Census of lobster seed captured from the central coastal waters of Vietnam for aquaculture grow-out, 2005-2008

摘要

The capture and on-growing of wild lobster seed, predominantly of Panulirus ornatus (ornate spiny lobster) is a flourishing village-based industry in Vietnam with an annual harvest production of around 1,5001 and a farm-gate value of US$90 million. The seed are collected from a settlement zone along the central Vietnamese coastline of about 700 km, from Da Nang in the north to Binh Thuan in the south. To gather information on the level of exploitation, a census of lobster seed capture in Vietnam was carried out during the settlement periods of September 2005 to April 2008. The census used a structured interview and questionnaire/logbook process and targeted both the fishing villages where the seed were captured and the dealers used to distribute the captured seed. Data from some 29-34 lobster farming villages and 71-97 known dealers for each census period for the years 2005-2008 are thought to represent around 90% of annual total seed captured in each period. Total catch of P. ornatus for 2005-06,2006-07 and 2007-08 was 5,196,820 seed, with similar amounts of seed being collected in 2005-06 (1,917,910) and 2007-08 (2,280,289) but only half that in 2006-07 (998,621). The number of seed lobsters caught in 2007-08 was still very high compared to that in previous years although demand for the seed has fallen as a result of the current severe lobster disease problems in Vietnam. Panulirus homarus was only a minor catch in 2005-06 (494,165) compared to that collected in 2006-07 (1,328,669) and 2007-08 (729,678). The three south-central provinces of Binh Dinh, Khanh Hoa and Phu Yen were major locations in contributing lobster seed of both P. ornatus and P. homarus to the annual total catch in Vietnam. The highest total catch and monthly catch of P. ornatus were from November to February following the lunar cycle. Catch rates showed a strong lunar pattern, with the greatest numbers caught in the dark phase between the 25th and 10th days of the lunar cycle.