Alligatorweed, a highly problematic invasive plant species originating from South America, has been spotted in Japan's northeastern Tohoku region for the first time, sparking worries among local farmers and officials. Its presence has been a significant issue in western Japan, where the weed's vigorous growth has hindered river maintenance and agricultural activities, leading to concerns about potential widespread damage.
With agriculture being a primary industry in Fukushima Prefecture, officials are urging the public to report any sightings of the troublesome alligatorweed promptly. The plant, which can grow over 1 meter tall and forms dense mats with roots extending over 50 centimeters, poses a severe threat to native species as it can outcompete them and disrupt drainage systems, as seen in cases like the clogging of drainage pipes on Lake Biwako in Shiga Prefecture.
Having been designated as an invasive alien species by Japan's Environment Ministry in 2005, alligatorweed's strong reproductive capabilities and adaptability to both land and water environments make it particularly worrisome for local ecosystems and agricultural productivity. In response to the weed's discovery in Fukushima Prefecture, authorities have mobilized efforts to eradicate the plant by encouraging farmers to implement preventive measures such as using herbicides and fine-mesh nets on rice paddy water inlets to contain its spread effectively. Despite various prefectures struggling to control the invasive species due to its rapid growth, some regions like Saga Prefecture have resorted to labor-intensive methods like manually removing and incinerating the plants to combat their proliferation.