Oral Presentation Australian Society for Fish Biology Conference 2018

The implications of varying environmental conditions on the development of a harvest strategy for the nt mud crab fishery (#192)

William M Bowman 1 , Mark Grubert 1
  1. Northern Territory Government, Darwin, NT, Australia

The commercial sector accounts for approximately 88% of the mud crab fishery harvest in the Northern Territory (NT). Important commercial fishing grounds exist in the Gulf of Carpentaria (GOC), and due to restricted access during the wet season the majority of effort in the GOC occurs between March and December. From 2014 – 2016 the GOC received below average rainfall and unfavourable environmental conditions for the successful recruitment of mud crabs. Stock assessment model outputs indicated that mud crab biomass in the GOC had dropped, but it could not separate whether the decline was a result of environmental conditions or fishing pressure. In 2016/17, the GOC received average rainfall or higher, the catches and catch rates of mud crabs increased, and high numbers of large mud crabs were observed in the commercial catch. It is yet to be determined if environmental conditions or fishing pressure had the greatest impact on mud crab stocks in the GOC, however the sudden influx of large crabs were not considered a result of recent spawning events. This suggested that during the period of unfavourable environmental conditions, the catchability of mud crabs was also a significant factor impacting the observed decline in biomass in 2016.