Bertarelli Summer2024 FINAL - Flipbook - Page 24
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of the most southern tip of the Indian
subcontinent, there lies a chain of islands quite unlike any
other. These are the Chagos Islands, a remote archipelago that
comprises seven atolls and more than 60 low-lying islands where
the land looks like it is all but guaranteed to melt into the sea at
any moment. Covered in tropical forest and surrounded by some
of the most biodiverse coral reefs in the world, these islands are both beautiful
and under threat.
OME 1,000 MILES SOUTH
island ecology in the Caribbean and Asia and
is the Caribbean Alliance director for Re:wild.
They talked about island connections, their
“aha” moments, and what they hope for the
future of island conservation.
To start, I think it is helpful to establish what we
mean by invasive species in the island context.
Pete Carr: Let me first reintroduce islands.
Islands make up about 5 percent of the global
terrestrial landmass. But islands also host an
estimated 40 percent of all globally endangered
and threatened species. Unfortunately, islands
have also hosted about 60 percent of all known
extinctions since the 1500s. And one of the driving reasons for these extinctions and losses of
biodiversity are alien, invasive species. I say
“alien” because they shouldn’t be there. And
“invasive” means that they come in and they
take over.
One of the solutions for these invasive species is eradication. I think that if we were talking about this 25 years ago, we might say that
eradication on these kinds of oceanic islands is
enough to save the islands, help the people, protect their surrounding oceans, and save nature.
For me, a key group are seabirds. For lots of
the oceanic islands, too, seabirds are what make
their ecosystems tick. That’s been the focus of
my research in the Chagos Archipelago.
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Rising seas and the effects of climate change
on the world’s oceans are urgent and present dangers to the Chagos Archipelago, as do
invasive species—and in particular, rats. These
rodents, brought to the islands by colonists in
the 18th century, decimated the seabird population, which in turn led to fewer nutrients making
it into the coastal seas, starving the coral reefs.
These islands’ story reveals why conservation
efforts to safeguard island ecosystems need to
encompass both the land and the sea together.
But Chagos is by no means alone in this
experience. In the Caribbean, too, human colonial occupation brought with it invasive species that have had an indelible affect on the
land and the sea. These invasions spark trophic
cascades: Rats kill the seabirds, no seabirds
means fewer droppings into the water, and
fewer droppings means less nutrients for coral
to grow and thrive. But, as coral scientist Casey
Benkwitt explains, scientists like her wouldn’t
necessarily notice this kind of connection just
by looking at a reef without collaborating with
conservation scientists working on land.
To explore these collaborations and how
they can benefit island and ocean restoration,
Benkwitt came together with two other leading
figures in conservation, Pete Carr, whose work
focuses on eradicating invasive species in the
Chagos Islands, and Jenny Daltry, who studies
