Harvesting of intertidal animals for bait for use in a recreational fishing competition

The magnitude of the harvest of callianassid shrimp (Trypaea australiensis) and other invertebrates by recreational fishers for use in a fishing competition in Moreton Bay, SE Queensland was estimated using a combination of creel and observational surveys. More than 3,900 yabbies were harvested in 55 harvesting events from two locations over the course of one week. Many harvesters substantially underestimated their catch, based on responses to the creel survey. Additionally, some harvesting teams were unwilling to be interviewed, or unwilling to have their catch counted, suggesting estimates of total harvest from such events should not be based on the results of creel surveys alone. The observational study provided a method for estimating the harvest of yabbies without the need to conduct an interview, thus reducing biases in estimates of the catch introduced through a dependence on human responses to questions. Removal of large numbers of callianassid shrimp may have important consequences for the structure of intertidal benthic communities because of the role these shrimp play in biogeochemical processes, deposit-feeding and bioturbation, and further work is required to assess the sustainability of the recreational harvest of intertidal invertebrates