• 한국수산과학회지
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• 제50권2호
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• pp.175-182
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• 2017

We examined the effects of environmental factors on zoospore release and germling growth of the green tide alga Cladophora albida under various conditions of temperature${\times}$irradiance (zoospore release), temperature${\times}$irradiance${\times}$ nutrient (germling growth), and a single factor test of salinity. Zoospore release was maximized at $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in the temperature irradiance experiment and at 34 psu in the salinity experiment. Maximum germling growth was observed at $25^{\circ}C$ with $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and PES (Provasoli's Enriched Seawater) in the temperature irradiance nutrient experiment, and at 34 psu in the salinity experiment. Germlings grew faster at higher irradiances for a given temperature level, and also grew faster as salinity increased over the range of 5-34 psu. Overall, optimal environmental conditions for zoospore release were $30^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and 34 psu. Maximal germling growth occurred at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, PES, and 34 psu. C. albida blooms are most likely to occur under these optimal environmental conditions, as plentiful zoospore release and rapid germling growth lead to population growth.

• 환경영향평가
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• 제10권1호
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• pp.1-8
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• 2001

Detection of red tides by satellite remote sensing can be done either by detecting enhanced level of chlorophyll pigment or by detecting changes in the spectral composition of pixels. Using chlorophyll concentration, however, is not effective currently due to the facts: 1) Chlorophyll-a is a universal pigment of phytoplankton, and 2) no accurate algorithm for chlorophyll in case 2 water is available yet. Here, red band algorithm, classification and PCA (Principal Component Analysis) techniques were applied for detecting patches of Cochlodinium polykrikoides red tides which occurred in Korean waters in 1995. This dinoflagellate species appears dark red due to the characteristic pigments absorbing lights in the blue and green wavelength most effectively. In the satellite image, the brightness of red tide pixels in all the three visible bands were low making the detection difficult. Red band algorithm is not good for detecting the red tide because of reflectance of suspended sediments. For supervised classification, selecting training area was difficult, while unsupervised classification was not effective in delineating the patches from surrounding pixels. On the other hand, PCA gave a good qualitative discrimination on the distribution compared with actual observation.

• 한국수산과학회지
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• 제49권5호
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• pp.657-664
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• 2016

The green macroalga Cladophora vadorum bloomed along the coast at Sangrok Beach, Buan, South Korea, in September 2015. To elucidate the cause of bloom, the effects of environmental factors on the vegetative growth of adult fragments were examined. Growth experiments were carried out under different combinations of temperatures and irradiances, and with a single factor of nutrients (nitrogen, phosphorus). The maximal growth of C. vadorum was reported under the combination of 25°C and 100 μmol photons m⁻²s⁻¹. The species grew under a wide range of N and P concentrations. The growth of C. vadorum peaked at 50 μM PO₄³⁻, 80 μM NH₄⁺, and 100 μM NO₃⁻. Adult fragments formed holdfasts and new branches within 3 days in culture and became adults, showing polarized growth patterns, in 2 weeks. This is the first report showing the development of numerous bladelets from a segment in Cladophora species. The present results indicate that Cladophora blooms appear under growth conditions that are favorable in terms of temperatures, irradiance, and nutrients via fragment growth patterns producing rapid holdfasts and many bladelets.

• 대한원격탐사학회지
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• 제33권1호
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• pp.97-109
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• 2017

Green tides that developed along the coast of China in 2015 were detected and tracked using vegetation indices from GOCI and Landsat images. Green tides first appeared near the Jiangsu Province on May 14 before increasing in size and number and moving northward to the Shandong Peninsula in mid-June. Typhoon Cham-hom passed through the Yellow Sea on July 12, significantly decreasing the algal population. An algae patch moved east toward Korea and on June 18 and July 4, several masses were found between the southwestern shores of Korea and Jeju Island. The floating masses found in Korean waters were concentrated at the boundary of the open sea and the Jindo cold pool, a phenomenon also observed at the boundary of coastal and offshore waters in China. Sea surface temperatures, derived from NOAA SST data, were found to play a role in generation of the green tides.

• 한국해양환경ㆍ에너지학회지
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• 제1권1호
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• pp.56-65
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• 1998

해상 누유의 이동경로 및 풍화와 관련된 여러 물리현상들의 모델링 기법들이 검토되었으며, 이에 기초한 해상누유 확산 예측모델 "푸른바다"가 소개된다. 실시간 누유확산을 시뮬레이션하기 위해서는 조류에 관한 데이터베이스가 필수적이며, 본 연구에서는 누유 사고가 빈번한 남해안 일대의 조류 데이터베이스가 구축되었다 남해 조석류의 실시간 예측을 위해 4개의 주요분조(M₂, S₂, K₁, O₁ 조석류)를 채택하였으며, 각 분조들의 각속도와 위상 값들은 천문상수들로부터 얻어진다. 주요분조들의 조화상수는 천해 조류 방정식을 풀어 구한다. 푸른바다는 사용자 편의성의 극대화와 해양환경 데이터베이스의 확장이 용이한 유연한 구조를 그 특징으로 한다. 매몰도 인근해역에서 좌초되어 누유를 발생시켰던 오성호 사고를 시뮬레이션함으로서 푸른바다의 유효성을 검증하였다. 시뮬레이션 결과를 관측된 누유확산 경로와 비교하였으며, 이를 통해 푸른바다가 누유의 거동 예측에 있어 타당한 추정치를 줄 수 있음을 확인하였다.

• 한국환경과학회지
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• 제11권3호
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• pp.149-154
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• 2002

This study was conducted to find the structure of phytoplankton community in the Hoeya river(Ulsan) from March 2000 to February 2001. The taxa of phytoplankton identified included 135 species, 5 divisions, 33 families and 82 genera. Among them, chrysophyta(diatoms) were 63 species(46.7%), chlorophyta(green algae) 47 species(34.8%), pyrrophyta(dinoflagellates) 13 species(9.6%), cyanophyta (cyanobacteria) 8 species(5.9%) and euglenophyta(euglenoids) 4 species(3.0%) respectively. Ecological important species is called frequently appearing species, red tide causative species, seawater species and pollution indicator. 22 species including Aulacoseira granulate were recorded frequently appearing species. 19 species including Ceratium furca were recorded as red tide causing species. And the pollution indicators were 33 species including Actinastrum hantzschii var. fluviatile. The highest standing crops were 3,103,441 cells/$\ell$ in August at the RW-1 and the lowest 1,245 cells/ $\ell$ in January at the RW-5. In the community analysis, the dominanance indices ranged from 0.34(October, RW-2) to 0.94(January, RW-1) and the diversity indices from 0.50(May, RW-2) to 2.57(September, RW-2). The saprobic indices were 2.43 in RW-1, 2.41 in RW-2, 2.375 in RW-3, 2.40 in RW-4, 2.43, in RW-5. Therefore, these areas were investigated "$\beta$-mesosaprobic". According to the similarity index among the stations, these areas were defined as residential district areas(RW-2 and RW-3), lower part of the dam (RW-1) and seawater areas(RW-4 and RW-5).

• 한국환경복원기술학회지
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• 제26권1호
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• pp.17-33
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• 2023

Disasters in coastal regions are a constant source of damage due to their uncertainty and complexity, leading to the proposal of green infrastructure as a nature-based solution that incorporates the concept of resilience to address the limitations of traditional grey infrastructure. This study analyzed trends in research related to coastal disasters and green infrastructure by conducting a co-occurrence keyword analysis of 2,183 articles collected from the Web of Science (WoS). The analysis resulted in the classification of the literature into four clusters. Cluster 1 is related to coastal disasters and tsunamis, as well as predictive simulation techniques, and includes keywords such as surge, wave, tide, and modeling. Cluster 2 focuses on the social system damage caused by coastal disasters and theoretical concepts, with keywords such as population, community, and green infrastructure elements like habitat, wetland, salt marsh, coral reef, and mangrove. Cluster 3 deals with coastal disaster-related sea level rise and international issues, and includes keywords such as sea level rise (or change), floodplain, and DEM. Finally, cluster 4 covers coastal erosion and vulnerability, and GIS, with the theme of 'coastal vulnerability and spatial technique'. Keywords related to green infrastructure in cluster 2 have been continuously appearing since 2016, but their focus has been on the function and effect of each element. Based on this analysis, implications for planning and management processes using green infrastructure in response to coastal disasters have been derived. This study can serve as a valuable resource for future research and policy in responding to and managing various disasters in coastal regions.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.506-510
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• 2013

본 연구의 목적은 국내 주요항에서 출현하는 식물플랑크톤 잠재적 위해종의 시 공간적 변화를 파악하고, 환경요인과의 관계를 이해하는데 있다. 부산, 울산, 인천 및 광양항에서 2007년 1월부터 12월까지 잠재적 위해종 및 환경요인을 계절별로 총 4회 조사하였다. 조사기간 중 출현한 잠재적 위해종은 총 25종으로, 이 중 적조 원인종이 20종이었으며 독소생산종이 5종이었다. 적조 원인종인 Skeletonema costatum은 전 조사 지역에서 우점종으로 나타났다. 이 종은 부산항에서 수소이온농도와 양의 상관관계를, 용존산소와 음의 상관관계를 보였고(p<0.05), 울산항에서는 부유물질과 수소이온농도와 양의 상관관계를, 염분과 음의 상관관계를 보였다(p<0.05). 또한, 광양항에서는 염분 및 질산염과 양의 상관관계를, 수소이온농도와 음의 상관관계를 보였고(p<0.05), 인천항에서는 질산염과 양의 상관관계를 보였다(p<0.01). 독소 생산종 중 기억상실성 패독인 도모익 산을 배출하는 것으로 알려진 Pseudo-nitzschia spp.는 전 조사지역에서 출현하였고, 질산염 및 규산염과 양의 상관관계를 보였다(p<0.05). 그리고 설사성 마비패독을 일으키는 Dinophysis acuminata 및 기억성 마비패독을 유발하는 Alexandrium spp.는 화학적 산소 요구량과 양의 상관관계를 보였다(p<0.01). 적조 원인종은 항구의 물리적 환경요인에 영향을 받은 반면 독소 생산종은 영양염류와 같은 화학적 요인에 영향을 받는 것으로 나타났다.

• 환경생물
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• 제31권4호
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• pp.233-242
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• 2013

Cyanobacteria (blue-green algae) are not only the first oxygenic organisms on earth but also the foremost primary producers in aquatic environment. Massive growth of cyanobacteria, in eutrophic waters, usually changes the water colour to green and is called as algal (cyanobacterial) bloom or green tide. Cyanobacterial blooms are a result of high levels of primary production by certain species such as Microcystis sp., Anabaena sp., Oscillatoria sp., Aphanizomenon sp. and Phormidium sp. These cyanobacterial species can produce hepatotoxins or neurotoxins as well as malodorous compounds like geosmin and 2-methylisoborneol (MIB). In order to solve the nationwide problem of hazardous cyanobacterial blooms in Korea, the following technically and strategically sound approaches need to be developed. 1) As a long-term strategy, reduction of the nutrients such as phosphorus and nitrogen in our water bodies to below permitted levels. 2) As a short term strategy, field application of combination of already established bloom remediation techniques. 3) Development of emerging convergence technologies based on information and communication technology (ICT), environmental technology (ET) and biotechnology (BT). 4) Finally, strengthening education and creating awareness among students, public and industry for effective reduction of pollution discharge. Considering their ecological roles, a complete elimination of cyanobacteria is not desirable. Hence a holistic approach mentioned above in combination to addressing the issue from a social perspective with cooperation from public, government, industry, academic and research institutions is more pragmatic and desirable management strategy.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.40-48
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• 2010

Saemangeum reclaimed area is needed to construct much green zone to make high-quality multi-functional land such as tide embankment, lake dike, industrial complex, environmental spaces, etc. However, growth of plants is somewhat difficult because a salinity of Saemangeum soil is very high and a soil fertility, water content of soil are low. Therefore, it is essential to initial desalination of soil and continuous management for planting base. It is recommended that a group of grassland to raise the efficiency of covering should be made in the first stage and a forest by improvement of vegetation should be made in the mid and long term stage. It is recommended that the construction of vegetation base should be made with a regular thickness of soil of good quality in multi-functional area such as a shrub and wood. In case of construction of a windbreak forest, it is necessary to make a wood base of suitable depth using soil brought from another place or filling of soil. Also, it is necessary to keep a maintenance of woods in early stage. Saemangeum reclaimed land will be brand-named worldwide tourist attractions due to construction of much green zone having high quality multi-functional facilities.