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Conspicuous amounts of microplastics have been discovered in bays near Antarctic research stations, including several types of microplastics in the water columns of Marian Cove. This study proposes an efficient operating strategy for a wastewater treatment plant to mitigate microplastic accumulations in the bay by assessing the transport and accumulation of microplastics using numerical simulations. Hence, microplastic particles were classified into falling and rising particles to find a mechanism for their vertical migration. The results showed that the characteristics of the vertical migration of the particles and flow conditions critically determined their traveling distance and accumulation location. Further, the amount of microplastics accumulated in the cove depended on the release time of the wastewater during the tidal cycle. Wastewater treatment plants need to be improved to reduce microplastics. However, it is necessary to adjust the location and schedule for releasing them into Marian Cove. • The transport and accumulation of microplastics in Antarctic Ocean are analyzed. • Numerical simulations are used to predict the travel path of the microplastics. • The effects of the vertical velocity of particles and flow conditions are studied. • The travel paths and deposition points are predicted for various discharge times. • Suitable discharge point and time are suggested based on the results. [ABSTRACT FROM AUTHOR]

Drastic sea ice retreats in the Antarctic Peninsula, and the consequent environmental changes have brought about the consequences of biological adaptation and food competition. The isotopic niche is reflected by the ecological position and functional role of a species, which can be altered depending on these environmental changes. We assessed the isotopic niche and trophic positions (TP) of 3 seabirds on the Barton Peninsula, King George Island, Antarctica, to understand ecological interaction among the species. The average TP of Antarctic krill (Euphausia superba) (hereafter "krill") (2.6 ± 0.1) was estimated by using the compiled published data of the compound-specific nitrogen isotope ratio of glutamic acid and phenylalanine in the Southern Ocean, and TP values of the seabirds based on that of krill to be reliable according to ecological knowledge. Our results on the overlap of the isotopic niches of seabirds suggests potential diet competition among the consumers, such as the brown skua (Stercorarius antarcticus) and south polar skua (Stercorarius maccormicki), whereas the distinct and broad isotopic niche width of kelp gulls (Larus dominicanus) suggesting that their adaptation through generalization was related to their extended habitat and various food sources. Our research indicates that isotopic niche of seabirds reflects their survival strategy for food competition. Consequently, these seabirds can be easily influenced by alternative food sources, including terrestrial and human-derived sources, by rapid environmental changes, indicating that they are valuable as key environmental species and require long-term monitoring in the Antarctic Peninsula. • Isotopic niche and trophic positions of 3 seabirds on the Barton Peninsula were investigated. • The estimated trophic position from stable isotope agree with ecological knowledge. • Isotopic niches of seabirds represent their adaptation to the environment through competition and segregation. • Therefore, long-term monitoring of the niche shift of seabirds in response to environmental changes is required. [ABSTRACT FROM AUTHOR]