Eradication of introduced seabird predators and restoration of island ecosystems

Background/Question/Methods Seabirds are important marine predators with high metabolic rates and large populations. They are important in structuring marine food webs, and play an important functional role on land by transporting nutrients from marine ecosystems. Due to their low fecundity and sensitivity to direct and indirect human impacts, they are the most threatened group of marine species, representing 25% of marine extinctions and 30% of species at some risk of extinction.

Results/Conclusions Although they range widely at sea, most seabirds are dependent on islands and isolated coastal areas where they often form remarkably dense breeding colonies – colonies that may contain most of the world's population of that species. It is at these colonies and in the nearby waters that seabirds are both most vulnerable, and where focused and often simple conservation actions can make a big difference. Invasive animals are the largest cause of seabird endangerment and extinction (responsible for 25-30% of impact). They impact seabirds directly through predation, disturbance and competition for space, and indirectly via changes in vegetation, soil compaction, and erosion. Fortunately, these impacts can be reversed. Invasive animals have been successfully eradicated from islands on over 625 occasions, often followed by significant seabird population recoveries. In the last 10 years there has been a dramatic increase in the size and ecological complexity of islands from which invasive animals have been eradicated and new techniques promise further advances in seabird conservation. Efficient use of this powerful conservation tool requires more research on 1) which seabird species, under what conditions, will most benefit from eradication, and 2) the economic cost of eradication projects and the resulting increase in seabird populations