11 October 2024, Aleipata, Samoa - Nu’utele Island, situated within the Aleipata Island Group off the eastern end of Upolu Island, in Apia stands as a vital focal point for conservation efforts in Samoa and is recognised as a critical biodiversity hotspot as it holds intact native forests and significant populations of endangered land-birds, seabirds, and nesting turtles.
The island could serve as a sanctuary for several of Samoa’s threatened species, offering potential refuge from the introduced mammalian pests that plague larger inhabited islands however, the island's ecological integrity has been severely threatened by the introduction of invasive rat species and, more recently, feral pigs.
Historically, rats were inadvertently introduced to Nu’utele Island by early Polynesian settlers. The Pacific rat (Rattus exulans) is known to be present on the island, however and the black rat (Rattus rattus), introduced to Samoa by European explorers, has not been recorded on the island to date.
The invasion of rats has devastating consequences for native biodiversity as these hungry rodents rapidly multiply and wreak havoc on the island's fragile ecosystem.
Rats prey upon native bird and turtle eggs, chicks, and small reptiles, leading to the decline of endemic species such as the Samoa flying fox (Pteropus samoensis) and the white-throated storm petrel (Nesofregetta fuliginosa). Other important bird species are the vulnerable shy ground-dove and remnant populations of seabirds such as noddies and boobies. Moreover, rats consume seeds, fruits, and plant material, disrupting the island's vegetation structure and seed dispersal dynamics.
Feral pigs have been present on Nu’utele for some time with the population now appearing to be widespread and posing a significant threat to the ecological integrity of the island. Feral pigs are known to be ecosystem engineers, capable of removing the ground layer of native forests and changing the composition of tree species over time. They are also hungry consumers of animal protein and pose a critical threat to ground-nesting seabirds, turtles and land crabs.
Invasive species pose multifaceted threats beyond ecological disruption. They negatively impact stored food and crops, transmit diseases affecting human and livestock health, and cause damage to infrastructure.
Consequently, invasive species emerge as the primary menace to remaining biodiversity. Many species have faced extinction since human arrival, and surviving endemic plants, birds, and reptiles waver on the brink of disappearance. Communities in the Aleipata surrounding area and across Samoa depend on this biodiversity and the ecosystem services it provides to fortify their resilience against the impacts of climate change.
In response to these challenges, collaborative initiatives have been established under the regional Predator Free Pacific (PFP) programme of the Pacific Regional Invasive Species Management Support Service (PRISMSS), within the framework of the PRISMSS-Restoring Island Resilience (RIR) project, funded by New Zealand’s Ministry of Foreign Affairs and Trade (MFAT).
The operation is made possible through the collaboration between SPREP, Samoa Ministry of Natural Resources and Environment (MNRE) and Island Conservation (IC) through PRISMSS.
A community consultation led by MNRE and supported by IC as the PRISMSS Technical lead for the PFP programme was held on 24 September at the Aleipata district. The consultation gathered the Village Mayor, representatives of the Women’s committees, untitled men and the youth groups from each of the 13 villages of the district to inform and engage the community on the efforts towards eradicating both rats and feral pigs from the island.
Participants of the consultation were informed that seabird populations and other native biodiversity will recover once rats and feral pigs are removed, which promotes climate resilience by restoring the nutrient exchange between ocean and island, improving the health of the island and the reef.
Research confirms that reefs around rat-free islands have more fish, larger fish, and recover four times faster from bleaching events. The increase in seabird numbers will also benefit local fishermen and improve food security as crops like coconut, banana and papaya will no longer be damaged by rats and feral pigs.
Once invasive mammals have been removed Nu’utele could provide a secure site for translocating threatened landbird species such as the Island Thrush (Turdus poliocephalus samoensis) and the Samoan white-eye (Zosterops samoensis).
SPREP Deputy Director General, Ms Easter Chu Shing while delivering the keynote address during the community consultation commented “the removal of rats from Nu’utele Island was identified as a priority by MNRE and SPREP is glad to be able to support this work through our PRISMSS Predator Free Pacific programme with Island Conservation.”
“Removing rats from the island will create a safe haven for important species in Samoa as biodiversity is key for climate change adaptation as it reduces the vulnerability and increases the resilience of communities to the effects of climate change”.
By removing invasive species, and fostering community involvement, the project aims to safeguard Nu’utele's unique ecosystems and species, ensuring their long-term viability in the face of mounting environmental challenges.
“Importantly, the overarching goal is ecosystem-based adaptation, integrating climate change considerations into conservation strategies to enhance the island's resilience to future environmental pressures”, added the SPREP Deputy Director General.
The SPREP Deputy Director General informed community members attending the consultation that the successful implementation of predator eradication efforts will contribute to building climate resilience, improving livelihoods, and strengthen regional coordination for invasive species management by aligning with the objectives of the PFP in the PRISMSS RIR Programme as the initiative represents a significant step towards achieving lasting positive impacts for Nu’utele Island.
“A predator free Nu’utele will create a safe haven for important and endangered species with this conservation effort contributing to Samoa’s climate change resilience by protecting its biodiversity”.
The PFP programme, led by IC leads the charge in removing invasive predators from Pacific islands and restoring balance to delicate ecosystems. With support from BirdLife International, the programme is implementing activities to prevent extinctions and enhance ecosystem health and resilience.
The benefits of eradicating invasive mammals like rats and feral pigs from Nu’utele will significantly contribute towards the protection of threatened species including the Hawksbill turtle, the shy ground dove and possibly the Manumea. Reef health will also improve from the eradication efforts which help build climate resilience.
Mr Paul Jacques, an Island Restoration Specialist with IC commented that “restoring the health of islands also restores the health of their surrounding reefs and many millions of seabirds have been lost from islands due to predation by invasive rats and pigs”.
“Through eradication and restoration of island ecosystems we see renewed abundance of seabirds, land crabs and turtles, species that join deep ocean, reef and islets in the ongoing cycle of renewal.”
Mr Jacques added the project proposes a multi-faceted approach to address the challenges posed by invasive rats and feral pigs, which has proven effective in large-scale rat eradication projects on islands with similar ecological characteristics.
“Eradication of feral pigs will be a prerequisite of rodent eradication as feral pigs would otherwise consume the rat bait and cause the rat eradication to fail,” added the IC island restoration specialist.
“The biodiversity of Nu’utele is critically threatened by the continued presence of invasive rats and feral pigs and by eradicating these pests we can restore the biodiversity of the island, improve food security for local people and strengthen the resilience of the Aleipata region in the face of our changing climate”.
Biosecurity measures will be implemented to prevent rat and feral pig reintroduction, including regular monitoring and maintenance of surveillance systems. Additionally, post-eradication monitoring will be conducted to evaluate the ecological recovery of Nu’utele Island's native ecosystems and ensure the long-term success of the eradication effort.
“We are thankful for these efforts to help our community better manage both rats and pigs on the island as we know the impact they have on our corals and ocean, which we rely on for not only our own sustenance but also for selling fish and supporting our families and the community,” said Mr Tuare Pai’aaua, a community member of Aleipata.
The on-going project actions for the eradication initiative represents a crucial step towards restoring the ecological balance of this biodiversity hotspot through a concerted effort to eradicate invasive mammal populations as activities aim to protect the native flora and fauna of the island and preserve its unique ecosystems for future generations.
“It is encouraging to see that all these organisations are willing to help us manage the pigs and rats on Nu’utele as we now understand after this community consultation the kind of damage these invasive species are doing n the island and how it can impact our environment and the community as well,” said Ms. Losivale Konelio, a participant from the Saleaumua community.
The PRISMSS RIR project aims to improve Pacific Island countries livelihoods and resilience to climate change by reducing the impact of invasive species on natural and agricultural ecosystems. The PRISMSS RIR works with 15 Pacific countries and territories across the region and the Nu’utele operation is one of the activities supported by the project.
SPREP through the PRISMSS RIR project will facilitate knowledge exchange and capacity building among project partners and stakeholders to enhance conservation outcomes and assist in developing adaptive management strategies based on scientific research and best practices. The PRISMSS team will also support project planning and implementation through policy guidance and regulatory support.
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About PRISMSS
The Pacific Regional Invasive Species Management Support Service (PRISMSS) is a coordinating mechanism designed to facilitate the scaling up of operational management of invasive species in the Pacific. PRISMSS brings together experts to provide support within the Pacific region with a focus on protection of indigenous biodiversity and ecosystem function. As a service provider, PRISMSS provides a comprehensive suite of support services in a cohesive, effective, efficient, and accessible manner to Pacific Island countries and territories.
Restoring Island Resilience (RIR)
The PRISMSS - Restoring Island Resilience (RIR) is a New Zealand-PRISMSS collaboration project that aims to improve Pacific Island Countries and territories livelihoods and resilience to climate change by reducing the impact of invasive species on natural and agricultural ecosystems through the five PRISMSS programmes.
Predator Free Pacific (PFP)
The PRISMSS Predator Free Pacific (PFP) programme, led by Island Conservation leads the charge in removing invasive predators from Pacific islands, restoring balance to delicate ecosystems. With support from BirdLife International, the collaborative efforts are focused on preventing extinctions but also enhancing ecosystem health and resilience.
For further information please contact Mr Nitish Narayan, PRISMSS Communications & Liaison Officer on [email protected]