SCIENCE
TUBBATAHA’S SHARKS
Before 2015, only a few studies had
been carried out to investigate the
sharks present in the park. In March
2015, as part of an effort to confirm all
shark species in TRNP, researchers
from LAMAVE in collaboration with
TMO made a call out to dive boats
for shark encounters captured in
images or on video. LAMAVE has been
operating in the Philippines since 2010
and today it is the largest independent
non-profit non-governmental
organisation dedicated to the
conservation of marine megafauna
and their habitats in the Philippines.
The collaboration between LAMAVE
and TMO is currently the biggest shark
study in the country.
While photos sent in by divers
provided vital information for
establishing past tiger shark
encounters, LAMAVE researcher
Ryan Murray went to live on the TRNP
ranger station and, together with the
rangers, set about rigging the park with
underwater cameras to see what shark
species were present and in what
numbers. Submissions from diversrevealed chance encounters with
tiger sharks within the recreational
diving range, whilst the remote
video cameras, which are mounted
on a metal frame and lowered into
the water by the team, allowed the
collection of information down to 100
metres, revealing a new perspective of
the park.
At least five different individual tiger
sharks have been identified (by their
first dorsal fin) from photos and videos
submitted by visiting divers. While
this established the presence of tiger
sharks in TRNP, it did not reveal howthey were using the park, and more
importantly, if the sharks were moving
outside its protected boundaries.
Previous research has shown that tiger
sharks are capable of making large
scale movements; one study showed
a tiger shark crossing the Atlantic
Ocean, travelling 6,500 kilometres
from northeastern US to the western
coast of Africa. Another study by a
research team in Western Australia
tracked a female tiger shark over
4,000 kilometres between Ningaloo
Reef in Western Australia and Sumba
Island, Indonesia. Long-distance
movements have implications for the
management and protection of tiger
sharks, as sharks initially encountered
in protected areas could be exposed to
fisheries outside protected waters, and
TRNP is no exception.
The park is the most successful
marine protected area in the
Philippines and is the country’s
largest strictly no-take zone, covering
97,030 hectares – an area larger than
Singapore (which is under 75,000
hectares). That’s very impressive, but
when we take into consideration thatABOVE: A female tiger shark swims away
after being fitted with a satellite tag, which
can be seen on her first dorsal fin
IMAGE: Alessandro Ponzo (LAMAVE)A study by a research
team in Western
Australia tracked a
female tiger shark over
4,000 kilometres between
Ningaloo Reef and Sumba
Island, IndonesiaSupported by