Surveying seaweed

Rainbo Dixon photographs seaweed at Ningaloo lagoon.
Image: Gary Cranitch


Rainbo Dixon went to Ningaloo as part of her PhD research through Murdoch University in Perth. She has been cataloguing the marine flora at the site.
"I am focusing on one genus of brown algae called sargassum. It is one of the most dominant seaweeds out there," she said.
"I am hoping to collect from as many locations from around Australia as I can, get vouchered DNA samples and with these construct a molecular phylogenetic tree of the Australian species."
She said people often collected sargassum and they don't always know which species it is. Having reproductive plants that are fertile is essential to be able to identify the plant.
"It is a bit of a problem group and I am going to try to work it out using the different DNA techniques," she said.
At Ningaloo, she made a total of over 400 individual collections.
After collecting, she returned to the lab to press her specimens in herbarium paper. Some of the samples would be stored with silica to dry it out. These will be used later for DNA analysis. Other samples are also stored in formalin which preserves their shape and form; to be studied further under a microscope in the laboratory.
She will describe any new species she finds.
She thinks that she and Fred Gurgel, one of her PhD supervisors (see story elsewhere in this blog), have collected new species as they had collected some samples that they hadn't been able to identify so far.