Abstract
Scales from hatchery‐reared, stocked and wild mulloway Argyrosomus japonicus (Temminck and Schlegel) captured in the Georges River, and a library of mulloway scales from coastal New South Wales, were examined for the presence of scale checks. Checks specific for hatchery‐reared fish were present in 100% of recaptured hatchery‐reared mulloway; the origin of which was confirmed by the presence of a chemical mark in the otolith or fin spine. Up to 7% of wild mulloway were incorrectly classified as hatchery‐reared on the basis of these checks. An abrupt reduction in salinity from 35 to 5 and 6 days starvation successfully induced checks in the scales of hatchery‐reared mulloway. The marking efficiency for stocking checks was comparable to that obtained using oxytetracycline hydrochloride, and supports the short‐term use of scale stocking checks to evaluate mulloway stock enhancement programmes in Australia.