At the convergence of the Indian, Pacific and Southern Oceans, and the Tasman Sea, the station, as it is known, was one of a dozen established around the Australian coastline.

Only three stations – Maria Island, Cronulla near Sydney and Rottnest in Western Australia – remain as continuous sources of oceanographic data; data that today is highly-prized. The three stations are part of the network of national reference stations, initiated through Australia's Integrated Marine Observing System.

By today's standards the monthly monitoring is a basic but no less accurate activity. Nansen 'bottles' or cylinders are lowered on rope to required depths, and then a brass weight sent down the line to tip the bottle upside down, and trap a water sample inside.

To record sea temperature a reversing thermometer was fixed to the Nansen bottle. When the bottle inverted, a thread in the thermometer broke trapping the mercury and fixing the temperature reading.

Collectively these measurements relate a story of change. None more compelling than the temperature record – an exceptional rise of 2 °C has been recorded since the first measurements.

It is thought that this temperature rise is due to a shift in winds across the Southern Hemisphere. Scientists report intensifying east-west winds at high latitudes pushing southward and speeding up the gyre (or swirl of currents) circulating in the South Pacific, extending from South America to the Australian coast.

Recent research (published January 2012) has found similar 'hotspot' features in each of the five east coast currents around the world – Agulhas (Africa), Kuroshio (Japan), Gulf Stream (US), Brazil (South America) and the East Australian Current – are the result of either a faster spinning ocean-wide gyre, or an extension of the current towards the polar regions. Or both, which is the case in Australia.

The faster flow in the gyre, in turn, has pushed the East Australian Current an estimated 350 kilometres further south bringing with it the warmer waters and substantial environmental change. 

An extensive ocean mooring array across the East Australian Current will commence near Brisbane in 2012 and generate more information on the current nearer its Coral Sea source.

Research in the past 18 months has identified the ecological changes such as:

• 34 sub-tropical species of fish from NSW and southern Queensland now reside in Tasmanian waters
• an invasion of non-native species such as sea urchins from north of Bass Strait have begun crowding out the endemic species on the inshore continental shelf
• a noted deterioration in giant kelp, one of the few locations in the world where this stunning species is found
• the first recorded impact of warming ocean temperatures on a fish species, at first responding healthily with faster growth and then losing condition as the animals' organs fail to keep pace with its body growth.

Scientists are also working with Atlantic salmon producers in Southern Tasmania to trial an ocean temperature forecasting system for growers.

Reported by teams from Australia's CSIRO Wealth from Oceans and Climate Adaptation Flagships and university marine scientists, these changes amount to environmental shifts they believe are evidence of climate change, where intensifying winds are induced largely by Antarctic ozone depletion and contributed to by increasing levels of atmospheric carbon dioxide.

Caption to regional map of currents: The monthly measurements provide an indicator for change in the East Australian Current, the southward flow of warm and low-nutrient water originating from the Coral Sea that extends and retracts with the seasons, diverting at times well into the Tasman Sea. 

In winter, an extension of the Leeuwin Current crosses from Western Australia and reaches around to Maria Island before diverting into the Tasman Sea.

Read the media release, Warming in the Tasman Sea a global warming hot spot.