Feed and Disease at Olive Flounder (Paralichthys olivaceus) Farms in Korea

Abstract

The objective of this study was to conduct field experiments comparing formulated (extruded pellets (E.P)) and raw-fish (moist pellets (M.P)) feeds at two flounder aquaculture farms for six months to obtain the basic data necessary for improving aquafarmers’ awareness of feed-quality issues and firmly establish and expand the use of formulated feed. According to the results, the M.P group was higher in weight gain, feed efficiency ratio, protein efficiency ratio, and specific growth rate and lower in mortality rate than the E.P group. All cases of mortality were caused by six kinds of disease, four of which (Vibrio sp., Edwardsiella sp., Streptococcus sp., and Scuticociliates) were common to the two groups, whereas Lymphocystis arose only in the M.P group and abdominal inflation only in the E.P group at both farms. As for mortality in the present experiment, the numbers were 1047 at Da-Hae farm and 1167 at Global farm, with more fish dying in the E.P tanks than in the M.P tanks. By multiplying the number of deaths by selling price, the economic losses were $9650 and $10,756, respectively. Therefore, it should be considered an urgent priority to develop flounder-exclusive formulated feed for improved digestion and absorption rate and also to establish a water-quality-improvement management plan.

Advancing production of marine fish in the United States: Olive flounder, Paralichthys olivaceus, aquaculture

“…In recent years, disease outbreaks have caused significant impacts to production in these regions (Jung et al, 2020;Kang, Kim, & Kim, 2013). Edwardsiella tarda has been a particularly problematic pathogen for the olive flounder industry in Asia, and efforts continue in the battle against this disease (Park, Aoki, & Jung, 2012).…”

“…Additionally, disease issues are not limited to those facilities which use coastal surface waters for flow-through operations, as a number of operators using saline wells in coastal areas have faced disease challenges. Salinity is typically lower in well-water facilities than in those using coastal waters, yet production facilities that have lower salinity appear to face greater challenges associated with scuticociliatosis disease in Asia than facilities with full-strength seawater (Jung et al, 2020). Given the issues associated with using flow-through production systems, there has been a move toward the use of RAS or semi-RAS systems to help overcome such challenges with scuticociliatosis (Takagishi, Yoshinaga, & Ogawa, 2009), as has also been discussed with other diseases noted previously.…”

Molecular detection and genotype analysis of Kudoa septempunctata from food poisoning outbreaks in Korea

“…That year, Korea ranked 7th among the world’s top 25 aquaculture producers [ 9 ]. In Korea, P. olivaceus accounted for 46.2% (37,240 metric tons) of the total fish farming yield (80,530 metric tons) in 2018 [ 10 ]. Foodborne outbreaks associated with P. olivaceus infected with K. septempunctata are crucial because they can lead to economic losses.…”

Apparent digestibility coefficients of plant feed ingredients for olive flounder (Paralichthys olivaceus)

“…Olive flounder requires high levels of animal-based protein as they are carnivorous (Hamidoghli et al, 2020;Kim et al, 2002). Therefore, farmers use fish meal as the best protein source usually used in their diets (Jung et al, 2020). However, fish meal is a limiting factor for olive flounder culture because of increasing price and uncertain reliability of supply (Bai & Lee, 2010).…”