Determining the spatial distribution and abundance indices for Moreton Bay Bugs, Thenus parindicus and Thenus australiensis in Queensland to improve stock assessment and management

Moreton Bay bugs are a commercially important fished resource in northern Australian coastal waters. About 600 tonnes of bugs is reported in logbooks annually, valued at about $15 million (~$25/kg) nationally. Historically, Moreton Bay bugs were retained as by-product of prawn and scallop trawling, but over time their popularity and price have increased and they have become increasingly targeted by fishers. In recent years in the Queensland scallop fishery, fishers have targeted bugs to such an extent that their catch value now exceeds that of the scallops. Despite their high value, a stock assessment of Moreton Bay Bugs, beyond yield-per-recruit analyses has not been previously undertaken. This is largely because the Bug catch is composed of two species, reef bugs and mud bugs which are not differentiated by fishers in the logbook data. This investment aims to examine and define the spatial distribution of the two bug species and use the available data to derive standardised catch rate time series for each species, which can be used as indices of abundance for improved management and assessment.