Variation in the Relationship between Shell Length and Meat Weight for Blacklip Abalone (Haliotis rubra, Leach, 1814) with Implications for Compliance in New South Wales, Australia

The relationships between shell length and the weight of a shucked and bled meat (final meat weight (FMW)) and a completely desiccated dry meat weigh (DMW) were investigated to provide guidelines for a minimum meat weight restriction (MMW) for blacklip abalone (Haliotis rubra, Leach, 1814) in New South Wales (NSW), Australia. Quantile regression was used to predict FMW and DMW for specific shell lengths with various levels of probability. The expected FMW and DMW for an abalone with a minimum legal shell length of 115 mm was 78 g and 20 g respectively. There was a 5% probability that the same abalone could weigh 59 g (FMW) and 15 g (DMW) and a 1% probability that it could have a FMW of 50 g and a DMW of 13 g. This allows predictions to be made about shell lengths of abalone using their FMW or DMW alone. For example, a MMW regulation could be set at the 5% probability of FMW for the current minimum legal shell length, and an allowance of no more than 5% of a seized catch below that. Such a MMW regulation could then provide significant benefits to compliance operations in the NSW abalone fishery.