The impact and legislative framework of invasive mammals on Portuguese Macaronesian islands: A case study on Corvo, Azores

Abstract

The Portuguese government has awarded islands with more protection statutes than continental ecosystems, so it seems to recognise the exceptional biodiversity of the insular regions. However, the effectiveness of these protection statutes is questionable since, in most cases, no measures are taken to guarantee the protection against invasive alien species (IAS). This study reviews the current legislative framework addressing IAS at national, regional and local levels. Information on ecological and socio-economic impacts of IAS was used to analyse whether regional laws covering island ecosystems are ensuring the protection of their biodiversity. We detected some weakness in the Portuguese legislation: IAS are not the main focus, inconsistent terminology, vectors not targeted, a few diversity of ecosystems covered, no coordination of actions and no enforcement of management plans. In addition, the uniqueness of biodiversity on Macaronesian islands is not protected by the regional legislation. Although some non-indigenous species introduced on islands are currently threatening the integrity of their fragile ecosystems and the socio-economic spheres, they are not considered as IAS. A stronger strategic framework to address the overall impacts of IAS is required mainly in these Macaronesian islands whose one of the most imposing threat is the presence of these introduced species.