167
C. margaritacea (South Africa); C. gasar (along the central West coast of Africa).
C. gigas has been recently introduced into France, England, Morocco, Australia,
and New Zealand (Garrido-Handong 1990).
Production and Trade of Oysters
Oysters are typically produced in one of three different ways: natural, managed and
cultivated. Natural oysters grow and reproduce without human intervention and are
often available for harvest by anyone with the appropriate licenses and permits. In
contrast, managed oysters are supervised by harvesters who scrape the oyster beds
periodically to reduce clustering. In the case of cultivated oysters, immature oysters
are transported to man-made beds where they can mature (Lutz 2012).
With a total of 135,000 tonnes in 2016, oyster catches represent 0.15% of the
global fisheries production. USA and Mexico provided 81% of the world catches in
2016. Spain and Croatia account for 56% of EU catches in 2016. From 2007 to
2016, the world oyster aquaculture production increased by 27% to reach 5.6 million tonnes in 2016, driven by the development of China’s harvest. China’s production represented 86% of the global oyster farmed production in 2016. EU oyster
farmed production decreased by 38% over the last decade. The main species produced in the EU is the Pacific cupped oyster (Crassostrea gigas), with 92% of harvested volumes in 2016. In 2016, France alone represented 79% of EU production
(EUMOFA 2018a).
Fishing/Harvesting of Oysters
Oysters are harvested in a variety of methods. In areas where oyster reefs are
exposed by low tide, they are handpicked. In shallow areas, tongs are used to harvest
oysters. Tonging is one of the oldest methods of harvesting, where tongs work like
a pair of post-hole diggers with handles. Oysters are also harvested by dredging
from oyster boats, using metal baskets with rows of spike-like teeth. Oysters are
harvested throughout the year, but the meat yield differs with the season. Oysters
harvested in the winter yield roughly eight pounds of oyster meat per sack while
oysters harvested in the summer on average yield six pounds per sack (Lutz 2012).
Some Important Species of Oysters
Commercially important species are classified in three major genera: Ostrea,
Saccostrea, and Crassostrea and a few minor genera.
Ostrea edulis (Linnaeus, 1758) (European Flat Oyster)
Ostrea edulis is a bivalve mollusc that has an oval or pear-shaped shell with a rough,
scaly surface. The irregular shell has a distinct hooked beak, patterned with delicate
3.1 Bivalves
C. margaritacea (South Africa); C. gasar (along the central West coast of Africa).
C. gigas has been recently introduced into France, England, Morocco, Australia,
and New Zealand (Garrido-Handong 1990).
Production and Trade of Oysters
Oysters are typically produced in one of three different ways: natural, managed and
cultivated. Natural oysters grow and reproduce without human intervention and are
often available for harvest by anyone with the appropriate licenses and permits. In
contrast, managed oysters are supervised by harvesters who scrape the oyster beds
periodically to reduce clustering. In the case of cultivated oysters, immature oysters
are transported to man-made beds where they can mature (Lutz 2012).
With a total of 135,000 tonnes in 2016, oyster catches represent 0.15% of the
global fisheries production. USA and Mexico provided 81% of the world catches in
2016. Spain and Croatia account for 56% of EU catches in 2016. From 2007 to
2016, the world oyster aquaculture production increased by 27% to reach 5.6 million tonnes in 2016, driven by the development of China’s harvest. China’s production represented 86% of the global oyster farmed production in 2016. EU oyster
farmed production decreased by 38% over the last decade. The main species produced in the EU is the Pacific cupped oyster (Crassostrea gigas), with 92% of harvested volumes in 2016. In 2016, France alone represented 79% of EU production
(EUMOFA 2018a).
Fishing/Harvesting of Oysters
Oysters are harvested in a variety of methods. In areas where oyster reefs are
exposed by low tide, they are handpicked. In shallow areas, tongs are used to harvest
oysters. Tonging is one of the oldest methods of harvesting, where tongs work like
a pair of post-hole diggers with handles. Oysters are also harvested by dredging
from oyster boats, using metal baskets with rows of spike-like teeth. Oysters are
harvested throughout the year, but the meat yield differs with the season. Oysters
harvested in the winter yield roughly eight pounds of oyster meat per sack while
oysters harvested in the summer on average yield six pounds per sack (Lutz 2012).
Some Important Species of Oysters
Commercially important species are classified in three major genera: Ostrea,
Saccostrea, and Crassostrea and a few minor genera.
Ostrea edulis (Linnaeus, 1758) (European Flat Oyster)
Ostrea edulis is a bivalve mollusc that has an oval or pear-shaped shell with a rough,
scaly surface. The irregular shell has a distinct hooked beak, patterned with delicate
3.1 Bivalves