• Journal of Wetlands Research
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• v.25 no.1
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• pp.1-13
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• 2023

Coastal shellfish in the shallow aquaculture waters form carbon contained shells as they grow. The existing researches showed that carbon flux can be improved, if the shells are re-treated by the carbon stored methods. In the present study, firstly, the mechanism and the quantitative flux of carbon dioxide in the shellfish individual have been analyzed. The re-treated methods of the useful by-product in the shellfish aquaculture, shells, have been reviewed. Finally, the potential effects to reduce the greenhouse gas has been suggested, if the shells can be properly re-treated.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.210-211
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• 2001

연안 해역은 어장환경 악화와 가용 먹이량을 초과한 시설량 증대로 양식 생물의 생존 및 성장률이 저하되어 생산량이 감소하고 있으며 (Keng et ai.,2000; Sugawara ＆ Okoshi, 1991), 부영양화가 진행적지 않은 일부 해역에서도 양식 생물의 미성숙으로 인해 양식 기간이 연장되고 있다 (Choi et al., 1997). 이와 같은 이유로 양식 어장의 지속적인 개발과 이용을 위해서는 해역의 환경용량 (Carrying capacity)에 적합하도록 양식 생물 시설량을 재 조정할 필요성이 제기되고 있다 (Heral et al., 1990; Kang et al., 2000) (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.83-84
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• 2001

우리나라 연안 해역의 공동어장과 패류양식장에 서식하는 굴, 가리비, 반지락등 유용 조개류를 무차별 포식하는 불가사리는 패류양식 어민에게는 해적생물이라 불리우져, 이들을 퇴치하기 위한 대대적이고 적극적인 포획작업이 이루어지고 있다. 제주도의 경우도 마을 어장의 주요수산물인 전복, 소라, 오분자기등의 자원보존을 위한 불가사리 제거작업을 실시함과 동시에, 자원조성을 위한 종패 살포를 지속적으로 실시하고 있다. (중략)

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.203-209
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• 2016

Growth and survival of the hard shelled mussel spat were investigated to confirm the possibe spat culture in seawater pond from September 2014 to April 2015. Also, we measured simultaneously environmental factors including water temperature, salinity, dissolved oxygen, pH, DIN, DIP, chlorophyll a, and abundance and dominant species of phytoplankton in seawater pond every month. Ranges of water temperature and salinity were $4.0-23.4^{\circ}C$ and 18.8-25.2 psu, respectively, which were rather lower than the reported optimal level. Monthly measured survival rates in all the spat cages were over 90%. Concentration of chlorophyll-a and abundance of phytoplankton were very high, and dominant species phytoplankton were cryptomonads and nanoflagellates. These dominant species were considered to be good food organisms for the bivalve spat. The experimental cage stocked 100 individuals per basket ($2,700ind.\;m^{-2}$) hanging in bottom of seawater pond revealed the highest growth in shell height ($7.63{\pm}4.65mm$), but all experimental cages stocked below 200 individuals per basket ($5,400ind.\;m^{-2}$) did not show statistically significant difference. We may expect that seawater pond would be one of the best culture ground for bivalve spats when appropriate measures are available.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.721-734
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• 2022

This study analyzed the spatio-temporal variation characteristics of major environmental factors such as primary productivity (PP), chlorophyll a, nutrients, sinking particle matters, and organic contamination and biochemical composition of surface sediment on a monthly basis for approximately 2 years around shellfish mariculture in Jaran Bay, Korea. In addition, PP in Jaran Bay was compared with that in other coastal areas and related policy plans were proposed. The average PP of the study area was high in summer and autumn with 6.43~115.43 mgC m^-2 hr^-1 range. This was lower than that in Gamak Bay and Masan Bay, whereas higher than that in Garorim Bay and the West Sea. The PP in coastal waters, where many aquaculture farms were distributed, significantly fluctuated. The different size compositions of phytoplanktons constituting chlorophyll a slightly varied by month, and little restriction existed on the productivity of phytoplanktons owing to the depletion of nutrients. Typically, the Redfield ratio was less than 16, indicating that nitrogen was the limiting factor for the growth of phytoplanktons. The biochemical composition of particulate organic matters in the water column showed the highest carbohydrates, but lipids and protein contents were high in surface sediments. The concentration of TOC and AVS of the surface sediments was high at inside of bay, and sometimes, exceeded the environmental criteria of fishing grounds. The organic C:N ratio of sediments ranged from 8.1 to 10.4 on average. PP had the highest correlation with chlorophyll a, nitrogen and protein of particle organic materials. Recently, chlorophyll a, DIN, and DIP of water column trends tended to decrease, however, the contamination of sediments increased. Considering the annual PP of 125.9 gC m^-2 yr^-1 and mariculture area (oyster) of 4.97 km², the annual carbon production from phytoplanktons was estimated to be about 625 tons, and the annual total wet weight of shellfish (oyster) was estimated to be about 6,250 tons.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.469-470
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• 2001

경남 통영 안정만은 북동쪽으로 진해만과 연결되어 있고, 고성 당동만과 가조도 서쪽 어의도, 수도, 지도 둥의 섬으로 둘러 쌓인 반폐쇄성 내만으로서 굴, 피조개 등 패류양식이 주로 행해지고 있어 유기물 오염이 심각한 해역으로 해양수산부에 의해 특별관리어장으로 지정되어 현재 어장정화사업이 시행되고 있다. 본 조사는 이 해역의 해양생태계 조사를 통해 공단조성이 해양생태계에 미치는 영향을 파악하는데 그 목적이 있다. (중략)

• Proceedings of the Malacological Society of Korea Conference
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• 2001.11a
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• pp.37-38
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• 2001

굴과 같은 이매패 양식장에서의 어장 환경 용량은 생물 서식환경의 질적, 양적 저하 없이 지속적으로 생산할 수 있는 생물의 양이라고 할 수 있다. 즉, 환경용량이란 환경의 악영향을 미치지 않으면서 지속적으로 최대 생산을 얻을수 있는 최대 생산을 오염부하 즉 자정 능력적 의미를 포함한다고 볼 수 있다. 연안 양식장은 대상해역에 따라 해수유동과 같은 물리적 특성, 해역이용 실태, 오염부하량 등 환경특성이 다양함으로 환경용량은 서로 다르다고 볼 수 있다. 이 연구에서는 통영시에 인접하여 도시하수의 영향으로 인하여 부영양화 되어 있다. 굴 양식이 행하여지는 북만을 대상으로 하여 양식 생물을 수용할 수 있는 환경용량을 생태유체역학 모델(藏本·中田,1991)을 이용하여 산정하고, 최적환경을 유지하기 위한 방안들을 검토하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.21-29
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• 2010

The concept of carrying capacity for bivalve culture of an area can be classified into four hierarchical categories, according to their level of complexity and scope, such as physical, production, ecological and social carrying capacity. Most scientific efforts to date have been directed towards modelling production carrying capacity and some of the resultant models have been used successfully. But, the modelling of ecological carrying capacity is still in its infancy, because it should consider the whole ecosystem and all culture activities. A more holistic approach is needed to determine the influence of bivalve aquaculture on the environment and ecological carrying capacity. As an alternative, we can use a set of ecological indicators which can show the environmental performance of bivalve farms and assess ecological carrying capacity. Clearance efficiency and filtration pressure indicators show the value of 0.331 and 0.203, respectively, and these indicators suggest that the present level of culture in GeojeHansan Bay is above the ecological carrying capacity of 0.05. Consequently, these indicators can provide a guidance on the present level of culture in regard to production and ecological carrying capacity in GeojeHansan Bay.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.605-617
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• 2021

The recovery of the sedimentary environment around a fallowing shellfish farm during its rest period after 20 years of long-running operation, was explored in Tongyeong Bay of Korea. Seasonal survey on macrobenthos community was conducted from July 2016 to September 2018 at five stations, which included the fallowing shellfish farm after 20-year operation (FF), a newly installed shellfish farm (NF), a shellfish farm for comparison around the closed shellfish farm (CF), and control stations with no farming activities (Con1, Con2). The total number of species and the density of macrobenthos were higher at the shellfish farm stations than the non-shellfish farm station, and their seasonal changes were significant. The dominant species at the shellfish farm stations was Capitella capitata while Paraprionospio patiens was dominant at the non-shellfish farm stations. The two dominant species were potential organic contamination indicators usually inhabiting the areas with dense organic matter. This suggests that the overall survey area was highly polluted with organic matters. Multivariate analysis showed that the macrobenthic community of CF changed to a level similar to that of Con1 immediately after the investigation, but not to a state above the Con1 level. Furthermore, the changes in NF were not significant when compared to those in CF.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.1
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• pp.20-31
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• 2024

This study was conducted to investigate the changes in the structure of benthic communities resulting from aquaculture activities and to assess the benthic health status of surface sediment in Gangjin Bay, a region known for concentrated shellfish aquaculture on the southern coast of Korea. Survey stations were divided into longline culture, bottom culture, and non-cultivation areas. The spatiotemporal distribution of physiochemical factors such as the grain size, water temperature, salinity, and total organic carbon in Gangjin Bay showed no significant differences between sampling stations. However, the species number, density, and diversity were relatively lower at the sampling stations in the bottom culture areas than at the other stations throughout the entire survey period. Cluster analysis and principal coordinates analysis also clearly distinguished the benthic communities in the bottom culture areas from those in the other sampling areas. At the sampling stations in the longline culture and non-cultivation areas, Scolectoma longifolia and Sigambra tentaculata, which are indicator species of organically enriched areas, appeared as dominant species. However, excluding some stations influenced by physical factors such as the water depth and current speed, the occupancy rate was not high. The health assessment results, conducted using the fisheries environment assessment method, revealed good conditions with Grades 1 and 2 across the entire area. However, an examination of the spatiotemporal changes in benthic communities and the benthic health index indicated that the benthic environment in the bottom culture areas was affected by physical disturbances.