We conducted a field survey from 2018 to 2020 to analyze the spatial distribution of phytoplankton communities at 13 stations in the East Sea. The diatom Chaetoceros curvisetus appeared as the dominant species in winter, and small flagellates less than 20 μm prevailed in all seasons except winter. The seasonal average range of the micro (>20 μm), nano (20 μm≥Chl-a>3 μm), and picophytoplankton (≤3 μm) was 20.6-26.2%, 27.1-35.9%, and 40.8-49.0%, respectively. The composition ratio of nano and picophytoplankton was high at the surface mixed layer from spring to autumn when the water columns were strongly stratified. Especially, the stability of the water mass was increased when the summer surface water temperature was higher than that of the previous year. As a result, the nutrient inflow from the lower layer to the surface was reduced as the ocean stratification layer was strengthened. Therefore, the composition ratio of nano and picophytoplankton was the highest at 77.9% at the surface mixed layer. In conclusion, the structure of the phytoplankton community in the East Sea has been miniaturized, which is expected to form a complex microbial food web structure and lower the carbon transfer rate to the upper consumer stage.

선박이 발달함에 따라 국제해사기구(IMO)에서는 인적과실에 의한 해양사고 예방을 위하여 기존의 선박운항·조선기술에 ICT를 융·복합한 차세대 해상안전종합관리체계인 e-Navigation 도입을 추진 중에 있으며, 세계 각 국에서는 네트워크를 통한 원격조종시스템을 활용한 무인선박(Unmmanded vessel)의 개발이 활발하게 진행되고 있다. 무인선박은 선박-육상간 통신체계 구축을 통한 원격조종시스템과 통합 센서를 활용한 자율항해시스템을 갖춘 선박이다. 그러나 개발로 인해 예상되는 해운환경에 대한 고찰은 이루어지지 않고 있는 상황이다. 본 연구에서는 무인선박의 출현으로 예상되는 해운환경의 변화를 살펴보고 무인선박이 실제 투입되기 전 갖추어져야할 규정과 법 제도, 또한 투입 후에 수반되는 상황에 대한 대책 등을 조사하며, 가장 효과적인 무인 선박투입 시기 및 범위, 방법 등을 다루고자 한다.