Invasive Species Specialist Group

The Invasive Species Specialist Group (ISSG) is part of the Species Survival Commission (SSC) of The World Conservation Union (IUCN). The ISSG is a global group of 146 scientific and policy experts on invasive species from 41 countries. Membership is by invitation from the group chair, but everyone's participation in the discussion on invasives is encouraged. In addition, to its headquarters in Auckland, New Zealand, ISSG has three regional sections in North America, Europe, and South Asia.

ISSG provides advice on threats from invasives and control or eradication methods to IUCN members, conservation practitioners, and policy-makers.

The group's activities focus primarily on invasive species that cause biodiversity loss, with particular attention to those that threaten oceanic islands.

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The Invasive Species Problem

Increasingly, global trade and communication are directly contributing to the mixing of faunas and floras across biogeographical boundaries. To describe this new epoch of widespread anthropogenic influence, some researchers have suggested the term Homogocene.

Species suddenly taken to new environments may fail to survive but often they thrive, and they become invasive. This process, together with habitat destruction, has been a major cause of extinction of native species throughout the world in the past few hundred years. Although in the past many of these losses have gone unrecorded, today, there is an increasing realisation of the ecological costs of biological invasion in terms of irretrievable loss of native biodiversity. All habitat types in all climate zones can be affected. Protected Areas are not immune. See for example, a paper on the Scale And Nature Of Invasive Alien Species Threats to Protected Areas and a short paper on Global Lessons. While the underlying causes of IAS threats are significant and global in nature the threat can effectively be dealt with at the local site level, especially through prevention, early detection and rapid response.

Invasive species are organisms (usually transported by humans) which successfully establish themselves in, and then overcome, otherwise intact, pre-existing native ecosystems. Biologists are still trying to characterise this capability to invade in the hope that incipient invasions can be predicted and stopped. Factors may include:an organism has been relieved of the pressures of predators or parasites of its native country; being biologically "hardy", for example, has short generations and a generalist diet; arriving in an ecosystem already disturbed by humans or some other factor. But whatever the causes, the consequences of such invasions - including alteration of habitat and disruption of natural ecosystem processes - are often catastrophic for native species.