Photographer: SeongJoon Cho/Bloomberg
Photographer: SeongJoon Cho/Bloomberg

The World of Oysters: How South Korea's Sea Farms Feed Global Appetites

Often called "the milk of the sea" for its high nutrient content, the oyster has long been a staple of the South Korean diet. Whether in porridge, rice soup, wrapped with boiled pork in salted cabbage leaves or eaten raw, oysters star in many traditional Korean dishes. Originally harvested by free divers, oysters are now grown in ocean farms along the country's southern coastline and shipped overseas to the U.S., Japan and Hong Kong. Appetite for the delicacy has made South Korea the world's second-largest exporter of the shelled mollusks. Photographs by SeongJoon Cho for Bloomberg

A barge and a ship are moored next to an oyster cultivation site in Tongyeong, the southern coastal city that produces about 80% of South Korea's oyster harvests. In 2015, oyster exports grew by 48.2%, according to the Korea International Trade Association. 

Oysters — which reproduce by releasing eggs and sperm in the water, forming larvae — are cultivated by allowing them to latch onto structures such as floating trays, racks and string or cages. The mollusks thrive best in brackish seawater. 

Fishermen raise a net filled with oysters during harvest season, which normally peaks in winter. Changing the salinity and temperature of the water can prompt oysters to reproduce — and some types of oysters can even change gender.

Harvests are done by hand or, if the racks or cages are too heavy, with machines.  Here, a crane moves a net filled with oysters onto a barge.

Oyster farming diversifies the income sources of fishermen and thus can ease pressure on over-fished areas, a report by the UN Food and Agriculture Organization’s fisheries department says.

This aerial photograph shows the expanse of the oyster farm in Tongyeong.

Using knives, workers pry open piles and piles of fresh oysters — a process called shucking — at the Namyeong Fisheries factory in Tongyeong. 

Factory workers shuck a sea of oysters. Don't expect any pearls; those are found in a different family of bivalves.

Workers clean the produce at another factory in Tongyeong.  Oysters can ingest toxins and bacteria if grown in polluted conditions. The Korean city's  coastal waters have been certified "clean" by the U.S. Food and Drug Administration.

Traders bid for oysters during an auction run by a local cooperative.

Bags of oysters are displayed for sale at a market stall.

South Korean restaurant diners feast on oysters.

A diner peels an oyster with a knife. The test of a good oyster is when the meat is full, creamy and tastes of the sea.