農業: Coypu are presently regarded as a pest species in Italy due to the damage they cause to rice farms. In a 2003 written communication, Piero Genovesi calculated that between 1996 and 2000, coypu caused 14 million euros in damage, and further losses from each year are projected to rise 9-12 million euros
捕食: Coypu eat native freshwater mussels. Some native fish species which lay their eggs in these mussels have become locally extinct. Two fish species predicted to be threatened in this manner are the Nippon-Bara-tanago or Japanese rose bitterling (Rhodeus ocellaus kurumeus) and the vulnerable Itasenpara or deepbody bitterling (see Acheilognathus longipinnis in IUCN Red List of Threatened Species), are listed in the Japanese Red Data Book of endangered species. A. longipinnis is endemic to small parts of Honshu and is a Japanese national natural treasure (Tatsuzawa, S., pers. Comm., 2004).
農業: Coypu cause minor damage to river and pond systems (Tatsuzawa, S., pers. comm., 2004).
降低本地生物多樣性: Coypu eat water plants that sustain native insect fauna. This has caused the local extinction of many insects that depend on the natural flora, including some species of dragon fly. One dragon fly species threatened with extinction is the critically endangered or Bekkou-tombo (see Libellula angelina in IUCN Red List of Threatened Species). Bekkou-tombo is related to species of painted grasshawk. It is endemic to Japan and is a Japanese national natural treasure (Tatsuzawa, S., pers. Comm., 2004).
農業: Coypu damages the sugar beet crop in the Netherlands and is therefore being considered a candidate for eradication by European agencies. (Litjens, 1980; in Carter, 2007)
United Kingdom (UK)
威脅瀕危物種: Coypu added to the decline of cowbane Circuta virosa, whicih is now a Nationally Scarce species in Britain. (Gosling and Baker, 1989)
滋擾人類: Coypu disrupted drainage systems in East Anglia due to their extensive borrow systems in river banks, and thus caused a flood risk. It also damaged agricultural crops (Gosling and Baker, 1989)
降低本地生物多樣性: Myocaster coypus destroyed large areas of reedswamp (Gosling and Baker, 1989)