A marine weed native to Moreton Bay is overgrowing waterways around Australia, in California and throughout the Mediterranean Sea.
The plastic-like weed called Caulerpa taxifolia, invades naturally occurring seagrass and is only eaten by an uncommon slug that can tolerate its toxins.
Waterway and environmental authorities in Australia, Europe and the United States have tried removing and killing Caulerpa with chlorine, copper sulphate, salt and by hand.
UQ PhD student Dana Burfeind is studying the weed to understand more about how it grows to produce a model predicting how far and how quickly can spread and how that will impact fish communities.
Miss Burfeind, who is studying through UQ’s Centre for Water Studies in the School of Engineering, said many authorities were still trying to settle on the best way to stop the weed’s spread, with its introduction blamed largely on the aquarium trade.
In 2000, Caulerpa covered 131,000 hectares throughout the Mediterranean Sea much of which was once home to a diverse plant community, including seagrass.
Attempts to eradicate the weed have been expensive with the South Australian government spending about $6 million and New South Wales about $500,000 on its removal.
Miss Burfeind said authorities in South Australia wanted to prevent the weed spreading into the Gulf Saint Vincent while New South Wales wanted to know its impact on fish stocks now that it had spread into nine estuaries.
Caulerpa thrives in dirty or polluted water and some scientists believe there is a cold-tolerant strain different from native Caulerpa.
Miss Burfeind said Caulerpa was native to Moreton Bay but it has spread across much of western and southern Moreton Bay, possibly to a decrease in water quality.
She said Caulerpa was a serious problem when it took over seagrass beds which were important marine nurseries.
“We’ve seen what it’s done in the Mediterranean and it’s important to understand the basic biology of Caulerpa in order to prevent its future spread.”
The 27-year-old Californian said all current removal methods were bulky, time-consuming and expensive and only a short-term solution.
She has a conceptual model and is collecting the biological data that will be used to build a predictive model.
MEDIA: Miss Burfeind (0423 047 497, burfeind@uq.edu.au) or Miguel Holland at UQ Communications (3365 2619)
.jpg)
