General University News
The research team, which included researchers from Microwave Telemetry, Inc., the Cape Eleuthera Institute, and the Institute for Ocean Conservation Science at Stony Brook University, attached pop-up satellite archival tags to one male and 10 female mature oceanic whitetip sharks off Cat Island in The Bahamas in May 2011, and monitored the sharks for varying intervals up to 245 days. The tags recorded depth, temperature, and location for pre-programmed periods of time. At the end of the time period, the tags self-detached from the sharks, and reported the data to orbiting satellites. Their findings, published online today in the journal PLOS ONE, show that some of these sharks roamed nearly 2,000 kilometers from the spot where they were caught, but all individuals returned to The Bahamas within a few months.
“While the oceanic whitetip shark is one of the most severely overexploited shark species, it is also among the least studied because it lives much of its life far from land in the open ocean,” said Lucy Howey-Jordan, scientific liaison for Microwave Telemetry, Inc. and lead author. “Before this study and our ongoing research, very few of these sharks had been fitted with satellite tags, and the data we obtained will help establish new conservation measures."
“Although these sharks are relatively safe from fishing in Bahamian waters, our study shows their long-range roaming takes them across the boundaries of different countries and into the high seas where they still encounter fishing gear set for other species,” said Dr. Demian Chapman, assistant professor in the School of Marine and Atmospheric Sciences and assistant director of science at the Institute for Ocean Conservation at Stony Brook University. “If we want to continue to see these animals in our oceans, fishing nations will have to work together to protect this species, and monitoring of trade and enforcement measures will need to be coordinated on an international level.”
World renowned for its healthy shark populations and proactive conservation stance, The Bahamas is one of the few places left in the world where this open-ocean species can be found in relatively large numbers. In July 2011, during the timeframe of this study, The Bahamas banned all commercial fishing of sharks throughout the 630,000 square kilometers of surrounding ocean waters. The sharks now benefit from this protection, and the shark diving industry, a major contributor to the Bahamian economy, benefits from their presence in surrounding waters. Additionally, recent studies have shown ecosystem health is dependant, in part, on the presence of apex predators like sharks.
“The Bahamian government had the foresight to protect these and other species of sharks within their waters, starting with the longline fishing ban in early 90s, and culminating with the more recent shark sanctuary initiative,” said Edd Brooks, program manager of the Shark Research and Conservation Program at the Cape Eleuthera Institute. “This level of protection is vital for the continued existence of these important apex predators, and I hope that the example set by The Bahamas will encourage other nations to follow suit.”
This research was funded by Microwave Telemetry, Inc., the Cape Eleuthera Foundation, The Pew Charitable Trusts, and the Roe Foundation.
For more information on “Complex movements, philopatry and expanded depth range of a severely threatened pelagic shark, the oceanic whitetip (Carcharhinus longimanus) in the western North Atlantic,” please visit http://dx.plos.org/10.1371/journal.pone.0056588 after 5 p.m. EST on Wed., February 20.
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 United States and The Bahamas, for whom the Cape Eleuthera Institute provides hands-on research experience through their in-house research programs. For more information, please visit www.ceibahamas.org.
The Institute for Ocean Conservation Science at Stony Brook University is dedicated to advancing ocean conservation through science. The Institute transforms real-world policy while pursuing serious science, both of which are essential for ocean health. For more information, go to: www.oceanconservationscience.org.
Microwave Telemetry, Inc. manufactures reliable and accurate electronic devices for tracking avian and marine species using cutting-edge technologies developed at its facility in Columbia, Maryland, USA. The company’s continual effort to develop smaller and smarter devices is driven by the needs of researchers worldwide. For more information, please visit: www.microwavetelemetry.com.
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