A study of the sand crab (Portunus pelagicus) and its exploitation in a sub-tropical multi-sector fishery
Final report
Based on logbook records the sand crab commercial pot fishery in Moreton Bay is worth in the vicinity of $2 million wholesale annually. Sand crabs are also taken as an incidental by-catch by otter trawlers and in addition Moreton Bay supports a substantial recreational fishery.
Sand crabs are caught throughout the year but fishing effort is greatest from October to June. Peak catches in the pot fishery occur during March and April when daily catch rates may exceed 3 legal males per pot. Gravid females are present throughout the year but the highest proportion of egg bearing females is found in the population during August and September. Peaks in mating activity occur in autumn and spring with recruitment of juvenile crabs commencing in November. The parasitic barnacle Sacculina granifera infects 3% of all sand crabs in Moreton Bay and a previously unreported microsporidian parasite is found in 0.7% of the population.
Tagging studies show that fishing effort and mortality of sand crabs is highly variable throughout the Bay. Recapture rates for different areas vary from 1% to 65% with an overall return rate of 14%. The pattern of tag returns does not indicate any ordered directional movement of crabs either into or out of the Bay.
Male and female sand crabs exhibit differences in preferred habitat. Large males are generally more abundant in deeper water, whereas females predominate in shallower water, particularly on the top of sand banks.
Management recommendations arising from the project work include a change in the method of sand crab measurement to the width at the base of the antero-lateral spines, lowering of the existing size limit, the introduction of a bag 1 limit for recreational fishermen and an abolition of the prohibition on taking females provided that suitable management conditions can be maintained.
Investigation and improvement of live Blue Swimmer Crab handling in NSW
Identification of muscle parasite in Yellowtail Kingfish (Seriola lalandi) and Mahi Mahi (Coryphaena hippurus), and determination as to the efficacy of non-invasive screening technology for the purpose of identifying infected fish in a commercial fish processing environment
Knowledge for Productivity: Phase I - Lake Wooloweyah
Sustainable Fishing Families: Developing industry human capital through health, wellbeing, safety and resilience
By developing an evidence-based health and safety training program for Australian fishing communities, this project meets the needs of the commercial wild-catch and aquaculture industry identified in FRDC’s RD&E Program 3, ‘Communities’ and particularly theme 10, which promotes resilient and supportive communities who are able to adapt to the social impacts of change in industry business environments.
The project will address a national need, identified by VicFRAB, to better understand the social and economic contribution of commercial fisheries, by identifying and addressing potential losses incurred through the poor health and wellbeing of the industry’s human capital.
Fishers tend to work in rural and remote communities, which means they have higher rates of mortality, disease and health risk factors than urban dwellers, further impacted by reduced access to primary health care services. Fishers are at particular risk of certain kinds of illnesses (eg. skin and diet-related), as well as injury (fatality rates are more than double those in the agricultural sector). Mental health concerns are higher than average in the fishing industry, exacerbated by uncertainties within the industry including often high debt and insecurity of tenure and licencing. While both women and men are at risk, 86.9% of fishers are male, a factor placing them at greater risk of suicide.
Fisher ‘attitudes’ also impact health, such as the culture of self-reliance, particularly among males. This may make fishers resilient, but also makes them less likely to adopt preventative health practices or to use health services, and they will usually wait longer before seeking medical assistance, particularly for issues of chronic poor mental health.
The Sustainable Fishing Families project will benefit fishing families’ health, safety and resilience by promoting a self-awareness of the value of the industry’s human capital, and building their health capacity.