Widespread ice shelf thinning has been recorded in the Amundsen Sea in recent decades, driven by basal melting and intrusions of relatively warm Circumpolar Deep Water (CDW) onto the continental shelf. The Dotson Ice Shelf (DIS) is located to the south of the Amundsen Sea polynya, and has a high basal melting rate because modified CDW (mCDW) fills the Dotson‐Getz Trough (DGT) and reaches the base of the ice shelf. Here, hydrographic data in the DGT obtained during seven oceanographic surveys from 2007 to 2018 were used to study the interannual variation in mCDW volume and properties and their causes. Although mCDW volume showed relatively weak interannual variations at the continental shelf break, these variations intensified southward and reached a maximum in front of the DIS. There, the mCDW volume was ∼8,000 km³ in 2007, rapidly decreased to 4,700 km³ in 2014 before rebounding to 7,300 km³ in 2018. We find that such interannual variability is coherent with local Ekman pumping integrated along the DGT modulated by the presence of sea ice, and complementing earlier theories involving shelf break winds only. The interannual variability in strength of the dominant south‐southeast coastal wind modulates the amplitude of Ekman upwelling along the eastern boundary of the Amundsen Sea polynya during the austral summers of the surveyed years, apparently leading to change in the volume of mCDW along the DGT. We note a strong correlation between the wind variability and the longitudinal location of the Amundsen Sea Low.

Recent rapid thinning of West Antarctic ice shelves are believed to be caused by intrusions of warm deep water that induce basal melting and seaward meltwater export. This study uses data from three bottom-mounted mooring arrays to show seasonal variability and local forcing for the currents moving into and out of the Dotson ice shelf cavity. A southward flow of warm, salty water had maximum current velocities along the eastern channel slope, while northward outflows of freshened ice shelf meltwater spread at intermediate depth above the western slope. The inflow correlated with the local ocean surface stress curl. At the western slope, meltwater outflows followed the warm influx along the eastern slope with a ~2–3 month delay. Ocean circulation near Dotson Ice Shelf, affected by sea ice distribution and wind, appears to significantly control the inflow of warm water and subsequent ice shelf melting on seasonal time-scales.

The ocean ecosystem and fisheries are highly vulnerable to climate change due to ocean warming, ocean acidification and extreme weather events in Korea. To overcome these vulnerabilities to climate change in ocean ecosystem and fisheries, effective adaptation strategies are needed based on scientific monitoring, accurate prediction/projection technologies and risk and vulnerability assessments based on these data. Data on ocean warming and its ecosystem impacts in Korean waters have been collected since 1968 by the National Institute of Fisheries Science. Information and data on ocean acidification in the Korea Waters are also shared with global observation network from 2020 . Real-time water temperature information is also collected and managed by the National Institute of Fisheries Science based on 180 coastal data collection stations along the Korean coast. To understand future fisheries conditions in Korean waters, projected monthly ocean data with water temperature, salinity and ocean currents until 2100 are also provided by the National Institute of Fisheries Science. These observed and projected data are used to assess the risk and vulnerability of fisheries in Korea. Fisheries in Korea are very complex and diverse. For future projection of fisheries in Korea, physical and biological ocean prediction data with high spatial resolution and short intervals are required. From such projections, it is possible to create effective adaptation strategies for sustainable fisheries to ensure food security.

The feeding characteristics of the chub mackerel, Scomber japonicus from Jeju Island waters and the Yellow Sea were compared by analyzing the stomach contents. Large and small purse seines were used to collect 1437 individuals from Jeju Island waters and 1066 individuals from the Yellow Sea. The fork length of S. japonicus ranged from 21.0 to 43.6 cm for individuals from Jeju Island waters and 19.6 to 41.5 cm for those from the Yellow Sea. Based on the index of relative importance and variation in stomach contents according to fish size, S. japonicus was identified as a piscivore and a spatiotemporally opportunistic feeder. The proportion of fish in the diet increased as the body sizes of S. japonicus from both Jeju Island waters and the Yellow Sea increased, whereas the proportion of copepods, amphipods, and euphausiids gradually decreased. Differences in stomach content compositions were observed due to interactions between size and location. Thus, the feeding characteristics of S. japonicus are affected by the abundance and composition of prey in its habitat.

The East Sea is a jointly managed maritime area of Korea, Russia, and Japan, where the frequency of strong typhoons is anticipated to increase with climate change, affecting its marine ecosystem and regional climate regulation. This study investigated the environmental and ecological impacts of summer typhoons entering the East Sea by analyzing satellite-derived chlorophyll-a (Chl-a) data, Argo float measurements, and ERA5 wind data. Our findings revealed that summer typhoons generally increased surface Chl-a concentrations by 65.4%, with typhoon intensity substantially influencing this process. Weak typhoons caused marginal Chl-a increases attributed to redistribution rather than nutrient supply, whereas normal and strong typhoons increased Chl-a through enhanced vertical mixing and nutrient upwelling in the East Sea. Stronger typhoons notably impacted the mixed layer depth and isothermal layer depth, leading to greater Chl-a concentrations within the strong wind radius. However, the increased Chl-a magnitude was lower than that of other strong typhoons in other regions. The East Sea uniquely responds to typhoons with fewer upper environment changes, possibly due to a stable barrier layer limiting vertical mixing. These findings underscore the importance of continuous monitoring and integrated observational methods in order to better understand the ecological effects of typhoons, particularly as their intensity increases with climate change.

Global climate change is accelerating warming, and our oceans are particularly affected by climate change compared to other regions. By the end of the 21st century, the pace of climate change is expected to accelerate. Therefore, by creating and analyzing basic data for risk assessment in the fisheries sector according to climate change, we intend to lay the foundation for promotion of risk assessment. The Intergovernmental Panel on Climate Change (IPCC) proposes to shift from vulnerability assessment to climate risk management for climate adaptation, and climate risk consists of risk, exposure, and vulnerability. In the fisheries sector, it is difficult to clearly distinguish between sensitivity and adaptability due to the interrelationships among biological attributes, so various definitions and measurement methods are used. In the case of coastal fishing, a precise analysis of water temperature variability and fisheries resource fluctuations due to climate change is required. In the case of aquaculture, it is necessary to develop technology to respond to high water temperatures according to climate risk. To advance the climate risk assessment in the fisheries issues, it is necessary to prepare detailed evaluation indicators according to the definition of IPCC and switch to the AR6 SSP scenario. Therefore, the current climate risk methodology in the fisheries issues will be summarized, and the latest data (fishing production, fisherman survey analysis, model results under climate change scenarios, etc.) will be used to lay the foundation for risk assessment in the fisheries issues according to climate change.