Moreton Bay, Queensland: A Nursery Area for Juvenile Penaeid Prawns

Abstract

Moreton Bay was separated into groups of similar areas using three different sets of environmental parameters. These were (1) salinity-temperature (S-T), (2) sediments, and (3) seagrasses.

Five seagrass communities were present, although only one was found in areas influenced by river outflow. Their abundance showed no distinguishable seasonal patterns, but differences were observed between the same communities at different locations.

Multivariate classification on S-T and sediments distinguished two major areas : (i) where oceanic influences predominate, typically in the north and east areas of the bay, and (ii) where river outflows predominate, typically in the south and west.

The distribution of four species of penaeid prawns, Penaeus plebejus, P. esculentus, Metapenaeus bennettae and M. macleayi, are described in relation to the differences in S-T regime, sediment type, seagrass community type, and overall geographic range.

These four species utilize all available littoral areas. Their distributions differ but are related to the prevailing S-T regimes, the presence of seagrass communities, and most were in littoral rather than infralittoral sites.

It is concluded that any destruction of littoral areas in Moreton Bay will be accompanied by a corresponding decrease in the commercial prawn fishery. This decrease will be magnified greatly where seagrasses are included in the destruction.