NARRATOR: What chain of events led to one of the biggest shark
invasions on Earth, culminating in the first two attacks
in Ascension's history?
The focus and tenacity of these events
catch the attention of global shark
attack expert George Burgess.
GEORGE BURGESS: Well, what makes Ascension
Island's situation so different, of course,
was first, its isolation.
And being as it's a small island with a small population,
one would think the chance of shark attack would be reduced.
And the species involved, which in this case,
was the Galapagos shark, a species that is not implicated
in shark attack all that often.
That suggested that something might have changed.
NARRATOR: Ascension has always been home to the Atlantic's
apex predators.
But now, the food chain has tilted out of balance.
The first clue is born by the sea itself.
The south Atlantic currents carry enormous predatory fish
like barracuda, marlin, and giant wahoo all over the ocean,
and Ascension Island is a major junction.
The bounty of this vibrant food chain, in turn,
attracts sharks, hundreds of them.
The schools that arrive join an already
healthy local population.
For any shark living at or passing Ascension,
there is a selection of big, tasty fish to eat.
For any shark to migrate to Ascension
takes serious commitment.
Once they reach the island, these sharks
are desperate to replenish their reserves.
Tigers, hammerheads, mako, and even the infamous great white
all visit these shores.
But the most prolific species found in these waters
are the resident Galapagos sharks.
A member of the requiem family, which
includes around 60 relatives, all with similar features.
These fast, gregarious pack hunters
are always on the search for food
and can follow prey across entire oceans.
Ever since Darwin set foot on Ascension,
sharks and humans have unwittingly agreed to a truce.
With enough food to go around, the shark population
has always been peppered more than two
miles offshore, spread out along the deep ocean drop off.
But for some reason, this population recently converged
on Ascension's shores.
Why?
A disturbing convergence of the man made kind.
Big game fishing.
Tales of Ascension's giant game fish
attract sports fishermen and trophy hunters
from all over the world.
This is high stakes fishing.
A trip out here costs over $50,000.
If you hit the jackpot, you secure
the trophy of a lifetime, plus a 400 pound yellowfin
valued at up to $12,000.
These are the same fish that the sharks are out to get.