https://repository.kopri.re.kr/handle/201206/14803 2026-04-18T13:47:08Z https://repository.kopri.re.kr/handle/201206/16186 Title: Seasonal foraging behavior of Weddell seals in relation to oceanographic environmental conditions in the Ross Sea, Antarctica Authors: Chung, Hyunjae; Park, Jikang; Park, Mijin; Kim, Yejin; Chun, Unyoung; Yun, Sukyoung; Lee, Won Sang; Choi, Hyun A.; Na, Ji Sung; Yoon, Seung-Tae; Lee, Won Young Abstract: . Understanding the foraging behavior of marine animals in Antarctica is crucial for assessing their ecological significance and responses to environmental changes, such as seasonal changes in seawater or light hours. However, studying their responses to these seasonal changes remains challenging due to the difficult logistics of conducting observations, particularly during the harsh austral winter months. In this study, we investigated the influence of changes in seawater properties and light conditions on the seasonal foraging behavior of Weddell seals (Leptonychotes weddellii) in the Ross Sea, Antarctica. We affixed 64 Weddell seals with conductivity？temperature？depth tags for 3 consecutive years from 2021 to 2023 to record their locations and dive profiles, including depth, head acceleration, temperature, and salinity. We found that seals foraged more frequently in Modified Shelf Water and Ice Shelf Water than in Antarctic Surface Water. This preference could be connected to greater food availability. Seals also dove to greater depths and displayed increased activity in capturing prey during daylight hours. This behavior may correspond to the diel vertical migration of pelagic prey in response to varying light conditions. Consequently, marine fauna were confronted with distinct seasonal changes in the Antarctic environment and adjusted their foraging behaviors to respond to them. This highlights the importance of extrinsic factors in estimating their seasonal foraging behavior.; 남극의 해양 동물들의 포식 행동을 이해하는 것은 생태학적 중요성과 환경 변화(예: 계절에 따른 해수 변화나 일조 시간 변화)에 대한 반응을 평가하는 데 필수적입니다. 그러나 극한의 남극 겨울철에 관찰을 수행하는 데 있어 물류적 어려움이 커 이러한 연구는 도전 과제가 됩니다. 이 연구에서는 2021년부터 2023년까지 3년간 64마리의 웨델물범(Leptonychotes weddellii)에 전도도-온도-수심(CTD) 태그를 부착하여 남극 로스해에서 물범의 위치와 잠수 프로파일(수심, 머리 가속도, 온도, 염도 등)을 기록했습니다. 연구 결과, 웨델물범은 남극 표면수보다 변형된 대륙붕수 및 빙붕수에서 더 자주 먹이를 찾았으며, 이는 더 풍부한 먹이 자원과 관련이 있을 가능성이 있습니다. 또한, 물범은 낮 시간에 더 깊은 곳으로 잠수하며 먹이를 사냥하는 활동이 증가했는데, 이는 먹이 생물의 주야간 수직 이동과 관련될 수 있습니다. 결론적으로, 남극의 계절적 환경 변화는 해양 동물들에게 뚜렷한 영향을 미쳤으며, 물범은 이에 맞춰 포식 행동을 조정했습니다. 이는 계절적 포식 행동을 추정하는 데 외적 요인의 중요성을 강조합니다. 2024-11-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/15068 Title: Responses of soil micro-eukaryotic communities to decadal drainage in a Siberian wet tussock tundra Authors: Myeong, Nu Ri; 권민정; Mathias Gockede; Binu M. Tripathi; Kim, Mincheol Abstract: Climate warming holds the potential to cause extensive drying of wetlands in the Arctic, but the warming-drying effects on belowground ecosystems, particularly micro-eukaryotes, remain poorly understood. We investigated the responses of soil micro-eukaryotic communities, including fungi, protists, and microbial metazoa, to decadal drainage manipulation in a Siberian wet tundra using both amplicon and shotgun metagenomic sequencing. Our results indicate that drainage treatment increased the abundance of both fungal and non-fungal micro-eukaryotic communities, with key groups such as Ascomycota (mostly order Helotiales), Nematoda, and Tardigrada being notably abundant in drained sites. Functional traits analysis showed an increase in litter saprotrophic fungi and protistan consumers, indicating their increased activities in drained sites. The effects of drainage were more pronounced in the surface soil layer than the deeper layer, as soils dry and warm from the surface. Marked compositional shifts were observed for both communities, with fungal communities being more strongly influenced by drainage-induced vegetation change than the lowered water table itself, while the vegetation effect on non-fungal micro-eukaryotes was moderate. These findings provide insights into how belowground micro-eukaryotic communities respond to the widespread drying of wetlands in the Arctic and improve our predictive understanding of future ecosystem changes. 2024-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/15084 Title: Molecular evidence for multiple origins and high genetic differentiation of non-native winter crane fly, Trichocera maculipennis (Diptera: Trichoceridae), in the maritime Antarctic Authors: Kang, Seunghyun; Kim, Sanghee; 박계청; Andrius Petrasiunas; Shin, Hyoung Chul; Jo, Euna; Cho, Sung Mi; Kim, Ji Hee Abstract: Native biodiversity and ecosystems of Antarctica safeguarded from biological invasion face recent threats from non-native species, accelerated by increasing human activities and climate changes. Over two decades ago, the winter crane fly, Trichocera maculipennis, was first detected on King George Island. It has now successfully colonized several research stations across King George Island. To understand the origin, genetic diversity, and population structure of this Holarctic species, we conducted mitochondrial DNA cytochrome c oxidase subunit I (COI) sequence analysis across both its native and invasive ranges. In parallel, we performed microsatellite loci analysis within the invasive ranges, utilizing 12 polymorphic microsatellite markers. Furthermore, we compared body sizes among adult males and females collected from three different locations of King George Island. Our COI sequence analysis exhibited two different lineages present on King George Island. Lineage I was linked to Artic Svalbard and Polish cave populations and Lineage II was related to Canadian Terra Nova National Park population, implying multiple origins. Microsatellite analysis further exhibited high levels of genetic diversity and significant levels of genetic differentiation among invasive populations. Body sizes of adult T. maculipennis were significantly different among invasive populations but were not attributed to genetics. This significant genetic diversity likely facilitated the rapid colonization and establishment of T. maculipennis on King George Island, contributing to their successful invasion. Molecular analysis results revealed a substantial amount of genetic variation within invasive populations, which can serve as management units for invasive species control. Furthermore, the genetic markers we developed in the study will be invaluable tools for tracking impending invasion events and the travel routes of new individuals. Taken together, these findings illustrate the highly invasive and adaptable characteristics of T. maculipennis. Therefore, immediate action is necessary to mitigate their ongoing invasion and facilitate their eradication. 2024-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16218 Title: Individual differences in responses to unmanned aerial vehicles among Weddell seals, Leptonychotes weddellii Authors: Park, Jikang; Lee, Won Young; Han, Chang S. Abstract: Unmanned aerial vehicles (UAVs) offer invaluable contributions to wildlife observation, reducing costs and human risk while minimizing disturbance to animals during aerial surveys. However, within a population, individual animals can exhibit different responses to UAVs. This indicates that the level of UAV disturbance might differ between individuals even when the disturbance is mild at the population level. However, few studies have investigated UAV disturbance at the individual level. In this study, we explored the variation in response to UAVs among individual Weddell seals along the Terra Nova Bay coastline in Antarctica. We also examined how internal factors such as age, group composition and whether their eyes were open, as well as external factors such as UAV flight schemes, influenced responses. Our findings showed substantial variation among individual seals in both their overall response and changes in response to descending UAVs. Notably, seals were more sensitive to UAVs with vertical f light schemes than to those with horizontal flight schemes. When seals were in groups or had their eyes closed, their vigilance responses to UAVs decreased. Therefore, our findings highlight the importance of not only considering individual factors but also avoiding vertical flight patterns during UAV-based aerial surveys of Weddell seals, thus minimising disturbance. Additionally, we recommend developing more effective approaches for wildlife research that utilize UAVs by incorporating the consideration of individual differences in responses to UAVs. 2024-01-01T00:00:00Z