Bertarelli-Annual-Report-2023-R9-low (1) - Flipbook - Page 39
Our Impacts in 2022
Marine Science 2022
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Collectively, these results reveal how rat introductions
disrupt nutrient flows among pelagic, island and coral reef
ecosystems. Removing invasive rats will therefore recover
seabird populations and all the benefits they provide
for islands and reefs. Research on existing eradication
projects show that seabird nutrients return to islands
and coral reefs within 16 years of rat removal. However,
de-ratting needs to be combined with the restoration of
native island vegetation. Models from the seabird team
show that restoring just 1 km2 of abandoned coconut
plantation to native forest and savannah could more than
double the number of breeding pairs of seabirds in the
Chagos Archipelago.
This body of science has informed and motivated plans for
re-wilding tropical islands, as a vital conservation action
to restore biodiversity and build resilience for vulnerable
ecosystems in a rapidly changing climate. The research
was central to a white paper produced by Re:wild that was
subsequently published as a peer-reviewed paper (Sandin
et al., 2022). In March, the Island-Ocean Connection
Challenge was launched at the Our Ocean summit in
Palau that aims to restore 40 globally significant islandocean ecosystems from ridge to reef by 2030 to benefit
people, wildlife and our planet. In July, the islands and reef
team collected data alongside the eradication of invasive
rats on Tetiaroa Atoll in French Polynesia. In October,
the team and collaborators ran a workshop to consider
priorities for re-wilding across Indian Ocean islands at the
WIOMSA conference in South Africa. At the same time,
programme scientists collaborated with the Seychelles
Islands Foundation as part of the Monaco Explorations
expedition to Aldabra, where knowledge exchange is
underway to inform their re-wilding efforts. In the Chagos
Archipelago, the Chagos Conservation Trust progressed
their ‘Healthy Islands, Healthy Reefs’ programme with
research into interactions between land crabs and rat
bait. In collaboration with Marine Science programme
scientists, this programme is working to complete the
detailed rat eradication plan and progress the vegetation
management plan that are the foundational for re-wilding
the Chagos Archipelago.
References: Benkwitt, C.E., Carr, P., Wilson, S.K., Graham, N.A.J. (2022) ‘Seabird diversity and biomass enhance cross-ecosystem nutrient
subsidies’ – Proceedings B [seabirds]. DOI: https://dx.doi.org/10.1098/rspb.2022.0195
Sandin, S.A. et al. (incl. Graham, N.A.J.) (2022) ‘Harnessing island–ocean connections to maximize marine benefits of island conservation’
https://doi.org/10.1073/pnas.2122354119