News Release December 7th, 2009
Colourful seaweed puzzle in Jervis Bay Marine Park
Under the microscope the green seaweed forms a
lattice-like pattern - image by John Huisman
from Murdoch University
Jervis Bay Marine Park researcher Dr Nathan Knott says the seaweed that has washed up on Jervis Bay beaches recently has had many visitors and locals puzzled because of its bright green colour.
Dr Knott said the seaweed or ‘wrack’ was different to the usual red drift algae that locals were used to seeing, and said he’d seen large amounts of the bright green seaweed washed up on beaches around the bay over the past few weeks.
He said the green wrack was a species of drift algae common to bays around Australia and it had been recorded in Jervis Bay by scientists several times before.
He said while some people may think of seaweed as nothing very special the opposite was true.
“Seaweed or ‘wrack’ can get pretty smelly but it plays a very important ecological role in the bay. It provides food for a diverse range of invertebrates such as amphipods, which are small prawn-like creatures, and polychaete worms, which in turn can be food for other animals such as fish.
“Once the alga is deposited on the shore and exposed to air it begins to decompose - marine animals such as the polychaete worms assist with this and are favourite fare for local fishes such as bream and leatherjackets.
“The alga forms a slick in the water, which some people find unsightly, but when you take a closer look under a microscope, it is incredibly beautiful and full of intricate patterns much like a snowflake.”
Dr Knott said the microscopic examination had also revealed the menagerie of marine animals that had been feeding from the algae.
“A great deal of research has been done on the effects of wrack on beaches and all of it demonstrates clearly that this process is an extremely important one for the ecology of beach habitats, with great benefits to local fish populations,” he said.Media Contact: Tonia Liosatos
Snr Public Affairs
Dept Environment, climmate chnage & water
0418 820 504
02 6495 5024
tonia.liosatos@environment.nsw.gov.au
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