Mote scientist receives award to study the survival of caught-and-released sharks
In all the world’s oceans it is hard to find a group of animals as charismatic and intriguing as sharks. A common historical perspective was that “the only good shark is a dead shark”, and thus shark fishing has increased on a global scale. In reality, sharks play a critical role in marine ecosystems, and it is essential to maintain shark populations in order to preserve healthy ocean ecosystems.
Dr. Heather Marshall, Postdoctoral Research Fellow at Mote Marine Laboratory in the Behavioral Ecology and Physiology Program, recently received the Christiane Howey Rising Scholar Award from Microwave Telemetry, which will help her launch a study of the survival of caught-and-released salmon sharks in Alaska, a vital piece of information in understanding how to protect these top predators and our oceans, and to educate today’s youth about the ecological importance of sharks in our waters.
Post-release mortality can occur when fishes become physiologically stressed during a capture event, and even when released alive, they may not be able to recover and could succumb to mortality later.
As the recipient of the Christiane Howey Rising Scholar Award, Marshall will receive five Microwave Telemetry High Rate X-Tags, which will help further her research on how salmon sharks in Alaska are affected after they are caught-and-released.
A High Rate X-Tag is fitted on a shark once it is caught. Once the tag is deployed and the shark released, the tag collects data from its sensors such as the depth and temperature the shark associates with. This data is stored on the tag, and once it is collected, scientists analyze the depth information to determine the post-release outcome of the individual.
For over a decade, a recreational fishery has existed in Alaskan waters for the salmon shark, a species known for its strong and aggressive fight on rod & reel gear. The fishery grew in popularity, and was advertised to visiting tourists as a fishery to experience. With increasing numbers of fishermen on the water targeting this species, and tourists coming to Alaska to catch their limit of one salmon shark per person per day, there has been growing pressure on this population.
This pressure may not have only increased the number of fish being kept and killed, but also the number of fish being returned to the wild in catch-and-release fishing once catch limits are met, under the assumption that the released sharks survive and thrive. However, how well a salmon shark does after its caught-and-released is relatively unknown, and that is what Dr. Marshall wants to find out.
“My goal is to not only conduct this highly important study, but to reach our next generation of scientists as well,” Marshall said. “Given my academic and research interests in conservation, I realize the importance of informing our next generation of ocean stewards about shark-related issues,” Marshall said. “In 2013 I formalized this focus by co-founding ‘The Gills Club,’ an online community with the goal of putting K-12 girls in direct contact with active female shark researchers through online discourse, newsletters and public events.”
The Christiane Howey Rising Scholar Award is intended to provide researchers who are starting out their careers with the means to get their projects off the ground.
“We established the annual award as a way to honor Chris; she was dedicated to education and helping the next generation of scientists, and she was particularly interested in encouraging more women to pursue careers in science,” said Cathy Bykowsky, Customer Support Representative at Microwave Telemetry. “Dr. Marshall’s proposal included a strong educational component which made her a standout candidate for the award.”
Heather interned at Mote Marine Laboratory’s Center for Shark Research, and went on to obtain her Master’s Degree in 2009 and PhD in 2014. She has now returned to Mote to complete her fellowship, which has included research on studying the stress physiology, post-release mortality and ecology of sharks.
To continue her research on the effects of tagging and releasing sharks, Marshall will be traveling to Alaska in the summer of 2016 to launch novel assessments of salmon shark mortality rates through the use of Microwave Telemetry High Rate X-Tags she will receive from the Award.
“These tags will serve a critical role in ensuring salmon shark sustainable fisheries in Alaskan waters,” said Marshall. “With results taken directly from this work, we can help promote sustainable fishing for salmon sharks in order to conserve this important species and the ecosystem within which salmon sharks are top predators.”
“A reliable way of assessing these rates are by using electronic tags such as the High Rate X-Tag,” said Marshall. “That is why I am so honored and grateful for receiving this award, which will allow me to elucidate vital information that will help establish post-release mortality rates for these sharks.”
About Microwave Telemetry, Inc.
The primary goal of the company is to provide state-of-the-art avian and marine tracking technology for scientists. Founded by biologists, the company’s innovative products are designed with biologists and their goals in mind. Its mission is to advance the integrative fields of electronics and ecology, with conservation as the driving motivator behind each new design.