One part of my PhD research was working with NSW DPI and UOW to assess the performance of marine protected areas (MPAs). We recently had an article published in Biological Conservation where we used seafloor mapping to improve the assessment of the Lord Howe Island Marine Park (free download here till July 20th). Here’s a quick rundown on what we found…
The giant mud crab (Scylla serrata) is a beast of a crustacean, capable of reaching 3kg in weight but often caught around the 0.5-1kg range. In Australia, they are distributed in sheltered waters from southern NSW, up through QLD, across the NT and over to Broome, WA.
Giant mud crabs have a short life cycle (3-4 years) and are reproductive machines. Females can carry between 2 – 5 million eggs and migrate up to 95km offshore to release their eggs. The young crabs hatch as tiny planktonic larvae, where they can remain in this stage for several weeks at the mercy of ocean currents. This aspect of their biology gives giant mud crabs substantial capabilities for dispersal.
Their prized meat and high numbers within estuaries make them a highly targeted recreationally and commercially harvested species. In NSW, annual commercial landings are approximately 100-120t and the annual recreational catch is estimated between 30-60t. The main method of capture by both commercial and recreational fishers are crab pots, however rec fishers also use hoop nets or dillies.