Great hammerhead sharks crucial: study

New research shows that great hammerhead sharks are crucial to Australia's coastal ecosystem.
New research shows that great hammerhead sharks are crucial to Australia's coastal ecosystem.

Great hammerhead sharks are "absolutely crucial" to Australia's coastal ecosystem and must be protected, new research reveals.

Marine ecologists from the University of Newcastle are hoping their fresh research leads to greater protections for the shark, given the animal's population has declined more than 90 per cent over 50 years.

The study has found the shark is the top of the food chain - also known as being the apex predator - in the coastal ecosystem on Australia's east coast, as it mainly eats whaler sharks and stingrays.

The great hammerhead has been known to be up to six metres in length and 450kg in weight.

"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," lead researcher Vincent Raoult said on Friday.

"Their role in our coastal ecosystem is absolutely crucial."

The scientists studied muscle, liver and vertebrae samples from large great hammerhead sharks caught as bycatch off eastern Australia.

The species is listed as vulnerable in NSW, and the researchers put its dwindling numbers down to demand for the shark fins, commercial fishing activities and drumlines on the east coast.

"Now that our study has shown just how important their role is in linking coastal food webs, it is absolutely crucial that we see urgent conservation of the species," Dr Raoult said.

"We know that the great hammerhead is vulnerable to commercial and recreational fishing, and that they die very easily when released after capture."

The research was released on Friday in the Journal of Fish Biology.

Australian Associated Press