Hidden ecological risk from overlooked invasive crayfish species

A new study highlights the hidden ecological risk posed by narrow-clawed crayfish, an invasive species in the U.K. that has been overlooked by ecologists. Research published in Biological Invasions reveals that the narrow-clawed crayfish is as aggressive as the well-known signal crayfish, which is already considered a damaging invasive species worldwide.

Both species share similar appetites for aquatic plants, algae, invertebrates, and even fish eggs, and can pose significant threats to ecosystems. The study, led by James Hodson from the University of Leeds School of Biology, found that narrow-clawed crayfish are just as predatory as signal crayfish under various temperature conditions, from 9°C to 22°C (48°F to 72°F).

The narrow-clawed crayfish reached the highest relative impact at 17°C (63°F), consuming large quantities of prey and being more abundant. This finding is crucial for shaping management actions, as the average summer temperature in U.K. still waters ranges from 15 to 20°C (59 to 68°F). Researchers emphasize the need to prevent the spread of narrow-clawed crayfish and urge environmental regulatory bodies to identify and proactively manage potential invasions, particularly in the context of climate change.