World Aquaculture Magazine - September 2021

6 SEP TEMBER 2021 • WORLD AQUACULTURE • WWW.WA S .ORG C H A P T E R R E P O R T S Year-round Scallop Farming by Changing Species The National Institute of Fisheries Science (NIFS, President Wan-Hyeon Choi) opened year-round scallop farming with bay scallop Argopecten irradians in summer and Yesso scallop Mizuhopecten yessoensis in winter. The NIFS of the Ministry of Oceans and Fisheries reported the transplantation of a coldwater (Yesso) scallop from the East Sea to the south coast in July. The Southeast Sea Fisheries Research Institute (hereafter Institute, NIFS Branch) transplanted small spat about 2 cm long from Sokcho, Gangwon-do to Goseong-gun, Gyeongnam-do. They succeeded in growing spat to commercial size (> 7 cm long) fromMay to June of the following year. Transplanted scallops have been grown to market size successfully in 2019 and 2020. On the southern coast, warmwater (bay) scallops are usually stocked around May, grown and harvested fromOctober to November. The farming is generally closed fromNovember to June of the following year. Farmers begin to harvest Yesso scallops in May and stock bay scallops into growing areas. When all Yesso scallops are harvested in June, bay scallops are redistributed for full-scale farming. The Institute, together with the Goseong-gun, Gyeongnam-do Scallop Aquaculture Cooperative, held an on-site report session on the research results for farmers on the south coast in early July. A spat shipping event was also held. Korea’s scallop production is 5,591 tons (about 24.5 billion won (KRW), about US$ 20M) in 2020, which is about 22 times higher than 253 tons (about 1.8 billion won, about US$ 1.5M) in 2010, establishing itself as a new income breed for shellfish farming. This region covers 95 percent of the total production of scallops in Korea. In Gyeongnam-do, the scale of scallop farming is 170 ha as of 2019, 1/20 of the oyster farming area. Fishery Production Increase by 5.2 Percent in the First Half of 2021 Fishery production was 2,383,000 t, up 5.2 percent from the previous year. Production in offshore fishing, aquaculture, and deep- sea fishing is all up. The Ministry of Oceans and Fisheries (MOF) announced in August that, in the first half of 2021 (January to June), the total domestic fishery production increased by 118,000 t from the same period last year (2,265,000 t). In particular, the increase in aquaculture and deep-sea fishery production led to the overall fishery production. The MOF supplies food through stable production amid the COVID-19 situation. Meanwhile, domestic fishery production amounted to 4.45 trillion won (KRW) in the first half of this year, up 8.7 percent from last year’s same period (4.1 trillion won). It seems that deep-sea fishery (860 billion won, 44.6 percent) and aquaculture (1.59 trillion won, 6.6 percent), which increased production, contributed to the overall increase in production in the fishery sector. Mr. Jun-Seok Kim, head of the Fisheries Policy Department of the MOF, said “Although there were difficulties in fishery production due to COVID-19, we were able to achieve a stable production in the first half thanks to the efforts of the fishermen. The MOF will also support safe and active production activities centered on fish and shellfish, which account for a high proportion of production in the second half of the year.” Aquaculture production in the first half of this year totaled 1,733,000 t, up 5.4 percent from the aver- age yield of the last five years (1,645,000 t) and 5.2 per- cent from the same period the previous year (1,647,000 t). Except for seaweeds, the primary seafood produc- tion was 173,000 t of oysters, 35,000 t of mussels, 20,000 t of flounder, 15,000 t of sea squirt, and 11,000 t of abalone. In the case of oysters, the representative winter seafood, shipments declined sharply last year due to slowing consumption due to the spread of COVID-19. However, this year, as consumer sentiment recovered, production returned to normal levels. On the other hand, flounder, a representative farmed fish, had a backlog of inventory since 2019, so there was a movement to control the stocking amount after 2019, centering on the production area. As a result, there were not many shipments available in the first half of this year, resulting in a 5.6 percent decrease in production com- pared to the same period last year. In the case of sea squirt, the amount decreased sharply in the first half of this year, with production falling by 46.6 percent compared to the previous year due to the oxygen-de- ficient water mass and anoxic bottom condition last year. Considering that the breeding period for sea squirts usually takes more than two years, the increase in the mortality of one-year-old sea squirts in 2020 has disrupted production this year. Fish Disease Diagnosis Method Developed in Korea is Listed as a Global Standard The NIFS announced that a diagnosis of viral hemorrhagic sepsis (VHS) gene was registered as an international standard by the World Organization for Animal Health (OIE) on June 1. This VHS gene was developed and verified by the Korean Standard Laboratory located within the NIFS. The OIE Aquatic Animals Committee and 182 OIE member countries reviewed the newKorean diagnostic method and decided on registration at the 88th General Assembly Meeting on May 24-28. The newVHS gene diagnostic method is a rapid method that can confirm results within three days, compared to the cell culture technique, which requires more than 14 days. In addition, the existing diagnostic process demonstrated high detection power for European viruses (Types I, II and III) prevalent in salmonid fish. However, it did not detect Asian viruses (Type IVa) that infect flounder farmed in Korea and Japan. This newKorean method now can detect Type IVa. The Korean standard laboratory research team developed a new diagnostic approach to detect all VHS viruses worldwide with high detection power. The Danish VHS OIE Standard Laboratory worked together to validate the strict OIE diagnostic method guidelines. This study has been conducted since 2014 and about seven years were required to register as an OIE standard. With this decision to amend the VHS Genetic Diagnosis Act, Korea has solidified its international position as a world-leading country in the field of aquatic disease diagnosis. The newly developed diagnostic method has been revised for epidemiological investigations through genetic analysis and quickly confirmVHS viral infection. Korean Chapter