• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.103-109
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• 1970

The results of this work concerning the growth of the mussel, Mytilus edulis cultured by the hanging method in Koje Bay are as follows: The major spawning time is confined to the period from March to April. The mean growth of the mussel is indicated by the following formula; $$Y\;=\;1.508+0.659X-0.0559X^{2}+0.00367X^3$$ The major growing seasons are June and October The variance varied in proportion to the growth of the mussel, and each ranged, in shell height, from $1.25\~2.75\;to\;2.25\~4.25$ (mean:1.60 to 2.78)cm, $2.25\~5.25(3.00)cm,\;2.25\~7.75(4.83)cm,\;2.25\~7.75(5.05)cm\;and\;2.25\~8.25(5.95)cm$, and the variance were $0.278\~0.230$, 0.368, 0.701, 1.053 and 1.209, respectively. On the other hand, the variances differed in proportion to the growth of the mussel. The average length of the mussel life was about eighteen months. The mussels growing on the hanging line for arrestation undergo seasonal vicissitudes, and the mussels which fall off, mass into countless numbers during the period from August to October and finally disappear completely in November. The dimensions of the largest mussel are as follows: The shell height : 9.48cm The shell length: 4.49cm The shell breath : 3.55cm The shell weight : 22.05g The weight of the soft parts 19.25g The relative growth of the mussel is indicated as follows: Relationship between the shell height and the shell length: Y =0.486X+0.334 Relationship between the shell height and the shell breadth: Y = 0.359X+0.107 Relationship between the weight of the soft part and the shell weight: Y = 0.882X+0.901 Relationship between the shell height and the weight of the soft part: $$Y\;=\;0.02828X^{2.90518}$$

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.21-30
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• 1991

In Summer, oxygen-deficient water masses were developed extensively in the closed eutrophic bays such as Chinhae Bay which results in mass mortality of marine organisms and severe decrease the production of the bay every year. Under the circumstances, this study was performed to investigate the oxygen depletion relating to eutrophication, and also to evaluate self-purfication capacity of Buk Bay by dissolved oxygen mass balance in 1988. The mean concentration of total inorganic nitrogen, phosphate phosphorus and chlorophyll-a were $11.06{\mu}g-at/l,\;0.80{\mu}g-at/l\;and\;1.11mg/m^3$ respectively, which were over eutrophication criteria. Oxygen-deficient water mass was formed in July with the minimum concentration of 2.08ml/l(mean) at the bottom of all stations and recovered slowly in August. The decay and reaeration coefficient calculated from dissloved oxygen sag curve were 0.222/day and 0.018ml/l/day, respectively. To maintain above 4ml/l of oxygen to prevent oxygen-deficient water mass, it is recommendable to supply as much as 0.856ml/l/day of dissolved oxygen or should be reduced the same mass loading of BOD from watershed by the construction of wastewater treatment plant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.671-675
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• 2002

The present study was conducted to elucidate functional properties of sulfated polysaccharides from ascidian tunics, In physical properties of the crude polysaccharides, emulsion ability and foaminess were more excellent compared with chitin and chitosan, particular dye binding capacity was prominent. Anti-blood coagulation of partially purified sulfnted polysaccharides showed with respect to APTT (Activated partial thromboplastin time). Especially, active fraction $(F_4)$ obtained by DEAE-cellulose ion exchange chromatography showed highest activity, which was approximately $20\%$ of the activity of heparin. ACE inhibitory activity also similar to anticoagulant activity. Active fraction $(F_4)$ obtained by DEAE-cellulose ion exchange chromatography showed about $34\%$, in ACE inhibitory activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.233-240
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• 1982

Some environmental parameters on the shell-fish farms in Deukryang and Gamagyang Bays during summer in 1981 were determined to find an eutrophication level for the conservation of the farm. Chlorophyll-a content in the seawater in the Deukryang Bay in September was $1.0{\sim}5.0{\mu}g/l$ with an average of $2.5{\mu}g/l$ In the superficial bottom muds, contents of COD were 5-10 mg/g, ignition loss $5-9\%$, phaeophytin pigment $2{\sim}5{\mu}g/g$, and sulfide 0.1-0.3 mg/g dry mud in both bays. High contents of both organic matters and sulfide were found in the innermost area of the Deukryang Bay and in the north western part of the Gamagyang Bay. All quantities including chlorphyll-a in the water are little less than or similar to those of Hansan-Geoje Bay, one of the most productive shellfish farms in the southern coastal waters in Korea . Eutrophication on both water and bottom mud was under way like other shellfish farms but pollution indices on the bottom mud calculated from the data of CODs and phaeophytin pigments shelved 6-11, which is much lower than those of Jinhae Bay and of the Hansan-Geoje Bay. This means that the bottom muds are in an early stage of eutrophication, unlike the Jinhae and Hansan-Geoje Bays though the water, similar to the other bays, shows a middle stage of eutrophication.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.464-469
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• 2011

Residues of ampicillin and amoxicillin in the muscles of olive flounder Paralichthys olivaceus were investigated after oral doses of 20 mg/kg body weight/day of ampicillin and 40 mg/kg body weight/day of amoxicillin in a first examination and 40 mg/kg body weight/day of ampicillin and 80 mg/kg body weight/day of amoxicillin in a second examination for 5-6 days. The ranges of seawater temperatures in the $1^{st}$ and $2^{nd}$ examinations were $13.4-15.6^{\circ}C$ and $16.8-21.4^{\circ}C$, respectively. Ampicillin and amoxicillin concentrations were analyzed by high performance liquid chromatography (HPLC). The average recovery rates of ampicillin and amoxicillin in fish samples ranged from 84.8-95.2% and 100.8-103.8%, respectively. Residual concentrations in the olive flounder peaked on the $5^{th}$ day, with average concentrations of 0.075 mg/kg and 0.311 mg/kg in the $1^{st}$ examination, and 0.098 mg/kg and 0.630 mg/kg in the $2^{nd}$ examination for ampicillin and amoxicillin, respectively, with maximum concentrations in muscle. In the $1^{st}$ examination, ampicillin concentrations in olive flounder after withdrawals of 1 and 3 days were 0.041 mg/kg and 0.023 mg/kg, respectively, and amoxicillin concentrations after withdrawals of 1 day and 10 days were 0.172 mg/kg and 0.023 mg/kg, respectively. In the $2^{nd}$ examination, the ampicillin concentrations in olive flounder after withdrawals of 1 and 3 days were 0.041 mg/kg and 0.023 mg/kg, respectively, and amoxicillin concentration after withdrawals of 1 day and 10 days were 0.172 mg/kg and 0.023 mg/kg, respectively. We suggest that the recommended withdrawal periods should be 3 days for ampicillin and 10 days for amoxicillin in the olive flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.4
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• pp.351-357
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• 2012

To determine whether the seaweed Saccharina japonica can effectively utilize dissolved nutrients from Sebastes schlegeli fish cultures, a laboratory experiment was conducted in a static system for 7 days at ESFRI, NFRDI in Korea. The experiment included an S. schlegeli monoculture system and an S. schlegeli-S. japonica IMTA system. Saccharina schlegeli density ($415{\pm}24g$; mean${\pm}$SE) remained the same in all treatments, whereas seaweed density varied across treatments of 0, 0.5, 1, 2, and 3 kg (control and T1-T4, respectively). During the experiment, nutrient ($NH_4^+$ and $PO_4^{3-}$) concentrations were measured at 24-h intervals. $NH_4^+$ concentration of the control group increased from $0.117{\pm}0.021mg/L$ at the start of experiment to $5.836{\pm}0.904mg/L$ at the end of experiment. $NH_4^+$ concentrations of each treatment were $3.004{\pm}0.040$, $2.086{\pm}0.133$, $1.642{\pm}0.121$ and $0.775{\pm}0.007mg/L$ in T1, T2, T3, and T4, respectively, at the end of experiment. The concentration of $PO_4^{3-}$ exhibited a similar trend to $NH_4^+$ concentration. $NH_4^+$ and $PO_4^{3-}$ concentrations significantly decreased with increased S. japonica thallus density each day (P<0.05). The nutrient removal efficiency (NRE) and nutrient uptake rate (NUR) showed different relationships with changes in thallus density; NRE increased but NUR decreased as thallus density increased. Based on measured concentrations of $NH_4^+$ and S. japonica weight, regression analysis defined the relationship between as an exponential function, $Y=3.8165e^{-0.505X}$ ($R^2$ = 0.9552). Our results demonstrated that S. japonica can function as an efficient component in IMTA with environmental and potentially economic benefits for fish hatcheries.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.329-334
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• 2009

The residues of fluoroquinolones in Olive flounder (Paralichthys olivaceus) and Black rockfish (Sebastes schlegeli) were investigated after oral doses of 20 mg/kg for 30 days. Blood samples were taken at 5 hours, 10 hours, 1 day, 2 days, 3 days, 5 days, 7 days, 9 days, 13 days, 20 days and 30 days after treatment. The concentrations of fluoroquinolones were detected by high performance liquid chromatography using a UV detector. The recovery rates of fluoroquinolones in fish samples ranged from 92.0-99.7%, 93.4-97.5% and 93.0-97.9% for treatment of 0.1, 0.5, and $1.0{\mu}g/g$, respectively. Ciprofloxacin, enrofloxacin, norfloxacin and sarafloxacin were detected in the blood of the olive flounder at 10 hours, 10 hours, 1 day and 10 hours after treatment with $6.43{\mu}g/g$, $6.07{\mu}g/g$, $11.83{\mu}g/g$ and $11.02{\mu}g/g$ as maximum level, respectively. Ciprofloxacin, enrofloxacin, norfloxacin and sarafloxacin were detected in the blood of black rockfish 1 day, 1 day, 1 day and 10 hours after treatment with $8.26{\mu}g/g$, $8.03{\mu}g/g$, $7.29{\mu}g/g$ and $9.38{\mu}g/g$ as maximum level, respectively. However, ciprofloxacin, enrofloxacin, norfloxacin and sarafloxacin were not detected in olive flounder samples at 20, 30, 20 and 20 days after treatment in any experiments (

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.699-705
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• 1999

The effects of iron on gill tissue and metabolic rate represented by oxygen consumption of olive flounder, Paralichthys olivaceus were determined. The effects were further studied by means of survival rate of the fish exposed to a serial concentrations of iron. The olive flounder exposed to iron concentrations over 0.93 mg/$\ell$ showed curvature and terminal clubbing of gill lamellae at 2 weeks post-exposure. In iron concentration 4.89 mg/$\ell$, gill of the fish were seriously damaged just after 2 weeks, showing hyperplasia of filament epithelia, deformation of lamella epithelia, chloride cell damage, and separation of lamella epithelial layer, Gills exposed to 9.78 mg/$\ell$ iron concentration resulted in fusion and necrosis of the lamellae after 2 weeks. Significant decreases of metabolic rate of the fish were observed after 4 weeks at iron concentration 0,93 mg/$\ell$ and after 2 weeks at iron concentrations over 4.89 mg/$\ell$. Survival rate of the olive flounder decreased significantly after 4 weeks at the iron concentration over 4.89 mg/$\ell$. These results lead us to conclude that, as far as the iron effects are concerned, its concentrations should not exceed at least more than 0.93 mg/$\ell$ in the fish farm and coastal waters for normal growth of the olive flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.431-437
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• 1996

The efforts of removing the specific fresh water fishy odor were studied by inducing tilapia, Oreochromis niloticus, to sea water in the use of the flavoring chemicals such as pyrrolidine and piperidine as experimental flavors. The amines added to the grinded muscle of tilapia were recovered by $88\%$ for pyrrolidine and $90\%$ for piperidine. When live tilapia were retained in a tank containing 100 ppm solution of the flavor for 30 min and then begun to start the acclimation into sea water with daily increase of $5\%_{\circ}$ salinity within 7days, no amines in the skin and the muscle of tilapia were detected after 4 days of acclimation to sea water. For the purge effects of amino in the skin and the muscle of tilapia, the concentration of pyrrolidine and piperidine lost $73.4\%,\;83.7\%$ in the muscle and $93.6\%,\;90.6\%$ in the skin of tilapia after purging in fresh water for 72 hrs, while $66.2\%,\;73.6\%$ of amines were removed in the muscle and $90.1\%,\;87.7\%$ in the skin of tilapia acclimated to sea water after purging in on sea water for 72hr. Loss rates of pyrrolidine and piperidine were found to be $0.0231h-^{1}\;and\;0.0333\;h^{-1}$ from the muscle and $0.0652h-^{1}\;0.0413\;h^{-1}$from the skin of tilapia in the fresh water, while $0.0131h-^{1}\;and\;0.0354\;h^{-1}$ from the muscle, $0.0674h-^{1}\;and\;0.0549\;h^{-1}$ from the skin of tilapia in the sea water after 24hrs of exposure, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.816-822
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• 1997

The immobilization of a microorganism has been rapidly progressed with the development of biotechnology in recent years. Although it has been used as a tool to isolate products from biological media in various areas, it has not yet been practiced in the treatment of waste water. In this paper, we suggest a possibility to apply the immobilization technique In the recirculating aquaculture system. We examined the ability of $NH_4^+$ removal by nitrifier consortium immobilized in $Ba^{++}-alginate$, k-carrageenan and agar bead at the concentration of 50 g/L, respectively. In order to use the immobilized nitrifier consortium as media in the fludized bed reactor, the strength of bead was measured. $Ba^{++}-alginate$ as a support material showed higher strength of bead. Also, the nitrifier consortium immobilized in $Ba^{++}-alginate$ showed higher nitrification activity that could remove 20 mg/L ammonium ion than those immobilized in other two support materials, carrageenan and agar. The immobilized nitrifier consortium showed better nitrification activity than free nitrifier consortium.