Biodiversity Threats In Gibraltar


The establishment of stronger trade links with the British Empire outposts resulted in the arrival of innumerable exotic species en route from the colonies to the British Isles (Cortes & Abrines, 1994). Some of these species were eventually incorporated into the gardens of military dwellings in Gibraltar, where the climate was favourable. Among them were many species from South Africa, Australia and South America, and many of them still survive in the wild today. Most were harmless, colourful exotics, but a few species that were introduced into Gibraltar have proven to be serious invasives, whilst others are potential invasives. For a list of all alien species of flora, with their country or region of origin, please click here.

The majority of these alien plant species are located within gardens and urban green areas and do not pose a threat to the native species of flora. Nevertheless, some species have established themselves in the wild, with varying degrees of success, and some are invasive and are causing considerable damage to the local habitats. An action plan was drafted by the Gibraltar Ornithological and Natural History Society to address their control and removal.

Those species of concern that have become established outside garden areas are listed here.  Among these are several that are extremely resilient invasive plant species. The removal of these alien species of concern is an on-going process.

Gibraltar’s main legislative tool is the Nature Protection Act which locally came into effect on the 9th May 1991. This legislation is comprised of EU legislation and International Agreements, including:

  • Directive 79/409/EEC
  • Directive 92/43/EEC
  • Directive 2006/105/EC
  • Directive 2009/147/EC


The Nature Protection Act was created to provide for the protection of wild birds, animals and plants and for the designation and preservation of protected areas for the purpose of nature conservation and related matters. The Nature Conservation Area (Upper Rock) Designation Order 1993 subsequently includes sections dealing with the introduction of fauna and floral species which are not indigenous.

Invasive species surveillance monitoring is routinely carried out by the GONHS on terrestrial habitats whereas the Department of the Environment and its appointed marine consultants undertake surveillance monitoring of invasive species in the marine environment.