Pesquería y crecimiento de la piangua (Arcoida: Arcidae) Anadara tuberculosa en la Bahía de Málaga del Pacífico colombiano, 2005-2007
Carlos Lucero, Jaime Cantera & Raúl Neira


ABSTRACT

The fisheries and growth of Ark Clams (Arcoida: Arcidae) Anadara tuberculosa in Málaga Bay, Colombian Pacific, 2005-2007. A. tuberculosa, is the most important bivalve species under exploitation in Colombia. Here, this species is found from Cabo Corrientes (Chocó) to the Ecuador border, in muddy substrates of mangrove forests. In order to determine the growth and the state of fisheries of A. tuberculosa, between December 2005 and April 2007, both, biological (in situ) and commercial studies were performed at Bahia Malaga (Colombian Pacific). The growth was estimated using the general equation of von Bertalanffy, with prior application of the methods of Bhattacharya and Powell-Wetherall. Mortality and exploitation rate were determined using the inverse model of von Bertalanffy. For the biological samplings, a total of 446 individuals of A. tuberculosa (0.64±0.13 individuals/m²) and 53 individuals (0.05±0.049 individuals/m²) of Anadara similis were collected. 79% of the catch was below 51mm. In the commercial samplings, 836 individuals of A. tuberculosa (size range: 31.1-92.2mm) were measured, but no A. similis samples were available for this. Recruitment of A. tuberculosa was higher during March, May, July and November. According to the data, A. tuberculosa might be reproducing during December, February, April and August. The data gathered with the biological samples were more reliable on explaining the growth of A. tuberculosa (K=0.332per year, L∞=88.256mm, t0=0.0556years) than the one taken from market samples (K =0.256per year, L∞=89.77mm, t0=0733years). The high exploitation rate (77%), the low density and the high mortality suggest that A. tuberculosa is in overexploitation state in Bahia Malaga and management strategies are urgently required.

RESUMEN

Anadara tuberculosa es el bivalvo de mayor explotación en la costa pacífica de Colombia, se distribuye en Colombia desde Cabo Corrientes (Chocó) hasta los límites con el Ecuador, está asociada al bosque de manglar. Con el objetivo de determinar el estado de la pesca y su crecimiento, entre diciembre 2005 y abril 2007, se realizaron muestreos comerciales no sistemáticos y un muestreo biológico intensivo en Bahía Málaga. El crecimiento, se estimó utilizando la forma general de von Bertalanffy, con previa aplicación de los métodos de Bhattacharya & Powell-Wetherall. La mortalidad y tasa de explotación fueron determinadas usando el modelo inverso de von Bertalanffy. Se encontró una densidad de 0.64±0.13 individuos/ m². En el muestreo comercial se midieron 836 individuos de Anadara tuberculosa con tallas entre 31.1mm y 92.2mm. Los datos biológicos fueron más confiables para explicar el crecimiento de Anadara tuberculosa (K=0.332 por año, L∞ =88.256mm, t0=-0.0556 años) que los datos comerciales (K=0.256 por año, L∞ =89.77mm, t0=0.733 años). La tasa de explotación alta (77%), baja densidad y alta mortalidad, sugieren que Anadara tuberculosa se encuentra en un estado de sobre-explotación y requiere urgentes estrategias de manejo.