A new study paints a picture of the rapidly changing southern NSW coastline.
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The University of Technology’s Professor David Booth co-authored the paper, and said the data shows climate change is causing a poleward shift of marine species.
The team looked at data collected on 30 tropical reef fish species over a 16 year period, and found more resources are needed for the early detection of shifts in order to develop appropriate management responses.
“There hasn’t been a lot of funding, it is a very shoestring operation,” Dr Booth said.
Dr Booth said the speed of change is accelerating, and what may have taken a millennia in the past is happening within a decade.
"There is interest growing for the idea to seed coral on reefs that would degrade over time..."
- Dr David Booth
“We are driving evolution, unfortunately, and with the bleaching of the Great Barrier Reef coral we are realising this is actually real,” he said.
Dr Booth said last year’s East Coast Low ripped up kelp around Sydney, helping the tropical species thrive.
“Just getting through the winter is enough to continue the breeding cycle,” he said.
The changes may also see coral move further south, and while he is not a supporter of artificial reefs, Dr Booth said other options are being discussed in the scientific community.
“We know there’s coral babies out there as well, they just don’t survive,” Dr Booth said.
“There is interest growing for the idea to seed coral on reefs that would degrade over time, and that’s not as bad,” he said.
Luke Brown has been collecting data from around Merimbula and Narooma for the last 16 years, and says although he has seen an increase in tropical vagrant species over the years, the majority currently do not survive through the winter months.
“The vagrants are not reaching adulthood and breeding, but that is what we’ll see into the future,” he said.
Dr Booth predicted these tropical species will be predominant around Sydney in 30 to 40 years, and a common sight along the Far South Coast beyond then.
Mr Brown uses temperature loggers in the water to collect his data which is then combined with broader data collected by the CSIRO.
“The general trend is an increase in diversity and abundance of these species,” he said.
“Some fish may be expanding their range, with the fish that enjoy cooler water are gradually being pushed southward.
“Kelp is also moving because it likes cooler water with nutrients, and the warmer water coming down has less nutrients.
“A lot of these cooler species, like abalone, are commercially viable,” he said.
Dr Booth said the warming of the ocean threatens some industries, especially in Tasmania.
“If it warms up there won’t be any Salmon industry in Tasmania left,” he said.
Mr Brown said Far South Coast data is important when understanding the wider picture of the situation.
“The current is not just a stream heading south, so in our results we can see these species at Merimbula before our Sydney sites,” he said.
“By the time the vagrant species get to Eden they spiral offshore, which is why it’s an important area.
“What we tend to find is if a southerly blows it pushes the warm current back on shore, and if a northerly pushes it offshore it is replaced by cooler water.”