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Evaluation of mixed layer depth in Korean Waters based on reanalysis data focused on Spatial and interannual variability
No full textThe MLD plays a crucial role in regulating climate by controlling the exchange of momentum, heat, and moisture between the ocean and atmosphere. Therefore, improving MLD simulations is essential for reliable climate predictions and projections. However, studies on the interannual variability of MLD using global reanalysis data remain limited. In this study, we analyzed the interannual variability of winter MLD in Korean waters over a 25-year period (1994–2018) using two widely used reanalysis datasets, the HYCOM and GLORYS, which are frequently employed in climate change studies in Korean waters. The reanalysis MLD data were compared with observational estimates from the KODC and NSO for February, the month with the deepest MLD. While the spatial distribution of MLD is generally well simulated, the long-term trend is poorly reproduced. Notably, the models underestimate the long-term mean MLD by approximately 25% in regions influenced by the Ulleung Eddy and the Yellow Sea Warm Current. EOF analysis reveals that the interannual variability of MLD is primarily influenced by variations in 10 m wind and 2 m air temperature (~18%), followed by Tsushima Warm Current (TWC) transport (~11%). These findings highlight the importance of oceanic processes in the interannual variability of winter MLD in Korean waters.1
Dissolved oxygen climatology with a quarter-degree resolution in the Northwestern Pacific
No full textThis study developed a monthly regional climatology for dissolved oxygen (DO) with quarter-degree horizontal resolution and 56 vertical levels over the northwestern Pacific. We used 586,851 observed profiles and a newly developed climatology with 1° resolution, applying simple kriging horizontal interpolation and vertical smoothing techniques to produce the new dataset. This approach efficiently mitigates artificial water masses and statistical noise. The new DO climatology provides detailed coastal information and renders realistic oxygen distribution associated with the current system in the western North Pacific, compared to WOA23. A meridional section demonstrates that the newly developed climatology does not yield artificial noise-like spikes frequently observed in WOA23 in the East Sea. This study expects that the new climatology can allow bio-geochemical numerical models to enhance diagnostic and forecasting performance.1
Development and Validation of the Therapy Index
No full textPurpose : This study attempted to demonstrate the effectiveness of therapy resources, products, and programs. To help consumers select the optimal health products and services for their needs, and to help providers scientifically demonstrate and improve the effectiveness of their products and services, a therapy index was developed and validation studies were conducted.
Methods : Starting with the definition of the concept of therapy through an analysis of laws related to the therapy industry, we secured content validity with a CVR value of .56 or higher by reflecting prior research and the opinions of 12 experts. Based on the definition of the concept of therapy, we established core areas and core goals for the therapy index, which represents the level of self-therapy capacity. Considering the context in which the therapy index will be used, we established the scope of its application and evaluation areas, and extracted dependent and independent variables accordingly. To calculate the therapy index, we collected data on these variables and analyzed them using regression analysis.
Results : As a result of analyzing the regression model of the dependent variable NK cells on the level of metabolic recovery, the adjusted R2 value indicating the explanatory power of the model was .506, confirming that the independent variables explained 50.6 % of the variance of the dependent variable NK cells. As a result of analyzing the regression model of the dependent variable limb muscle mass on the level of functional maintenance, the adjusted R2 value indicating the explanatory power of the model was .932, confirming that the independent variables explained 93.2 % of the variance in the dependent variable limb muscle mass. As a result of analyzing the regression model of the dependent variable cognitive function on the level of cognitive enhancement, the adjusted R2 value indicating the explanatory power of the model was .572, confirming that the independent variables explained 93.2 % of the variance in the dependent variable cognitive function.
Conclusion : The results of this study are significant in that they demonstrate that the therapy index is not simply the sum of individual health indicators, but rather has the potential to comprehensively evaluate an individual's self-healing capacity in multidimensional areas such as metabolism, physical function, and cognition. Therefore, the therapy index can be used as basic data to objectively verify the effectiveness of products and programs in various therapy industries, such as forest therapy, marine therapy, therapy agriculture, and therapy tourism, and to provide personalized services.22Nkc
Biological regulation of microplastic aggregation and vertical transport by Chattonella marina: Implications for sinking dynamics and resuspension stability
No full textMicroplastics (MPs) are widespread pollutants in marine environments, and their vertical distribution is strongly influenced by biological interactions, such as aggregation with phytoplankton. This study experimentally investigated the effects of the harmful algal bloom (HAB) species Chattonella marina on the aggregation, sinking, and resuspension of polyethylene (PE) and polypropylene (PP) MPs. Aggregation was primarily induced by intracellular materials released upon C. marina cell lysis, leading to the progressive binding of MPs and the formation of large aggregates. Low-density spherical PE particles (PE1.0) exhibited a logistic sinking pattern, with a maximum sinking ratio of 9% and a half-saturation time of 13 days. In contrast, small PP fragments showed negligible sedimentation ( 0.05) were observed between PE1.0 and high-density PE (PE1.4) in terms of aggregate size, sinking velocity, or the number of MPs per aggregate. Notably, the mean area of PE1.0 aggregates significantly increased from 0.19 ± 0.13 × 10⁶ μm² on day 43 to 0.42 ± 0.45 × 10⁶ μm² on day 92. During the declining phase of C. marina, larger aggregates exhibited enhanced sinking velocities, reaching up to 78.62 m·day⁻¹. A strong positive correlation was found between C. marina chlorophyll a (Chl. a) concentration and the sinking rate of PE1.0 particles (R² = 0.92, P 0.05), indicating strong resistance to microbial degradation. This pioneering study comprehensively evaluates MP aggregation and vertical transport throughout the full 92-day growth cycle of C. marina, establishing sedimentation thresholds driven by harmful algal blooms and providing empirical data to improve predictive models of MP vertical flux and fate in marine environments.1
Application of marine biotoxins for pathogen control in aquaculture
No full textParasitic diseases pose a significant challenge to olive flounder (Paralichthys olivaceus) aquaculture in South Korea, with scuticociliate infections being particularly problematic due to their year-round prevalence and resistance to conventional treatments. Although various chemical treatments, such as formalin and hydrogen peroxide, have been widely used, their adverse side effects underscore the need for safer and more environmentally sustainable alternatives. In this study, we investigated the potential of marine toxins derived from marine organisms, including dinoflagellates, as novel agents for the control of parasitic scuticociliates. Scuticociliates were isolated from infected olive flounders exhibiting typical symptoms at aquaculture farms in Busan and Jeju, South Korea. Four species were identified: Mesanophrys carcini, Miamiensis avidus, Paralembus digitiformis, and Pseudocohnilembus persalinus, with M. carcini and P. digitiformis being newly reported in this study. To assess their susceptibility, the effects of 15 marine toxins on the survival and morphological changes of scuticociliates were evaluated. Several toxins demonstrated complete parasiticidal acitivity, and transcriptomic analysis further elucidated their modes of action. These findings provide valuable insights into the development of eco-friendly antiparasitic strategies in aquaculture and expand the potential applications of marine-derived bioactive compounds.1
동해 최북단 남하 해류 감시를 통한 위기 대응 기획연구
No full text동해는 한반도, 일본, 러시아에 둘러싸인 반폐쇄성 해역으로 대서양과 유사한 자오순환을 구조를 가지는 등 기후변화에 따른 전지구 해양변화를 확인하거나 전망하는 자연실험실의 역할을 하고 있다. 동해의 해수순환은 북서태평양 쿠로시오 해류로부터 분지되어 동해로 유입되는 대마난류나 동한난류에 초점이 맞춰져 있었으며 상대적으로 러시아 연안에서 형성되어 동해연안을 따라 남하하는 북한한류의 해류의 세기나 수송량, 그 변동성 및 역학을 제시한 연구는 극히 드묾다. 대마난류와 함께 동해의 수평 및 자오 해양 순환의 주축인 북한한류는 차갑고 염분이 낮은 해수를 유입시켜 한류성 어종의 서식환경을 결정하고 동해 조경 해역의 형성과 동해 연안의 해양생산성을 조절한다. 남하 해류를 따라 북한 기원 해양 쓰레기나 부유물, 표류 어선 등이 우리나라 관할해역으로 유입되고 있어 환경오염 및 안보 문제를 유발하기도 한다. 동해 연안을 따라 해양 성층을 결정할 수 있어서 열파 혹은 냉수대 발생에 기여할 수 있다. 본 발표에서는 북한한류에 대한 기존 연구 결과를 개관하고, 이를 종합적으로 감시할 수 있는 동해 관할해역 최북단 해역에서 실시간 입체관측망 구축 기획 연구의 성과 및 연구 사업의 방향성을 토의할 예정이다. 본 연구를 통해 동해 기후변화와 현안 문제 대응 측면에서 북한한류의 역할을 조명할 수 있을 것으로 사료된다.2
Development of Rapid Field Monitoring System for Tiered Source Identification of Marine Hazardous Substances
No full textCoastal environments are contaminated by diverse pollution sources originating from industry, agriculture, and urban activities. For effective coastal management, it is crucial to characterize their pollution levels and identify the sources. Traditionally, marine investigations have relied on sampling conducted without prior knowledge of the pollution characteristics of the area, followed by laboratory-based analyses. However, such approaches often require a high level of expertise for instrument operation and data interpretation, and they are both time- and cost-intensive. With the worsening of environmental issues and the emergence of diverse pollutants from non-point sources, there has been a growing demand for field-deployable technologies that can detect pollutants in real-time on-site. The increasing importance of field monitoring has led to the application of compact analytical devices, such as sensors, in on-site monitoring systems. These systems complement traditional research and are being increasingly employed for pollutant source tracking. Machine learning and a variety of statistical approaches are now applied to large datasets acquired in the field to characterize pollution signatures and predict pollution sources. Moreover, real-time or near-real-time field monitoring data can be integrated with geographic information systems (GIS) to spatially visualize and analyze contaminant concentrations and potential sources. Despite these advances, challenges remain in improving the accuracy of field-based instruments, ensuring data integration, and implementing robust calibration strategies. In this study, we present the development of a rapid field monitoring system for tiered source identification of marine hazardous substances in seawater, sediments, and the atmosphere, and we discuss the future directions of this research.
Acknowledgements
This research was conducted as part of the projects entitled “Development of Source Identification and Apportionment Methods for Toxic Substances in Marine Environments (No. 20220534) of Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries, Republic of Korea.2