For the assessment of the benthic community health of Jinhae Bay using the Benthic Pollution Index, macrobenthic fauna samples were seasonally collected from 23 different sites between February, 2011 and November, 2012. The macrobenthic community health status was classified as “Poor” or “Very Poor” except for the bay mouth part of Jinhae Bay at the northern part of Geoje Island. A large proportion of functional Group IV and even azoic conditions appeared due to summer hypoxia at sites in sheltered regions of Jinhae Bay. Some of the dominant species recruited after summer hypoxia were Paraprionospio patiens, Sigambra bassi, and Theora fragilis belong to typical opportunistic species. By comparing the BPI values of the macrobenthic communities from other special management areas of Korea, Jinhae Bay was considered to have the lowest condition that was heavily polluted among special management areas.

본 연구는 남해안 38개 특정도서의 암반조간대에서 2019년 8월부터 10월까지 방형구(50x50cm)를 이용하여 대형저서동물의 공간 분포와 우점종 조사를 실시하였다. 특정도서에서는 총 80종이 출현하였으며, 연체동물이 54종으로 67.4%를 차지하여 가장 우점하였고, 절 지동물은 15종(18.7%)이었다. 그 외 자포동물, 해면동물, 극피동물은 1~6종의 범위내에서 출현하였다. 지역별로 보면, 여수의 특정도서에서 61종으로 가장 많았으며, 하동, 남해, 추자도 등에서는 각각 42~46종으로 유사하였고, 보성과 고흥은 29종으로 출현종수가 가장 적었다. 정 점별 출현종수는 6종(정점 6)~33종(정점 20)의 범위로 큰 차이를 보였다. 주요 우점종은 좁쌀무늬총알고둥으로 15개 특정도서에서 우점하 였으며, 그 다음으로 검은큰따개비가 11개 특정도서에서 우점종으로 출현하였다. 좁쌀무늬총알고둥은 36개 특정도서에서 출현하여 가장 넓게 분포하였으며, 대수리 30개, 굵은줄격판담치 29개, 갈고둥 28개, 갯강구 27개, 총알고둥 26개의 특정도서에서 출현하였다. 국외반출승 인 대상종은 연체동물 9종, 절지동물 4종, 자포동물 2종이며, 국가적색목록은 총 50종으로 관심대상(LC)은 44종, 정보부족(DD) 3종, 미평가 (NE), 준위협(NT) 및 미적용(NA)은 각각 1종씩 출현하였다. 남해안 특정도서에서 출현한 대형저서동물은 지역에 따른 노출시간, 암간 조간 대의 길이, 암반기질 등 서식환경 차이에 의한 출현종수와 우점종의 차이를 보였다. 본 연구 결과는 추후 특정도서 모니터링과 관리방안 수립시 기초자료로 활용될 수 있을 것으로 생각된다.

Severe damages will result in human society, when several different critical natural phenomena coincide. One example relates to the resting cysts of Alexandrium species (dinoflagellates that cause paralytic shellfish poisoning), which are preserved in surface sediments throughout Osaka Bay, Japan. These cysts have been found to accumulate particularly densely in shallow areas in the inner parts of Osaka Bay, where a tsunami caused by an earthquake could occur any time. Damage by a tsunami could cause a change of the coastal ecosystems at Osaka Bay including the resuspension of surface sediments containing resting Alexandrium tamarense cysts and the subsequent redistribution of the cysts in newly deposited sediment. Under certain environmental conditions, these cysts could germinate and form dense blooms, leading to paralytic shellfish poisoning. Such a scenario could also affect other coastal areas, including the southern coast of the Korean Peninsula.

This study is aimed to evaluate the technology levels of shellfish farming in southern coast of Korea and status analysis on research of shellfish aquaculture. With achieving these objectives, it will be possible to present the direction of shellfish farming research and related project. Five major breed of shellfish aquaculture that would be adaptive and sustainable were proposed through consultation and agreement with professional group with more than 15 years of working experience. Moreover also evaluated that levels of technology, industry and market are also evaluated. The evaluation result of the expert group showed that the shellfish farming level occupied the third place in comparison with the US, Japan, Europe, and China. It is estimated that about 13~14 years will reach the level of the highest on average. In addition, most countries are expected to grow by about 10% on average over the next five years. Based on the result of the analysis of 670 research projects (2008~2017), there was little research on climate change and shellfish aquaculture. Besides some of shellfish have not been studied since 2008 and 2013, so it can be mentioned as a future task to be overcome.

During the winter of 2017/2018, significantly low water temperatures were detected around the western and southern coasts of Korea (WSCK). In this period, sea surface temperature (SST) in the Korea Waters was about 2℃ lower than mean temperature. Using the real-time observation system, we analyzed the temporal variation of SST during this period around the western and southern coasts. Low water temperature usually manifested over a period of about 10 ~ 20 days. The daily Arctic oscillation index was also similarly detectable with the variation of SST. From the cross-correlation function, we compared two periodic variations, which were SST around the WSCK and the Arctic oscillation index. The cross correlation coefficients between both variations were approximately 0.3 ~ 0.4. The time lag of the two time series was about 6 to 7 days. Therefore, significanlyt low water temperatures during winter in the Korean coastal areas usually became detectable 6 to 7 days after the negative peak of Arctic oscillation.

본 연구는 우리나라 제주 해역의 여름철 해조 군집 특성과 갯녹음 현황을 파악하고자 수행하였다. 연구는 2017년 7월부터 9월까지 스쿠버 다이빙(SCUBA Diving)을 이용하여 정량 조사 및 정성 조사를 시행하였다. 연구 결과 녹조류 11종(9.1%), 갈조류 24종(19.8%), 홍조류 86종(71.1%) 등 총 121종의 해조류가 확인되었다. 지역별로는 형제섬이 60종으로 출현종수가 가장 많았으며, 하례가 18종으로 가장 적었다. 연구 지역의 평균 생물량은 1,503.0g·m-2이며, 주변 도서의 평균 생물량(3,268.7g·m-2)이 본섬의 평균 생물량(914.7g·m-2)보다 높았다. 우점종은 주변 도서에서 Sargassum macrocarpum, 본섬에서 Ecklonia cava로 나타나 생물량뿐만 아니라 종 조성에서도 차이를 보였다. 해조 군집 특성(종 조성, 생물량, 대형 갈조류의 생물량 비율), 무절산호말류의 피복도, 조식동물의 밀도 등을 토대로 연구 지역의 여름철 해조 군집 상태를 평가한 결과, 형제섬과 마라도 두 지역은 우수한 해조 군집을 유지하고 있는 것으로 판단되어 보전 및 지속적인 관리가 요구되며, 다른 6개 지역은 각 지역별로 해조 군집의 조성 내지 복원이 필요한 실정이다. 갯녹음 현상이 가속화됨에 따라 모니터링뿐만 아니라 현재 해조 군집의 현황 파악이 제대로 이루어지지 않은 지역을 대상으로 해양 생태계의 실태를 파악하는 일도 시급한 것으로 판단된다.

The toxic dinoflagellate Gymnodinium catenatum isolated from the southern coast of Korea was described under light and scanning electron microscopy, and its large subunit (LSU) rDNA was sequenced. In addition, the effects of temperature and salinity on its growth were investigated. The cells of G. catenatum, as viewed under the electronic microscope, were green-brown color, 38.1-77.4 μm in length and 26.1-40.8 μm in width. The epicone was conical, while the hypocone was trapezoidal. The nucleus was located at the central part of the cell. The apical groove was horseshoe-shaped and small pores were irregularly distributed on the cell surface. Molecular phylogeny based on LSU rDNA gene sequences showed that the Korean G. catenatum and previously reported species formed a monophyletic clade within Gymnodinium sensu stricto clade. The maximum growth rate of 0.37 day-1, was obtained at 25°C and 35 psu, and the maximum cell density of 1,073 cells mL-1, was observed at 20°C and 25 psu. However, G. catenatum did not grow at temperature <15°C and <30°C. These results suggest that environmental conditions of summer and autumn in the southern coast of Korea may be favorable for the growth of G. catenatum.

한국 남해안에서 8월 수온의 변동 특성을 파악하기 위해, 수온, 조위, 및 기상자료(바람·기온)를 power spectrum과 coherence 분석 하였다. Power spectrum 결과, 수온과 조위는 부산을 제외한 완도, 고흥, 여수, 통영, 마산 등 5개 지역에서 약 12hr과 24hr 주기에서 peak를 보였다. 또한 coherence 분석 결과에 의한 수온변동은 완도, 고흥, 여수 및 통영에서 조석의 영향을 가장 많이 받았다. 그러나 연구해역의 동쪽에 위치한 마산과 부산의 수온변동은 조차가 큰 서쪽해역에 비해 조석의 영향이 작았다. 특히, 마산의 수온변동은 바람의 환경요인에 가장 큰 영향을 받는 것으로 나타났다. 수온은 창조시 하강하고 낙조시 상승하는 형태를 보이고 있다. 즉 완도에서 수온의 하강(상승)은 창 조(낙조) 약 1.5hr 후, 고흥과 통영에서 수온의 하강(상승)은 창조(낙조) 0.3hr 후에 나타났다. 그러나 마산에서의 수온 상승은 남풍이 시작되 고 약 3hr 후에 나타났다. 한편 한국 남해안의 동쪽에 위치한 부산의 수온변동은 기온, 조석 및 바람의 영향을 작게 받는 것으로 나타났다.

본 연구에서는 신안 장산도 남부해역 육상오염원의 위생상태와 영향 반경을 분석하였다. 배수 유역에 대한 해안선 조사를 실시해 오염원 종류를 구분하고, 해역으로 방출되는 오염원 유량과 위생실태를 분석하였으며 오염원의 영향 반경을 산정하였다. 육상오염원은 생활하수 21개소, 농 업용수 1개소, 육상양식장 11개소로 총 33개소(St. 65~97)이었고 이 중 농업용수 1개소, 육상양 식장 8개소의 오염원이 해역으로 배출되었다. 방출오염원의 유량은 72,857~281,250 l/min이었 고, 분변계대장균은 St. 72(농업용수)에서 490 MPN/100 ml, St. 74(육상양식장)에서 49 MPN/ 100 ml으로 비교적 높았다. 이들 영향 반경은 각각 4,389 m와 1.900 m로 나타났고, 해역의 안 전한 위생을 확보하기 위해서는 이들 오염원들에 대한 관리 및 해수 위생조사가 필요할 것으 로 판단된다.

본 연구는 해수유동모델을 이용하여 하계 한국 남해안 양식장 부근에서 수온의 시·공간적인 분포를 파악하였다. 한국 남해 조류의 흐름은 창조시 서향, 낙조시 동향하며, 쓰시마 난류의 흐름은 50 m보다 깊어지는 외양에서 연안에 비해 강하게 동북향 하였다. 조류, 바람, 쓰시마 난류 및 실시간 수온을 고려한 해수유동에서 하계 수온의 분포는 반폐쇄성 해역에서 26~28℃로 높게 나타났으며, 외양으로 갈수록 낮아져 18~22℃로 나타났다. 반폐쇄성 내만의 형태를 가지는 해역의 해수교환량을 계산한 결과 광양만 10,331 m³/sec, 여수-가막만 16,935 m³/sec, 그리고 거제-한산만은 13,454 m³/sec로 나타났다. 해수교환량이 적은 해역일수록 수온이 비교적 높게 나타난다.

Seagrasses, sea flowering plants, comprise approximately 60 species globally and are often called ‘ecosystem engineers’ because they create their own habitats by modifying the surrounding environments, which provide coastal zones with a number of crucial ecosystem services. Zostera marina (the common name ‘eelgrass’) is one of the seagrass beds-forming species distributed widely in northern hemisphere including the Korean coast, which plays a pivotal role in ecosystem as a primary producer and a nursery habitat or refuge for other marine organisms. However, due to global climate change and anthropogenic activities such as reclamation and dredging, there has recently been a drastic decline in population sizes of Z. marina in Korea. In order to develop effective conservation and restoration management programs of Z. marina populations, it would be helpful to consider all biological aspects of this species such as genetic characteristics as well as ecological and physiological features. This study first provides information on genetic diversity and genetic structure of Jeju Island and Namhae populations of Z. marina, which will contribute to the establishment of appropriate conservation and restoration management plans for future persistence of this species. Using six microsatellite markers, we investigated the level of genetic diversity and genetic structure among 10 geographic populations of Z. marina inhabiting Jeju Island (Hamdeok, Tokki-seom, Sungsan, Woljeong, Ojo) and Namhae (Gamak bay, Jindong bay, Nampo, Anggang bay, Geoje) on the southern coast of Korea. The level of genetic diversity within Jeju populations (mean allelic richness [AR]: 1.57 ~ 3.09) was found to be significantly lower than Namhae populations (AR: 3.09 ~ 4.29) (Mann-Whitney U-test, P < 0.05). These findings suggest that effective population sizes (Ne) of Jeju populations are generally smaller than those of Namehae populations. Within Jeju Island, Hamdeok population had the smallest population size (coverage: 138 m2) and the lowest genetic diversity (AR: 1.57), while Ojo population had the largest population size (coverage: 275,736 m2) and the greatest level of genetic diversity (AR: 3.09). Hamdeok population showed evidence of genetic bottleneck. These results again suggest that Ne of Jeju populations is generally low (except Ojo population). Among Jeju populations, all pair-wise comparisons of FST values (i.e., degree of genetic differentiation) were highly significant (FST = 0.0612 ~ 0.7168, P < 0.001) despite Jeju populations that were geographically closely located, indicating that these local populations are genetically divergent, probably due to a lack of gene flow among the populations. The observed strong population structure was substantiated by evidence that five genetic clusters are most likely, based on population assignment test (STRUCTURE). The Mantel test showed a positive relationship between genetic distance (FST) and geographic distance (km) across all the populations sampled (R2 = 0.4118, P < 0.05), suggesting that our data follow Isolation By Distance (IBD) model. Woljeong population revealed the highest level of FST values compared to other populations within Jeju Island in IBD. STRUCTURE and factorial correspondence analysis (FCA) further showed that some Woljeong individuals included genotypes of Namhae populations. Population size of Woljeong (coverage: 310m2) was approximately 50 % smaller than that of Sungsan (coverage: 841m2); however, extent of its genetic diversity (AR: 2.39) was even higher than that of Sungsan population (AR: 1.77). We speculated that Woljeong population underwent a transplantation from Namhae populations with relatively higher level of genetic diversity. FST values within Namhae populations were relatively lower (compared to within Jeju Island) despite the populations that were geographically more distant. It means that level of gene flow is higher among Namhae populations than among Jeju populations. Z. marina is known to have different life histories by water depth. In subtidal zone (deep water depth) populations predominantly undertake sexual reproduction through seeds such as annual life history, whereas those of intertidal zone (shallow water depth) undertake both sexual and asexual reproductions through horizontal rhizomes i.e., perennial life history. STRUCTURE analysis showed no clear differences between shallow and deep populations at Namhae, but some FST values were statistically significantly different despite their low values. For Geoje population sampled in 2005, intertidal and subtidal populations were not significantly different (FST = 0.0045, P = 0.033), but these populations sampled in 2015 showed a significant difference (FST = 0.0328, P < 0.001). It means that genetic structure of Geoje has been changed over the 10 year period between shallow and deep populations. Overall, the Jeju and Namehae populations analyzed in the current study have relatively low levels of genetic diversity and distinct genetic compositions, which warns the message that this ecologically important species should be conserved separately in the local populations and with high priority. We propose that future conservation and restoration plans for seagrasses should consider genetic characteristics particularly because a close relationship between genetic diversity and ecological performance in marine species has been well documented.