Original Article PNIE 2021;2(1):42-52 https://doi.org/10.22920/PNIE.2021.2.1.42 pISSN 2765-2203, eISSN 2765-2211 Distribution of Fish Species in Wetland Protected Areas in South Korea Yeounsu Chu , Jungdo Yoon* , Kwang-Jin Cho , Mijeong Kim , Jeongcheol Lim , Changsu Lee Wetlands Research Team, Wetland Center, National Institute of Ecology, Seocheon, Korea ABSTRACT In order to secure basic data on biodiversity for wetland conservation and management used the data from Wetland Protected Area surveys conducted in South Korea (2015-2019) to analyze the distribution of fish from a total of 15 orders, 45 families, 134 species, and 12,972 individuals. The predominant species identified were Zacco platypus (Temminck and Schlegel) (19.47%) and Zacco koreanus (Kim, Oh and Hosoya) (8.16%). Of all emergent species, 52.9% (n=71 species) were freshwater species, 26.9% (n=36) were brackish species, 3.0% (n=4) were migratory species, 27% (n=36) were marine species, and 9.0% (n=12) were riffle benthic species. Overall, 5.2% (n=7 species) were endangered species, 3.0% (n=4) were exotic species, and 23.1% (n=31) were Korean endemic species. The eight identified Wetland Protected Areas (WPA) were classified based on their habitat characteristics and on the analysis of their emergent fish communities, as estuarine (n=2), coastal dune (n=1), marsh (n=2), stream (n=2), and stream-marsh (n=1) types. The environmental factors revealed to have the greatest influence on the species diversity of emergent fish were maintenance and repair, installation of reservoirs, and construction of artificial wetlands around them. The present study offers basic information on the diversity of fish species in different Wetland Protected Area types that can be used to inform conservation and management decisions for WPA. Keywords: Biodiversity, Endangered species, Estuaries, Habitat, Ramsar convention, Rivers Introduction 25 inland wetlands, including Yongneup of Mt. Daeam, have been designated as Wetland Protected Areas (WPA) Wetlands are transition zones between terrestrial and by the Ministry of Environment in South Korea. Since aquatic ecosystems, and are recognized for their high bio- 2006, the Ministry of Environment has been conducting diversity and conservation value. National reports on the intensive surveys on the WPAs under Article 4 (Wetland roles of wetlands as habitats for migratory birds as well as Investigations), Article 5 (Formulation of Master Plans their roles in preserving biodiversity are being published for Wetland Conservation), and Article 11 (Formulation worldwide (Kim & Lee, 2015). and Implementation of Conservation Plans) of the Wet- Since the Wetland Conservation Act in 1999, a total of land Conservations Act. Currently, the National Institute of Ecology is performing the third WPA intensive survey (2016-2020) under Article 18 (Delegation and Entrust- Received September 10, 2020; Revised October 19, 2020; ment of Authority) of the Wetland Conservations Act. Accepted October 19, 2020 This study identified the emergent fish species in the *Corresponding author: Jung-do Yoon WPAs within inland wetlands. As the top predators of e-mail [email protected] aquatic ecosystems, fish are an important group that https://orcid.org/0000-0001-9012-5621 regulates the biological structures and functions within This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/4.0), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © National Institute of Ecology. All rights reserved. Fish Species in Wetland Protected Areas water bodies (An et al., 2001; An & Kim, 2005; Lee et al., characteristics of the fish species inhabiting the WPAs (Kim 2017; Shin et al., 2012). In wetlands, fish are not only the et al., 2016; 2017; Lim et al., 2019) (Fig. 1). These wet- higher-level consumers (Choi & Byeon, 2010) but they lands consisted of stream type wetlands (n=5) and marsh also dominate important niches at the center of wetland type wetlands (n=3) (Table 1). food chain, acting as both consumers and producers. In- Intensive surveys of the WPAs followed the monitor- habitation of rare and endangered species is an especially ing guidelines of the Ministry of Environment for Korean important factor when evaluating the value of domestic inland wetlands (ME, 2011). In large areas where general wetlands and their designation as protected areas. How- fish investigation methods (e.g., cast net and skimming ever, intensive surveys and focused research efforts are net) were not possible (e.g., the Han River estuary and needed because the environmental preferences of fish Nakdong River estuary), we enlisted the help of fisher- species can result in them having narrow distributions men to capture individuals using fixed shore nets, gill and small populations that are hard to detect (Engler et nets, dredge nets, and other methods. Species of captured al., 2004; Kim et al., 2018). Presently, information regard- individuals were either identified in the field and released ing the distribution of fish species in WPAs and the char- after recording the required data, or were fixed with 10% acteristics of such areas that serve as important habitats formalin and identified in lab if identification in the field for organisms is limited. was not possible. Fish species were identified with refer- This study, therefore, aimed to investigate the distribu- ence to Chae et al. (2019), Choi et al. (2002), Kim et al. tion of fish species that were identified during intensive (2005), and Kim and Park (2002), and the taxonomic se- surveys on the WPAs to compare and analyze their popu- quencing was based on the National Species List of Korea lation distribution and inhabitation characteristics based (NIBR, 2019). on wetland patterns. Here, we provide basic reference data that can be used to develop plans for the conserva- Data analysis tion, restoration, and management of future WPAs. We compiled a list of the fish species based on the re- ports of the intensive surveys conducted for the WPAs Materials and Methods to analyze the diversity and distribution of the emergent fish in the WPAs. We analyzed the fish community char- Research targets and methods acteristics and similarities using the diversity and popula- Among the 22 intensive surveys of the WPAs over the tion data of emergent fish, as well as the richness index last 5 years (2015-2019), we used the data for 8 wetlands (Margalef, 1958), dominance index (McNaughton, 1967), in 2016, 2017 and 2019 in which fish surveys had been evenness index (Pielou, 1975), and species diversity index conducted, to understand the diversity and distribution (Shannon & Weaver, 1963). 123 00'00'' 126 00'00'' 129 00'00'' 132 00'00'' 38 00'00'' Han River 00'00'' Estuary 38 Hanbando Duung Gonggumji 36 00'00'' 00'00'' Upo 36 Damyang stream Nakdong River Estuary Cimsil Fig. 1. Map showing the Wet- 34 land Protected Areas in which 00'00'' intensive surveys were conduct- 00'00'' 050 100 200 34 km ed in South Korea during 2015- 123 00'00'' 126 00'00'' 129 00'00'' 132 00'00'' 2019. https://doi.org/10.22920/PNIE.2021.2.1.42 43 Yeounsu Chu et al. Table 1. Details of the WPA fish surveyed in South Korea 2016, 2017, 2019 Wetland name Date designated as a WPA Area (km2) Survey year Nakdong River Estuary Aug 9, 1999 37.718 2017 Upo Aug 9, 1999 8.609 2016 Duung Nov 1, 2002 0.067 2019 Damyang Stream July 8, 2004 0.981 2019 Han River Estuary Apr 17, 2006 60.668 2016 Gonggumji June 29, 2011 0.264 2019 Hanbando Jan 13, 2012 2.772 2019 Cimsil Nov 7, 2016 2.037 2019 WPA, Wetland Protected Area. All statistical analyses were performed using R (R ver- 9 species in the Duung wetland, 46 species in the Cimsil sion 3.5.2, R Core Team 2020). First, we performed a hier- wetland, and 36 species in the Hanbando wetland. The archical cluster analysis using the ‘hclust’ (method='ward. most species appeared in the mouth of the Nakdong River D2') function in the Vegan package to understand the estuary, and the proportion of marine fish species was relationship between wetland types (Bang et al., 2006) high. Next, the second most abundant species appeared and the fish community structure (Oksanen et al., 2020). in the Cimsil wetland (Table 2). The total species population of the collected individuals (S) The Nakdong River estuary, a partially-mixed estuary, was converted to log(S+1) to be used as the input data, has an estuary bank and coastal or bay characteristics that and the species that emerged in only one wetland were have enabled the high occurrence of marine fish species excluded from the analysis to eliminate regional specific- as well as the largest overall number of species. Blockage ity. of the freshwater inflow by the estuary bank had gradu- Second, we applied non-metric multidimensional scal- ally transformed the brackish water zone into a marine ing (NMDS) using the ‘metaMDS’ function in the Vegan environment; which is consistent with the observations of package (Oksanen et al., 2020), and analyzed the fish previous studies (Kang et al., 2012). community structure and relationship in the investigated On the other hand, the Han River estuary does not have sites using ordination methods. Again, we converted the an estuary bank, and the brackish water zone is extended species population data to log(S+1) to produce the input due to the direct influence of the tides. The Han River data for the analysis. We calculated the distance between estuary is a well-mixed estuary that maintains the typi- the investigation sites using the Bray-Curtis method (Bray cal ecosystem structure of estuaries along the Korean & Curtis, 1957).