Status of scallop farming: A review of techniques
Alessandro Lovatelli *
Many species of scallop are cultured and harvested all over the world. However, only few species, in particular the Pecten genus, dominate the world harvest. The Japanese are the leaders in scallop landings from natural fisheries and in culturing and manipulation of scallop. Other countries where commercial harvesting is important include Korea, USSR and Australia in the West Pacific, and Canada, the United States of America, Peru, Argentina and Chile in the East. Important landings also occur in the Atlantic rim countries such as Iceland, France, United Kingdom, and Norway.
* Bivalve expert, Associate Professional Officer, Seafarming Development and Demonstration Project, Network of Aquaculture Centres in Asia, Bangkok, Thailand.
The current world harvest of scallop is not accurately known. In 1985 the harvest of the most important species was 596,282 tonnes (FAO, 1987a), however, the landings from many other countries are often excluded either because landings are relatively small or because scallop are grouped with other bivalves or demersal fish. The principal countries harvesting scallop are as follows (Fig. 1):
|Japan||226,786 tonnes||Pactinopecten vessoensis|
|USA||192,249||Pecten caurinus, Placopecten magellanicus, Argopecten gibbus, Argopecten irradians.|
|United Kingdom||18,312||Pecten maximus, Chlamys opercularis|
|France||10,466||Pecten maximus, Chlamys opercularis, Pectinidae.|
|New Zealand||3,204||Pecten novaezealandiae|
|Chile||2,107||Argopecten purpuratus, Pectinidae|
|Faeroe Is||1,930||Chlamys opercularis|
|Ireland||462||Pecten maximus, Chlamys opercularis.|
|Spain||91||Pecten maximus, Pectinidae.|
|Others||54||Pactinopecten vessoensis, Pecten jacobeus, Pectinidae,|
The world scallop harvest has declined considerably compared with the 1984 world catch, which was 834,186 tonnes. This decline is possibly due to the over-exploitation of important fisheries and poor spatfall. The USA P. magellanicus fisheries have been declining since 1982, when the annual catches reached 75,778 tonnes compared with the 57,709 tonnes of 1985. The USA landing of the calipo scallop (A. gibbus) for 1985 has decreased by over 31% compared with the landings of the previous year.
Although natural fisheries are responsible for the great majority of the scallop produced, a considerable portion comes from active aquaculture. Japan in 1984 landed 209,187 tonnes of P. yessoensis and an additional 73,948 tonnes were farmed (FAO, 1987b). However, the present aquaculture of scallop is certainly more successful than these production figures indicate; over 50% of the Japanese production is currently from culture.