Harmful algal blooms in the Australian region: changes between the 1980s and 2010s

While microalgal blooms in a strict sense are completely natural phenomena [e.g. Trichodesmium cyanobacterial blooms reported in the Coral Sea by Captain Cook in 1770], since the 1980s their impacts on Australian public health, tourism, and fisheries have increased in frequency, intensity and geographic distribution. To a major extent this reflects increased scientific awareness [pinnatoxins in SA oysters]. In other cases, algal bloom problems reflect increased utilisation of coastal waters for aquaculture and fisheries [fish-killing Chattonella marina raphidophytes in Port Lincoln, dinoflagellate Dinophysis Diarrhetic Shellfish Toxins in NSW pipis, diatom Rhizosolenia amaralis causing bitter mussels in Port Philip Bay]. Eutrophication has only rarely been rarely invoked as a causative factor [dinoflagellate Karlodinium veneficum in Swan River; haptophyte Prymnesium parvum in NT barramundi ponds]. Other harmful species have been newly introduced via ship ballast water discharge [PST dinoflagellate Gymnodinium catenatum into Tasmania] or exhibit significant range expansions in relationship to climate change [Noctiluca scintillans red tides into the Southern Ocean]. Algal blooms may also pose unexpected problems for desalination plants. Heightened scientific and regulatory attention has triggered the development of many new technologies (molecular probes, remote sensing) and approaches for monitoring (continuous plankton recorder) and management of algal bloom phenomena.