Invasion and Dispersion of the Exotic Species (Decapoda Cambaridae) in Yeongsan River Basin, South Korea.

The introduction of exotic species negatively affects the distribution and interactions within local biological communities in an ecosystem and can threaten ecosystem health. This study aimed to provide the basic data required to manage in the Yeongsan River basin. We identified the dispersion pattern and evaluated the ecosystem risk of this newly introduced species. The distribution survey investigated populations at 25 sites in the Yeongsan River basin over a four-year period. The initial introduction occurred in Jiseok Stream. The larvae of were most abundant in areas with a dense aquatic plant cover, whereas adults preferred silt/clay areas. The alterations in the water flow by the river refurbishment project (carried out in 2012) increased their preferred habitats and contributed to dispersion. However, stable isotope analysis showed that the dispersion has had little effect on the freshwater ecosystem. The interrelationship between (i.e., larvae and adults) and other biological communities has been limited. Although the rapid dispersion by in the Yeongsan River basin has not impacted the freshwater ecosystem, further ecological information is required on how to manage beyond this early stage of invasion.