POOR Queensland water quality and warm southerly ocean currents are thought to be responsible for a spate of sea turtle deaths in Byron Bay over the past fortnight.
Rochelle Ferris from Australian Seabird Rescue said 13 had washed ashore since October 29, but of those, only four had survived.
"We're doing everything we can to revive them," she said.
"Nine of them were hawksbills and four were green sea turtles but only two of each are still alive.
"It's the hawksbills that we're really concerned about because they are a critically endangered species and we don't see them often.
"We'd only see four or five in a year so to see nine of them wash up in the space of two weeks is of very high concern."
Ms Ferris serious water quality problems had been identified near most Queensland cities and called for governments to start taking the issue seriously.
"Gladstone harbour has a lot of dying turtles at the moment - that's mainly from turbidity (from dredging), water pollution and agricultural runoff - it all contributes," she said.
"These particular turtles get so ill that they float on the surface of the water and don't have the energy to fight against the current.
"They get pushed down the coast on the East Australian Current - a warm band of water washing into Cape Byron - and in the last couple of weeks we've had some really hefty north-easterly onshore winds which exacerbates their vulnerability of being blown onto the coastline."
Ms Ferris said the water-quality issue had been identified at a sea turtle health and rehabilitation conference in Townsville last year.
"Then those extreme weather events last year decimated the seagrass beds on the coastline - there has been a spate of turtle and dugong deaths as a result," she said.
"Even the half healthy ones are now having to look further afield for food.
"James Cook University is doing a lot of work in this field but we really have to do everything we can to protect those seagrass beds.
"We're also hoping there are no more big floods or cyclones this year which will give those beds a chance to regrow."