Sydney, August 8 (ANI): Tasmania's east coast is recording its highest-ever winter water temperatures of more than 13 degrees Celsius, which is up to 1.5 degrees C above normal, due to a strengthening of an ocean current originating north of Australia.
The current in question is the Leeuwin Current, which is significantly extending around the southern tip of Tasmania and reaching as far north as St Helens.
It has been observed in recent days by remote sensing specialists at CSIRO's Wealth from Oceans Flagship, using satellite data, and ocean measurements made near Maria Island on Tasmania's east coast.
According to CSIRO oceanographer George Cresswell, scientists use ocean observations from satellite, ocean instruments and research vessels - such as the Marine National Facility, RV Southern Surveyor - to track the currents but there are also other indicators such as tropical species reaching Tasmania.
"It's important for us to monitor these changes in the ocean, as they can have consequences for marine ecosystems, fisheries, aquaculture, coastal communities and more," he said.
The Leeuwin Current forms north of Australia and flows right around the western half of the country, meeting its better-known cousin, the East Australian Current (EAC), at Tasmania.
The exact location of this meeting point varies both seasonally and from year-to-year, depending on how strongly each current is flowing.
Oceanographers believe the EAC has gradually been getting stronger, and the Leeuwin Current weaker.
Changes in the EAC are among the most significant in the global ocean, with a continuous record of monthly measurements one of Australian oceanography's most valuable indicators for climate and environmental monitoring.
Observations of temperature, salinity and nutrients have been collected monthly just east of Maria Island since 1944, showing how the influence of both the EAC and Leeuwin Current systems varies in Tasmanian waters.
As part of the Integrated Marine Observing System (IMOS), a National Reference Station mooring has been deployed at the same site, and data is now available online every 10 minutes.
Monthly samples are taken by boat to measure nutrients, phytoplankton, and zooplankton (biomass and species composition).
Satellite images indicate the surface water temperature over the continental shelf current is around 13 degrees, a degree or two warmer than at this time in recent years. (ANI)