SYDNEY, Nov. 15 (Xinhua) -- Great hammerhead sharks are crucial to Australia's ecosystem due to their position as apex predators, according to a study released on Friday by the University of Newcastle.
The bizarre-looking hammerheads have for the first time been proven to prey upon other sharks and rays, putting them at the very top of the food chain.
However, their numbers have dramatically reduced right around the world and by as much as 90 percent in the past 50 years on Australia's east coast.
"What our research has found is that the great hammerhead shark is in fact the 'shark predator', it confirms that they are at the top of the food chain and highlights that their role in our coastal ecosystem is absolutely crucial," lead researcher Dr. Vincent Raoult said.
"Apex predators keep the balance of our ecosystem in check, they keep it healthy, so this discovery about the great hammerhead really emphasises its importance," Raoult said.
By taking samples of muscle, liver and vertebrae from hammerhead sharks caught off the coast of Australia, Raoult and his team were able to confirm that animals greater than three meters feed primarily on whaler sharks and stingrays.
The species' uniquely shaped head means they are specialized in catching a limited type of prey, a fact which puts them at a high risk of extinction.
Already they are considered "vulnerable" in the state of New South Wales, and are frequently caught both deliberately and accidentally by fishermen.
"We know that the great hammerhead is vulnerable to commercial and recreational fishing, and that they die very easily when released after capture," Raoult said.
"As apex predators their extinction would have a vast ecological impact on the coastal ecosystem and protection is essential to support stability across economically important coastal ecosystems," Raoult added.
