I am writing this from my Spartan hotel accommodation in Tongyoung city in the southern part of South Korea. Early morning is a good time to write because my biological clock is exactly opposite the actual time here. The Tongyoung area, along with sister city Geoje, is the epicenter for Korean oyster production. I am on what amounts to another foray in my personal mission to plaster the planet with polyploid oysters.
If you want to understand the extent of oyster culture in a global sense, then I recommend a trip to Asia, where the big three producers – China, Japan, Korea – together culture 95% of the oysters, Crassostrea gigas, on Earth (although in China, recent findings suggests that a good proportion of Chinese production comes from C. hongkongensis). China produces about 85% of the world’s oysters, or around 3,800,000 metric tonnes (mt = 1,000 kilograms or 2,200 pounds), and the “laggards” – Japan and Korea – about 250,000 mt each. Virtually all of this production is what we would call “spat-on-shell,” with the shell hung from long-lines whose buoys fill many of the bays around here (see video).
In Korea, the major product from culture is oyster meat with a production of about 40,000 mt. Koreans like their oysters small so they are marketed at an average meat weight of 12g, which translates to about 3.3B oysters per year. Some are grown larger, of course, and go to half shell trade mostly in Japan and China.
Although only 10% of production in Korea comes from hatcheries, 10% of a very large number is pretty big itself – in the neighborhood of 50B eyed larvae per year. The scale of the operations are industrial-size and measurements are expressed in unfamiliar units. “How many eggs do you stock in your 120 tonne (= 120,000L or 32,000 gal.) tank.” Answer – “70 grams.” “How many eggs is that?” Answer: “We don’t know.” Or “How many eyed larvae do you put in your setting tank?” Answer: “One kilogram.” “How many larvae is that?” Answer: “About 120M.”
In that the major product is meat, there is increasing interest in growing triploids. In addition to the likely increase in meat yield from a triploid compared to a diploid, triploids in Korea portend an interesting twist in marketability. Korea has occasional outbreaks of norovirus that occur primarily in the winter, while rare in the summer. In summer, diploid oysters are not in prime condition, so some see triploids as a way to more productively fill the summer niche. Marketability during the spawning season is the theme song of triploid (spawnless) oysters.
Korea is but another case of the hatchery world awakening to the possibility of adding value to the oyster product. In the Chesapeake, added value from breeding is now axiomatic. In Korea, and Asia in general – again where 95% of the oysters come from – adding value through breeding, triploidy, or both is rudimentary principally because the vast majority of seed still comes from natural spatfall. But hatchery production is picking up especially to get those specialty products, and triploids are leading that charge, as they did in France. To paraphrase Everett Dirkson in his infamous “real money“ quote, a billion triploids here and a billions triploids there, pretty soon you’re talking about real added value.
Video: The below video was taken on Saturday, May 25 looking out at one of the many Bays where oyster culture is practiced in the Tonyoung region, southeast Korea. Click the link below to view the video.