We conducted a seasonal field survey to analyze the distribution patterns of a phytoplankton community and biological oceanographic characteristics in the Geum river estuary in 2018. The results showed that the phytoplankton community consisted of 58 genera and 116 species, showing a relatively simple distribution. It was controlled by diatoms at 70.2%, a low number of species in winter and spring, and a high number in summer and autumn. The phytoplankton cell density ranged from 10.0 to 2,904.0 cells mL-1, with an average layer of 577.2 cells mL-1, which was low in autumn and high in winter. The seasonal succession of phytoplankton dominant species was mainly centric diatoms from winter to summer, including Thalassiosira nordenskioeldii, Cerataulina bergonii, and Skeletonema costatum-ls in winter, S. costatum-ls and C. bergonii in spring, and Eucampia zodiacus and Th. nordenskioeldii in summer. However, the autumn species depended upon the regions, with the inner bay dominated by the centric diatom, Aulacoseira cf. granulata, the mixed areas by S. costatum-ls, and the open sea by the dinoflagellate, Lingulodinium polyedra. According to principal component analysis (PCA), the phytoplankton community was greatly affected by the inflow and expansion of freshwater, including high nutrients, which are introduced annually through the rivermouth weir in Geum river estuary. However, the estuary, which is strongly affected by annual freshwater, was limited to areas near Geumran Island, which is adjacent to the river-mouth weir.

Toxic assessment of antifouling agents (diuron and irgarol) was conducted using the fertilization and the normal embryogenesis rates of the sea urchin, Mesocentrotus nudus. Bioassessment began with male and female reproductive cell induction. White or cream-colored male gametes (sperm) and yellow or orange-colored female gametes (eggs) were acquired and fully washed, separately. Then, the fertilization and normal embryogenesis rates were measured after 10 min and 48 h of exposure to the toxicants, respectively. The fertilization and embryo development rates were greater than 90% in the control, validating the suitability of both endpoints. The normal embryogenesis rates were significantly decreased with increasing concentrations of diuron and irgarol, but no changes in the fertilization rates were observed in concentrations ranging from 0 to 40 mg L-1. The EC50 values of diuron and irgarol for the normal embryogenesis rates were 20.07 mg L-1 and 22.45 mg L-1, respectively. The no observed effect concentrations (NOEC) were <1.25 mg L-1 and the lowest observed effect concentrations (LOEC) were 1.25 mg L-1 and 2.5 mg L-1, respectively. From these results, concentrations of diuron and irgarol over 1.25 mg L-1 and 2.5 mg L-1, respectively, can be considered to have toxic effects on invertebrates, including M. nudus. The ecotoxicological bioassay in this study using the noted fertilization and normal embryogenesis rates of M. nudus can be used as baseline data for the continued establishment of environmental quality standards for the effects of antifouling agents (especially diuron and irgarol) in a marine environment.

Sea trial tests are necessary to verify speed-power performance, and are an import contract between ship owners and shipyards. The International Organization for Standardization (ISO) published ISO 15016:2015, which specifies the correlation method between model and full-scale ships. The results of sea trials have been questioned because of the uncertainty of speed and power measurements, especially when sea conditions differ from ideal calm water conditions. In this paper, such uncertainties were investigated by utilizing the standard speed-power trial analysis procedure defined in ISO 15016:2015 through Monte Carlo simulations. It was found that the expanded uncertainty of the delivered power (PDid) at 95 % confidence interval (k = 2) was ±1.5 % under 75 % MCR conditions.

This study examined the effects of freshwater discharge by artificial dikes from the Kanwol and Bunam lakes on the dynamics in the Chunsu Bay, Yellow Sea, Korea, during the summer season based on three-dimensional numerical modeling experiments. Model performances were evaluated in terms of skill scores for tidal elevation, velocity, temperature, and salinity and these scores mostly exceeded 90 %. The variability in residual currents before and after the freshwater discharge was examined. The large amount of lake water discharge through artificial dikes may result in a dramatically changed density field in the Chunsu Bay, leading to an estuarine circulation system. The density-driven current formed as a result of the freshwater inflow through the artificial dikes (Kanwol/Bunam) caused a partial change in the tidal circulation and a change in the scale and location of paired residual eddies. The stratification formed by strengthened static stability following the freshwater discharge led to a dramatic increase in the Richardson number and lasted for a few weeks. The strong stratification suppressed the vertical flux and inhibited surface aerated water mixing with bottom water. This phenomenon would have direct and indirect impacts on the marine environment such as hypoxia/anoxia formation at the bottom.

We examined long-term variations in sea surface temperature (SST) and annual amplitudes of SST around the Korean Peninsula. Two SST data sets with data periods of approximately 51 years and longer than 100 years, respectively, were obtained from the National Institute of Fisheries Science and Japan Meteorological Agency. SST of Korean waters clearly increased during last 51 years (1968-2018), which was 2.5 times higher than the global trend. This significant increasing trend was caused by the dominant increasing SST trend during winter. However, a negative and positive SST anomaly frequently appeared during winter and summer, respectively, in a recent decade. These features of seasonal SST variation have changed the annual amplitude of SST, and resulted in a drastically increasing trend after 2009. Using the longer SST data set, it was revealed that the decreasing SST trend in winter began in the 2000s and the increasing SST trend in summer bagan in the 1990s. During a recent decade, there was a distinctive SST increase in summer, whereas a clear decrease in winter. In summary, the annual amplitude of SST around the Korean Peninsula significantly changed from a decreasing trend to an increasing trend during a recent decade.

Global warming, or climate change, could be the main reason why small islands in many areas of the Earth, including those in Indonesian territory, are sinking. Many small Indonesian islands are between 1 and 3 metres under the surface of the sea because of raised sea levels caused by climate change. If this situation continues, it would affect many of the outermost islands of Indonesia, so that we should anticipate the danger that the outermost islands would be submerged. The basepoints and archipelagic baselines would then be replaced, among other serious consequences for Indonesia. The Paris Climate Agreement, signed by almost 200 states in 2015, is the main instrument for mitigating global warming through reducing the emission of greenhouse gases. Indonesia ratified the Paris Climate Agreement, because it has a great interest in mitigating the phenomenon that is causing the sea level to rise, which is having a serious impact on its islands.

Sea-level rise (SLR) is considered one of the most serious consequences of climate change. The risk of SLR compels legal consideration of this phenomenon related to many interrelated domains including the Law of the Sea. The Western Pacific region contains the most low-lying coastal countries and small island States seriously affected by SLR in the world. This research has been carried out as a contribution paper on the State practice in the Western Pacific region to the topic of “Sea-level rise in relation to international law” conducted by the Study Group of the United Nations International Law Commission in the period of 2020-2021. It aims to summarize the consequences of SLR for the Western Pacific States and outline their legal positions in relation to the sea-level rise. It also discusses specific issues, challenges and opportunities facing the Western Pacific States in supporting the maintenance of maritime baselines and limits notwithstanding physical changes caused by SLR.

동해 명태 서식처 환경은 한랭기와 온난기를 교차하며 변동을 지속하고 있다. 특히 1980년대 후반 이후 수온은 급격히 상승하였으며, 2000년대 후반 이후 다시 하강하는 특성을 나타내었다. 반면, 명태 주요 산란장이 위치한 동한만과 어장 중심이 형성되는 동해 중부 연안의 수온은 서로 다른 변동 특성을 나타내었다. 동한만의 겨울철 수온은 1980년 후반 이후 급격히 상승하였으며, 2000년 후반 이후 다시 하강하는 특성을 나타내었으며, 이러한 장기 변동특성은 2월과 3월에 더욱 뚜렷하였다. 반면 어장의 중심이 형성되는 동해 중부 연안의 수온은 1990년대 중후반 이후 지속적으로 상승하였으며, 2000년 후반 이후 수온이 하강하는 특성은 뚜렷이 나타나지 않았다. 이러한 산란장과 어장의 수온변화는 명태 자원량과 변동 특성이 유사하였다. 특히 산란장의 수온 변화는 난과 자·치어를 포함한 초기 생활사 시기의 생존율에 영향을 미치는 주요 인자로 작용한다. 1980년대에는 명태의 산란에 적합한 환경이 조성되는 면적과 지속시간이 평년보다 증가하였으며, 반대로 동해에 서식하는 명태의 자원량이 급격히 감소한 1980년대 후반 이후에는 산란장 면적과 적합한 환경이 지속되는 시간이 급격히 감소하였다. 명태 자원량 변화는 서식처의 물리적 환경변화와 유의한 상관성을 가지며, 특히 산란장의 수온 상승에 따른 산란에 적합한 환경이 조성되는 면적과 지속시간의 감소 그리고 어장의 축소는 명태 자원량 변화에 영향을 미치는 주요 인자로 작용하였다.

20세기 초부터 비상업용 정부선박의 법적 지위에 대한 검토와 법제화가 이루어졌다. 특히 전통적 국제법상의 절대적 주권면제 이론에 대한 비판이 발생하고, 이에 대한 대체 이론으로 제한적 주권면제이론이 등장하면서 주권면제이론은 더욱 구체화 되었다. 국제관 습법 및 국제해양법에서는 군함과 함께 비상업용 정부선박에 대한 주권면제를 규정하고 있다. 이러한 주권면제와 관련하여 고려되어야 하는 것이 우리나라 국립대학의 실습선이다. 우리나라 국립대학은 고급해기사 양성 및 어업 실습 등의 교육목적으로 실습선 및 조사선을 건조하여 운용하고 있다. 이러한 실습선은 국내 관할수역 뿐만 아니라 타국의 관할수역 및 공해까지를 활동범위로 하고 있을 뿐만 아니라 타국의 항구에도 입항하고 있다. 따라서 국제법상 국립대학 실습선의 법적지위를 명확하게 하는 것은 국제 항행에 있어 중요한 요소 중에 하나라고 할 수 있을 것이다. 그러나 실습선이 어떠한 법적 지위를 누리느냐에 대해서는 단순히 답할 수 없는 요소들이 다수 존재한다. 이에 본 논문은 국제법상 비상업용 정부선박의 개념 및 의의에 대해 살펴보고, 국립대학 실습선이 이와 일치하는지에 대해 검토하였다. 또한 전통 국제법상의 주권면제 범위와 현행 국제협약상의 주권면제에 대한 규정을 살펴봄으로써 우리나라 국립대학 실습선이 해양에서 누릴 수 있는 주권면제의 범위에 대해 살펴보았다.

1992년 개최된 유엔지명표준화총회 이후 ‘동해’ 지명 표기에 관한 관심이 커지면서 동해 표기에 관한 연구가 다양하게 이루어졌으며 다수의 논문과 책자가 발간되었다. 하지만 ‘Japan Sea’로 표시된 해역의 범위에 관해서는 정작 관심이 적은 편으로 제주도 서단과 진도 앞바다를 연결하는 선부터 부산 앞바다에 이르는 대한해협 해역까지도 포함하고 있음에 대해서는 잘 알려지지 않았다. 이 연구는 2002년 회람된 IHO S-23 ｢해양과 바다의 경계(Limits of Oceans and Seas)｣ 초안에 첨부된 지도를 분석하였다. 1~3판과는 달리 1986년과 2002년 초안에는 바다지명에 계층이 도입되어 있다. 대한해협이 ‘Japan Sea’에 포함되어 있음을 새로이 인식하고 그 배경에 대한 종합적 이해가 필요하다. 1905년 러·일 전쟁 중에 작성된 조선해협 경계 작전도의 경계선과 유사함을 지적하고자 한다. 일본해의 일부로 대한해협이 포함되기 시작한 배경에 대한 가설은 러·일 전쟁 후 일본군부가 대한해협의 승리를 일본해 해전의 승리로 선전한 것에 기인하고 있다는 것이다. 추후 근대 일본 사료와 IHO의 문서들에 대한 사료검토를 통해 가설이 확실하게 증명된다면 동해･일본해 표기 문제에서도 전환점을 마련할 수 있을 것으로 기대한다.