Appendage damage effects on Southern Rock Lobster growth and mortality

Abstract

Handling of crustaceans can result in injuries such as limb damage, reducing post-release survival and subsequent growth. Quantifying the impact of handling damage can provide insight into the effects of increased handling, which can occur when undersized animals are released by fishers or during translocations of animals between areas. We investigated the impact of handling on the Southern Rock Lobster (Jasus edwardsii) using three decades of scientific tag-recapture data from a no-fishing reserve. We used a Bayesian modeling approach with a modified Von Bertalanffy growth model which is robust to measurement error and Cormack-Jolly-Seber capture-recapture model to estimate growth and survival probability parameters. We found that even low levels of damage (1–4 appendages) can decrease growth by ∼ 10 % in the subsequent moult. Male lobsters suffered greater effects of handling-induced damage than did females, potentially due to the additional energy reserves available to brooding females.