Many people believe that the spread of IAS is a natural occurrence and that we should allow nature to take its course. For the IAs issue, we are only concerned with harmful species that are spread by human activity, either intentionally or unintentionally and become invasive. There are many pathways by which species can spread, but some of the most common ones are the trade of goods and materials, the shipping industry, and recreational activities.
Why are Invasive Alien Species a problem?
IAS are one of the biggest threats to biodiversity worldwide, and we need biodiversity! Native species evolve and adapt to form their own unique niche, and a delicate balance is required to keep all elements of the environment functioning in a healthy way. IAS alter that delicate balance. In many cases invasive species can displace a similar native species by competition or can carry a disease that can kill the native. The crayfish plague, carried by invasive crayfish, has resulted in the extinction of the white clawed crayfish in many European countries.
Impacts can also be economical, e.g. invasive alien crop pests can reduce agricultural yields. Biofouling shellfish, e.g. zebra mussel, can block water abstraction pipes.
Growing global trade and transport creates ever increased risks of spread. Once an IAS is established, it is usually impossible, or economically prohibitive, to eradicate. Management then becomes an ongoing issue, with a high cost. The estimated associated cost of IAS management in the EU is €12 billion per annum.
Invasive Alien Species (IAS)
Biodiversity is Good
Biosecurity is important