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The effects of expanded polystyrene particle on energy metabolism of the sea slater (Ligia cinerascens) originating from a highly EPS-polluted area
No full textDue to its high concentration and persistence, microplastic (MP) pollution is a major threat to marine environments. Expanded polystyrene (EPS) particles are the most abundant MP type in Asian regions, including the Korean coastal region. Although many previous studies have reported the toxicity of MPs to marine biota, the toxicity of environmentally relevant MPs to coastal organisms is not well understood. Thus, we investigated the toxicity of EPS on the growth and energy metabolism of the juvenile marine isopods, Ligia cinerascens, obtained from a population that has been exposed to EPS through multiple generations. After 14 and 21 days of dietary EPS exposure, body weight and molting of L. cinerascens were unaffected. However, the energy reserves (carbohydrates, proteins, and lipids) were significantly reduced, resulting in a decrease in the total energy budget (Ea) by dietary EPS exposure. The transcriptional modulation patterns of genes related to energy metabolism suggested that dietary EPS exposure may increase the digestion of non-carbohydrate sources, such as proteins and lipids, to compensate for increased energy expenditure. Our findings suggest that dietary EPS exposure, although no toxic at the individual level, can reduce the energy status of juvenile marine isopods, which provides useful information on the toxic effects of environmentally relevant MPs to coastal ecosystem.11Nsciescopu
Impact of Heterosigma akashiwo on the environmental behavior of microplastics: Aggregation, sinking, and resuspension dynamics
No full textAggregation processes of microalgae have significant effects on the vertical distribution of microplastics (MPs) in the marine environment. This study explored how the harmful microalga Heterosigma akashiwo affects the aggregation and sinking characteristics of four types of MPs: low and high-density polyethylene (PE) spheres, and small and large polypropylene (PP) fragments. The aggregation of MPs was primarily driven by extracellular polymeric substances (EPS) rather than direct attachment to the cells, contributing to their sinking. The sinking of low-density PE spheres followed a logistic function, saturating at 28 % with a half-saturation time of 9 days. In contrast, small PP fragments sank minimally (under 2 %) and large PP fragments showed almost no sinking, indicating the varying impacts of MP density and size. The sinking velocity of the MP aggregates was significantly lower for low-density PE spheres (0.63 mm∙s−1) than for high-density PE spheres (0.81 mm∙s−1), despite no significant differences in aggregate size or MP particle number. This result may suggest that low-density MPs could potentially affect marine carbon cycle. Furthermore, no clear evidence was found for the resuspension of the settled aggregates due to bacterial decomposition under dark and cold conditions. As the first experimental study to explore the aggregation, sinking, and resuspension of different MPs in the presence of H. akashiwo, these findings, when integrated with field observations and modeling studies, provide valuable insights for predicting MP distribution in marine environments.11Nsciescopu
Method for producing phycocyanin according to light conditions
No full text본 발명은 광조건에 따른 스피룰리나 배양을 통한 피코시아닌의 제조방법에 관한 것으로, 피코시아닌 생산량을 향상시킬 수 있는 스피룰리나 배양의 광조건을 제공할 수 있다
A New Record of Simognathus Halacarid Mite (Acari, Halacaridae) from Korea
No full textA marine halacarid mite, Simognathus fuscus Viets, 1936, was discovered in the intertidal and subtidal sandy sediments of the southern coast of Jeju Island, Korea. Simognathus fuscus, which is distributed in the Caribbean, southwestern Atlantic, and southwestern Pacific, is characterized by a round ocular plate, secondary dorsal setae located on the membranous cuticle anterior to the ocular plate, an anterior epimeral plate almost entirely covered with foveae, the anterior area of the genitoanal plate without foveae, a pair of adanal setae on the sides of the anal cone, positioned ventrodistally, and one ventral and one parambulacral seta on tarsi III and IV, respectively. The Korean specimens corresponded well with the original description of S. fuscus from Bonaire in the Caribbean, as well as records from other regions, although they showed one minor morphological difference in that the Korean specimens have slightly larger body sizes. This is the first report of S. fuscus from Korea.22Ykc
Environmental DNA Metabarcoding Reveals Spatial Variation in Eukaryotic Communities at Hydrothermal Vents of the Central Indian Ridge
No full textHydrothermal vents are unique deep-sea ecosystems characterized by extreme environmental conditions and high biodiversity, playing a crucial role in supporting complex ecological interactions. Growing concerns about the potential impacts of anthropogenic activities, such as resource exploitation and climate change, underscore the need for effective monitoring tools to manage and conserve these ecosystems by
establishing environmental baseline data. In this study, we applied environmental DNA (eDNA) metabarcoding as a less-invasive and cost-effective tool to analyze the eukaryotic community structures of hydrothermal vents in the Central Indian Ridge, a large and hard-to-access ecosystem. Seawater samples, totaling four liters each, were collected from eight hydrothermal vent sites and one control site in the adjacent abyssal plain using Niskin bottles attached to a remotely operated vehicle (ROV). High-throughput sequencing targeting the 18S rRNA gene on the Illumina MiSeq platform yielded 907 amplicon sequence variants (ASVs) from 794,255 eukaryotic merged reads, which were assigned to 29 phyla and 62 classes. The majority of ASVs belonged to "Unknown", showing less than 90% sequence identity to currently deposited databases, indicating a high level of unexplored biodiversity. Among the identified ASVs, the phyla Radiozoa, Ascomycota, Euglenozoa, and Mollusca were most prevalent. Similarity analysis revealed that each eukaryotic community had its distinct structures and clustered into three groups at a 40% similarity cut-off, showing more related to latitudinal location rather than vent activity. Our results demonstrate the effectiveness of eDNA metabarcoding as a monitoring tool for hydrothermal vent ecosystems, providing valuable insights into community structures and their spatial variation without environmental disturbance. Continued efforts in expanding sequence databases are essential to enhance our understanding of hydrothermal vent ecosystems and establish tailored conservation strategies.1
Compulsory dispute settlement system under the BBNJ agreement: some considerations on future constraints
No full textThe newly adopted BBNJ Agreement introduces UNCLOS Part XV as its Part IX, which regulates a compulsory dispute settlement mechanism to resolve disputes related to the Agreement. Given that this Agreement is the third implementing agreement of UNCLOS, it may be the default approach to adhering to the Part XV system rather than taking other measures. However, this article contends that specific functions should be expected for Part IX of the Agreement, especially in ensuring State parties’ compliance with obligations under the BBNJ Agreement for pursuing its common goals and objectives. Rather than taking an overly optimistic approach, this article explores some of the challenges that the Part XV system is likely to face in future disputes over the BBNJ Agreement. In addition, other institutional arrangements within the BBNJ Agreement that will supplement the compulsory system of the Agreement to fulfil its function are looked into.11Nssciscopu
COOLING SYSTEM FOR UNDERWATER DATA CENTER
No full text4차 산업혁명 유관기술의 보급과 다양한 산업 분야에서의 응용으로 데이터 네트워킹 및 스토리지를 제공
할 수 있는 데이터센터에 대한 요구량이 2015년부터 2020년까지 연평균 10.9%씩 성장하였으며, 향후 2025
년까지 연평균 15.9% 성장할 것으로 예측된다. 단, 데이터센터 산업은 탄소 다 배출 업종으로 글로벌 탄
소 배출량의 약 0.8%에 해당된다. 특히, 데이터센터의 전체 소비전력의 38%는 데이터센터 내부 기기들의
냉각시스템에 활용된다. 반면, 수중 데이터센터는 일정한 온도와 습도가 유지되는 해저면에 데이터센터를
구축하는 형태로, 냉각 및 유지관리 시스템에 할당되는 전력을 획기적으로 절감할 수 있을 것으로 기대된
다. 최근 미국 마이크로소프트에서는 “Natick” 프로젝트를 통해 스코틀랜드 해저면에 수중 데이터센터
에 대한 실증실험을 진행하였으며, 2년간 운영한 결과 수중 데이터센터는 일반적인 지상 데이터센터에 비
해 장애 발생율이 1/8 수준으로 안정적이고 경제적인 데이터센터 운영이 가능한 것으로 나타났다.
수중 데이터센터의 에너지 소비를 추가적으로 절감하기 위해서는 해수와 데이터센터 간의 열교환을 유도하
는 것이 중요하다. 따라서, 본 발명에서는 수중 데이터센터에 기존 출원 특허인 해수 순환 구조를 통해 해
수와 데이터센터 간의 열교환을 하는 방식에서 폐쇄형 냉각시스템(그림 1)을 적용한 수중데이터센터를 제
안한다. 기존의 해수를 유입하여 냉각하는 방식은 해수유입 시 이물질이 유입을 장지하기 위한 필터가 필
요하며, 해수 특성상 따개비와 같은 각종 해양 부착생물의 유입과 부착으로 필터의 빈번한 교체 및 관로
내부의 청소가 필요하다. 하지만 폐쇄구조의 냉
Antioxidant and Anti-Inflammatory Activities of Cutlassfish Head Peptone in RAW 264.7 Macrophages
No full textThe rapid growth of the fisheries industry has resulted in numerous by-products, usually called waste, causing environmental and economic challenges. Recent advances in valorization techniques have highlighted the potential of these by-products as sources of bioactive compounds. This study aimed to investigate the antioxidant and anti-inflammatory activities of cutlassfish (Trichiurus lepturus) head peptone (CP) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. CP exhibited significant antioxidant activity, reducing ABTS and DPPH radical scavenging activity by up to 79.66% and 64.69%, respectively, with a maximum ferric-reducing antioxidant power (FRAP) value of 224.54 μM. CP enhanced macrophage proliferation (33.3%) and significantly mitigated LPS-induced oxidative and inflammatory responses, reducing nitric oxide (NO) production (60%) and reactive oxygen species levels (49.14%). CP suppressed the expression of inflammatory mediators, including inducible nitric oxide synthase (iNOS) and cyclooxygen-ase-2, and selectively inhibited the pro-inflammatory cytokines interleukin (IL)-1β and IL-6. Western blot analysis revealed that CP inhibited the phosphorylation of mitogen-activated protein kinases, including ERK, JNK, and p38, highlighting its role in modulating upstream inflammatory signaling pathways. CP exhibited significant antioxidant effects, particularly in scavenging ABTS and DPPH radicals, as well as reducing oxidative stress markers and inflammatory responses in LPS-stimulated macrophages. These findings suggest its potential not only as a therapeutic agent for conditions related to chronic inflammation, such as cardiovascular diseases and arthritis, but also as a functional ingredient in foods and nutraceuticals aimed at alleviating inflammation-related disorders.11Ysciescopu
Optimization of a multi-sensor satellite-based waterline method for rapid and extensive tidal flat topography mapping
No full textTidal flats are crucial ecosystems at the land-ocean interface. As the ecological value of tidal flats is emphasized, there is a need for precise tidal flat topographic maps as basic data for ecosystem protection and restoration planning. This study presents an optimized satellite-based waterline method for mapping the topographic changes in tidal flats, along the west coast of South Korea. We evaluated the accuracy and efficiency of digital elevation model (DEM) generated using multi-sensor satellite data (Landsat 8/9, Sentinel-2A/B, and Sentinel-1A) collected over a one-year period. The optimal data collection period was found to be 5 months, as extending the collection period beyond this did not result in a significant improvement in DEM quality, based on the mean absolute error (MAE) threshold. At a data collection period of 5 months, the Fusion DEM had an MAE of 25.6 cm, making it approximately 8.16% more accurate than the Optical DEM and about 49.56% more accurate than the SAR DEM. Our method accounts for rapid environmental changes due to climatic effects and human activities, providing a reliable model for monitoring vital tidal-flat ecosystems.11Nsciescopu
Characteristics of different scuticociliates from an infected olive flounder (Pararlichthys olivaceus) farm in South Korea
No full textParasitic diseases are considered to be a major problem in olive flounder (Paralichthys olivaceus) farms in South Korea, with scuticociliate infections being especially problematic due to their year-round occurrence and difficulty in control. In this study, we collected scuticociliates from flounder showing typical symptoms of scuticociliasis, such as ulcers, hemorrhages, and necrosis, at farms in Busan and Jeju, South Korea. Four species of scuticociliates were identified: Mesanophrys carcini, Miamiensis avidus, Paralembus digitiformis, and Pseudocohnilembus persalinus, the M. carcini and P. digitiformis being recorded for the first time in this study. Pathogenicity tests on healthy and wounded fish revealed that M. avidus was highly lethal, while the other species had minimal effects on healthy fish. However, P. digitiformis and P. persalinus impeded wound healing and showed high infection rates in wounded fish without causing high mortality. These two species also triggered early up-regulation of stress-related genes, such as complement C3, followed by a decrease in pro-inflammatory cytokine expression in the olive flounder. These findings emphasize the varied pathogenicity depending on scuticociliate species and suggest that, in addition to the known scuticociliates such as M. avidus, other potential parasites may pose significant risks to olive flounder farms in South Korea.11Nsciescopu