PROJECT DESCRIPTION
BACKGROUND
The Porto Santo Islets are a group of small Portuguese islands located within the Madeira archipelago, 43 km northeast of Madeira. The islands are part of the Autonomous Region of Madeira. The largest of the islands is Porto Santo Island, which is about 11 km long and 6 km wide. The project targeted the Natura 2000 site of the Porto Santo Islets: Ilhéu de Porto Santo e área marinha envolvente. The site is made up of a terrestrial area of vegetated sea cliffs and the marine area around the islets. The area is home to a large number of species endemic to the Macaronesian coasts, notably seabirds, land snails and plants, many of which are included in the Annexes to the Habitats and Birds Directives. Since the discovery of Porto Santo Island, these species and habitats have come under increasing threat from the spread of invasive alien species and human activities. Appropriate habitat management is therefore essential for the long-term conservation of biodiversity on and around these islands.
OBJECTIVES
The main objective of the LIFE Ilhéus do Porto Santo project was to remove threats to the natural ecosystems of the Natura 2000 site of the Porto Santo islets and to improve the conservation status of species endemic to this region. The project planned to research the distribution, density and conservation status of endangered species of seabirds, terrestrial molluscs, plants and arthropods in the project area. It would also explore ways of tackling the problem of artificial lights from Porto Santo Island, which can disorientate seabirds. A programme of conservation measures specific to the endemic species was planned, including the control of rabbits, mice and invasive plants, and the establishment of quarantine measures to prevent the (re)introduction of exotic species, particularly rats (Rattus sp.) Endangered indigenous plants would be reinforced and trails introduced to control the human impact on biodiversity.
RESULTS
The project LIFE Ilhéus do Porto Santo carried out a series of measures to control and eradicate introduced herbivores and rodents, as well as invasive alien flora, in order to create conditions for the establishment and expansion of local endemic flora. The measures also helped increase knowledge of the biology/ecology and taxonomy of the target species, while monitoring showed how the target groups respond to the removal of the invasive alien species. It also identified key marine and land areas for the target species.
The project site included the entire land area of the six islets of Porto Santo and the marine area surrounding the Cima and Cal Islets. At the beginning of the project, several threats directly or indirectly related to current or past human activities were identified. These could lead to the degradation of a range of habitats found in the Natura 2000 network site and the species of seabirds listed in Annex I of the Birds Directive and species of terrestrial molluscs and plants listed in Annexes II and IV of the Habitats Directive. The threats included the accidental or intentional introduction of invasive rodents and plants, uncontrolled human use of land, lack of knowledge and ecologically awareness, and the impact of urban infrastructures.
The project organised actions across all groups of habitats and species (such as the eradication of invasive alien species) and actions specifically directed towards those species whose conservation status was cause for greatest concern (seabirds, molluscs and plants). Based on their conservation status, 14 target species were chosen, including six species of seabirds (Puffinus baroli, Sterna hirundo, S. dougalii, Calonectris borealis, Bulweria bulwerii and Hydrobates castro), four terrestrial molluscs (Hystricella turricula, Idiomela subplicata, Caseolus commixtus and C. calculus) and four plants (Monizia edulis santosii, Sideroxylon mirmulans, Phagnalon lowei and Chamaemeles coriacea).
The project led to the drafting and approval of new regulations and management documents including:
Specifically, the project eradicated rabbits in Ilhéu de Cima and mice in Ilhéu da Cal, along with other introduced rodents. It furthermore removed introduced invasive alien plants such as agave (Agave americana) in Ilhéu de Cima and tree tobacco (Nicotiana glauca) in Ilhéu de Cima and Ilhéu de Ferro. It also reduced the population of Atlantic yellow-legged gull (Larus michahellis) by controlling their eggs in the different Islets. Other conservation measures included the collection, storing and germination of seeds of 47 taxa of five islets at the Madeira Botanical Garden Seed Bank as well as the reintroduction of indigenous plants (> 120), such as Euphorbia piscatorial, Sideroxylon mirmulans, Monizia edulis and Phyllis nobla. Finally, the project increased vegetation cover on two islets (Cima and Cal) where the invader rodents were removed. These measures led to an increase in the population size and distribution area of the target species of terrestrial molluscs.
The LIFE project moreover contributed to our knowledge of the presence of two new habitats of the Habitats Directive. Thermo-Mediterranean and pre-desert scrub, and Olea and Ceratonia forests were discovered and a plant sub-species (Monizia edulis santosii) new to science was described. At the target Islets new taxa were recorded for plants (up from 94 to 173) and terrestrial molluscs (increased from 33 to 60). Furthermore, a network of meteorological stations was installed and the chemical and organic proprieties of the soil outlined to support ecological modelling. The taxonomy of endemic terrestrial snail species of Porto Santo islets were clarified using molecular analysis and the ‘Lazarus species’ land snail (Serraturotula acarinata) was rediscovered. New taxa of arthropods were recorded for the islets of Porto Santo, and marine areas important for the little shearwater and Cory’s shearwater were identified.
A plan for minimising the negative effects of urban lighting on marine birds involved all the main stakeholders; awareness campaigns and two forums were held on the subject. The project also implemented a programme for collecting marine birds blinded by lights, with the involvement of the local community. A welcome centre for environmental awareness activities was set up and two promotional events were held in Ilhéu de Cima. Around 7 000 people were reached through dissemination activities carried out in schools and public venues.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).
