• 한국수산과학회지
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• 제57권3호
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• pp.262-277
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• 2024

The mid-eastern coast of Korea is located at the boundary between cold and warm currents, which causes changes in the distribution and composition of marine organisms in response to fluctuations in the marine environment. To understand the seasonal changes in the seaweed community, we investigated its species composition, biomass, coverage, and frequency from November 2022 to August 2023. A total of 45 species (7 green, 18 brown, and 20 red algae) were found in the study area. In the intertidal zone, the number of species decreased from autumn to summer; the biomass peaked during winter (471.94 g wet weight m^-2). Seaweed groups were the dominant functional groups, which were coarsely branched, filamentous, and sheet-like during autumn, winter, spring, and summer. The morpho-functional group was dominated by turf species. In the subtidal zone, the number of species increased during autumn to spring, whereas the biomass peaked during spring (655.27 g wet weight m^-2). The functional group was dominated by coarsely branched species throughout all four seasons, whereas the morpho-functional group was dominated by canopy species. Consequently, changes in the biomass of brown and red algae are recognized as key drivers of seasonal changes in seaweed communities.

• Ocean and Polar Research
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• 제30권4호
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• pp.475-484
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• 2008

The word 'Saemangeum' indicates an estuarine tidal flat in the southwestern part of the Korean peninsula. The Saemangeum Reclamation Project was launched as a national project in 1991 to reclaim a large coastal area of $401\;km^2$ by constructing a 33-km long dyke. The final dyke enclosure in April 2006 has transformed the tidal flat into lake and land. An integrated oceanographic study has been conducted since 2002 as a part of the Government Action Plan to monitor and assess changes in the marine environment. Prior to the dyke enclosure, the coastal environment in the Saemangeum was a complex system governed by tidal motion, estuarine processes, and coastal circulation of the Yellow Sea. The dyke construction has radically changed not only the estuarine tidal system inside the dyke, but also the coastal marine environment outside the dyke. Post to the dyke enclosure, subsequent changes such as red tide, hypoxia, and coastal erosion/deposition occur successively. Red tides appear almost the year round in the inner area. Even under the condition that the sluice gates are fully open, the water quality does not improve as much as the developers would expect, mainly due to the critical reduction of the hydrodynamic stirring power. We will introduce details of our monitoring program and significant changes in the Saemangeum marine environment, based on observations and model results.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.193-193
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• 2017

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.479-487
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• 2014

Leptin plays an important role in energy homeostasis and reproductive function in fish, especially in reproduction. Migrating fish, such as salmonoids, are affected by external environmental factors, and salinity changes are a particularly important influence on spawning migrations. The aim of this study was to test whether changes in salinity affect the expression of leptin, estrogen receptors (ERs), and vitellogenin (VTG) in chum salmon (Oncorhynchus keta). The expression and activity of leptin, the expression of ERs and VTG, and the levels of estradiol-$17{\beta}$ and cortisol increased after the fish were transferred to FW, demonstrating that changes in salinity stimulate the HPG axis in migrating female chum salmon. These findings reveal details about the role of elevated leptin levels and sex steroid hormones in stimulating sexual maturation and reproduction in response to salinity changes in chum salmon.

• 한국양식학회지
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• 제20권4호
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• pp.205-211
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• 2007

Stress-inducible proteins may function in part as molecular chaperones, protecting cells from damage due to various stresses and helping to maintain homeostasis. We examined the mRNA expression patterns of a 68-kDa heat shock protein (HSP68) and 78-kDa glucose-regulated protein (GRP78) in relation to physiological changes in Pacific oyster Crassostrea gigas under osmotic stress. Expression of HSP68 and GRP78 mRNA in the gill significantly increased until 48 h in a hypersaline environment (HRE) and 72 h in a hyposaline environment (HOE), and then decreased. Osmolality and the concentrations of $Na^+$, $Cl^-$, and $Ca^{2+}$ in the hemolymph of HRE oysters significantly increased until 72 h (the highest value) and then gradually decreased; in HOE oysters, these values significantly decreased until 72 h (the lowest value), and then increased. These results suggest that osmolality and $Na^+$, $Cl^-$, and $Ca^{2+}$ concentrations were stabilized by HSP68 and GRP78, and indicate that these two stress-induced proteins play an important role in regulating the metabolism and protecting the cells of the Pacific oysters exposed to salinity changes.

• 해양환경안전학회지
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• 제24권6호
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• pp.726-734
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• 2018

최근 3년간 검토된 환경관리해역에서 이루어진 해역이용협의 건수는 총 60건으로 조사되었다. 환경보전해역에서는 지속적으로 감소하였고, 특별관리해역에서는 증가하는 양상을 나타내었다. 환경관리해역의 개별사업유형을 분석한 결과 인공구조물 설치사업이 가장 높은 비율을 차지하였고, 그 외 항만 어항개발, 연안정비 및 해수 인 배수사업유형이 많이 이루어졌다. 환경관리해역에서 국가해양환경정보통합시스템(MEIS) 자료를 활용하여 2006~2017년까지 경년별 수질변화경향을 비교한 결과, COD는 뚜렷한 증감의 변화는 보이지 않았으나 환경보전지역은 다소 증가하였으며, TN과 TP의 농도는 다소 감소하는 경향을 보였다. 특별관리해역인 광양만과 마산만 및 환경보전해역인 가막만에서는 주로 하계에 빈산소수괴가 출현하였다. 이러한 환경관리해역에서의 이용 개발행위가 지속적으로 이루어지고 있으므로, 이에 따른 해양환경부문 환경영향평가(해역이용협의)시에는 충분한 수질변화에 대한 실태분석 및 사업추진에 따른 수질영향과 퇴적물의 오염상태를 철저히 진단해서 오염원관리에 대한 대책이 중점적으로 평가되어야 할 것으로 판단된다. 특히, 각 환경관리해역의 지정 목적에 따른 유지 수질목표를 명확히 설정하여, 오염원 및 연안오염총량관리와 연계하여 오염 부하량 저감대책을 제시하여야 할 것이다.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.399-407
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• 2013

Morphological changes in the reared rock bream, Oplegnathus fasciatus, from hatching to six days after hatching were examined during the early growth stage under starvation. All the larvae died within five days when feeding was delayed for three days after hatching. These results imply that initial larval food should be supplied within two days of hatching. Changes in the pectoral angle and the ratios of eye height to head height, gut height to standard length, and gut height to myotome height in the rock bream are alternative indicators for the identification of starving fish. These indicators might prove useful in evaluating the successful transition from endogenous to exogenous feeding in this species.

• 해양환경안전학회지
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• 제15권2호
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• pp.105-110
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• 2009

국내에서는 해양오염을 예방하기 위하여 해양오염방지관리인 제도를 운영하고 있다. 2007년 1월 19일 해양환경관리법(법률 제8260호)이 제정되어 2008년 1월 20일부터 시행으로 됨으로써 1977년 제정되어 시행되어 오던 해양오염방지법이 폐지됨에 따라 해양오염방지관리인 교육 제도에도 변화가 생겼다. 주요 개정 내용은 교육훈련기관, 교육훈련과정, 교육훈련대상자, 해양오염방지관리인 업무내용 및 준수사항, 해앙시설의 범위, 교육과목 등이다.

• Journal of Advanced Marine Engineering and Technology
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• 제33권8호
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• pp.1196-1202
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• 2009

본 논문에서는 ROV 제어 시스템 구축을 위하여 관측기를 이용한 수중환경 추정기 설계를 다룬다. 먼저, 수중환경변화는 ROV 시스템의 입력항목에 가해지는 외부외란으로서 다루어질 수 있으며, 이러한 수중환경변화를 추정하기 위하여 외부외란에 영향을 받지 않는 PI 관측기를 제안한다. 이후 본 논문에서는 계단형 및 정현파형 수중환경변화를 가정하여 제안한 방법에 대해 시뮬레이션을 행하였으며, 그 결과 유효성을 확인하였다. 향후, 본 제안법을 ROV 시스템에 대한 햅틱제어기 설계에 이용하고자 한다.

• 한국수산과학회지
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• 제46권4호
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• pp.424-436
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• 2013

Organic enrichment was investigated in surface sediments from the Yeoja and Gangjin Bays of Korea, which contain dense shellfish farms, in order to evaluate the contamination status and temporal changes in shellfish farming along these coasts. The degree of organic enrichment was determined using geochemical indicators (chemical oxygen demand, ignition loss, acid volatile sulfide, total organic carbon in sediments, and total nitrogen in sediments, ammonium and nitrate in pore water, and bioluminescence inhabitation for sediments). Temporal changes in organic enrichment conditions were detected by comparing our 2012 data to those previously reported from a survey conducted in 1999/2000. Organic enrichment was significantly higher in September than in May and July, in Gangjin Bay than in Yeoja Bay, and significantly higher in shellfish farms than in reference sites not used to culture shellfish. Ammonium concentrations in pore water were two orders of magnitude greater than nitrate concentrations, suggesting that these bays represent nitrogen-reducing environments.