https://repository.kopri.re.kr/handle/201206/11609 2026-04-22T07:42:56Z https://repository.kopri.re.kr/handle/201206/13558 Title: Application of Dual Metabarcoding Platforms for the Meso- and Macrozooplankton Taxa in the Ross Sea Authors: Lee, Ji-Hyun; La, Hyoung Sul; Kim, Jeong-Hoon; Son, Wuju; Park, Hyun; Kim, Young-Mog; Kim, Hyun-Woo Abstract: Meso- and macrozooplankton play crucial roles in the trophic web and the biological carbon pump in the ocean by transferring energy from lower to higher trophic levels and vertically exporting carbon from the surface to the deep ocean and seabed. In this study, zooplankton community structures in the Ross Sea, Antarctica, were analyzed using metabarcoding methods. Both regular barcode (RB) (using a PacBio Sequel system) and mini barcode (MB) (using the Illumina MiSeq platform) methods were utilized. As the result of a combination of the two bioinformatic pipelines used in the RB, 55 reliable haplotypes were obtained from the pooled zooplankton net samples, whereas 183 amplicon sequence variants (ASVs) were isolated from the MB metabarcoding analyses of 14 individual stations. Among these, 39 (70.9%) and 125 (90.6%) showed higher than 99% sequence identity to the database, indicating that there were sufficient reference sequences to employ metabarcoding analysis―except for several taxa, including small-sized copepods, cnidarians, and pneumodermatids. A high degree of shared taxa showed that both metabarcoding analyses were feasible for use in the analysis of zooplankton assemblages in the Ross Sea. However, RB would be more useful for the construction of a reference database due to its relatively high cost, whereas MB would be more economic for ecological surveys due to its relatively low cost (albeit, only if reference sequences were well documented using RB). Zooplankton assemblages were highly diverse in each sample site, presumably due to the narrow covered volumes of the vertical net-towed samples from polynyas in the Ross Sea. As metabarcoding data accumulate, we will gain better insights into zooplankton communities and their ecological implications in the Ross Sea. 2022-05-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/13006 Title: Mare incognita: Adelie penguins foraging in newly exposed habitat after calving of the Nansen Ice Shelf Authors: Park, Seongseop; Thiebot, Jean-Baptiste; Kim, Jeong-Hoon; Kim, Kil Won; Chung, Hosung; Lee, Won Young Abstract: Rapid environmental changes can dramatically and durably affect the animal's foraging behavior. In the Ross Sea (Antarctica), calving of the Nansen Ice Shelf in 2016 opened a newly accessible marine area of 214 km2. In this study, we examined the foraging behavior of Adelie penguins from the nearby Inexpressible Island in December 2018, by tracking 27 penguins during their at-sea trips using GPS, depth and video loggers. The penguins mainly foraged within 88.2 ± 42.9 km of their colony, for 23.4 ± 6.8 h. Five penguins headed south to the newly exposed habitat along the Nansen Ice Shelf, whereas 22 penguins exploited previously available foraging areas. There was no significant difference in any of the foraging trip or diving parameters between the two penguin groups; however, in the calved region the penguins were diving into shallow areas more often than did the other penguins. These results show that Adelie penguins on Inexpressible Island had explored the newly exposed area after calving. We conclude that the penguins respond to newly available habitat following stochastic environmental events, either through information sharing at the colony, and/or by balancing prey availability per capita across the foraging sites. Considering that this penguin breeding area is under investigation for the establishment of an Antarctic Specially Protected Area (ASPA), the results of this study may provide insights for evaluating the ecological importance of this area and formulating an ASPA management plan for conservation. 2021-10-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/12979 Title: Isotope Fractionation from In Vivo Methylmercury Detoxification in Waterbirds Authors: Poulin, Brett A.; Janssen, Sarah E.; Rosera, Tylor J.; Krabbenhoft, David P.; Eagles-Smith, Collin A.; Ackerman, Joshua T.; Stewart, A. Robin; Kim, Eunhee; Baumann, Zofia; Kim, Jeong-Hoon; Manceau, Alain Abstract: The robust application of stable mercury (Hg) isotopes for mercury source apportionment and risk assessment necessitates the understanding of mass-dependent fractionation (MDF) as a result of internal transformations within organisms. Here, we used high energy-resolution X-ray absorption near edge structure spectroscopy and isotope ratios of total mercury (δ202THg) and methylmercury (δ202MeHg) to elucidate the chemical speciation of Hg and the resultant MDF as a result of internal MeHg demethylation in waterbirds. In three waterbirds (Clark’s grebe, Forster’s tern, and south polar skua), between 17 and 86% of MeHg was demethylated to inorganic mercury (iHg) species primarily in the liver and kidneys as Hg-tetraselenolate [Hg(Sec)4] and minor Hg-dithiolate [Hg(SR)2] complexes. Tissular differences between δ202THg and δ202MeHg correlated linearly with %iHg [Hg(Sec)4 + Hg(SR)2] and were interpreted to reflect a kinetic isotope effect during in vivo MeHg demethylation. The product-reactant isotopic enrichment factor (εp/r) for the demethylation of MeHg → Hg(Sec)4 was -2.2 ± 0.1‰. δ202MeHg values were unvarying within each bird, regardless of Hg(Sec)4 abundance, indicating fast internal cycling or replenishment of MeHg relative to demethylation. Our findings document a universal selenium-dependent demethylation reaction in birds, provide new insights on the internal transformations and cycling of MeHg and Hg(Sec)4, and allow for mathematical correction of δ202THg values as a result of the MeHg → Hg(Sec)4 reaction. 2021-05-20T00:00:00Z https://repository.kopri.re.kr/handle/201206/12968 Title: Penguins Strike Back: A Report on the Unusual Case of Adelie Penguin (Pygoscelis adeliae) Attacks on South Polar Skua Nests Distant from the Breeding Colony Authors: Kim, Youmin; Kim, Jong-U; Chung, Hosung; Oh, Yeon-Soo; Oh, Young-Geun; Kim, Jeong-Hoon Abstract: In Antarctica, penguins aggressively defend their territory from skuas in order to guard their offspring, since skuas frequently prey on penguins’ eggs or chicks. We present unusual photographs in which south polar skua (Stercorarius maccormicki) nests were attacked by Adelie penguins despite being far from the penguin colony. To the best of our knowledge, this is a previously unreported interesting case in which the Adelie penguin attacked and caused egg loss at skua nests far from the penguins’ colony. The aggressive behaviors of the Adelie penguins to breeding skuas are expected to have occurred elsewhere without penguin colonies, but this has not been reported yet. In this study, such cases were captured on motion capture cameras for the first time. Although penguins broke a skua egg, when we checked the situation before and after the incident in a series of photos, they seemed to take interest in only adult skuas rather than the eggs. Only one skua egg was lost in the three nests, and we confirmed that all of the other eggs and chicks fledged with success. Therefore, the egg loss by Adelie penguins seems to be unintended, and our observation is an interesting case of showing aggression to the predator regardless of the prey’s reproduction. Unusual inter-specific behavior and reciprocal interactions between two Antarctic top predator avian species observed from our survey will be helpful to enrich understanding of interactions among the biodiversity in the Ross Sea region. In addition, we expected that the motion-capture camera can improve observation of Antarctic seabirds without time limit. 2021-05-01T00:00:00Z