Distribution and Management of Nutria (Myocastor coypus) Populations in South Korea

Abstract

In 2014, the South Korean government initiated the “Nutria Eradication Project” to actively manage and control populations of nutria, an invasive alien species that threatens national biodiversity. In the present study, we examined domestic nutria habitats in 2014 to 2018 and analyzed spatial shifts in habitat distribution to develop management policies and eradication strategies for the South Korean Ministry of Environment. A total of 27,487 nutria individuals were captured over five years upon the initiation of the eradication project. We found that the number of habitat tracks decreased from 1510 in 19 administrative districts in 2014 to 176 in 14 districts in 2018. We examined the distribution of nutria habitat tracks and found a northwestward shift at an average angle of 313.9° and 46,656.9 m. This distribution shift prompted improvements in control policies focused on nutria capture to suppress rodent movement and shifting distributions. We redefined the spatial scope of our control regions accordingly and established isolated environments in each region to prevent further spread. Additionally, resource management was focused in areas showing habitat expansion. Overall, we observed an estimated 54% decrease in nutria habitat tracks from 2016 to 2017. Our results have since been enacted in government policies and provide a basis for establishing flexible strategies for effectively controlling nutria habitats and populations. In 2017, the South Korean government allocated additional funds for research and for the development of further control strategies working toward the project’s goals.

Genetic Diversity and Population Structure of Nutria (Myocastor coypus) in South Korea

“…In line with previous nutria distribution studies in South Korea, the kernel density results support the middle and lower reaches of the Nakdong River having slow water flow leading to tributaries and wetlands, with a warm winter and abundant food sources, providing a good habitat for nutria populations to establish and proliferate [19,50]. A previous investigation reported that nutria management efforts are focused on the Nakdong River basin in South Korea because nutria individuals are mainly clustered in this region [22]. Although the previous management was effective to decrease nutria habitat tracks, we tried to apply genetic analysis for the developed nutria eradication project in South Korea.…”

“…The Korean Ministry of Environment began investigating the status of nutrias in 2006 and designated the nutria as an invasive alien species in 2009. Previous studies reported that the settlement of nutrias in South Korea is concentrated in the Nakdong River basin [19][20][21][22].…”

“…Several government bodies are currently involved in this program-including the Ministry of Environment, local environmental agencies, the National Institute of Ecology (NIE), local governments, and private organizations. Furthermore, the Ministry of Environment organized a strategic committee to establish relevant policies and detailed plans [22]. The local offices hired hunters to capture nutrias throughout the year and the NIE supported eradication strategies and techniques.…”

“…The local offices hired hunters to capture nutrias throughout the year and the NIE supported eradication strategies and techniques. Due to these efforts, 27,487 nutrias were captured in the Nakdong River basin from 2016 to 2018 [22].…”

“…Prior to the initiation of the Nutria Eradication Program, the Korean government focused on the three strategic approaches: (1) monitoring of nutria individuals and habitats; (2) predicting the population distribution by analyzing the genetic structure; and (3) developing eradication programs based on nutria ecology. In a recent study, Kim and colleagues have focused on characterizing habitat location and distribution patterns to provide fundamental data for estimating habitat change in South Korea [22]. However, not enough is known about the genetic information of nutrias to estimate the relationship among nutria populations in South Korea.…”