JAPANESE SEABASS – Lateolabrax japonicus

Lateolabrax japonicus is a coastal perch species found in brackish and marine waters in the Western Pacific, from Japan to the South China Sea. It is known commonly as Japanese sea bass, Japanese seaperch, or Suzuki in Japan. Two other species of “sea bass” native to Asia are also marketed under similar common names: the Asian sea bass or barramundi (Lates calcarifer), and the Korean sea bass or blackfin sea bass (Lateolabrax latus). Further, the spotted sea bass (Lateolabrax maculatus) is considered a sister species to Lateolabrax japonicus that was only formally recognized in 1996 (Yokogawa, 2019).

General aspects of small (fingerling) and large (adult) individuals of Lateolabrax japonicus (A, B), L.maculatus (C, D) and L. latus (E, F) in fresh condition. (source: Yokogawa, 2019).

Lateolabrax japonicus, the Japanese sea bass, is an important species to the region, providing for commercial fisheries, recreational opportunities, and aquaculture production. According to the FAO, Japan accounts for the largest wild capture fishery for Lateolabrax japonicus, followed by Korea, and Taiwan, amounting to a total of 8,146 tonnes of global marine landings in 2017. However, aquaculture production of this species far surpasses capture fisheries, with a total of 166,340 tonnes of L. japonicus global aquaculture production in 2017. The vast majority of this comes from China (approximately 94%), followed by Taiwan where much research has gone in to fry and fingerling production. Korea also produces a small amount of L. japonicus through aquaculture, largely for domestic consumption.

Japanese Sea Bass farmed risk assessment November 2020 1

Farmed Lateolabrax japonicus is not listed on the Monterey Bay Aquarium’s Seafood Watch, FishChoice, or the Aquaculture Stewardship Council. There are, however, two L. japonicus farms in Guangdong, China certified by Best Aquaculture Practices, the first of the species to achieve BAP certification (BAP, 2016).

China Marine cage farming reached commercial scale in China in the early 1980s and continued to develop rapidly with the advancement of techniques for culture of several species, including L. japonicus. Specific regulations for aquaculture were extremely limited or absent in these early decades, but in recent years China’s government has worked to address aquaculture development. China is responsible for the majority of the world’s supply of farmed Japanese sea bass, and in 2017 produced 156,595 tonnes of the species through aquaculture. The main regions for Japanese sea bass farming include Guangdong Province (Zhuhai and Zhanjiang), Guangxi Province, Shandong Province, Fujian Province, and Zhejiang Province. The Pearl River Delta, located in Doumen, Zhuhai district of Guangdong, is of particular significance for aquaculture due to an ideal mix of rainfall, sunshine, and brackish water salinity levels. There are over 3,000 farmers in this area alone, where 120,000 tons of sea bass were produced in 2018, accounting for 70% of China’s total output (IFFO, 2019).

Risk Assessment • Farm siting: Medium Risk o The Fisheries Law (1986, amended 2000) describes China’s fishery resources and “requires the state to adopt a policy that calls for simultaneous development of aquaculture, fishing and processing, with special emphasis on aquaculture,” (FAO 2004-2020). ▪ “The people's governments at or above the county level may grant licenses to use state-owned water surfaces and tidal flats to state and collectively- owned units to develop aquaculture. Natural spawning, breeding and feeding grounds of fish, shrimp, crab, shellfish and algae in state owned water surfaces and tidal flats as well as their major migration passages must be protected and cannot be used as aquaculture grounds.” (FAO).

Japanese Sea Bass farmed risk assessment November 2020 2 ▪ Sea Area Use Management Law adopted in 2002, “requires sea area users to obtain use rights by applying for sea area use permits, and to pay user fees. The Law also provides for the establishment of Marine Functional Zonation Schemes, which define the uses of a given sea area in the order of priority.” (FAO). ▪ No EIA guidelines specifically provide for aquaculture, but “Environmental impact statements of construction projects – including large-scale aquaculture projects – must assess the pollution that the projects are likely to produce, their impact on the environment and describe preventive and curative measures.” • Nutrient pollution: Medium Risk o There is some monitoring of water quality and feed use though not to any prescribed standard. The cumulative impacts of nutrient pollution from neighboring farms in the area are not taken into account during site planning. o Nutrient pollution is a concern in the culture of L. japonicus in China: ▪ Trash fish and commercial feed are used, both of which contribute to accumulation of residue and organic matter on the sea floor, polluting the area and leading to eutrophication. ▪ Floating pen cages are the typical method of farming, which relies on water movement to dissipate nutrients and pollutants, creating a natural risk for spread. • Feed source: Medium Risk o A commercial feed has been developed for the species and is widely available, however the feed conversion ratio is still above 1:1. o Trash fish was originally the most common type of feed in L. japonicus aquaculture, however, an artificial extruded feed was developed and is now widely available. o Significant research continues on improving the sustainability of feed for L. japonicus by identifying alternative protein sources to fishmeal: ▪ Study in China found that black soldier fly could be used in up to 50% of replacement (of fish meal) in feed for Japanese seabass without affecting fish’s growth (Gonazalez, 2019). ▪ Another study found replacing up to 50% of fishmeal with soybean meal did not significantly influence growth performance, though higher levels caused adverse health effects (Zhang et al., 2017). • Disease, medicine, chemicals: Medium Risk o The farm can evidence that medicines and chemicals are legal, though records incomplete. o In China, “fishery authorities at or above county level are responsible for the administration of drug use and drug residue tests for the aquaculture industry,” (FAO, 2004-2020). o Antibiotics are utilized in the culture of L. japonicus in China to control disease. o A recent study by Han et al. (2020) found antibiotics in all water samples from aquaculture ecosystems surrounding the Yellow Sea, as well as in feed samples and organism samples. While antibiotics pose a risk to the ecosystem, to human

Japanese Sea Bass farmed risk assessment November 2020 3 health, and to resistance, “All antibiotics detected in seafood were lower than the respective maximum residue limits.” • Introductions/Genetics: Medium Risk o There is a risk of escapes from the farm, although the species is native to the region, mixing could be detrimental to wild populations. o While Lateolabrax japonicus is native to the areas in which it is farmed in China, years of selective breeding for aquaculture have made the farmed individuals’ genetics less suited to the wild; mixing with wild populations could threaten wild stock by reducing fitness. • Wild Seed: Low Risk o The operation does not rely on the collection of wild seed. o Lateolabrax japonicus was one of several marine finfish species heavily researched in the 1980s and 1990s; hatchery technology was developed early and enabled aquaculture for this species to expand across China. o Over 10 million fry of Lateolabrax japonicus are produced annually through aquaculture (Hong & Zhang, 2003). • Fish Welfare: Medium Risk o Aspects of animal husbandry not properly controlled (stocking densities not recorded/no veterinary care plan). o There are no specific regulations for aquaculture stocking densities and pen cleanliness, two important factors for fish welfare.

Chinese Taipei (Taiwan) In 2017, Taiwan produced 7,640 tonnes of Lateolabrax japonicus through aquaculture (FAO). Much research on aquaculture development has occurred in Taiwan over the past few decades, and Lateolabrax japonicus is one such species of focus. Broodstock and artificial propagation technology has been well established since the 1990s and fry producers in Taiwan often export their product, though there are some who also stock their own grow out facilities.

Republic of Korea In 2017 Korea produced 2,105 tonnes of Lateolabrax japonicus through aquaculture (FAO). Marine finfish aquaculture in Korea is dominated by olive flounder and Korean rockfish, both of which are cultured in land-based tanks. Production of mullet, sea bass, and sea bream take place in floating cages (Yun et al., 2015). Aquaculture products follow the same distribution pattern as fishery products, ending up at domestic supermarkets and wholesale markets. When it comes to exports, Korea sends processed aquatic products to Japan, the USA, and Europe (Yun et al., 2015).

Japanese Sea Bass farmed risk assessment November 2020 4 References

BAP Welcomes First Certified Sea Bass Farm. (2016, September 14). Retrieved from https://bapcertification.org/blog/bap-welcomes-first-certified-sea-bass-farm/

FAO 2004-2020. National Aquaculture Legislation Overview. China. National Aquaculture Legislation Overview (NALO) Fact Sheets. Text by Spreij, M. In: FAO Fisheries and Aquaculture Department [online]. Rome. Updated 3 May 2004.

Gonzalez, R. (2019, August 9). Study probes black soldier fly diet for Japanese seabass. Retrieved from https://www.hatcheryinternational.com/study-probes-black-soldier-fly-diet-for- japanese-seabass/

Halwart, M. (2007). Cage aquaculture: regional reviews and global overview. Retrieved from https://books.google.com/books?id=myCXhIIWeLoC&lpg=PA55&dq=china lateolabrax japonicus aquaculture system&pg=PA51#v=onepage&q=china lateolabrax japonicus aquaculture system&f=false

Han, Q., Zhao, S., Zhang, X., Wang, X., Song, C., & Wang, S. (2020). Distribution, combined pollution and risk assessment of antibiotics in typical marine aquaculture farms surrounding the Yellow Sea, North China. Environment International, 138, 105551. doi: 10.1016/j.envint.2020.105551

Hong, W., & Zhang, Q. (2003). Review of captive bred species and fry production of marine fish in China. Aquaculture, 227(1-4), 305–318. doi: 10.1016/s0044-8486(03)00511-8

IFFO. Report on the 2019 Sea Bass Industry Development Forum. (2019, July 2). Retrieved from https://www.iffo.net/blog/report-2019-sea-bass-industry-development-forum

Onsanit, S., Ke, C., Wang, X., Wang, K.-J., & Wang, W.-X. (2010). Trace elements in two marine fish cultured in fish cages in Fujian province, China. Environmental Pollution, 158(5), 1334–1342. doi: 10.1016/j.envpol.2010.01.012

Yokogawa, K. (2019). Morphological differences between species of the sea bass genus Lateolabrax (Teleostei, Perciformes), with particular emphasis on growth-related changes. ZooKeys 859: 69-115. https://doi.org/10.3897/zookeys.859.32624

Yun, H., Taddese, F., and Bai, S.C. (2015). Korean Aquaculture at a Glance. World Aquaculture. 10.13140/RG.2.2.28170.82882.

Zhang, C., Rahimnejad, S., Wang, Y., Lu, K., Song, K., Wang, L., and Mai, K. (2017). Substituting fish meal with soybean meal in diets for Japanese seabass ( Lateolabrax japonicus ): Effects on growth, digestive enzymes activity, gut histology, and expression of gut inflammatory and transporter genes. Aquaculture. 483. 10.1016/j.aquaculture.2017.10.029

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