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Title |
Distribution Patterns of Oligochaete Assemblages in Relation to Environmental Factors in Freshwater Sediments of Korea
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Authors |
공동수(Dongsoo Kong) ; 송재하(Jea-ha Song) ; 정찬영(Chanyoung Jeong) ; 김명철(Myoung Chul Kim) ; 이종현(Jong Hyeon Lee) ; 곽인실(Ihn-Sil Kwak) |
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DOI |
https://doi.org/10.15681/KSWE.2026.42.3.254 |
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Keywords |
Annelida; Freshwater; Indicators; Oligochaeta; Sediment |
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Abstract |
This study identified 25 species of oligochaetes from fine-grained sediments collected across 320 sampling units at 80 sites in rivers and lakes within Korea's five major river systems. The ecological niches of each species were analyzed in relation to environmental factors, including sediment organic matter and heavy metal concentrations. Limnodrilus hoffmeisteri and Tubifex tubifex were the most frequently observed and numerically abundant species, indicating their widespread distribution in freshwater fine sediments in Korea. Canonical correspondence analysis (CCA) revealed that the first axis was strongly correlated with all measured environmental variables, particularly total ammonia nitrogen (TAN) and mud content, suggesting a nutrient and organic matter gradient. The second axis was associated with acid volatile sulfide (AVS), mud content, and heavy metals, reflecting redox conditions and levels of contamination. The third axis correlated with total organic carbon (TOC), indicating an organic matter gradient. Species composition exhibited patterns consistent with these environmental gradients. Tolerance analysis utilizing a Weibull model showed that L. hoffmeisteri and T. tubifex had broad tolerance ranges. Both L. hoffmeisteri and Henlea sp. demonstrated high tolerance to mud, AVS, and heavy metals. Conversely, Lumbriculus variegatus and Nais variabilis exhibited low tolerance to mud and heavy metals but high tolerance to TOC and TAN. Eisenia koreana was sensitive to all environmental variables, while Bothrioneurum vejdovskyanum displayed overall weak tolerance. Additionally, Haplotaxis gordioides and Branchiura sowerbyi were sensitive to TAN.
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