Research lifts blindfold on shark vision

Sandbar sharks might have prized flesh and fins which are culinary delicacies but scientists are more interested in their eyes.

University of Queensland PhD student Lenore Litherland along with researchers in Hawaii and Virginia, USA, have been investigating the adaptability of the shark’s vision.

Sharks are thought to have poor eyesight but little is known about their visual capabilities.

Sandbar sharks grow up to 2.5 metres long and feed on small fish, other sharks, octopus and crustaceans.

Miss Litherland said she was trying to find out what role vision played in shark behaviour.

She has observed and tested sandbar shark vision in the murky coastal waters of Virginia and in the clear waters of Hawaii’s fringing reefs.

She has also studied the anatomical features of the eye and recorded eye responses in different light intensities with an electroretinogram.

“The sandbar shark’s eyes have a retinal specialisation enhancing vision for tracking predators and prey,” Miss Litherland said.

“Preliminary results suggest the shark’s eyes can respond to a broad range of light levels enabling it to function efficiently in the different environments it inhabits.”

She said she chose to study the sandbar shark because they were docile and found in a range of habitats allowing a comparison of visual capabilities.

“My study will provide insights into foraging and prey detection, habitat use and interactions with fishing gear — information that is important for the management and conservation of this heavily fished species.”

Miss Litherland, 26, originally from North Stradbroke Island, will head to Virginia in July to continue her studies on shark vision.

Her study has allowed her to snorkel with sandbar sharks, tiger shark pups and ancient sharks from the deep in Hawaii while researching their vision.

Miss Litherland will present her shark vision results in September to scientists at the American Fisheries Society-Visual Ecology in Fisheries Symposium in San Francisco.

Fish and shark vision is one of UQ’s special research strengths, with several research groups working in the field including Miss Litherland’s supervisor, Dr Kerstin Fritsches, a research fellow at the School of Biomedical Sciences.

MEDIA: Miss Litherland (0416 029 305) or Miguel Holland at UQ Communications (3365 2619)