The impact of Invasive non-native species on the Freshwater Envrionment.
Welcome to day two of #INNSWEEK 2022. INNS Week is a national initiative to raise awareness of the negative impact of invasive species across the UK. Each day we will be discussing a different theme. Today we will be talking about the impact of INNS on the freshwater environment.
What is a freshwater environment?
Freshwater environments include lakes, ponds, rivers, streams and becks. Freshwater ecosystems only account for 3% of the worlds surface but are a crucial habitat for many organisms. As you can imagine, working on the River Tees and its tributaries, a lot of our work revolves around freshwater environment. The Tees is home to many diverse fish, plant, and crustacean species.
INNS Impact
Invasive non native species are one of the top 5 causes of decline in biological diversity in the world. Invasive species are capable of causing extinctions of native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. When invasive species are present in terrestrial environments, they cause a negative knock on effect to the native species present on the land.
Example
Unfortunately, we do have a presence of a few different invasive non native species spread throughout the catchment in the rivers and around the freshwater environments. One invasive species that causes a lot of problems is the American Signal Crayfish (pictured below). Signal crayfish were brought to the UK from America for use in restaurants and food shops. There was accidental (and deliberate) releases, which has resulted in establishment of signal crayfish in our rivers.
So what's the problem?
American signal crayfish cause huge problems to our native species specifically the white clawed crayfish. As well as bringing disease which kills our native crayfish off, they also eat a lot of other wildlife such as fish eggs. They can walk up to 2km a day along riverbanks meaning they can easily spread, with females producing up to 200-400 eggs each cycle!
Control
Unfortunately, when it comes to control signal crayfish, there aren't a lot of options. One option is to use trapping (such as bait trapping), however, this does not make a large impact on huge population sizes. Other methods may prove difficult, as affect other native species.