Analysis of the Fish Community in the Chiaksan National Park Region, Korea

This study was conducted to survey the fish community in the Chiaksan National Park region in Korea over three different seasons (from April to October 2022) and to analyze its characteristics. Using GIS program, 15 fixed stations and nine random stations that were considered likely to have high fish species diversity were selected for study. Most environments at the surveyed stations were first- to fourth-order streams, corresponding to mountainous or upper-middle streams. Additionally, the composition of the stream substrates varied depending on the altitude, stream width, and water depth, as revealed by principal component analysis of the physical environmental factors at each station. In total, 3,053 individuals from 26 species across 11 families were identified in the survey. The dominant species was Zacco koreanus (30.9%), followed by the subdominant species Rhynchocypris oxycephalus (24.1%). Four legally protected species were identified; namely, Acheilognathus signifer, Hemibarbus mylodon, Brachymystax lenok tsinlingensis, and Cottus koreanus. Additionally, 16 species endemic to Korea were identified, including Coreoleuciscus splendidus, Squalidus gracilis majimae, and Microphysogobio yaluensis. Cluster analysis based on the number of individuals per species at each station classified the stations into two large groups, which were further subdivided according to the number of dominant and key species determining the characteristics of each station. Rank abundance curve model analysis of the fish clusters within and outside the national park area resulted in the ‘Preemption’ model being adopted for the park area and the ‘Mandelbrot’ model for the area outside the park. Thus, on the basis of this survey and previous studies, 32 fish species have been identified in Chiaksan National Park. Principal coordinate analysis of the presence or absence of fish species by period divided the fish community into two groups. Therefore, the fish community in the Chiaksan National Park region has very high biodiversity and protection values, including four legally protected species and 16 species endemic to Korea. Hence, continuous monitoring and preservation measures are needed.