Survival and movement of naive juvenile spiny lobsters returned to the wild

Using multistate Arnson-Schwartz (AS) mark-recapture models, we show that naïve (captive reared) juvenile southern rock lobsters (Jasus edwardsii, Hutton 1875) survived as well as wild-caught lobsters when released to an area of coastal reef. Lobsters captured as pueruli were ongrown in tanks for 12 to 18 months where they were fed to satiation in the absence of predators. Lobsters were marked with antennal tags each carrying a unique code, and released to coastal reef along with tagged wild-caught lobsters of similar size. During 8 dive surveys of the release reef and 3 surveys of adjacent reefs over a 28 day period, divers resighted 40.3% of the naïve lobsters and 70.2% of the wild lobsters. We show that this discrepancy is a function of differing movement rates and spatial differences in resighting probability. The probability of naïve lobsters moving from the release reef to adjacent areas in the first 4 days post-release (0.72 ± 0.04 S.E.) was almost twice that of wild-caught lobsters (0.38 ± 0.08 S.E.). This behavioural difference did not influence daily apparent survival (0.98 ± 0.016 S.E.), which was constant between groups and over time. Our results are encouraging for the potential of enhancing spiny lobster stocks by releasing juveniles, and demonstrate the utility of AS mark-recapture models as a tool for evaluating medium-term survival of mobile marine species.