AT RISK: Experts claim that sick whales may have to be euthanised due to a lack of food (krill) in the Southern Ocean.

AT RISK: Experts claim that sick whales may have to be euthanised due to a lack of food (krill) in the Southern Ocean. Contributed

A NORTHERN Rivers whale expert has spoken out following claims Queensland's Department of Environment may euthanise whales off the east coast in future due to sickness brought on by food shortages.

In a recent ABC Sunshine Coast report, Sea World director of marine sciences, Trevor Long, said whales would likely be euthanised along the coast of Australia in coming years by the department due to rising migration numbers and a lack of krill in southern oceans.

He said the ocean off south-east Queensland, a direct migration path for whales such as beloved albino humpback Migaloo, would see a rise in sick whales, making euthanasia necessary.

Mr Long said the drug Lethabarb would be used to euthanise smaller whales, while high-powered rifles and solid shot would be used for other whales.

"Before whaling nobody was harvesting krill," Mr Long told The Northern Star.

"Now, it is harvested for a variety of purposes..."

He believed this would have a considerable impact on krill stocks.

A Queensland National Parks spokeswoman did not refute euthanisation claims, instead saying "the response to a sick or injured whale will always depend on the specific circumstances".

"Any decision to euthanise the animal would be made with expert advice and the assistance of an experienced veterinary surgeon," she said.

"Consideration would also need to be given to the safety of staff and the public."

A NSW National Parks spokeswoman said whale euthanisation was "not something we're doing, or considering".

The Oceania Project researcher Wally Franklin, who is part of the Southern Cross University Whale Research Centre Group, said he believed food supplies were stable.

He said stranded whales were sometimes euthanised out of necessity, but he had not heard of euthanisation at sea.

"If that was happening it would be totally unacceptable, but I haven't heard anything about it," he said.

Mr Franklin disputed Mr Long's claims food stocks were depleting due to overpopulation of migration routes, which the Sea World scientist described as at "two-thirds" of capacity.

"That's absolute nonsense," he said.

"Population levels are about half of what they were prior to whaling.There's no evidence the food supplies are depleted or that this is a problem."