Many islands dot the bays of the ria coastline of South Gyeongsang Province in South Korea. But around Tongyeong, a city of 140,000 people, satellites observe something else of note in the water—a series of structures that look a bit like the squares of a chess board. In most cases, the squares are areas where oysters are being farmed.
On November 6, 2019, the Operational Land Imager (OLI) on Landsat 8 acquired this natural-color image of long-line oyster cultivation near an industrial facility. In this area, oysters are often grown by suspending them from ropes or wires, which are held near the surface with buoys. The technique encourages oysters to grow quickly and develop strong shells.
After China, South Korea is the second-largest oyster producer in the world. Roughly 80 percent of this production comes from Tongyeong, which exports oysters to the United States, Japan, Canada, Hong Kong, and the European Union. Around Tongyeong, the oyster harvesting season begins in the fall, and this year’s haul appears to be unusually large. Downpours in the summer added extra nutrients to water and promoted growth, according to Arirang News.
While oyster farming has been a boost for the Tongyeong economy, the concentrated production has had noticeable effects on the environment. Notably, beaches in the area have unusually high concentrations of sytrofoam debris and microplastics because of the many buoys in the area, one study found.
Other types of mariculture are common in South Gyeongsang, including seaweed, mussel, halibut, and rockfish farming.
References & Resources
- Arirang News (2019, October 20) In-season oysters selling fast in South Korea. Accessed November 20, 2019.
- Bloomberg (2016, January 26) The World of Oysters: How South Korea's Sea Farms Feed Global Appetites. Accessed November 20, 2019.
- Bburi Kitchen (2015, December 18) Consider the Oyster. Accessed November 20, 2019.
- Food and Agriculture Organization of the United Nations (2008) Oyster capture-based aquaculture in the Republic of Korea. Accessed November 20, 2019.
- Hong, Y.S. et al. (2014) Evaluation of Beach Pollution by Aquaculture Styrofoam Buoys in Tongyeong, Korea. Journal of the Korean Society for Marine Environment and Energy, 17 (2), 104-115.
- Hyun, J.H. (2013) Impacts of long-line aquaculture of Pacific oysters (Crassostrea gigas) on sulfate reduction and diffusive nutrient flux in the coastal sediments of Jinhae-Tongyeong, Korea. Marine Pollution Bulletin, 74 (1), 187-98.
- Ocean Outcomes (2018, July 31) Worldâs Second Largest Oyster Producer Working Towards More Sustainable Practices. Accessed November 20, 2019.
NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.
