Population structure and recruitment of penaeid shrimps in mozambique

Abstract

This study characterizes the population structure and identifies nursery areas and recruitment seasons of penaeid shrimps in the Pungué river estuary of Mozambique. Shrimp samples were obtained from 12 trawl stations at monthly intervals during 2004. Six species were found, two of which (Fenneropenaeus indicus and Metapenaeus monoceros) constituted
99% in numbers of the total. Both had a size distribution of 10-50 mm carapace length. Males represented the dominant sex in both species. The estuary is important in their life cycles in supporting large numbers of juveniles. M. monoceros juveniles were abundant in all sections of the estuary during the latter part of the rainy season. F. indicus, juveniles were in lower proportion than adults throughout the estuary, but increased in abundance over the rain season. Recruits migrating from the estuary reach adjacent industrial fishing areas after 1-2 months. It is confirmed that the current annual seasonal closure (November-March) of the entire Sofala Bank is adequate for the protection of juveniles in the estuary. Given the contribution of this estuary to the entire shrimp fishing industry of the Sofala Bank there is a need to strengthen enforcement of management regulations.