Spawning and nursery habitat partitioning and movement patterns of Pagrus auratus (Sparidae) on the lower west coast of Australia

Abstract

The ages and lengths of Pagrus auratus caught by line fishing in three marine embayments (Owen Anchorage, Cockburn Sound and Warnrbo Sound) and inshore (<80. m depth) and offshore waters (>80. m depth) on the lower west coast of Australia (31°45'-32°45' S) were used to infer the movement patterns and habitats occupied by this species at different stages in its life cycle on this coast. These data were supplemented by results obtained by tagging individuals in spawning aggregations in the embayments. 0+ P. auratus <200. mm FL were caught exclusively in the three adjacent embayments. The ages and lengths of immature P. auratus, ranging from 1+ (ca. 200. mm FL) to 5+ years (ca. 400. mm FL), increased progressively with distance from these embayments. During the spawning period (from September to January), the relative abundances of P. auratus with either developing, developed or recently spent gonads were far greater in the three embayments (91%) than in either inshore (12%) or offshore waters (30%). Some tagged P. auratus were recaptured among spawning aggregations in the same embayment during subsequent spawning seasons, while others were recaptured in these embayments outside the spawning period. However, some other tagged individuals were recaptured up to 92. km north, 33. km west and 134. km south outside the spawning period and up to five years after tagging. The results of this study emphasise that the above three adjacent marine embayments constitute important spawning and nursery areas for P. auratus and are thus potentially critical for sustaining the stocks of this recreationally and commercially important species on the lower west coast of Australia. © 2011 Elsevier B.V.