitoring of the industrial trawl fleet per year, between 2009 and 2015. In each haul in situ morphometric characteristics and sexual maturity of 20262 individuals were recorded. 56.2% of individuals collected were females, however the ratio female: male of 1:0.8 was not significant. The size range caught by the fishing fleet did differ between sexes and years, showing that females were larger (50 mm and 200 mm in total length) than males (75 mm to 170 mm). In this regards, females showed the highest mean catch size in 2012 (128.04 mm) and the lowest in 2011 (114.9 mm), while males were larger in 2011 (166.6 mm) and smaller in 2015 (106.3 mm). The maturity function had a different pattern between sexes and constant variability in maturity curves among years, which meant estimating the average size at maturity (TMM) for F. brevirostris based on an average curve of seven years (TMM females = 130.6 mm and TMM males = 83.2 mm). The size structure obtained and maturity curves indicated that females are more susceptible to fishing (between 66% and 94% of immature individuals are harvested). However, catches showed that only 1% to 32% of males are immature, which enables a success reproductive strategy of the population to offset the fishing effect. Better control of gear selectivity and implementation of spatial-temporal fishing closures are suggested for the management and conservation of this resource.