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Breeding success of 5 Cory’s shearwater Calonectris diomedea sub-colonies of Lavezzu Island (Lavezzi Archipelago, Corsica) was checked annually for 25 consecutive years from 1979 to 2004. Between 1989 and 1994, 4 ship rat Rattus rattus controls were performed in several subcolonies. In November 2000, rats were eradicated from Lavezzu Island and its 16 peripheral islets (85 ha) using traps then toxic baits. We compare cost (number of person-hours required in the field) and benefit (Cory’s shearwater breeding success) of control and eradication. The average breeding success doubled when rats were controlled or eradicated (0.82) compared to the situation without rat management (0.45). Moreover, the average breeding success after eradication (0.86) was significantly (11%) higher than after rat controls (0.75). Furthermore, the great variation in breeding success recorded among sub-colonies both with and without rat control declined dramatically after eradication, suggesting that rats had a major impact on breeding success. The estimated effort needed to perform eradication and checking of the permanent bait-station system during the year following eradication was 1360 person-hours. In contrast, rat control was estimated to require 240 or 1440 person-hours per year when implemented by trained and untrained staff, respectively. Within 6 yr, eradication cost is lower than control cost performed by untrained staff and confers several ecological advantages on more ecosystem components than Cory’s shearwater alone. Improved eradication tools such as hand or aerial broadcasting of toxic baits instead of the fairly labour-intensive eradication strategy we used would dramatically increase the economic advantage of eradication vs. control. Therefore, when feasible, we recommend eradication rather than control of non-native rat populations. Nevertheless, control remains a useful management tool when eradication is not practicable.

Climate variability is the variation around the average climate, including seasonal variations as well as large-scale variations in atmospheric and ocean circulation such as the EI Nino/Southern Oscillation (ENSO). Climate change operates over decades or longer. Changes in climate occur as a result of internal variability within the climate system and external factors (natural and anthropogenic). Although climate is always changing, over the past 10,000 years it has been both relatively stable and warm.

Small island states are the countries likely to be most vulnerable to climate variability and long-term climate change, particularly extreme weather and climate events (such as cyclones, floods and droughts) and sea-level rise. Many small island states share characteristics that increase their vulnerability, these include their small sizes, isolation,limited fresh water and other natural resources, fragile economies, often dense populations,poorly developed infrastructures and limited financial and human resources. To understand better the potential health impacts of climate variability and change in small island states and to build capacity to cope with climate change through adaptation planning, a series of workshops and a conference were organized by the World Health Organization (WHO) in partnership with the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP)(WHO 2000; Aron et al. 2003; WHO 2003). This report synthesizes the information presented and identifies key recommendations for improving the health sector’s capacity to anticipate and prepare for climate variability and change. There is ample evidence that many small island states currently are vulnerable to climate variability. Climate change projections increase the level of concern because models suggest that small island states will experience not only warmer temperatures, but also increased climate variability. The consequences of increased climate variability are likely to be related to changes in rainfall, soil moisture budgets, prevailing winds (speed and direction), regional and local sea levels and patterns of wave action. El Niño events are likely to strengthen the short-term and inter annual variations. In addition, global mean sea level is projected to increase by0.09 m to 0.88 m by 2100. To understand better the potential human health consequences o fthese projected changes, the following questions were addressed