Marine Algae
By Taroona High School
Professor Gustaaf Hallegraeff talks about the differences between green, brown and red seaweeds. The green species live mostly close to shore (they have the same grass green pigments as higher plants can withstand high light intensities); the red seaweeds can live deepest; the browns in between in dim light.
Gustaaf is researching, at the University of Tasmania, the effects of climate change on marine life. Brown seaweeds like the string kelp prefer cold water. Scientists have monitored their decline off the east coast of Tasmania since the 1970s, which is associated with a 2.3°C temperature increase. Another effect of climate change is the occasional red surface slicks and bioluminescence, which can be seen at night on Taroona Beach. These are caused by microscopic dinoflagellate algae that have expanded their range from Sydney, first found in Tasmania in 2003.