Broiled, in a chowder, or served raw with some hot sauce and lemon, oysters are a popular food around the world. The Pacific Oyster, Crassostrea gigas, is the most commonly grown oyster, with aquaculture operations on every continent except Antarctica. Pacific oysters grow to 10 inches long, with an elongated cupped shell that is white with purple streaks on the inside. Their rapid growth rates and adaptability to a variety of environmental conditions make them an ideal organism for aquaculture.
Aquaculture of the Pacific Oyster began in Japan, where they have been grown and harvested for centuries. Pacific Oysters were introduced to other regions to combat overfishing of native stocks. Aquaculture of oysters can be intensive or extensive, depending on the region and available resources. Extensive aquaculture requires minimal input from humans, instead allowing natural process to govern the growth and maturation of stocks. Intensive aquaculture is highly labor-intensive, with extensive care over the entire life cycle of an organism.
Oysters begin life as planktonic larvae which settle on substrates such as rock or other oysters. Aquaculture operations can induce spawning of oysters by maintaining them at specific temperatures. Oyster larvae, known as veligers, are maintained in large tanks and fed algae for a two-week period, at which point they settle on substrate and are called spat. Spat may also be collected on ropes or other material suspended in the water column if populations are reliable. Once settled, spat are allowed to grow to adult oysters over a period of 18-30 months.
This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.
Script Authors: Attikos Hutras and Aaron Rose
Contributing Professor: Dr. Lisa Campbell
Editor: James M. Fiorendino
Feautred Image: http://www.leefishusa.com/products/shellfish/oysters-pacific