INIDEP Informe Técnico, 51: 57-76.

INIDEP Informe Técnico, 51: 57-76.

Renzi, M., Santos, B.  &  Simonazzi, M. 2003. Estructura por edad y sexo de la población de merluza.   Ver texto completo

Age and sex structure of hake population. Hake population structure in 1993, 1994, 1996, 1997 and 1998 and age and sex distribution during 1997 are analyzed. Data were obtained in research surveys. At the end of winter 1997 concentrations of juveniles were found in the San Jorge Gulf, with maximum yields of 10,000 individuals per trawl hour for age 1 and 2,500 individuals per trawl hour for age 2. The highest concentrations of adults were found in the Gulf and south of 47° S, between the 100 and 200 m isobath, (maximum yields of up to 1,700 individuals per trawl hour for age 3 and up to 90 individuals per trawl hour for age 7 and older). In spite of the decrease in population abundance, the basic age structure (juveniles, young adults and old adults) was stable in the period studied. Sex ratio of total population was approximately 1:1. Nevertheless, when sex and age proportion was estimated it was observed that, as of age 3, females were more abundant than males. The highest mortality rates for both sexes in the 1996-1997 period were observed in ages 3 and 4; in 1997-1998 they corresponded to ages 6 and 7.