Penaeid and carid community changes in the St Lucia estuarine lake system, South Africa, under low water level, extended closed periods and marine reconnection conditions

Samples were collected biannually in spring and autumn from November 2004 to May 2012 using seine nets. Seven penaeid and seven carid species were recorded, of which Palaemon pacificus , P. peringueyi , Penaeus indicus and Metapenaeus monoceros were the most abundant.

The decline from 2004 to 2007 in both species recorded and densities of freshwater, estuarine and marine species during the initial closed period was linked to increased salinity, lack of recruitment and reduced estuarine surface area. Increased wave action and high seas following Cyclone Gamede opened the mouth in March 2007 after a 57-month closed period, resulting in recruitment of marine species, predominantly P. indicus , followed by a decline in densities after reclosure in August 2007.