The Environment Agency (EA) has outlined the ten biggest threats to the
water quality of the UK's lakes and rivers.
Representatives from the organisation have insisted that invasive species and plants are costing the country nearly £2 billion each year.
This huge sum is required to repair the damage caused to riverbanks and buildings, as well as boosting flood controls. The pests are also making it increasingly difficult for Britain to meet EU waterway standards.
Non-native killer shrimp were highlighted as one of the worst offenders, while plants including water primrose and floating pennywort are also causing problems in the environment.
Despite claiming that the UK's rivers are in the best shape for 20 years, the EA's invasive species expert Trevor Renals said work needs to be done to stop the influx of rogue creatures.
"If we don't control invasive species, we risk losing some of our precious native species and incurring even more clean-up costs," he remarked.
Last week, the EA set up a number of traps in Yorkshire waters to see if the county has been infested by killer shrimps.
Posted by Lauren Steadman