WIRES volunteer and veterinary nurse Janine Green said prior to February 2011, she had not seen green sea turtles on our stretch of coastline.

However, following that month’s devastating Cyclone Yasi in northern Queensland, she started noticing – and assisting – adolescent green turtles appearing in South Coast waterways. 

“I have been with WIRES for 18 years and it has only been the last six to seven years that I have seen a marine turtle. The first two arrived after Cyclone Yasi.”

The effects of extreme weather events, like Yasi, can last for decades if not centuries, according to the Great Barrier Reef Marine Authority. 

As the marine ecosystem in northern Queensland recovers from Yasi, and other extreme weather events, more young turtles appear to be moving south. 

“These turtles are small around 30cm long and are called ‘Tiddlers’. They are adolescents, and until they reach adulthood they feed primarily on sea lettuce. Cyclones wipe out the sea lettuce, forcing young turtles to seek out food further afield,” Ms Green said.

Some young turtles get swept into the Eastern Australian Current (EAC) that runs along the east coast of New South Wales and Queensland and have been spotted as far south as Tasmania.

Sapphire Coast Marine Discovery Centre manager Kerryn Wood explained that the increase in green turtles turning up down south could be attributed to a range of factors.

One she suggested was the changing range of the EAC. The CSIRO reported that over the last 50 years the EAC has extended 350km further south.

This has resulted in new species visiting our coast, including green turtles.

Sapphire Marine Discovery employee Rowan Carew has researched the EAC documenting its movement south. 

The southward movement of this major ocean current has been attributed to changing wind patterns brought about by ozone depletion and an increase in greenhouse gases. 

More and more species usually confined to tropical waters are finding their way down south.

Professor Gretta Pecl from the Institute of Marine and Antarctic Studies explained that the New South Wales coast, Victoria and the east coast of Tasmania are significant sites for the study of changing marine environments due to climate change.

“These areas are warming at 3 to 4 times the global average,” she said, “but estimates vary.”

The warmer water brings with it an array of species not usually found on the Far South Coast. In 2012, a manta ray was spotted off Mowarry Point in Eden and in 2016 a dugong was found in Merimbula Lake. Both of these species are rarely seen this far south. 

Sapphire Marine Discovery employee Rowan Carew observed a redfin butterfly fish at Bar Beach, Merimbula, on Sunday, January 7. Also known as the pinstripe butterfly fish, their usual habit stretches from the warmer waters of the Northern Great Barrier Reef to southern Queensland. 

Professor Pecl explained that one sighting does not necessarily equate to a change in species habitat. 

“We need to look at patterns over time so we can start to piece things together,” she said.

Professor Pecl is the founder of Redmap, which is an initiative that invites people to share sightings of species that are uncommon to their local waterways. Redmap brings together citizen scientists and species experts to help amass a database explaining the changing distribution of marine species.

Ninety scientists are linked to Redmap, verifying species that are shared by citizen scientists to the website. Professor Pecl said citizen scientists are pivotal to researching climate change in marine environments.This includes anyone that utilises and enjoys the ocean and lakes.