April 30, 2018 | Published by | , ,

Centre of Excellence researchers have identified 12 marine heatwave types off the east coast of Tasmania, a location recognised as a global warming hotspot.

Average sea surface temperatures here have been rising at four times the global average rate and trends in marine heatwaves are showing significant increases in number. Southeastern Tasmania in particular showed strong trends, with marine heatwaves also extending deeper through the water column in recent years. These are having impacts on marine biodiversity, fisheries and aquaculture industries off Tasmania’s east coast.

Using a high-resolution ocean model representing Tasmania’s eastern continental shelf, the researchers looked back on the period 1993-2015 to provide daily estimates of the three-dimensional temperature and circulation fields for this area.

The East Australian Current has been found to be the dominant driver of heatwaves in this region, with warm air temperatures and northerly winds coming second. The researchers have identified 12 heatwave types, each with its own regional focus, seasonality, and associated large-scale oceanic and atmospheric circulation patterns.

These heatwaves have significant implications for marine ecosystems. Management of these impacts were revealed through a review of past impacts, and outcomes from a stakeholder workshop discussion held as part of this study. It included participants from science, fisheries and aquaculture industries and Tasmanian state government departments.

 

  • Paper: Oliver, E.C.J., Lago, V., Hobday, A.J., Holbrook, N.J., Ling, S.D., Mundy, C.N., 2018. Marine heatwaves off eastern Tasmania: Trends, interannual variability, and predictability. Progress in Oceanography 161, 116–130. https://doi.org/10.1016/j.pocean.2018.02.007