Posted on January, 16 2004

Mafia Island, Tanzania - Local fishermen accidentally caught a dugong in a drift gillnet set off the Rufiji Delta, Tanzania, this week. Sadly, the two-metre long female, weighing at least 200kg, drowned before it was discovered in the net. However, the fact that the fishermen delivered the dugong to district authorities, rather than selling or eating the meat, marks a significant milestone in on-going efforts to protect this species from extinction both in Tanzania, and in the wider Western Indian Ocean, where its existence is highly threatened.

"In 2002 we caught a young dugong in the same area," says Abdul Said, the captain of the boat. "We brought it to Mfuruni village in Mafia where the meat was eaten.

"On this occasion, we decided to deliver the dugong to the Fisheries Office in Kilindoni, the main town on Mafia Island, because we knew there was a project on Mafia that was interested in dugongs (the Mafia Island Turtle & Dugong Conservation Programme) and that would compensate us for the value of the meat." 

Over the past 3 years, the Mafia Island Turtle & Dugong Conservation Programme, funded by WWF, the Wildlife Conservation Society (WCS), and the UK Born Free Foundation with occasional support from the SEA Trust, has been raising awareness about the threatened status of  the dugong amongst local communities in Tanzania's Mafia, Rufiji, and Kilwa Districts as well as Koma and Kwale Islands. The actions of the fishermen illustrates the growing effectiveness of the combined efforts of the programme, Mafia Island Marine Park, WWF, and the Mafia District Council. 
 
Various concerned parties were contacted when the dugong arrived at Kilindoni, including the District Fisheries Officers, Mafia Island Marine Park, WWF, and the Turtle & Dugong Conservation Programme. The carcass was preserved in a freezer on Mafia, kindly provided by Tanpesca, before being transferred to DSM for detailed measurement and analysis. 
 
Fifty years ago, dugong were relatively abundant along the Tanzanian coast. By 2002, many national experts thought they had become extinct. However a national survey of coastal fishing communities conducted in 2003 by the Mafia Island Turtle & Dugong Conservation Programme and the Wildlife Conservation Society, with support from WWF and UNEP, revealed that remnant populations of dugong still exist in two areas along the Tanzanian coast: off the Rufiji Delta, and north of Tanga near the border with Kenya.

"I usually catch about one dugong per year around the Rufiji Delta," says Abdul Said. "I fish there throughout the year but I never see live dugong in the area, they are very shy."

The latest capture highlights the special importance of the Rufiji-Mafia-Kilwa area for marine biodiversity. The marine habitats in the area, including the extensive seagrass beds which form the main diet of dugongs, provide important feeding grounds and shelter not only for dugong but also other endangered species such as turtles and the prehistoric coelacanth fish, a specimen of which was caught off Kilwa in September 2003, the first-ever sighting of in Tanzanian waters. 
 
Dugongs are mammals, and live in shallow, sheltered bays and lagoons where seagrass beds are plentiful and the water is less than 5m deep. They occasionally move into river mouths and creeks and occasionally dive in deeper water 20–25m in depth. Dugongs routinely travel up to 40km a day around their feeding grounds, but movements of up to 600km per day have also been recorded in Australia. Although dugongs can live up to 70 years, like most large mammals they are slow to reproduce. The largest recorded individual was 4.1m long and weighed 1000kg. 
 
Dugongs are classified by international conservation agencies as "vulnerable to extinction", the criterion for which is a worldwide population decline of at least 20 per cent in the last 90 years. The main global populations in eastern Australia and the Arabian Gulf are in slow long-term decline. However in the Western Indian Ocean, including Tanzania, Kenya, and Mozambique, their plight is far more serious. Dugong populations in these countries have certainly declined by more than 90 per cent  in the last 30–40 years due to hunting, accidental capture in gillnets & trawlers, propeller injuries, pollution, coastal development, and disease.

For further information: 
Joyce Bayona
Communications Officer, WWF-Tanzania 
Tel: +254 20 577355
E-mail: JBayona@wwftpo.org