Migration and stock studies on the Australian school prawn Metapenaeus macleayi

The results of tagging studies conducted to determine the relationship between estuarine (juvenile) populations and adults at sea suggest that maturing Metapenaeus macleayi leave the estuaries and move along the coast in a northerly direction; the longest migration recorded was 120 km, but most prawns appear to disperse in shallow water (<40 m) within about 70 km of their juvenile habitat. There are approximately 60 estuarine populations of M. macleayi in south-east Australia; the geographical range of prawns emigrating from most estuarine populations overlap (at sea) to some degree with that of adjacent or nearby populations, but there is little or no overlap between any two of the 6 major populations. The mixing of individuals from a major population and from nearby smaller populations is negligible for the purposes of fisheries management, hence the prawns in each of the major estuarine populations and the adults in the coastal area north for about 70 km may be regarded as a unit stock.