A non native species is an animal or plant species which is recorded outside its distribution area, due to a natural reason or due to human activities. This species are interesting to spot on the coast, and to report to scientists and public authorities. Their progression rate of and new area(s) of occurrence provide really important informations to help to control and manage them !
- 1 - Because among these species, some (not all) are "invasive“. That means they can proliferate rapidly : their distribution area can expand widely and/or the abundance of plants or animals increases rapidly . And so, the installation of an invasive species in a new environment may have impacts for the hosting ecosystem ! In the Mediterranean, you may have heard about the two algaes Caulerpa racemosa and Caulerpa taxifolia ? In the Atlantic and North Sea, do you know the slipper limpet Crepidula fornicata ?
- 2 – Because looking for helps us to identify the most sensitive zones which may be more affected by biological introductions (for example, some zones next to some harbours...). Human activites dealing with the importation of non-native species, or shipping with the associated releases of ballast waters ... can explain some cases of introduction of non-native species.
- 3 – And because the studies of biological introductions of a “new immigrant" species, invasive or not, in coastal areas and the sea are scarce compared to the terrestrial habitats, there is a lack of data ! Species doesn’t care about our administrative boundaries, and reporting about these species in new areas helps to understand the spreading routes and mechanisms, from local to international scales, and makes sense for maritime European countries working together for the protection of the marine environment (Marine Framework Strategy Directive).
When and where ?
- Everywhere, all year long ! Make your observations along your coasts, walking, shipping or by scuba diving !