From:TheBahamasWeekly.com
Scientists and divers tag record number of threatened oceanic whitetip sharks in the Bahamas; now tracking them via satellite
By Shark Research and Conservation Program at the Cape Eleuthera Institute
May 26, 2011 - 12:16:18 PM
Figure 1 - A ‘pop-up satellite archival transmitter’ (black), and an experimental fin tag (grey), attached to an oceanic whitetip shark. The archival transmitter will log temperature, depth and ambient light level, prior to detachment from the animal, floating to the surface and transmitting the stored data via satellite to the research team. The fin tag provide accurate location data for up to eighteen months, after which the steel nuts will rust through and the transmitter will detach from the animal.
|
The oceanic
whitetip shark (
Carcharhinus longimanus) was once considered
to be one of the most numerous large vertebrates on the planet. Yet
ongoing exploitation of this species for it fins, for use in the Asian
delicacy shark fin soup, has caused precipitous population declines
in many parts of the world. This species has been especially hard-hit
in the northwest and western central Atlantic Ocean, where it is now
difficult to find them in significant numbers. Despite the inherent
difficulties in finding and studying large, relatively rare oceanic
sharks, an international team of researchers successfully satellite-tagged
a large number of these animals off Cat Island, The Bahamas, this month
in order to track their movements to enable more effective conservation
of this top ocean predator.
Edd Brooks, Annabelle Oronti and Sean Williams of the Shark Research
and Conservation Program at the
Cape
Eleuthera Institute
,
Lucy Howey-Jordan and Dr. Lance Jordan of
Microwave
Telemetry, Inc.
,
Stuart Cove and the staff of
Stuart
Cove’s Dive Bahamas
,
Dr. Demian Chapman of
Stony
Brook University
and Debra Abercrombie of
Abercrombie & Fish, undertook a
10-day expedition to Cat Island to conduct the first instalment of a
long-term project to study the movements and habitat use of oceanic
whitetips.
“I have been trying
to get down to the Cat Island aggregation since the Shark Research and
Conservation Program was founded five years ago, and now, with the incredible
support offered by Microwave Telemetry and Stuart Cove and his staff,
we have finally got our chance. This species is one of the most
endangered pelagic sharks in the world, yet virtually nothing is known
about its basic biology and ecology, something this project will hopefully
change.” said Edd Brooks, Program Manager of the Shark Research
and Conservation Program at
Cape
Eleuthera Institute
.
“This project has been a very unique collaborative initiative between
shark diving operators and scientists. In addition to Stuart Cove’s
generous support, we were very lucky to be assisted by Jim Abernethy
of
Jim
Abernethy’s Scuba Adventures
,
who helped locate sharks during a couple of slow days, and Vinnie and
Debra Canabal of
Epic
Diving
who
have been keeping an eye out for our tagged animals. The future
success of the project will depend in part on the ongoing support of
our partners in the shark diving industry.”
Figure 2 – “Lisa” a tagged oceanic whitetip shark, photographed by Jim Abernethy four days after her capture and showing no ill effects from her experience.
|
Oceanic whitetips grow to over 10 feet in length, but take at least
6-7 years to reach maturity, making them vulnerable to fishing pressure.
Over the 10-day expedition, the research team captured and tagged the
sharks with pop-up satellite archival transmitters (PSATs) to record
depth, temperature and light-level data which are later transmitted
to a satellite. The researchers then get emails that relay the shark’s
estimated position, dive history and temperature profile over the life
of the transmitter. Five of the 17 satellite tags deployed were experimental
fin tags that will provide accurate, and near real-time, geo-location
information over the next 18 months. Safety of the research team and
the sharks themselves was paramount during the study and all sharks
were held in the water during attachment of both types of satellite
tags. Three of the captured animals have since been spotted during
shark dives in the area and all appeared to be healthy and happy.
“The technology
to make this study a reality has been around for nearly 15 years and
it’s a shame that it took so long to begin a thorough study of this
dwindling species.” said Lucy Howey-Jordan, Scientific Liaison
at
Microwave
Telemetry, Inc.
“It required incredible efforts from our multidisciplinary team to
make this project happen. Hopefully, the data we collect will aid fisheries
managers in their decision making and give this species a real shot
of rebuilding.”
The Bahamas
is widely credited as being a leader in shark conservation after banning
longline fishing in the late 1990s. The opportunity to study the
wide variety of species that exist here, both in deep and shallow water,
in a relatively undisturbed state has put The Bahamas on the map for
shark researchers and filmmakers from all around the world.
“In many places, a large concentration of adult oceanic whitetips
relatively close to shore like this would have been targeted for their
fins and possibly fished out “ said Dr. Demian Chapman, the Assistant
Director of Science at the
Institute
for Ocean Conservation Science
based at Stony Brook University.
“The abundance of these threatened
sharks off Cat Island is a testament to the conservation ethic and ingenuity
of the people of The Bahamas”.
Dr. Chapman
also noted ongoing efforts of the
Bahamas
National Trust
,
Pew Environment
Group
and others
to strengthen shark conservation within the Bahamas.
“The
government of the Bahamas is in a unique position to build on the longline
ban by developing specific policies to protect sharks. This would solidify
the reputation of the Bahamas as a global leader in marine conservation
and would help ensure the survival of these top predators for future
generations”.
Figure 3 - An oceanic whitetip shark being held in tonic immobility following capture, measurement, DNA sampling and tagging. Tonic immobility is used to facilitate hook removal just prior to the animal’s release.
|
The project has been off to a successful start, and the first of the
deployed satellite tags have begun transmitting data on the shark’s
whereabouts and will continue to relay crucial habitat-use information
over coming months. In the meantime the research team has already
started planning next year’s trip with members of the local dive community
“The shark diving
industry provides vital, non-consumptive value for sharks in Bahamian
waters and injects a significant amount of money into the Bahamian economy”
said Stuart Cove, a local dive operator who provided much of the logistical
support for the trip.
“The Bahamas is at the forefront of this
rapidly growing industry and it is
essential that that we work with scientists and policy-makers to understand
and manage these important economic and ecological resources in a sensible
fashion.”
For more
detailed information or comment please contact Edd Brooks , the Program
Manager of the Shark Research and Conservation Program (
eddbrooks@ceibahamas.org Office Telephone - +1 242
334 8552
).
Institutional
Information:
Cape Eleuthera
Institute: Cape Eleuthera Institute is a marine field station situated
on Cape Eleuthera, Eleuthera The Bahamas. It undertakes research
on local environmental issues as well as acting as a host facility for
marine and terrestrial scientists and visiting education groups of all
ages. Cape Eleuthera Institute has especially focussed on developing
new methods of resource use and management applicable to the Caribbean,
such as effective use of solar energy and local recycling of waste organic
and other materials. Its sister organisation, The Island School
(www.islandschool.org), is a semester abroad program for high school
students from the US and The Bahamas, for whom the Cape Eleuthera Institute
provides hands-on research experience through their in house research
programs. These programs include shark research, flats ecology
and conservation, patch reef ecology and sustainable offshore aquaculture.
www.ceibahamas.org
Microwave
Telemetry, Inc.: Located in Columbia, Maryland, Microwave Telemetry,
Inc. has been providing satellite-tracking technology for avian and
marine scientists for over 20 years. Research using their technology
has aided in the conservation and management of dozens of species worldwide.
For more information, visit their website at
www.microwavetelemetry.com
Stony Brook
University Institute for Ocean Conservation Science: The Institute for Ocean
Conservation Science is dedicated to advancing ocean conservation through
science. We conduct world-class scientific research that increases knowledge
about critical threats to oceans and their inhabitants, provides the
foundation for smarter ocean policy, and establishes new frameworks
for improved ocean conservation.
www.oceanconservationscience.
org
Stuart Cove’s
Dive Bahamas: Originally opened in 1978, the operation has
grown to a fleet of fifteen dive vessels, with operations in 4 locations
around New Provience . The feature activity at Stuart Cove’s
is the “Extreme Shark Adventure”, a two-dive experience which provides
an up-close encounter with Caribbean Reef Sharks. As the company
has grown so has their commitment to conservation projects, especially
with regards to sharks. From our daily efforts to educate the
general public through our Shark Adventures, to hosting and assisting
research scientists and organizations, Stuart Cove’s is dedicated
to helping preserve the wonders of the underwater world.
www.stuartcove.com
© Copyright 2011 by thebahamasweekly.com -