Análisis de indicadores macro y microscópicos para establecer el periodo de máxima intensidad de desove de la anchoveta Engraulis ringens en la zona norte de Chile

Abstract

Although the period of maximum reproductive activity of anchoveta has long been established between July and December, this period can be further defined using microscopical maturity information. This rather unknown biological information is relevant to specify the period of maximum spawning intensity for the management of the fishery. In this work the period of anchoveta maximum spawning intensity is defined using macro and microscopic sexual maturity data from the years 2000 to 2010. The monthly variability of the Gonadosomatic Index (IGS) showed a higher reproductive activity from July onwards reaching a maximum value in August, with high IGS values been observed until December. Microscopical analysis allowed to precise this period between the first half of July and mid October. On the basis of expert judgment, the onset of maximum spawning intensity of anchovy can be established when the Spawning Activity Index (IAD) attains a sustained value of at least 25% during over 2 weeks non necessarily in a row, with a IGS equal or higher than 6%.