New research centre to tackle problem of invasive crayfish

Czech crayfish are in trouble, and a new multimillion-crown research centre is coming to their rescue. The project aims to reduce the threat of rival crayfish species brought here from America and restore the indigenous population, while at the same time being of practical benefit to the water system.

The American crayfish was originally introduced in Europe as a restocking measure, because it was immune to a serious disease that killed off much of the native European crayfish population. Its effect though was to wreak havoc on Czech streams and ponds, as the director of the Research Institute for Fish Culture and Hydrobiology, Pavel Kozák, told me.

American crayfish, photo: David Perez, CC BY 3.0 Unported

“They spread very quickly, they reproduce and grow more rapidly, and the main problem with the American species is that while they are less sensitive the crayfish plague, they are carriers of it. So they carry the problem that has caused the native crayfish mortality.”

Now a new research centre under the auspices of the University of South Bohemia is beginning a major project to confront that problem. The centre will take two years to complete and will cost 370 million crowns, largely paid for through EU funding. The crayfish issue will be at the top of its agenda.

“The main research now is focused on restocking native crayfish in new locations and making sanctuary areas for them, protecting the native crayfish and trying o eliminate the negative impact of the non-native species.”

Crayfish play a large role in freshwater habitats, being both major predators and important prey. They purify water by eating dead matter, and their sensitivity to the quality of the water provides other benefits to man.

“They have very good receptors for sensing any changes in water quality. And we have systems that can record their heart activity and changes in their heart activity, so we can make equipment that will tell us if the water quality is good or if it changes.”

The hydrobiology institute has already been working with the Šumava National Park for the last nine years, monitoring the crayfish population and looking for an appropriate location for a sanctuary where they will be safe from the non-native species. But crayfish will not of course be the only subject that the new research centre will study.

Native crayfish, photo: Lubomír Popovič

“Crayfish research is only one part of what the new centre will do; there are also other focuses like fish meat quality, technology of caviar production and innovation of systems for monitoring water quality.”

The introduction of New World plants and animals very often causes large problems in the Czech Republic as elsewhere. The jellyfish-like Pectinatella arrived here only six years ago and has spread across the country, while a small American crustacean has destroyed native micro-invertebrates all over Europe. The new hydrobiology centre will be only one of many projects dealing with this issue in the Czech Republic.