• Fisheries and Aquatic Sciences
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• 제6권2호
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• pp.74-80
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• 2003

Two cellular biomarker parameters of the farmed Pacific oyster Crassostrea gigas were studied in vivo and in vitro after exposure to concentrations of polychlorinated biphenyls in terms of neural red uptake (NRU) and lysozyme activity. The oysters exposed in vivo to the xenobiotic concentrations, 0, 30, 90, and 180 ng/g for 14 days, enhanced hemocyte NRU with occasional significant differences (P<0.05), depending on the chemical concentration and duration. An adverse tendency was manifest in the lysozyme activities both in the hemocyte and serum of the oyster treated with the chemical in a same manner, rendering these two cellular parameters as biomarker candidates against the chemical. The oysters exposed in vitro to the chemical concentrations, 0, 1, 5, 10, 100, 1,000, and 10,000 ng/g for 24 hrs at $10^{\circ}C$ showed a similar tendancy as those exposed in vivo to the chemical. Unlike in vivo response, however, the in vitro NRU was first influenced by very low concentration of the chemical. In in vitro results, marked but not significant increase of hemocyte NRU was noticed at the chemical concentration of 5 ng/g, where the value was almost as high as those exposed to higher chemical concentrations, up to 10,000 ng/g. An unusual result was observed in the in vitro lysozyme activity of hemocyte in which significant decrease was first noticed at the chemical concentration of 100 ng/g.

• 한국수산과학회지
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• 제53권5호
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• pp.773-783
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• 2020

In order to evaluate the recovery of fishing ground environment after the cessation of aquaculture farming, we examined the variation in sediment quality over time using different geochemical factors and investigated whether these factors are indicators of sediment quality recovery. The study area was an oyster Crassostrea gigas, farm in Tongyeong, Geyongsangnam-do, South Korea, where aquaculture activities had been carried out for 20 years, and the changes in water and sediment environment were monitored for 14 months after the abandonment of the farm. The mean water depth was 14 m, with a tidal range of 3 m, and seawater current velocity ranged from 4.7 to 7.0 cm/s. After the abandonment of the farm, total organic carbon and total nitrogen concentrations in the surface sediments decreased significantly over time compared to those in the control site; in particular, immediately after farm abandonment, acid-volatile sulfide concentrations decreased relatively rapidly. Carbohydrate and protein concentrations in the sediments showed no significant changes; however, lipid concentrations markedly decreased. Further studies on other aquaculture taxa and various aquaculture areas are needed to establish new policies for environmental management of fishing grounds, such as relocation of fishing grounds and determination of optimal fallowing periods.

• 한국패류학회지
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• 제32권1호
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• pp.31-36
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• 2016

In the present study, we observed a unique association of the flat oyster, Ostrea denselamellosa obtained from a muddy substrate at Haechang Bay, the south coast of Korea in the spring of 2013. Fossilized or semi-fossilized veneriid clam shells, possibly Ruditapes philippinarum, were found adhering to the umbonal area of the flat oyster valves. This unique association of the flat oyster shells with the fossilized clam shells suggested that the flat oyster larvae utilized the clam shells as substrate during settlement. Since availability of clam shells in the muddy subtidal environment is limited, this unique substrata for the flat oyster larvae may limit recruitment of the flat oysters in the bay.

• 한국수산과학회지
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• 제31권2호
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• pp.210-216
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• 1998

(1) 통영시 관내 북만해역의 굴양식장군의 8개 조사양식장에서 $1994\~1996$년까지 매월 1회씩 굴 시료를 채취하여 양식굴의 집단생태학적 특성치를 조사하고, 굴 육질의 지방산조성을 분석하여 얻은 자료를 토대로, DHA 함량조성과 굴의 집단생태학적인 몇가지 특성간의 관련성을 검토하였다. (2) 굴의 지질중 DHA 함량조성은 연중 $0\~25\%$ 범위로 변동하였으며, 6월에 최저치를 나타내었고, 11월에 최고치를 나타내었다. (3) DHA함량조성과 굴의 사망계수 및 성장계수와의 사이에는 관련성이 나타나지 않았다. (4) 11월의 DHA 함량조성과 수확시 개체군의 크기사이에는 강한 (+)상관성이 인정되었고, 수확시 개체육 중량과의 사이에는 (-)상관성이 인정되었다. (5) 굴에 있어서 DHA는 산란기에 생식소의 성숙과 방출에 에너지원으로 다량 소모되는 것으로 보이며, 북만해역에서 11월의 DHA 함량조성은 수확시의 집단크기의 선행지수로 사용해 봄직하고, 체중과의 역 관련성을 잘해 석 하면 밀도효과를 유추할 수 있을 것으로 고찰되었다.

• 한국수산과학회지
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• 제18권2호
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• pp.180-194
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• 1985

The author investigated the history of oyster culture in Korea through examining old books and reports dealing with the fishery. Oysters have been produced in the all coastal areas in Korea, especially the center areas of production were the Hwangupo (Hamkyongbuk-do), Younghungman (Hamkyongnam-do), the estuary of Nakdonggang (Kyongsangnam-do), Kwangyangman, Haechangman, the estuary of Yongsangang (Chollanam-do), Yonghoto (Hwanghae-do) and the estuary of Uprockgang, where the large size oyster (more than 40cm in shell height) inhabited in form of groups. It was called by nine different names in the old times, Gul, Seukhwa and Moryeo were the most common names. The oyster was used as 46 kinds of medicinal stuff. The habitat forms of natural oyster can be distinguished to two types; one is that oyster is exposed to the air during the period of low tide (A-type), another is that oyster is not (B-type). The first oyster culture by the old books in Korea was started about 530 years ago as the bottom culture method derived from the A-type of oyster. After long years, the hanging culture method might have been started from the hint of the habitat form of B-type. The oyster culture in Korea developed based on the habitat forms of natural oyster at the biginning of 1900s. After World War II, the Korean government strongly recommded the laver farmers to culture oyster as relief measures. At that time, the stone culture method was mainly adopted. The quantity of oyster production is now about $15{\times}10^6{\sim}19{\times}10^6\;\frac{M}{T}$, and the half of oyster production including seed oyster is exported to the foreign countries.

• 한국패류학회지
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• 제29권3호
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• pp.251-258
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• 2013

본 연구에서는 굴, Crassostrea gigas의 계획적인 인공종묘생산 및 우량형질의 정자를 보존하기 위하여 냉동보존 시 적정 결빙억제제 (cryprotective agent, CPA) 및 농도를 알아보고자, CPA 종류 및 농도별 독성 및 냉동보존 효과를 파악하고 해동 후 정자의 세포 손상을 조사하였다. CPA 종류 및 농도별 침지시간에 따른 굴 정자의 독성평가를 실시한 결과, 생존율 및 운동성은 DMSO가 가장 좋았으며, 다음으로 EG, glycerol, Methanol 순이었다. 희석액으로 여과해수를 사용하여 CPA 종류 및 농도별 냉동보존 결과, 15% DMSO로 냉동보존 한 정자의 생존율 및 운동성이 가장 높았다. 굴의 냉동/해동 정자를 주사전자현미경으로 관찰한 결과, DMSO, EG, methanol, glycerol 순으로 세포 손상이 적었으며, 농도는 15, 20, 10, 5% 순이었다. 이상의 결과를 종합한 결과, 굴 정자의 냉동보존 시 여과해수를 희석액으로 사용할 경우 적정 CPA는 DMSO이며, 농도는 15%였다.

• 수산경영론집
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• 제51권2호
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• pp.71-87
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• 2020

Oysters are the most abundantly harvested type of shellfish in Korea. As export of this marine product increases, oysters have greatly contributed to an increase in fishing income. As the oyster aquaculture industry has rapidly grown since the late 1990s, issues of oyster-shell processing that occur in production processes have re-emerged as important topics in the oyster industry. The amount of oyster shells harvested in 2019 is estimated to be approximately 300,000 tons. With reductions in demand for pyrolytic fertilizer and feed, which are currently the greatest sources of demand, unprocessed shell quantities have doubled compared to 2018, causing them to be an issue once more. Such oyster-shell processing also incurs great costs, and a total of forty-six billion three hundred fifty million Korean won (46,350,000,000 KRW) has been provided from 2009 to 2020 for the use of oyster shells as a resource. According to current Korean laws, oyster shells are considered to be industrial waste if more than 300 kilograms are sent out in a day. Collection and processing must be conducted by a waste-consignment company. Consequently, there are many limitations to the use of oyster shells in Korea as a resource. However, in Japan, only oyster-shell waste is regulated by waste-processing As a result, local governments may apply exceptions when utilized as organic matter. Consequently, in Japan, oyster shells are being used as resources in more diverse fields than in Korea. This study observes the conditions and problems of oyster-shell processing in Korea and attempts to find new domestic oyster-shell resource solutions in light of Japan's recycling practices.

• 한국조리학회지
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• 제23권8호
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• pp.206-215
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• 2017

Sprout ginseng paste were prepared with pine nut, dry oyster and dry shrimp to examine the antioxidant properties(total polyphenols, total flavonoids, and electron donating ability) and sensory test(attribute difference and acceptance). Sprout ginseng paste were measured based on color value, pH, viscosity, total bacteria cell numbers for 0 and 20 days at $4^{\circ}C$. The higher total polyphenol and total flavonoid content of sprout ginseng paste added with pine nuts, dry oyster, and dry shrimp were higher antioxidant capacity. DPPH radical scavenging activity was increased from 52.2% (SGP0) to 79.5.0 % with SGP5. The attribute test results reveal that the color intensity, bitter taste, and oily taste were decreased in SGP3 to SGP6. Taste, flavor, and coarseness did not show significant difference in SGP0 to SGP6. Thickness and After taste were increased in SGP4 to SGP6. The preference test results reveal that the appearance, flavor, and texture level did not show significant difference in SGP0 to SGP6. Taste and overall preference were increased in SGP4 to SGP6. L value, pH, decrease while a value and b value show no change in sprout ginseng paste with pine nut, dry oyster and dry shrimp. Total cell number was not detected during storage.

• 한국패류학회지
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• 제28권2호
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• pp.109-116
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• 2012

In order to understand the effect of introduction of oyster rack culture on natural short-necked clam, Ruditapes philippinarum, stock, we investigated the status of natural clam stock prior to introduction of oyster rack culture at Yeongheung Coast of Wando Island. The growth equation of the clam was estimated as: $L_t=61.46{\cdot}(1-e^{-0.172(t+0.155)})$ from ring radius composition of shell. Instantaneous coefficient of total mortality and natural mortality were calculated as: 2.4087/year and 0.478/year, respectively. The age at first capture was estimated to be 2.55 year. The total biomass was estimated to 3.23 ton in the bed (0.8 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit (Y/R) was corresponded to $114.7individuals/m^2$ and $92.0g/m^2$, respectively. Maximum sustainable yield (MSY) was estimated 0.77 ton/year which was close to annual catches, 0.74 ton/year, in the area.

• 한국패류학회지
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• 제25권3호
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• pp.213-222
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• 2009

해수 및 양식 참굴의 중금속 농도를 분석한 결과 일부 지역에서 간헐적으로 기준치를 초과하였지만 아직까지 뚜렷한 오염 현상은 확인되지 않았다. 그러나 기존 조사한 결과와 비교하면 미량이지만 증가 추세를 보이고 있어 지속적인 감시 및 관리체계 구축이 필요하다고 생각된다. 참굴의 중금속 생물농축계수를 조사한 결과 경남 연안에 서식하는 참굴의 생물농축계수는 청정해역과 오염해역의 중간이행 단계에 해당하였다. 특히 카드뮴의 생물농축계수가 다른 금속에 비해 월등히 높으므로, 이러한 특성을 활용하면 참굴을 Cd 등 중금속 오염 모니터링에 활용할 수 있을 것이다. 특히 카드뮴은 다른 원소들의 생물농축과 가장 밀접한 상관관계가 있는 것으로 조사되었다. 특히 카드뮴과 납이 가장 일정한 상관관계를 나타내는 것은 경남 연안의 해역의 주요 중금속 유입원은 화석연료유의 연소에 의해 유래된 것으로 추정된다. 다차원척도분석법에 의한 수질자료와 중금속 농축경향을 분석한 결과 경남 연안의 양식 참굴의 중금속 유입원은 강우에 의한 일시적 유입보다는 클로로필 a 및 투영도 등과 밀접한 유사성을 지니는 것으로 보아 통영연안에 서식하는 참굴의 중금속 축적은 대부분 먹이연쇄를 통해 이루어지는 것으로 본다.