UM Rosenstiel School researchers evaluated movements of highly mobile sharks in relation to protected areas
Researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science published new findings that suggest the expansion of protected areas into U.S. federal waters would safeguard 100 percent of core home range areas used by three species of sharks tracked in the northwestern Atlantic Ocean.
The study investigated the core home range of 86 bull, great hammerhead and tiger sharks tagged in waters off south Florida and the northern Bahamas to understand if these highly mobile shark species might benefit from spatial protection, such as marine protected areas (MPAs). The team examined shark movements in core habitat use areas, or CHUAs, where the sharks were spending the majority of their time, in relation to zones that prohibited fishing or were these sharks were already fully protected within areas of the U.S. and Bahamas exclusive economic zones (EEZs).
"There are concerns that spatial protections may not benefit large sharks since they are highly mobile and likely to regularly move in and out of MPAs," said study co-author Neil Hammerschlag, a research assistant professor at the UM Rosenstiel Marine School and UM Abess Center for Ecosystem Science and Policy. "While it's not feasible to protect highly mobile species wherever they go, our findings suggest that significant conservation benefits can be achieved if they are protected in areas where they spend the majority of their time, such as their core habitat use areas."
The results show that none of the tracked bull shark's regional CHUAs were in areas that are fully protected from fishing, and for the great hammerhead and tiger sharks tracked, only 18 percent and 35 percent, respectively, of their core use areas were currently protected. The study also found that the majority of the CHUAs utilized by all three shark species were within the U.S. EEZ.
"Our results will help enable policy makers to make more informed decisions when developing conservation plans for these species, particularly when considering a place-based management approach," said UM Rosenstiel School alumna Fiona Graham, the lead author of the study.
In 2011 the Bahamas declared a ban on all commercial shark fishing in its more than 650,000 square kilometers (251,000 square miles) of waters under their federal EEZ. The state of Florida enacted new measures in 2012 to fully protect four shark species, including tiger and great hammerhead sharks, by prohibiting their harvest and possession in state waters. These new findings have important implications for marine conservation and spatial planning, such as to better evaluate the effectiveness of current, and placement of future MPAs, according to the researchers.
Current research has shown that waters off Florida and the Bahamas are important pupping and feeding grounds for several sharks, providing them with the critical habitat required for the conservation of these slow-to-mature ocean animals.
Many shark populations are threatened worldwide due to overfishing, a trend that is largely driven to fuel the shark fin trade as well as from accidental bycatch from fishing operations. Populations of hammerhead sharks in the northwest Atlantic and other areas have declined more than 80 percent over the last two decades, according to some research reports, which has resulted in great hammerheads being listed as globally endangered by the International Union for the Conservation of Nature (IUCN) Red List. Both bull sharks and tiger sharks are listed as near threatened by the IUCN.
"This is of particular importance for hammerheads sharks since they are experiencing the greatest declines in the region and are of high conservation concern," said Hammerschlag. However, this species is susceptible to death from capture stress, so effective conservation strategies would also need to prevent great hammerheads from capture in the first place."
The study, titled "Use of marine protected areas and exclusive economic zones in the subtropical western North Atlantic Ocean by large highly mobile sharks," was published in the Jan. 2016 early online edition of the journal Diversity and Distributions. The study's authors include: Fiona Graham, Neil Hammerschlag, Patrick Rynne, Maria Estevanez, Jiangang Luo, and Jerald S. Ault from the University of Miami Rosenstiel School.
This work was supported by the Batchelor Foundation, Disney Conservation Fund, Wells Fargo, Guy Harvey Ocean Foundation, and the West Coast Inland Navigation District.
About the University of Miami's Rosenstiel School
The University of Miami is one of the largest private research institutions in the southeastern United States. The University's mission is to provide quality education, attract and retain outstanding students, support the faculty and their research, and build an endowment for University initiatives. Founded in the 1940's, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world's premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. For more information, visit: http://www.
Diana Udel | EurekAlert!
Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.
How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
14.12.2017 | Life Sciences
14.12.2017 | Life Sciences
14.12.2017 | Health and Medicine