Vietnam Ben Tre clam hand gathered
Certified as sustainable on the 9th November 2009.
Species: Lyrate hard clam (Meretrix lyrata)
Location: Ben Tre Province, Vietnam
Fishing methods: By hand or metal rakes with a net pocket.
Vessels: 0 (Hand gathered)
Number of fisheries: 1
More about Asiatic hard clam
Meretrix lyrata is a bivalve mollusc inhabiting intertidal and shallow sub tidal sand flat areas, typically in outer estuary areas where the proportions of sand and mud are around 80% and 20%, respectively. It is reported from large parts of South East Asia including Indonesia, the Philippines, Thailand and Vietnam, but is densest from Taiwan to Vietnam. It commonly grows to 50mm in length inter-tidally but can be much larger subtidally. In the Mekong Delta, Vietnam, the species is widely distributed in sand flat areas of which the highest density and production are recorded in Ben Tre province.
The life history of Meretrix lyrata is divided into three stages as follows:
- The stage of plankton post-larvae (Trochophora): The post larvae move up to the water surface at night time, and down to bottom during day time. When the high tide occurs the post-larvae also move up to water surface, and during the low tide they move down to the bottom. The vertical movements do not exceed 4 – 5m. This is the reason why during the plankton stage, post-larvae can exist in areas next to river mouths and avoid being carried off shore.
- The stage of attached post-larvae (Veliger) which represents the transfer to bottom living: for a short period, the post-larvae develop byssus for attaching to hard substrates such as stones and shells in sand flat areas.
- Adult stage, in which the clams are buried in sand.
More about the fishing methods
Commerical harvesting takes place all year round, but the great majority takes place in the period April to October. Over low tide the commercial size clams are harvested manually, usually with the aid of a rake. A net to allow the return of small clams is used.. In some cases the net is attached to the rake while in other cases the two are separate. The width of the rake and the mesh size on the net must abide by the regulations of management organizations.
The use of machines for harvesting clams is fully banned. Bags of clams are taken to a boat moored on the sand where they are checked, counted and weighed, and transport to markets or processors is normally by boat.
8,660 tonnes (2008).
Local markets, both in Ben Tre and elsewhere in Vietnam, are still the main markets for the clams. However, following the achievement of HACCP (Hazard Analysis Critical Control Point) standards in a number of processors, IQF (Individual Quick Frozen) clam meat and other clam products have increasingly been exported to international markets such as the EU, Japan, China, Taiwan, USA, of which the EU is usually the most important.
Actual eligibility date
The actual eligibility date for the Vietnam Ben Tre clam hand gathered fishery is the 14th February 2009.