Overview
- The goby is established in the Oberweser, Fulda and Werra in Hesse, and reports from North Rhine-Westphalia say it now occurs in many waters there.
- Fisheries experts say eradication is no longer possible and officials in Hesse require anglers to keep any gobies they catch.
- Managers are trying to hold numbers down by stocking predators, including a recent release of 600 trout into the Weser by a local club.
- Native predators such as pike, zander, perch, catfish and trout eat gobies, though scientists say wider ecosystem effects remain uncertain.
- The species spreads along shipping routes and thrives in warm, slow water, which helps explain rapid growth in rivers and lakes but not in cold, fast brooks.