Supervisors:

  • Dr. Gabriela Pilo (IMAS, CoE-CLEX)
  • Professor Neil Holbrook (IMAS, CoE-CLEX)
  • Dr. Madeleine Cahill (CSIRO, Hobart)

In the summer of 2017, thousands of dead fish were found on NSW and Victoria beaches. Off the southern tip of NSW, this high mortality rate was associated with the occurrence of a marine heatwave (MHW) rapidly followed by the occurrence of a marine cold spell (MCS) (Cahill, 2017). This means that anomalously warm waters were rapidly replaced by anomalously cold waters at that given place and time of the year. The cold spell might have been caused by the interaction between the EAC encroaching upon the coast and the wind regime, as reported on previous occasions (Roughan & Middleton, 2004). Similar events have occurred in the past. However, the frequency, intensity, and trends, of MHWs followed by MCSs along Australia’s east coast is unknown, and their risks to marine species have not been previously investigated in detail. The causes for these events therefore require further investigation.

Aims: To investigate rapid shallow-water/coastal marine cooling events characterised by sudden transitions from MHW to MCS conditions, and the risk likelihood to vulnerable fish species.

Objectives:

  • To use satellite sea surface temperature datasets to determine the frequency and trends of MHWs followed by MCSs off Eastern Australia;
  • To analyse satellite ocean colour datasets aiming to identify possible causes for these occurrences; and
  • To establish a “potential mortality index” for risk of fish deaths in specific regions along Australia’s east coast.

Location of Project: IMAS Waterfront, University of Tasmania, Hobart, Tasmania

Contact Details: Gabriela Pilo (gabriela.semolinipilo@utas.edu.au)

References