When native seaweed goes rogue - is pollution to blame?

Research into the connection between pollution and the rapid expansion of a native seaweed species that is threatening marine life along the NSW coast has been boosted by a research grant from the NSW Environmental Trust.

The vast expansion and extremely difficult living conditions created by the seaweed, Caulerpa filiformis, will have a direct impact on biodiversity according to C3 Biodiversity Research Group researcher Dr Paul Gribben, who has received $100,000 to investigate the cause of the seaweed's growth.

Dr Gribben said Caulerpa filiformis is native to NSW, but its rapid spread had shown its invasive capabilities and capacity to replace other important seaweeds in NSW urban coastal waters.

"If coastal pollution is responsible for this expansion, then our research can make recommendations of how to manage the spread of this species," Dr Gribben said. 

"Caulerpa filiformis poses a serious threat to coastal biodiversity in NSW. It disrupts the natural habitat and is inedible to many species of invertebrates and fish that occur in our coastal habitats.

Caulerpa filiformis. Picture by Dilys Zhang

"Seaweed forms the base of the food chain for many species, so large scale changes can have a significant impact on an entire ecosystem. We could begin to see a cascading effect on the habitats of communities including fish."

Dr Gribben's research will also make recommendations on how to potentially rehabilitate the habitat in affected environments and prevent the loss of many species. 

Meanwhile, back on land, another Environmental Trust grant of $80,000 has been awarded to UTS researchers Dr Daniel Ramp and Dr John Gollan, with Dr Mick Ashcroft from the Australian Museum, to research the relationship between the over and understorey in forest canopies and their role in providing refuge to species by buffering climate extremes.

"There is limited knowledge of how the understory of a canopy contributes to resilience. Often the understorey is removed or overlooked, putting biodiversity at risk, as the more complex the understory the more stable the environment for plants and animals to exist," Dr Ramp said. 

"Our research will be based on a topoclimate (topographical/climate) map we have developed from our previous research that involved collecting data on humidity and temperature of over from 250 sites around the NSW Hunter Valley. 

"The information from our research will inform landowners and on-ground government managers about the best way to preserve biodiversity on their land."

Results from both research studies will be available in late 2013.