Submitted:
23 October 2024
Posted:
23 October 2024
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Abstract
Rhynchocypris kumgangensis, endemic to Korea, is limited to the upper Hangang River and Gucheondongcheon Stream. As a key and climate-sensitive biological indicator species in Deogyusan National Park, it has a southern range limit in the Gucheondong Valley. Due to climate change, notable shifts in the activity, vertical distribution, and population of R. kumgangensis in the Gucheondongcheon Stream are expected. Owing to the rapidly changing climate, significant changes in the activity, vertical distribution, and population size of R. kumgangensis in the Gucheondongcheon Stream are anticipated, and continuous surveys of the distribution of R. kumgangensis in this river area have been conducted. This study assessed the habitat of R. kumgangensis at 13 sites, including five in the Gucheondongcheon Stream, from July to October 2020 and compared the results with historical data to evaluate the impacts of climate change. At the five Gucheondongcheon Stream sites, 102 individuals were recorded from April to October 2020, and 378 were recorded between June 2018 and July 2019. Additionally, the subdominant species shifted from R. kumgangensis (2014–2018) to Zacco koreanus (2020). In the two southernmost Gucheondongcheon Stream sites, only 18 R. kumgangensis were observed in 2020 compared to 82 in 2019, indicating a significant population decline.
Keywords:
Rhynchocypris kumgangensis
; Gucheondongcheon
; climate change
; southern range limit
; Geumgang River
1. Introduction
Rhynchocypris kumgangensis is an endemic Korean species that belongs to the Rhynchocypris genus of the Cyprinidae family. As a cold-water freshwater fish species, R. kumgangensis inhabits mountain streams with clear water and low temperatures [1]. Members of the Rhynchocypris genus include six species distributed across South Korea and North Korea. Due to the similarity in morphological traits, among other things, many taxonomic discussions have been conducted [2,3,4,5]. Initially, R. kumgangensis was reported as an unidentified species named Moroco sp. by Uchida [6] in samples collected from the Amnokgang and Bukhangang rivers. Later, a researcher in North Korea renamed it R. kumgangensis and Phoxinus kumgangensis [7]. In South Korea, R. kumgangensis has been used to identify novel species [4] based on characteristics of the genus Rhynchocypris [8]. Rhynchocypris kumgangensis, the target fish species in the current study, showed limited distribution in the following regions: the Daedonggang and Amnokgang Rivers in North Korea, the uppermost waters of the Hangang River, the Muju Gucheondong Valley of the Geumgang River, the Bakdal Valley in Bonghwa-gun, Gyeongsangbuk-do, the Sobaeksan Valley in Danyang-gun, and Chungcheongbuk-do in South Korea [9].
R. kumgangensis is a representative Climate-sensitive Biological Indicator Species (CBIS) suggested by the Ministry of Environment (MOE) to analyze the effects of climate change on the habitat of stream-river ecosystems [9]. In particular, R. kumgangensis is sensitive to changes in water temperature; its highest water temperature does not exceed 20 °C throughout the year [9,10,11]. Thus, the investigation and analysis of the vertical distribution of R. kumgangensis can indirectly evaluate the impact of climate change on the ecosystems of organisms that are more sensitive to external factors, such as climate change, than humans.
This study investigated the accurate distribution of R. kumgangensis from the origin to the upper waters of the Geumgang River water system in Deogyusan National Park to provide details of the distribution and sympatric species of R. kumgangensis in Deogyusan National Park. In addition, this study can be used as important data for predicting environmental changes in stream-river ecosystems due to climate change and is vital in strategies for the protection of R. kumgangensis and the preservation of fish diversity.
2. Materials and Methods
2.1. Study Period and Location
The fish fauna and physicochemical properties of the streams in Deogyusan National Park were investigated during two periods: July 9, 2020, and October 8–16, 2020. The study locations included 13 sites in Deogyusan National Park, which joins the Geumgang River, including four sites adjacent to the Gucheondongcheon Stream, four sites adjacent to the Wondangcheon Stream, two sites adjacent to the Bukchangcheon Stream, and three sites adjacent to the Myeongcheon Stream. All study sites were in the Muju-gun Administration District (Figure 1).
st. 1: Isokdae, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 2: Geumpotan Valley, Samggong-ri, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 3: Bipadam, Samggong-ri, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 4: Inwolahm Valley, Samggong-ri, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 5: Samgong-ri 101-1, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 6: Sushimdae, Shimgok-ri, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 7: Dugil-ri, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 8: Dugil Bridge, Dugil-ri, Seolcheon-myeon, Muju-gun, Jeollabuk-do
st. 9: Jeoksang-myeon, Muju-gun, Jeollabuk-do
st. 10: Bukchang-ri, Jeoksang-myeon, Muju-gun, Jeollabuk-do
st. 11: Jukcheon-ri, Anseong-myeon, Muju-gun, Jeollabuk-do
st. 12: Jukcheon-ri, Anseong-myeon, Muju-gun, Jeollabuk-do
st. 13: Jukcheon-ri, Anseong-myeon, Muju-gun, Jeollabuk-do
2.2. Survey Method
The physicochemical properties of the study sites (water temperature, dissolved oxygen (DO), pH, and electrical conductivity) were measured using a water quality sensor (Pro Quatro, YSI Inc., OH, USA). The width and depth of the water in the environmental quality survey were measured using a tape measure, and the substrate structure was visually examined at each site [12]. Kick nets (4 × 4 mm mesh) and cast nets (7 × 7 mm mesh) were used for fish collection. The collected fish were identified to the species level and their numbers were recorded at the site [1] before being released into the water. For fish community analysis at each site, the following indices were measured: dominance [13], species diversity [14], evenness [15], and species richness [16]. The similarity in fish communities in each stream was estimated by drawing a similarity matrix [17] based on the square root transformation of the total number of fish species that appeared during the study period and the Bray-Curtis similarity index. The similarity between the two groups was analyzed using permutational multivariate analysis of variance (PERMANOVA) and one-way analysis of similarity (ANOSIM). Between-group variation was analyzed using non-metric multidimensional scaling (NMDS) and visualized in two dimensions [18]. The contributing species and percentage contributions were determined using a similarity percentage (SIMPER) analysis to determine the similarity of fish communities. Habitat variation between the Gucheondongcheon and Wondangcheon Streams was examined using comparative analyses of PERMANOVA and one-way ANOSIM tests for substrate, DO, and water temperature. PERMANOVA, SIMPER, and NMDS analyses were performed using the Primer v6 software (Primer-E Ltd. Plymouth, UK) and PERMANOVA+ add-on modules.
3. Results
3.1. Physicochemical Properties
The water temperature ranged from 11.0 to 20.0℃ with seasonal and regional variations (Table 1). The regional variation in water temperature is thought to be due to the difference in water depth between mountain streams and upper river water. Dissolved oxygen (DO) was 10.93–12.04 mg/L in the first survey and 6.84–8.02 mg/L in the second survey, displaying seasonal variation (Figure 2). The estimated pH was 6.58–8.39 (Table 1). In the first survey, the pH at sites 1, 2, 3, and 4 of the Gucheondongcheon Stream was relatively low (6.58–6.74). The estimated salinity was 0.01–0.03‰, corresponding to freshwater (Table 1).
The substrate structure at the study sites consists mainly of rocks, boulders, and pebbles. The upper mountain streams, the Gucheondongcheon and Myeongcheon Streams, showed an abundance of rocks, boulders (> 256 mm), and cobbles (64–256 mm), whereas the Wondangcheon and Bukchangcheon Streams were mainly comprised of cobbles and pebbles (16–64 mm) and gravel (2–16 mm). Site 8 in the area downstream of the Wondangcheon Stream and site 13 downstream of the Myeongcheon Stream were mainly composed of sand (Table 2).
3.2. Fish Fauna
The investigation of the 13 sites in Deogyusan National Park indicated 17 species and 996 fish, of which the Cyprinidae family showed the highest frequency with 12 species and a 95.58% relative abundance (Table 3). Based on 337 fish and 37.85% relative abundance, Rhynchocypris oxycephalus was confirmed as the dominant species in the target national park, and Zacco koreanus (360 fish and 36.14% relative abundance) was confirmed as the subdominant species. R. oxycephalus showed the highest frequency, based on its appearance at 10 of the 13 investigated sites, followed by Z. koreanus, which appeared at seven sites. In addition, one fish each of Pseudobagrus koreanus and Silurus microdorsalia were found at sites 8 and 10, respectively. The target species in this study, R. kumgangensis, appeared only at sites in the Gucheondongcheon Stream. In the Deogyusan National Park, 11 endemic species were found: Pseudopungtungia nigra, Coreoleuciscus splendidus, Hemibarbus mylodon, Microphysogobio yaluensis, R. kumgangensis, Z. koreanus, Iksookimia koreensis, Pseudobagrus koreanus, Silurus microdorsalia, Coreoperca herzi, and Odontobutis platycephala, indicating endemic speciation of 64.71%. This level was higher than that across all the rivers in South Korea (25.9%) [19].
National parks tend to show higher levels of endemic speciation than other rivers and reservoirs [5]. In this study, Deogyusan National Park showed a higher level of endemic speciation than Odaesan National Park (30.77%) [20], Mudeungsan National Park (35%) [21], and Sokrisan National Park (53.8%) [22]. The Geumgang River exhibited approximately 26 endemic species [23]. Eleven of those species were found in Deogyusan National Park, indicating the richness of endemic species. This finding is thought to be due to the appropriate levels of fish habitat diversity and conservation in Deogyusan National Park, which facilitate the settlement of endemic species. Pseudopungtungia nigra (n = 17), a Class I endangered wildlife species, was found at Site 8, and Hemibarbus mylodon (n = 5), a natural heritage fish, was found at Sites 7 and 8 (Table 2).
Wondangcheon Stream had the highest species diversity and number of fish, with 13 species and 423 fish. The lowest species diversity was observed in the Bukchangcheon Stream, with only three species: R. oxycephalus, Z. koreanus, and S. microdorsalis. Mountain streams (Gucheondongcheon and Bukchangcheon) contained fewer species, whereas Wondangcheon and Myeongcheon Streams in the upper reaches of the river contained more species. In addition, fish communities varied across streams (PERMANOVA; Pseudo-F = 11.029, P = 0.001). Separate groups were observed in the Gucheondongcheon and Wondangcheon Streams, whereas fish converged into a single group in the Bukchangcheon and Myeongcheon Streams (Figure 2).
The dominant and subdominant species in most streams were R. oxycephalus and Z. koreanus. Still, the dominant species in the Gucheondongcheon Stream was R. kumgangensis (49.28% relative abundance), and the subdominant species in the Wondangcheon Stream was P. herzi (14.42% relative abundance) (Table 5).
3.3. Fish Community Indices
Among the investigated streams, the dominance indices ranged from 0.839 to 0.991. Bukchangcheon Stream exhibited the highest dominance index at 0.991, whereas Wondangcheon Stream had the lowest (0.839). This high dominance was presumed to be due to the greater number of fish of the dominant species collected. The diversity index was highest in Wondangcheon Stream (1.163) and lowest in Bukchangcheon Stream (0.414). This is presumably because the Bukchangcheon Stream is a mountain stream with a high flow rate and low water temperature. It is dominated by torrential species, which reduces species diversity.
In contrast, the Wondangcheon Stream has a low flow rate and more diverse habitats than mountain streams, facilitating habitation by a greater species diversity with a concomitantly higher diversity index. The evenness index was highest in the Gucheondongcheon Stream (0.828) and lowest in the Wondangcheon Stream (0.454). The species richness index was the highest in Wondangcheon (1.984) and lowest in Gucheondongcheon (0.375) (Table 6). The Gucheondongcheon, Bukchangcheon, and Myeongcheon mountain streams exhibited fewer inhabiting species with a higher level of dominance but lower levels of diversity and species richness. In contrast, the Wondangcheon Stream, which joins the Gucheondongcheon Stream, showed relatively low dominance but high species richness as an upstream river reach. This feature is common in the upstream (which has a lower number of fish species) and downstream reaches (which has an increased number of fish species) [24].
3.4. Distribution of R. Kumgangensis
This study investigated the distribution of R. kumgangensis in Deogyusan National Park. Sites 1–4, corresponding to the Gucheondongcheon Stream, were inhabited by this species (Figure 3). The R. kumgangensis habitat environment in the Hangang River water system has repeating riffle-pool sequences, and the substrate consists of large cobbles and pebbles with an average annual water temperature of 2.0–19.2℃ and an average dissolved oxygen of 9.2–14.0 mg/L [24]. The Gucheondong Valley of the Deogyusan National Park was found to have an annual water temperature of -0.1–18.4℃ and dissolved oxygen of 8.4–13.6 mg/L in the R. kumgangensis habitat [10], in contrast to the findings in the current study (water temperature, 11–16.5℃; DO, 6.84–12.04 mg/L). The results of this study were influenced by the timing of measurements during the summer months. onsequently, the water temperature readings were comparatively high, whereas the dissolved oxygen levels were relatively low.
At site 1 (upstream reaches of the Gucheondongcheon Stream), 17 fish were detected. In contrast, at site 4 (downstream reaches), 29 fish were detected, indicating a larger distribution of fish in the lower parts of the Gucheondongcheon Stream with inhabitation throughout the stream. The highest number of R. kumgangensis was observed at site 3. This seems to be due to the collection of a greater number of fish at site 3, with increased water width and depth in the pools, compared with sites 1 and 2, with narrower water and a lack of areas with greater depth. At Site 4 in the Gucheondongcheon Stream, a small concrete weir did not serve its purpose. R. kumgangensis was not detected in the Wondangcheon Stream, which joins the Gucheondongcheon Stream, R. kumgangensis was not detected. Compared with the Gucheondongcheon Stream, the substrate structure in the Wondangcheon Stream had fewer parent rocks, although no statistical significance was found (PERMANOVA, Pseudo-F = 4.784, P = 0.055). Dissolved oxygen was similar (PERMANOVA, pseudo-F = 7.259, P = 0.069), but the water temperature was different (PERMANOVA, pseudo-F = 27.062, P = 0.027). Hence, the most critical factor influencing inhabitation by R. kumgangensis is likely to be the water temperature.
4. Discussion
R. kumgangensis and R. oxycephalus are characterized by their inhabitation of stream waters rich in dissolved oxygen and at low temperatures [1]. Rhynchocypris kumgangensis primarily inhabits the uppermost reaches of mountain streams, with a decrease in habitat density towards the lower reaches [25]. Similarly, R. kumgangensis habitats in Deogyusan National Park were limited to the Gucheondongcheon Stream, whereas R. oxycephalus inhabited the Gucheondongcheon and Wondangcheon Streams. Generally, species sharing similar ecological statuses separate their space and food to use limited resources [26,27,28] efficiently. Rhynchocypris kumgangensis and R. oxycephalus inhabiting the Bangdongcheon Stream in Inje-gun, Gangwon-do, were shown to inhabit different tributaries for spatial separation [10]. In the Gucheondong Valley, the main feed of R. kumgangensis is mayflies, and that of R. oxycephalus includes caddisflies and terrestrial insects to reduce competition for food [10]. Although the two species shared similar habitats, R. kumgangensis was not found in the Wondangcheon Stream, inhabited by R. oxycephalus.
R. kumgangensis has been declared an indicator species of climate change by the Ministry of Environment in South Korea, as it is considered to represent climate change significantly through alterations in its region of distribution and population size. This species was also reported to have the most significant influence on water temperature during spawning [9]. The reported spawning period of R. kumgangensis is April–May, with a required water temperature of 11–14 °C [25]. The spawning period of R. oxycephalus is similar to that of R. kumgangensis from May to June, but the mean water temperature is 19 ± 0.5°C [29]. Thus, the distribution of R. kumgangensis was conjectured to be limited to hydrospheres with water temperatures lower than R. oxycephalus.
Climate change could lead to a population decline in R. kumgangensis. The climate of the Korean Peninsula is projected to experience a significant increase in the maximum temperature (TMAX) with increasing warming levels, with a corresponding increase in precipitation reaching tropical temperatures. The SSP-8.5 scenario projects a further increase of 1.8℃ by 2040 and 3.3℃ by 2060 [30,31,32]. Therefore, an increase in water and air temperatures at Deogyusan National Park, the southern range limit of R. kumgangensis, is inevitable, and it is thought that R. kumgangensis, a cold-water fish species, is at risk of localized extinction. Therefore, it is necessary to observe and track changes in biota through long-term monitoring.
To assess the long-term changes in The Fish Assessment Index (FAI) values, the Stream/River Ecosystem Survey and Health Assessment data were checked [33]. We found that the FAI values of the six points corresponding to the Gucheondongcheon Stream near the survey site for 11 years (2013–2023) were A-grade in most years and B-grade in 2016, 17, 22, and 23. In recent years, there has been a trend towards declining health ratings. The results of this survey were also confirmed as A-B, depending on the location. The decreasing trend in FAI was influenced by decreases in sensitive species (SS), insectivorous species (I), and domestic species (D). Therefore, along with climate change, stream/river ecosystem survey results and health assessments should be monitored annually to monitor changes in population status.
In this study, R. kumgangensis was the dominant species in the Gucheondongcheon Stream. These findings indicate that their distribution is limited to the Gucheondongcheon Stream; as a species inhabiting mountain streams, it is likely to be sensitive to changes in the surrounding environment. The narrow distribution range also implies that this species requires protection. In South Korea, R. kumgangensis has been reported to inhabit certain regions of the Hangang and Geumgang river water systems. However, as their habitats are limited to the Gucheondongcheon Stream in the Geumgang River, extinction in this region is expected to prevent further detection of R. kumgangensis habitats in the Geumgang River water system. Thus, environmental fluctuations in R. kumgangensis habitats should be periodically monitored in preparation for climate change. The level of protection of the natural ecosystem of Deogyusan National Park should be increased to preserve biological species diversity in the Geumgang River water system.
Author Contributions
Conceptualization, S.-H.Y., S.S., Y.-J.C., J.E.J., and J.-G.K.; methodology, S.-H.Y., S.S., Y.-J.C., J.E.J., and J.-G.K.; software, S.-H.Y., Y.-J.C., and J.-G.K.; validation, S.-H.Y., S.S., Y.-J.C., J.E.J., and J.-G.K.; formal analysis, S.S., Y.-J.C., and J.-G.K.; investigation, S.S., Y.-J.C., J.E.J., and J.-G.K.; resources, S.S., Y.-J.C., J.E.J., and J.-G.K.; data curation, S.S., Y.-J.C., S.-H.Y., J.E.J., and J.-G.K.; writing—original draft preparation, S.-H.Y., S.S., Y.-J.C., J.E.J., and J.-G.K.; writing—review and editing, Y.-J.C., S.S., and J.-G.K.; visualization, S.S., and J.-G. K.; supervision, J.-G.K.; project administration, J.-G.K., and S.S. funding acquisition J.-G.K., and S.S. All authors have read and agreed to the published version of the manuscript.
Funding
This research was supported by grants from the Korea National Park Research Institute, grant number no. NPRI 2021-10.
Data Availability Statement
The data presented in this study are available upon request from the corresponding author.
Acknowledgments
The authors thank all researchers affiliated with the Alpha Ecology Institute for their cooperation in facilitating sample collection. Special thanks go to Jong-Wook Kim, and Cheol-Woo Park (Ph. D).
Conflicts of Interest
The authors declare no conflicts of interest.
References
- Kim, I.S.; Park, J.Y. A Field Guide to the Freshwater Fishes of Korea; Kyohaksa: Seoul, Korea, 2002; p. 465. [Google Scholar]
- Jeong, M.G. The Fishes of Korea; Iljisa: Seoul, Korea, 1977; p. 727. [Google Scholar]
- Choi, G.C.; Jeon, S.R.; Kim, I.S.; Sohn, Y.M. Color Illustrations of Freshwater Fishes in Korea; Hyangmoonsa: Seoul, Korea, 1990; pp. 89–94. [Google Scholar]
- Kim, I.S. Illustrated Flora and Fauna in Korea. In Animals (Freshwater Fishes); Ministry of Education: Seoul, Korea, 1997; Vol. 37, p. 529. [Google Scholar]
- Chae, B.S. Number of freshwater fishes inhabiting the Korean National Parks. Journal of National Park Research 2010, 1, 76–84. [Google Scholar]
- Uchida, K. The fishes of Tyosen. Part 1. Nematognathi, Eventognathi. Bull. Fish. Exp. Sta. Gov. Tyosen. 1939, 6, 458. (In Japanese) [Google Scholar]
- Kim, L.T. A new species of genus Phoxinus from D.P.R. of Korea. Science Report (North Korea) 1980, 28–29, (In Korean with English abstract). [Google Scholar]
- Howes, G.J. A revised synonymy of the minnow genus, Phoxinus Rafinesque, 1820 (Teleostei : Cyprinidae) with comments on its relationships and distribution. Bull. Br. Mus. (Nat. Hist.) Zool. V. 1985, 48, 57–74. [Google Scholar] [CrossRef]
- Kim, S.J.; Noh, H.S.; Hong, S.J.; Gwak, J.W.; Kim, H.S. Impact of climate change on the habitat of Rhynchocypris kumgangensis in Pyungchang River. Journal of Wetlands Research 2013, 15, 271–280. [Google Scholar] [CrossRef]
- Lee, Y.G. The ecological study of the Endemic Korean Fat Minnow, Rhynchocypris kumgangensis (Cyprinidae) in Deogyusan National Park. Journal of National Park Research 2020, 11, 1–20. [Google Scholar]
- Byeon, H.G. Ecological Characteristics of Rhynchocypris kumgangensis (Cyprinidae) at the Spring Water in Eocheon Stream, Korea. Korean J. Environ. Eco. 2019, 33, 677–685. [Google Scholar] [CrossRef]
- Cummins, K.W. An evaluation of some techniques for the collection and analysis of benthic samples with focus on lotic waters. Amer. Midl. Natl. 1962, 67, 477–504. [Google Scholar] [CrossRef]
- McNaughton, S.J. Relationship among functional properties of California grassland. Nature 1967, 216, 168–144. [Google Scholar] [CrossRef]
- Shannon, C.E.; Weaver, W. The Mathematical Theory of Communication; Univ. Illinois Press: Urbana, USA, 1963; p. 125. [Google Scholar]
- Pielou, E.C. The measurement of diversity in different types of biological collection. J. Theoret. Biol. 1966, 13, 31–144. [Google Scholar] [CrossRef]
- Margalef, R. Information theory in ecology. Gen. Syst. 1958, 3, 36–71. [Google Scholar]
- Platell, M.E.; Potter, I.C. Partitioning of food resources amongst 18 abundant benthic carnivorous fish species in marine waters on the lower west coast of Australia. J. Exp. Mar. Biol. Ecol. 2001, 261, 31–54. [Google Scholar] [CrossRef] [PubMed]
- Field, J.G.; Clarke, K.R.; Warwick, R.M. A practical strategy for analysing multispecies distribution patterns. Marine Ecology Progress Series 1982, 8, 37–52. [Google Scholar] [CrossRef]
- Kim, I.S. Current Statuses of Habitats and Preservation of Endangered Freshwater Fish Species in South Korea. In Proceedings of the 1995 Joint Symposium of The Korean Society of Environment and Ecology and The Ichthyological Society of Korea; 1995; pp. 31–50. [Google Scholar]
- Choi, J.S.; Choi, J.G. Fish fauna and disturbance in Odaesan National Park, Korea. Korean Journal of Environmental Biology 2005, 19, 177–187. [Google Scholar]
- Lee, S.R.; Cho, Y.S.; Lee, D.W. Fish fauna in Seorak National Park. Journal of National Park Research 2011, 2, 194–202. [Google Scholar]
- Park, S.K.; Lee, S.R. Freshwater fish fauna in Sokrisan National Park. Journal of National Park Research 2013, 4, 105–110. [Google Scholar]
- Yoon, J.D.; Kim, J.H. , Park, S.H.; Jang, M.H. The distribution and diversity of freshwater fishes in the Korean peninsula. Korean Journal of Ecology and Environment 2018, 51, 71–85. [Google Scholar] [CrossRef]
- Choi, J.S.; Kim, J.G. Ichthyofauna and fish community in Hongcheon River, Korea. Korean Journal of Environmental Biology 2004, 18, 446–455. [Google Scholar]
- Song, H.B. The ecology of Rynchocypris kumgangensis (Cyprinidae). Korean J. Ichthyol 2000, 12, 101–110. [Google Scholar]
- Hardin, G. The competitive exclusion principle. Science 1960, 131, 1292–1297. [Google Scholar] [CrossRef]
- Nilsson, N.A. Interactive segregation between fish species. In The Biological Basis of Freshwater Fish Production; Gerking, S.D., Ed.; Blackwell Sci. Publ.: Oxford, 1967; pp. 259–313. [Google Scholar]
- Sale, P.F. A suggested mechanism for habitat selection by juvenile manini Acanthurus triostegus sandvicensis Streets. Behaviour. 1969, 35, 7–44. [Google Scholar] [CrossRef]
- Han, G.H.; Noh, B.Y.; Oh, S.H.; Park, J.T.; Cho, J.G.; Seong, G.B. Early life history and spawning behavior of Chinese Minnow, Rhynchocypris oxycephalus reared in the laboratory. Korean J. Ichthyol. 1999, 11, 177–183. [Google Scholar]
- Kim, J.U.; Kim, M.H.; Chung, C.Y.; Byun, Y.H.; Kim, T.J. High-resolution projection of future climate change over South Korea under global warming levels of 1.5 °C, 2 °C, and 3 °C based on shared socioeconomic pathways scenarios. JCCR 2023, 14, 501–520. [Google Scholar] [CrossRef]
- Kim, S.T.; Lee, W.S.; Jung, I.W.; Han, J.M.; Byun, Y.H.; Kim, J.U. Change in extreme precipitation by watersheds of South Korea under future Shared Socio-economic Pathway (SSP) scenarios. JCCR 2023, 14, 83–93. [Google Scholar] [CrossRef]
- NMS. 100 Years of Climate Change on the Korean Peninsula; National Institute of Meteorological Sciences (NIMS): Jeju, Korea, 2018; p. 31. [Google Scholar]
- Ministry of Environment (MOE)/National Institute of Environmental Research (NIER). Guidelines for stream/river ecosystem survey and health assessment - part of stream -; National Institute of Environmental Research: Incheon, Korea, 2024; 148p. [Google Scholar]
Figure 1.
Map of the study location showing sampling sites in Deogyusan National Park, Jeollabuk-do, Korea.
Figure 1.
Map of the study location showing sampling sites in Deogyusan National Park, Jeollabuk-do, Korea.
Figure 2.
Non-metric multidimensional scaling of samples based on Bray-Curtis’s similarities. Site a, Gucheondongcheon Stream; Site b, Wondangcheon Stream; Site c, Bukchangcheon Stream; Site d, Myeongcheon Stream.
Figure 2.
Non-metric multidimensional scaling of samples based on Bray-Curtis’s similarities. Site a, Gucheondongcheon Stream; Site b, Wondangcheon Stream; Site c, Bukchangcheon Stream; Site d, Myeongcheon Stream.
Figure 3.
Vertical distribution of Rhynchocypris kumgangensis along the Gucheondongcheon Stream.
Table 1.
Physical and chemical properties of study streams in Deogyusan National Park from April 2020 to October 2020 (mean ± standard deviation).
Table 1.
Physical and chemical properties of study streams in Deogyusan National Park from April 2020 to October 2020 (mean ± standard deviation).
| Gucheondongcheon Stream | Wondangcheon Stream | Bukchangcheon Stream | Myeongcheon Stream | |
|---|---|---|---|---|
| Water temperature (℃) | 13.9 ± 2.74 | 16.1 ± 2.39 | 16.8 ± 1.06 | 14.9 ± 3.46 |
| Dissolved oxygen (mg/L) | 9.38 ± 2.45 | 9.33 ± 1.74 | 8.34 ± 3.32 | 9.15 ± 2.48 |
| pH | 6.98 ± 0.34 | 7.49 ± 1.28 | 7.49 ± 1.02 | 6.45 ± 0.51 |
| Salinity (‰) | 0.01 | 0.03 | 0.03 | 0.01 |
Table 2.
Environmental characteristics of the sampling sites in Deogyusan National Park in 2020.
| Streams | Site | Water width(m) | Water depth (m) | Bottom structure (%) | ||||
| B | C | P | G | S & M | ||||
| Gucheondongcheon | st. 1 | 5 | 0.1–0.5 | 40 | 20 | 20 | 10 | 10 |
| st. 2 | 5–10 | 0.5–0.1 | 20 | 30 | 20 | 30 | 10 | |
| st. 3 | 5–10 | 0.5–1.5 | 30 | 10 | 20 | 30 | 10 | |
| st. 4 | 3–8 | 0.1–0.8 | 30 | 10 | 20 | 20 | 20 | |
| Wondangcheon | st. 5 | 10–20 | 0.1–1 | - | 30 | 20 | 30 | 10 |
| st. 6 | 10–20 | 0.1–1 | 10 | 20 | 30 | 30 | 10 | |
| st. 7 | 10–20 | 0.1–1 | 10 | 10 | 30 | 30 | 20 | |
| st. 8 | 20–30 | 0.1–2 | - | 20 | 20 | 20 | 40 | |
| Bukchangcheon | st. 9 | 2–5 | 0.1–1 | - | 30 | 30 | 30 | 10 |
| st. 10 | 1–2 | 0.1–1 | - | 40 | 20 | 20 | 20 | |
| Myeongcheon | st. 11 | 5 | 0.1–1 | 40 | 20 | 10 | 20 | 10 |
| st. 12 | 5 | 0.1–0.5 | 30 | 20 | 20 | 20 | 10 | |
| st. 13 | 5 | 0.1–1 | 10 | 10 | 10 | 20 | 50 | |
*B (boulder), > 256 mm; C (cobble), 64–256 mm; P (pebble), 16–64 mm; G (gravel), 2–16 mm; S & M (sand and mud), < 2 mm [12].
Table 3.
List and individual numbers of fish collected at each site in the Deogyusan National Park from April to October 2020.
Table 3.
List and individual numbers of fish collected at each site in the Deogyusan National Park from April to October 2020.
| Species | st. 1 | st. 2 | st. 3 | st. 4 | st. 5 | st. 6 | st. 7 | st. 8 | st. 9 | st. 10 | st. 11 | st. 12 | st. 13 | Total | RA |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cypriniformes | |||||||||||||||
| Cyprinidae | |||||||||||||||
| Pungtungia herzi | 11 | 19 | 31 | 4 | 65 | 6.53 | |||||||||
| Pseudopungtungia nigra*※ | 17 | 17 | 1.71 | ||||||||||||
| Coreoleuciscus splendidus* | 3 | 4 | 7 | 0.70 | |||||||||||
| Squalidus gracilis majimae | 1 | 1 | 0.10 | ||||||||||||
| Hemibarbus mylodon*※ | 3 | 2 | 5 | 0.50 | |||||||||||
| Pseudogobio esocinus | 3 | 2 | 5 | 0.50 | |||||||||||
| Microphysogobio yaluensis* | 10 | 10 | 1.00 | ||||||||||||
| Rhynchocypris oxycephalus | 17 | 24 | 19 | 29 | 4 | 68 | 34 | 58 | 46 | 78 | 377 | 37.85 | |||
| Rhynchocypris kumgangensis* | 8 | 10 | 65 | 19 | 102 | 10.24 | |||||||||
| Zacco platypus | 3 | 3 | 0.30 | ||||||||||||
| Zacco koreanus* | 73 | 69 | 59 | 93 | 14 | 40 | 12 | 360 | 36.14 | ||||||
| Cobitidae | |||||||||||||||
| Iksookimia koreensis* | 2 | 1 | 3 | 0.30 | |||||||||||
| Siluriformes | |||||||||||||||
| Bagridae | |||||||||||||||
| Pseudobagrus koreanus* | 1 | 1 | 0.10 | ||||||||||||
| Siluridae | |||||||||||||||
| Silurus microdorsalis* | 1 | 1 | 0.10 | ||||||||||||
| Salmoniformes | |||||||||||||||
| Salmonidae | |||||||||||||||
| Oncorhynchus masou masou | 12 | 4 | 1 | 17 | 1.71 | ||||||||||
| Perciformes | |||||||||||||||
| Centropomidae | |||||||||||||||
| Coreoperca herzi* | 2 | 5 | 7 | 0.70 | |||||||||||
| Odontobutidae | |||||||||||||||
| Odontobutis platycephala* | 9 | 3 | 3 | 15 | 1.51 | ||||||||||
| Number of individuals | 25 | 34 | 96 | 52 | 81 | 89 | 91 | 162 | 68 | 49 | 113 | 46 | 90 | 996 | |
| Number of species | 2 | 2 | 3 | 3 | 4 | 3 | 7 | 11 | 1 | 3 | 5 | 1 | 2 | 17 |
Total, total individuals; RA, relative abundance (%); *, Korean endemic species; ※, endangered species.
Table 4.
Similarity percentage analysis for differences in fish assemblages in each stream.
| Streams | Average similarity (%) | Species | Average abundance | Average similarity | Ratio similarity/standard deviation | Speciescontribution(%) | Cumulative contribution(%) |
|---|---|---|---|---|---|---|---|
| Gucheondoncheon | 74.94 | Rhynchocypris oxycephalus | 4.69 | 42.10 | 4.69 | 56.17 | 56.17 |
| Rhynchocypris kumgangensis | 4.60 | 30.43 | 6.66 | 40.61 | 96.78 | ||
| Wondangcheon | 59.18 | Zacco koreanus | 8.54 | 42.18 | 4.06 | 71.28 | 71.28 |
| Pungtungia herzi | 3.31 | 8.36 | 0.90 | 14.13 | 85.41 | ||
| Odontobutis platycephala | 1.62 | 4.02 | 0.89 | 6.79 | 92.2 | ||
| Bukchancheon | 59.37 | Rhynchocypris oxycephalus | 7.23 | 51.24 | 4.21 | 86.30 | 86.30 |
| Zacco koreanus | 3.36 | 8.13 | 0.58 | 13.70 | 100 | ||
| Myeongcheon | 71.10 | Rhynchocypris oxycephalus | 7.81 | 71.10 | - | 100 | 100 |
Table 5.
The most abundant species in each stream of Deogyusan National Park.
| Streams | Dominant species (RA, %) | Sub-dominant species (RA, %) |
|---|---|---|
| Gucheondongcheon | Rhynchocypris kumgangensis (49.28) | Rhynchocypris oxycephalus (43.00) |
| Wondangcheon | Zacco koreanus (69.50) | Pungtungia herzi (14.42) |
| Bukchangcheon | Rhynchocypris oxycephalus (87.18) | Zacco koreanus (11.97) |
| Myeongcheon | Rhynchocypris oxycephalus (73.09) | Zacco koreanus (20.88) |
RA, relative abundance.
Table 6.
Biological indices of fish communities in Deogyusan National Park.
| Gucheondongcheon | Wondangcheon | Bukchangcheon | Myeongcheon | Total | |
|---|---|---|---|---|---|
| Dominance index | 0.923 | 0.839 | 0.991 | 0.940 | 0.740 |
| Diversity index | 0.910 | 1.163 | 0.414 | 0.774 | 1.574 |
| Evenness index | 0.828 | 0.454 | 0.377 | 0.481 | 0.556 |
| Species richness index | 0.375 | 1.984 | 0.420 | 0.725 | 2.318 |
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