BALLAST BLOG – Invader of the Week – Asian Topmouth Gudgeon

Malin Group Ballast Blog

This weeks article looks at a species considered to be one of the most potentially damaging to enter Western Europe.

Native to East Asia, it was first recorded in Europe in the 1960’s and has subsequently spread throughout the continent, as well as in North Africa and parts of Central Asia. It was introduced to the UK from mainland Europe in 1984, and these are now 23 confirmed sites. It is suspected that the species either escaped from the aquaria trade or was deliberately introduced as fish bait.

The topmouth gudgeon severely impacts on other fish species through egg predation and consumption of invertebrates and plant life. It also carries a parasite which is a big threat to salmonids and cyprinids. Due to the potential for severe environmental and economic impacts if the topmouth gudgeon population is left unattended, prevention and eradication is being taken very seriously in the UK.

(Photo courtesy of