Bertarelli-Annual-Report-2023-R9-low (1) - Flipbook - Page 16
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Bertarelli Foundation
Island Reef Connections
Lead investigator: Prof. Nick Graham,
Lancaster University
When seabirds forage at sea, they deliver large
quantities of nutrients back onto the islands on which
they roost and breed. The introduction of the invasive
black rat (Rattus rattus) has caused the decimation of
seabird populations on the islands it had invaded. With
seabirds gone, the precious nutrient subsidies from
their guano no longer percolates through the islands
to fertilise adjacent reefs and support the fish and
other animals that live amongst them. The loss of these
supplementary nutrients affects the resilience and
recovery rate of reef communities in the face of other
human anthropogenic factors, such as climate change.
Seabird guano boosts nutrient cycles and affects
island ecosystems, coral reef ecology, and how coral
reefs form and change over time. As expected, these
important nutrients can increase plant biomass on land
and the abundance of land invertebrates. Research
by this team has also shown how seabird guano can
enhance coral reef productivity, biodiversity, and how
they work. The team are conducting this research
in the Chagos Archipelago, Seychelles, and French
Polynesia, incorporating into their study sites, islands
with and without rats, and those with ongoing rat
eradication programmes. The research will help inform
tropical island conservation and restoration efforts all
around the world.