Cetacean bycatch and stranding in Jeju Island, Republic of Korea between 2013 and 2016

Mi Yeon Kim,Soojin Jang,Yikweon Jang,Jae C. Choe,Hyeung Ko,Jang-Young Ahn,Suk-Jang Kim,Chan-Moon Choi,Chang-Heon Lee,Byung-Yeob Kim 한국수산과학회 양식분과 2016 한국수산과학회 양식분과 학술대회 Vol.2016 No.10

패류 중 자연정화 및 인공정화에 의한 위생지표세균의 변화

오은경,유현덕,유홍식,하광수,신순범,이태식,이희정,김지회,손광태 한국수산과학회 2012 한국수산과학회지 Vol.45 No.1

In coastal areas that are affected by continuous, seasonal or occasional pollution sources, bivalves accumulate biological contaminants such as pathogenic bacteria. We investigated the effect of natural seawater relaying and electrolyzed seawater depuration on the bacteriological quality of artificially contaminated oysters Crassostrea gigas and shortnecked clams Ruditapes philippinarum to suggest an alternative method of shellfish sanitation control.When artificially contaminated oysters and short-necked clams (fecal coliform level 1,700 MPN/100 g) were relayed into a sea area of safe bacteriological water quality, the fecal coliform level dropped to below 110 MPN/100 g after 1 day. The bacteriological quality of oysters and short-necked clams that are contaminated at a fecal coliform level of 1,700 MPN/100 g could be improved, and become appropriate for raw consumption by a single day relay under proper environmental conditions. When artificially contaminated oysters (fecal coliform level 330 MPN/100 g) were depurated with electrolyzed seawater, 94% of fecal coliform was eliminated after 12 h and fecal coliform was undetectable after 24 h. After 24h depuration with electrolyzed seawater, the fecal coliform level of short-necked clams with initial fecal coliform of 2,400 MPN/100 g was below 20 MPN/100 g. However, the fecal coliform level of short-necked clams with initial fecal coliform of 17,000 MPN/100 g was relatively high, at 790 MPN/100 g, even after 24 h of depuration with electrolyzed seawater, because of the repeated cycle of excretion and accumulation of fecal coliform in shellfish tissue under the closed depuration environment. Such natural seawater relaying and electrolyzed seawater depuration can be restrictively applied to improve or secure the bacteriological quality of oysters and short-necked clams in accordance with safety levels for bivalves for raw consumption.

우리나라 남해에 분포하는 붕장어(Conger myriaster )의 연령과 성장

김영혜,이은희,김정년,최정화,오택윤,이동우 한국수산과학회 2011 한국수산과학회지 Vol.44 No.6

Age and growth of whitespotted conger Conger myriaster were estimated using right sagittal otoliths from 495 fish collected from February, 2004, to January, 2005, in the southern coastal waters of Korea. Examination of the outer margin of the otoliths showed that opaque zones formed once a year and annual rings formed from April to June. The ages of the specimens examined ranged from 3 to 8 years. Whitespotted conger spawn from December to March. Allometry between preanal length and total weight can be expressed as TW=0.0350×PL^(2.9173) (R^2=0.89). There was no significant difference in allometry between females and males (P>0.05). The estimated VBF growth equation was L_t =415.2(1-e^(-0.1457(t+0.4654))).

난질과 유생발생을 이용한 4개 멍게(Halocynthia roretzi ) 어미계군 특성 비교

허영백,김은경,임영섭,전창영,조기채,명정인 한국수산과학회 2011 한국수산과학회지 Vol.44 No.5

To compare four populations of sea squirt Halocynthia roretzi adults, their egg quality and larval development were investigated in the hatchery. The populations were: south sea wild (SSW), south sea cultured (SSC), east sea wild (ESW) and Iwate Japan cultured (IJC). Egg quality and larval development were compared using 13 factors (fertilization rate and diameter, proximate composition, amino acid and fatty acid contents of eggs, hatching rate and various sizes of tadpole larvae) which were obtained from each population. Fertilized egg diameter, hatching rate and size of tadpole larvae were significantly different among the four populations (P<0.05). Eggs were produced with higher crude protein (5.20±0.00% SSW, 4.71±0.01% ESW, 4.66±0.01% SSC and 3.96±0.01% IJC) and lipid (1.22±0.01% ESW, 1.01±0.00% SSW, 0.77±0.01% SSC and 0.69±0.00% IJC,) contents from domestic wild populations than from Japanese or cultured populations. Also amino acid and fatty acid contents were different. The extent of similarity between domestic and Japanese populations (30.5% IJC:SSW, 34.3% IJC:SSC and 40.7%IJC:ESW) was relatively low but was very high between SSW and SSC (73.9%). These results may have been due to differences in the abundance of food types and environmental conditions in the four localities and consequent differences in the diets of the sea squirts.

Spirulina, Astaxanthin, Canthaxanthin 및 Paprika 함유 사료가 비단 잉어(Cyprinus carpio var. koi) 홍백 치어의 체색에 미치는 영향

김이오,이상민 한국수산과학회 2012 한국수산과학회지 Vol.45 No.1

A feeding trial was conducted to investigate the effects of dietary carotenoid source and level on growth and skin color of red- and white-colored fancy carp Cyprinuscarpiovar. koi. Nine experimental diets (designated as CON, SP5, SP10,AS50, AS100, CA50 CA100, PA5 and PA10) were formulated to contain 5-10% Spirulina powder, 5-10% paprika powder, 50-100 ppm astaxanthin and 50-100 ppm canthaxanthin. The CON diet without supplementation of carotenoid source was considered as the control diet. Each experimental diet was fed to three replicate groups of fish (3.6 g/fish) to visual satiation three times a day for 8 weeks. Survival, growth and feed efficiency of fish were not significantly affected by dietary inclusion of carotenoid source and level (P>0.05). After 8 weeks feeding period, the values of a*, L*and b* of fish skin were significantly changed by dietary carotenoid source (P>0.05), but not carotenoid level. The a* value of fish fed the diets containing CA and PA was higher than control and SP diets (P>0.05). Based on the results of this study, it can be concluded that dietary inclusion of 50 ppm canthaxanthin or 5% paprika powder could increase the redness of red-and white-colored fancy carp fingerling.

다영양입체양식을 위한 다시마(Saccharina japonica)의 생물여과효과

박미선,유현일,민병화,김영대 한국수산과학회 2012 한국수산과학회지 Vol.45 No.4

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±24 g; mean±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 (NH4+ and PO43-) concentrations were measured at 24-h intervals. NH4+ concentration of the control group increased from 0.117±0.021 mg/L at the start of experiment to 5.836±0.904 mg/L at the end of experiment. NH4+ concentrations of each treatment were 3.004±0.040,2.086±0.133, 1.642±0.121 and 0.775±0.007 mg/L in T1, T2, T3, and T4, respectively, at the end of experiment. The concentration of PO43- exhibited a similar trend to NH4+ concentration. NH4+ and PO43- 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 NH4+ and S. japonica weight, regression analysis defined the relationship between as an exponential function, Y = 3.8165e-0.505X (R2 = 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.

해양소재를 이용한 마스크팩의 유용성 : 피부재생효과

박대환,박상욱,최성곤 한국수산과학회 2012 한국수산과학회지 Vol.45 No.2

Minerals from marine materials such as deep ocean water and Dead Sea water have been used since ancient times. We made a mask pack sheet including deep ocean water and salt from the Dead Sea and evaluated the function of the mask pack sheet through animal study.Three full-thickness skin defects were made on the backs of Sprague-Dawley rats. The wounds were left untreated in group Con, and mask pack sheets including deep ocean water or deep ocean water and Dead Sea water were used as treatment for 20 min on the skin of animals in groups DP and DDP, respectively. We analyzed the gross, histological and biochemical findings.Groups DDP and DP showed decreases in wound size,as compared to group Con at 7 days after wound infliction. The histological findings revealed that wound healing had progressed further in groups DP and DDP than in group Con, with more rapid collagen deposition and regression of neutrophils. Also, the expression of vascular endothelial growth factor and transforming growth factor β1 were increased in groups DDP and DP compared with those in group Con at 3 days after wound infliction. Mask sheet packs including deep ocean water and Dead Sea salt affected wound healing by reducing the inflammatory phase and stimulated wound contracture by facilitating the deposition of collagen.

꽁치(Cololabis saira ) 과메기의 품질에 세척수가 미치는 영향

이소정,심길보,임치원,홍유미,김점돌,윤호동 한국수산과학회 2012 한국수산과학회지 Vol.45 No.3

We investigated the effects of various washing methods on the quality of semi-dried Pacific saury Cololabis saira,known in Korea as Guamegi. We immersed samples for 5 min in seawater, tap water, chlorinated water (100 mg/kg),ammonia water (100 mg/kg), citric acid (0.1 M), butylated hydroxyanisole (BHA, 0.2 g/kg), or sesame oil (5 g/100 g),and then dried them in the sun for 3 days. The moisture and crude lipid contents after drying were 26.62-32.49 g/100g and 26.40-33.01 g/100 g, respectively. The moisture content significantly decreased while the crude lipid content increased during drying. The different washing methods did not have a significant effect on the acidity, peroxide values,or levels of thiobarbituric acid or biogenic amine in Gwamegi. The lightness of Gwamegi during drying significantly decreased, but this decrease was not significantly different among washing methods. The degree of acceptance in a sensory evaluation was higher for Gwamegi treated with sesame oil. Our results suggest that these washing methods should not be used to inhibit lipid oxidation, biogenic amine formation, or color changes in semi-dried Pacific saury, because effective components are extracted by the lipids during drying.

제주산 우뭇가사리(Gelidium amansii )로부터 DMSO 추출과 EDTA 수세법에 의한 상용화 아가로스 제조

강태환,이승홍,백종석,강병식,이정석,이남호,전유진 한국수산과학회 2011 한국수산과학회지 Vol.44 No.6

Agar was prepared from Gelidium amansii collected from Jeju Island, South Korea. This agar preparation has high gel strength and low sulfate content compared with G. amansii agar from Morocco. Accordingly, agarose was made from the Jeju agar through the consecutive refining processes of dimethyl sulfoxide (DMSO) extraction and ethylene diamine tetra acetic acid (EDTA) washing. The physicochemical properties of the resulting agarose were compared with those from agarose prepared using only DMSO extraction. Consecutive DMSO extraction and EDTA washing more strongly affected the physicochemical properties of the agarose (purified agarose) compared with the use of DMSO extraction alone. These properties were similar to those of commercial agarose used for electrophoresis. In DNA electrophoresis, the separation and movement speed of the purified agarose were similar to those of the commercial agarose. In a ^(13)C NMR analysis, the purified agarose exhibited the same carbon peak as the commercial agarose. When observed under scanning electron microscopy, the agar had an even and smooth surface without irregularities or pores, and the purified agarose had a wide surface area with a large number of pores; the commercial agarose had an irregular surface that would allow the solvent to easily permeate. These results illustrate that the physicochemical properties of agarose prepared from DMSO extraction and EDTA washing were more effective than those observed after DMSO extraction alone; thus, these processes used in succession will be useful in agarose industries.

보관 방법에 따른 Rotifer Brachionus plicatilis 내구란의 부화

윤주연,허성범 한국수산과학회 2011 한국수산과학회지 Vol.44 No.6

The rotifer Brachionus plicatilis is one of the most important food organisms in aquaculture. The resting eggs produced by mictic female rotifers are easily stored and hatched, making them useful as the starter for the mass culture of rotifers in marine larval culture. This study examined the optimum preservation method for resting eggs to ensure a high hatching rate. To produce resting eggs, the marine rotifer B. plicatilis was cultured with Nannochloris oculata (KMMCC 16). The resting eggs were harvested and cryopreserved using 5% and 10% methanol (MeOH), dimethylsulfoxide (DMSO), and glycerol as cryoprotectant agents (CPAs). The cryopreservation comprised slow or rapid freezing and the resting eggs were stored for one month in liquid nitrogen (-196˚C). The resting eggs were also dried at different temperatures (30, 40, and 50˚C) and for different times (1, 2, and 3 h). In general, the hatching rates of the resting eggs preserved with CPA were higher than those without CPA and the slow freezing method was better than the rapid freezing method. However, the optimum CPA concentration for the hatching rate of the resting eggs varied with the freezing method and kind of CPA, and the CPA also affected the viability of the resting eggs. Dried resting eggs had a high, rapid hatching rate over 80%. The moisture content of the resting eggs cryopreserved in liquid nitrogen affected the hatching rate. Drying at 30˚C for 1 hour resulted in a high hatching rate of the resting eggs. In conclusion,drying at 30˚C for 1 hour and preservation in liquid nitrogen with the slow freezing method, without CPA, is recommended for a high hatching rate (ca. 95%) of rotifer resting eggs.