Influence of stocking density and feed type during short-term rearing on the growth, behaviour and post-release survival of a coral reef fish

Widespread anthropogenic impacts are pushing many coral reef fish populations below the carrying capacity of their habitats. Short-term Post-larval Capture, Culture, and Release (PCCR) is a recruitment enhancement technique designed to support wild-caught fishes during settlement. This period is an ontogenetic habitat shift characterised by intense predation-induced mortality, which can exceed 60% within 48 h of arrival to the reef. PCCR provides a predator-free, food-rich environment to facilitate accumulation of energy reserves and completion of metamorphosis. However, it remains unclear how stocking density and food type influence the growth, behaviour, and post-release survival of wild-sourced fish during brief (< 1 week) rearing periods. This study examined the effects of stocking density (1.2 fish L −1 vs 8 fish L −1 ) and food type (live vs dead Artemia ) on the growth, behaviour and survival of the Ambon damselfish ( Pomacentrus amboinensis ) in a 2 × 2 factorial design experiment. Settlement-stage fish were captured using light traps, reared in treatment tanks over five days, and individually released onto patch reefs where behaviour was quantified and survival monitored over 53 h. Fish fed live Artemia and reared under high stocking density exhibited faster growth and expressed increased post-release boldness and higher vertical positioning. No statistically significant effects of stocking density or food type were detected, suggesting that these factors do not introduce negative effects on post-release survival following brief rearing periods. By demonstrating flexibility in feeding and stocking protocols, this study highlights the potential of PCCR as a scalable and efficient tool for recruitment enhancement and coral reef restoration.