Distribution of invasive Procambarus clarkii (Girard, 1852) (Decapoda: Astacidea: Cambaridae) in South Korea, with a study of the spatial variation of benthic macroinvertebrate taxa

Abstract

Abstract The introduction and spread of non-native species pose major threats to biodiversity and ecosystem stability. We conducted a study to assess the spread, growth rate, and interactions of the exotic crayfish Procambarus clarkii (Girard, 1852) throughout South Korea. A total of 343 individuals (223 from reservoirs, 120 from streams) were studied in four provinces. This species has expanded its distribution to 24 regions in South Korea. The length-weight relationship indicated positive allometric growth, expressed as W = 2.855L3.0073. The highest number of adult P. clarkii individuals eradicated was 11,438 in 2022. Using the MaxEnt model and environmental variables related to the climate, a highly accurate forecast was generated for the potential distribution of P. clarkii in South Korea. The factors influencing the current distribution probability were identified as the highest temperature of the warmest month, mean temperature of the wettest quarter, and mean temperature of the warmest quarter, which contributed the most to the present distribution probability. The predicted distribution indicated a rapid increase in P. clarkii density in the southwestern region, extending towards the southeastern and central regions, including the brackish zone. Non-metric multidimensional scaling analysis (stress = 0.07) was conducted based on benthic macroinvertebrates, revealing distinct variations among the four sampling sites. The distribution of benthic macroinvertebrates was significantly influenced by the proportion of sand in the substrate (R = 0.39, P < 0.05) and water quality as estimated by the electrical conductivity (R = 0.51, P < 0.05).