Giant mud crabs could be a significant source of income in Madagascar if crab fishing becomes sustainable © M. ANDRIATIANA
Scylla serrata, commonly known as the giant mud crab, is in high demand on the global market. On the island of Madagascar, there are 325,000 ha of the species’ natural habitat. Although annual catches stand at an estimated 3,500 t (compared with the potential of around 7,500 t), signs of over-fishing have been observed in the last 10 years. Dwindling numbers meant that boats were hauling in smaller catches and post-catch losses were on the rise. The use of non-selective techniques appeared to be at fault, with many crabs becoming injured by fishing gear. However, efforts to establish fairer fisheries governance practices have seen post-catch mortality fall by 22%, and by as much as 50% during the wet season. This is the result of the SmartFish programme, managed by the Indian Ocean Commission and funded by the European Union. The initiative, covering every step of the production chain, seeks to keep giant mud crabs alive and healthy from catch to market, using innovative, low-cost methods, local materials and traditional techniques.
A range of activities have been implemented since 2012, in consultation with crab fisheries operators (fishermen, wholesalers, sub-collectors, collectors, operating companies and retailers) and in line with the sector’s code of conduct. The use of hooks, which injure crabs and damage burrows, has now been limited and nets with a mesh of less than 10 cm have been banned. The programme has also improved storage methods, introducing recommendations such as packing crabs in mud and tying them before landing, storing them in more spacious sheds and in bags on shelves, reducing storage time to less than 5 days, sorting, and systematic spraying. Transport methods have also evolved: mobile shelves have been installed in vehicles; crabs are now protected from the sun, wind and rain when being transported by dugout canoes; and crates are being used instead of bags.
Five regions (Melaky, Menabe, Sofia, Boeny and Diana) have benefited from information campaigns and special support measures, including local technique contests involving around 100 competitors, a documentary film and comic strip, a demonstration site and the provision of small-scale equipment.
Smart crab fishing has generated plenty of interest in the region, with operators encouraging their peers to make the transition to sustainable catch management. Small-scale fishermen have formed their own associations, and exporters have set up a dedicated platform. In late 2014, the government strengthened crab fisheries management regulations in the country in an effort to encourage these initiatives. The new framework includes rules governing minimum catch sizes (no individuals less than 10 cm), the closure of fisheries, a ban on catching egg-bearing females and rules on crab pens and culture.
If farmed sustainably, crabs can provide an important, viable income stream for Madagascar’s coastal communities.