• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.373-378
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• 2015

Postprandial ammonia excretion and oxygen consumption in olive flounder Paralichthys olivaceus fed two different feed types, moist pellet (MP) and expanded pellet (EP) diets, to satiation were determined at $12^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$ for 48 h. The ammonia excretion and oxygen consumption rates increased with increasing water temperature. However, the postprandial times for the maximum rates of ammonia excretion and oxygen consumption were shortened from 12 h to 6 h after feeding with increasing water temperature. The ammonia excretion and oxygen consumption rates of the fish fed EP were significantly higher (P < 0.05) than those fed MP at 12 h post-feeding both for $12^{\circ}C$ and $15^{\circ}C$. The highest (P < 0.05) weight-specific ammonia excretion rates at $12^{\circ}C$ were observed in the fish fed EP and MP at $12.1mg\;NH_3-N\;kg^{-1}h^{-1}$ and $8.7mg\;NH_3-N\;kg^{-1}h^{-1}$, respectively, for 12 h and 9 h after feeding. The highest (P < 0.05) weight-specific oxygen consumption rates at $12^{\circ}C$ were observed in fish fed EP and MP at $116.4mg\;kg^{-1}h^{-1}$ and $101.0mg\;kg^{-1}h^{-1}$, respectively, for 12 h after feeding. The highest ammonia excretion rates at $25^{\circ}C$ in the fish fed EP and MP increased to $16.9mg\;NH_3-N\;kg^{-1}h^{-1}$ and $18.3mg\;NH_3-N\;kg^{-1}h^{-1}$, respectively, for 6 h after feeding. The highest (P < 0.05) weight-specific oxygen consumption rates at $25^{\circ}C$ were observed in fish fed EP and MP at $184.3mg\;O_2kg^{-1}h^{-1}$ and $197.3mg\;O_2kg^{-1}h^{-1}$, respectively. These data are valuable for the design of biofilters and development of effluent treatment technologies for the land-based flounder farms.

• ALGAE
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• v.33 no.4
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• pp.329-340
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• 2018

The present study was to determine the effects of salinity on the growth and nutrient bioextraction abilities of Gracilaria and Ulva species, and to determine if these seaweeds can be used for nutrient bioextraction under hypo- and / or hyperosmotic conditions. Two Gracilaria species, G. chorda and G. vermiculophylla, and two Ulva species, U. prolifera and U. compressa, were cultured at various salinity conditions (5, 10, 15, 20, 30, 40, and 50 psu) for 3 weeks. Results showed that the growth rates, nutrient uptake, tissue nutrient contents and nutrient removal were significantly affected by salinity and species. All four species were euryhaline with the highest growth rates at 20 psu. Among the four species, U. prolifera, U. compressa, and G. vermiculophylla showed potential to be used for nutrient bioextraction in estuaries and / or land-based fish farms due to their rapid growth, high nutrient uptake, high tissue carbon and nitrogen accumulation and removal capacities.

• Journal of fish pathology
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• v.25 no.3
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• pp.231-241
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• 2012

Diagnostic monitoring in fish farms with land-based tanks and netpen cases were conducted in eastern, western, southern and Jeju island of Korea during summer of 2007~2011. In total, 2413-fish samples of 4 marine fish species were tested for the detection of bacteria and parasite. Fish species tested were olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), red sea bream (Pagrus major), pacific white shrimp (Litopenaeus vannamei). During the diagnostic monitoring from 2007 to 2011, the infection rates by single infection of bacterial or parasitic pathogens were relatively higher than the mixed infections. The main bacterial pathogens in olive flounder, black rockfish and pacific white shrimp were Vibrio spp. (V. harveyi, V. ichthyoenteri, Vibrio sp.). The main bacterial pathogens in red sea bream were also Vibrio sp. and Photobacterium damselae subsp. damselae. The main parasitic pathogens were both Miamiensis avidus and Trichodina sp. in olive flounder, Microcotyle sebastes in black rockfish, Microcotyle tai in red sea bream and Zoothamnium sp. in pacific white shrimp.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.2
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• pp.1-10
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• 2019

Based on the land system of Joseon Dynasty and contemporary perception of land, this study analyzed the reason Yun seon-do entered Bogildo Island and a characteristic of Buyong-dong garden. According to this analysis, this study interpreted the purpose that Yun seon-do had built Buyong-dong garden at a socio-economic perspective. The land such as Sarlimchontack(山林川澤) is recognized as a commonland in the Joseon Dynasty. Except the reserved area(禁山), however, actions to make commonland private through Ib-an(立案) and protecting graves was frequent. Bogildo Island was a place difficult to build a private garden because the island had been appointed a reserved forest to protect pine trees. Right after Byungjahoran, Yun seon-do entered the island on the pretext of protecting forests, and built Buyong-dong garden. The island was easy to move to manage private farms as well as possessed abundant forest resources and resources that have economic value such as fish and salt. It indicates that, unlike his pretext, economic benefits have also been considered.

• Journal of fish pathology
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• v.19 no.3
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• pp.207-214
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• 2006

Diagnostic monitoring in fish farms with land-based tanks and net cases was conducted in eastern, western, southern and Jeju island of Korea for the summer period from 2000 to 2006. Total 3,518-fish samples of marine and freshwater fishes in 25 fish species were tested for pathogens. Fish species tested were olive flounder (Paralichthys olivaceus), fleshy prawn (Fenneropenaeus chinensis Osbeck), black rockfish (Sebastes schlegeli), rock bream (Oplegnathus fasciatus), red sea bream (Pagrus major), black seabream (Acanthopagrus schlegeli), sea bass (Lateolabrax japinicus), gray mullet (Mugil cephalus), rainbow trout (Onchorhynchus mykiss) and others. The infection rates by bacterial pathogens in the years of 2000, 2001, 2002, 2003, 2004, 2005 and 2006 were 22.4%, 34.5%, 14.1%, 15.3%, 17.7%, 13.5% and 5%, respectively. The infection rates by parasitic pathogens were 20%, 33.8%, 12.4%, 14.1%, 9.2%, 10.5% and 10.7%, respectively. The infection rates by viral pathogens were 22.4%, 13.5%, 10.3%, 5.4%, 9.7%, 10.2% and 15.8%, respectively. The infection rates by mixed pathogens were 10.3%, 0%, 44.9%, 50.9%, 31.9%, 38.4% and 39.6%, respectively. The rates of mixed infections were very low until 2001. The rates were higher than those of singer infections from 2002 to 2006. During the diagnostic monitoring from 2000 to 2006, the main bacterial pathogens were Vibrio (41.2%) and Streptococcus (28.8%). The infection rate by protozoa (85.7%) mainly including Scuticociliates and Trichodina was highest. The infection rate by viral necrosis virus (VNNV, 42.2%) was the highest of the viral pathogens.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.78-91
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• 2018

In order to understand the distributions of organic matter and heavy metal concentrations in the surface sediment of Jaran Bay, we measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in surface sediments collected at 15 stations in this bay in November 2014. The sediment consisted of finer sediment such as mud and clay, with 8.6-9.8Ø($9.3{\pm}0.3$Ø) of mean grain size. The concentrations of TOC and TN in the sediment ranged from 1.51-2.39 % ($1.74{\pm}0.22%$) and 0.20-0.33 % ($0.23{\pm}0.03%$), respectively, and did not show spatial difference. The carbon to nitrogen ratio (C/N ratio) ranged from 5-10, indicating that organic matter in the sediment originated from oceanic sources such as animal by-products from fish and shellfish farms. The concentrations of Cr, Fe, and Mn were much higher in the mouth of the bay than in the inner bay, and the concentrations of As, Cd, Cu, Hg, Pb, and Zn showed an opposite distribution pattern. Based on the results of the sediment quality guidelines (SQGs), enrichment factor (EF), geoaccumulation index ($I_{geo}$), pollutant load index (PLI), and ecological risk index (ERI), the surface sediment in Jaran Bay is not polluted or only slightly polluted with Cd, Cr, Cu, Hg, Pb, and Zn, whereas it is moderately to strongly polluted with As. In particular, some regions in the bay were identified as having a considerable risk status, indicating that metal concentration in the sediment could impact benthic organisms. Thus, the systematic management for marine and land sources of organic matter and heavy metals around Jaran Bay is necessary in order to ensure seafood safety and maintain sustainable production on shellfish farms.