Tracking White Sharks with Environmental DNA Evidence

Published September 17, 2018

LONG BEACH, Calif. (Sept. 17, 2018) –Future conservation leaders and marine safety officials may be able to use environmental DNA tests to check coastal waters for the presence of white sharks, according to a new paper co-authored by Long Beach State University Shark Lab director Chris Lowe.

Researchers from U.S. Geological SurveyUC Santa Barbara and Central Michigan University also worked on the project. Their paper, published in Frontiers in Marine Science, reports their development of a method of testing water samples for environmental DNA (also known as eDNA) for evidence of shark activity. The research creates the possibility of improving the test to help observers track rising white shark populations without needing to actually see or tag the animals.

three people on boat

“We can use eDNA not only to determine whether white sharks have been present at a beach, but also to determine if their favorite food is there is well, such as stingrays,” Lowe said. “Once we are able to better refine and calibrate the methods, another goal will be to integrate eDNA technology into autonomous surface vehicles that can be programmed to move along the coast sampling water and send data into the cloud, along with text alerts to local lifeguards, of the presence of white sharks at a particular location. This technology holds great promise for future, near real-time monitoring.”

The technology could also add another layer of protection for the beachgoers.

“One of the goals of this research is for a lifeguard to be able to walk down to the shore, scoop up some water, shake it and see if white sharks are around,” said Kevin Lafferty, a U.S. Geological Survey ecologist and the new paper’s lead author.

Environmental DNA is genetic material collected from the environment, as opposed to within a living organism. Things animals may leave behind — such as mucus, feces or shed skin — contain their genetic signatures, which can be parsed out and identified through genetic sequencing. Scientists can extract and amplify specific genes within the DNA fragments found in water samples and determine if the DNA contained in those samples is from a specific species.

Because eDNA can drift with currents, and sharks can swim long distances in the time it takes eDNA to degrade, the new approach only gives a rough idea about where sharks actually are at a particular moment. Still, “Chris Lowe can now add eDNA to his new white shark monitoring program, which includes real-time acoustic tracking and drone flights,” Lafferty said.

For surfers, ocean swimmers and beachgoers, the increase in white shark population may be a cause for concern. Although white sharks don’t feed on humans (and juveniles favor rays and other fish), they have certainly been known to bite out of defensiveness, curiosity or mistaken identity, causing grave or lethal injuries. Environmental DNA monitoring could give lifeguards and other people responsible for public safety clues as to when to be extra vigilant, and also help marine biologists understand how well white sharks are recovering in response to protection.

About the campus:Long Beach State University is a teaching-intensive, research-driven university committed to providing highly valued undergraduate and graduate degrees critical for success in the globally minded 21st century. Annually ranked among the best universities in the West and among the best values in the entire nation, the university’s eight colleges serve more than 37,500 students. The campus values and is recognized for rich educational opportunities provided by excellent faculty and staff, exceptional degree programs, diversity of its student body, fiduciary and administrative responsibility and the positive contributions faculty, staff, students and more than 300,000 alumni make on society.

About the U.S. Geological Survey:Created by an act of Congress in 1879, USGShas evolved over the ensuing 125 years, matching its talent and knowledge to the progress of science and technology. USGS is the sole science agency for the Department of the Interior. It is sought out by thousands of partners and customers for its natural science expertise and its vast earth and biological data holdings.

About UC Santa Barbara:At UC Santa Barbara, we offer a dynamic environment that prizes academic inquiry and interpersonal connection to inspire scholarly ambition, creativity, and discoveries with wide-ranging impact. We’re inquisitive and curious, community-driven and globally-focused. Across our campus, you’ll find independent thinkers and consensus builders, Nobel Laureates and leaders chasing noble causes. But no matter how you define us, we are above all Gauchos — diverse in our pursuits, yet connected in our collective drive toward excellence.

About Central Michigan University;Welcome to Central Michigan University, a nationally ranked institution that fosters the transformative power of advanced learning while embracing a sense of community among our students, faculty, staff and more than 225,000 alumni around the world. From our roots as a teachers' college, CMU has grown to offer nationally acclaimed programs in areas ranging from the health professions and engineering, to business and communications, and science and technology.