Invasive predators are one of the most damaging species groups to biodiversity. In the Nakdong River, the lake skygazer Chanodichthys erythropterus is a dominant species that is fiercely carnivorous and a concern for commercial fish. Although it is important to understand the ecological characteristics related to the feeding habit, studies on the diets of lake skygazer in Nakdong River have been limited to studies of gut contents. In this study, the trophic position (TP) and feeding habits of C. erythropterus were studied by calculating TPs using samples collected from 13 sites throughout the Nakdong River. Compound-specific isotopic analysis of amino acids provided reliable TPs from the muscle of Lake skygazer C. erythropterus without any isotope baseline. The results were approximately 3 to 3.6 and suggesting a carnivorous but size-dependent prey variation. In particular, the TP variability of C. erythropterus observed in the Nakdong River showed that it had a selective feeding habit compared to carnivorous fish species of relatively similar trophic levels.

Despite the consumption of disinfectants have been increased by COVID-19 pandemic, the fate of the chemicals in aquatic food webs are still unclear. In order to understand the trophic transfer of the chemicals, the concentration of disinfectants including six benzalkonium chloride (BACs) and five didecyldimethylammonium chlorides (DDACs) were measured at the Geum (2020), Han (2021), and Yeongsan River (2021), before and after rainfall. The highest concentration of ΣBACs (mainly C12 and C14) and ΣDDACs (mainly C10 and C14) were observed in the Han River, followed by Yeongsan River, Geum River Estuary, and Gapcheon. After rainfalls, both concentration and detection frequency were decreased in all sites. Although the BAC and DDAC seems to be accumulated in organisms, they were bio-diluted rather than magnified in the aquatic food web with the biomagnification factor (BMF) of less than 1, trophic magnification slope (TMS) from - 0.236 to 0.001, and trophic magnification factor (TMF) from 0.85 to 1.01.

The risk of various hazardous substances in aquatic environment comprises not only the concentration of substances in the environmental medium but also their accumulation in fish through complex food web and the health risks to humans through the fish. In Korea, the monitoring of residual toxicant in aquatic ecosystems began in 2016 following the enforcement of the Acts on registration and evaluation for the management of chemicals used in daily life (consumer chemical products), and attention has been paid to potentially hazardous substances attributed to them. Recently, studies have been carried out to investigate the distribution of these hazardous substances in the ecosystem and calculate their emission factors. These include the accumulation and transport of substances, such as detergents, dyes, fragrances, cosmetics, and disinfectants, within trophic levels. This study summarizes the results of recently published research on the inflow and distribution of hazardous substances from consumer chemical products to the aquatic environment and presents the scientific implication. Based on studies on aquatic environment monitoring techniques, this study suggests research directions for monitoring the residual concentration and distribution of harmful chemical substances in aquatic ecosystems. In particular, this study introduces the directions for research on trophic position analysis using compound specific isotope analysis and trophic magnification factors, which are needed to fulfill the contemporary requirements of selecting target fish based on the survey of major fish that inhabit domestic waters and assessment of associated health risk. In addition, this study provides suggestions for future biota monitoring and chemical research in Korea.

본 연구는 간호 대학생이 느끼는 간호사 이미지와 전공만족도가 간호전문직관에 미치는 영향을 분석하여 간호 대학생이 긍정적인 간호전문직관을 형성할 수 있도록 교육과정편성과 비교과활동의 활성화를 위한 기초자료를 제시하고자 시행하였다. 연구 대상자는 서울과 충청권 거주 대학생으로 2019년 5 월 30일부터 6월 4일까지로 총 184부의 자료를 t-test, ANOVA, Pearson’s Correlation Coefficient, Multiple regression analysis로 최종 분석하였다. 연구결과는 성격, 간호학 선택 동기, 간호직의 미래전망, 간호사 이미지 및 전공만족도를 예측변수로 간호전문직관을 설명하는 선형회귀모형은 통계적으로 유의하 였고(F=43.637, p<.001), 회귀모형의 설명력은 간호전문직관 총 변화량의 63.6%를 설명하고 있다. 따라서 본 연구는 간호 대학생의 간호전문직관을 증가시키기 위해서 긍정적 자아상을 통한 긍정적 이미지를 창출 하고 학습 만족도를 높이기 위한 교육프로그램 개발의 기초자료로 활용할 수 있을 것이다.