Migration and growth of two tropical penaeid shrimps within Torres Strait, northern Australia

In total 9259 brown tiger shrimp, Penaeus esculentus and 4705 endeavour shrimp, Metapenaeus endeavouri, were tagged and relaeased in Torres Strait. Within 4 months 8% of tagged P. esculentus and 2% of tagged M. endeavouri were recaptured by commercial shrimp trawlers. Return rates were three to six times greater for shrimp released within the commercial fishery to the east of Warrior Reefs, than those released to the west. Shrimp released to the west of the Warrior Reefs, which is permanently closed to fishing, averaged 7-10 weeks at liberty and travelled an average of 55 km before recapture, compared with a 3-4 week, 5-km journey for those released in the east. We established that the growth parameter K should be estimated separately for males and females of the two species. In contrast to P. esculentus, a common estimate of the growth parameter L ∞ was indicated for both sexes of M. endeavouri. Although female M. endeavouri generally did not grow as large as female P. esculentus the males of the two species grew to a similar size. Net migration speeds, distance and direction were estimated. After correction for the spatial-temporal distribution of fishing effort there was still evidence of an eastward and southward movement of all tagged shrimp indicating that P. esculentus and M. endeavouri migrated from the unfished West into the East and contributed to commercial catches in the fishery. © 1993.