With the help of one of the planet’s oldest marine organisms, an ANU scientist is revealing the natural environment’s true history. By LUCY WEDLOCK.
She may have grown up in Africa’s land-locked Republic of Uganda, but Aimée Komugabe has always felt the inescapable pull of the ocean tide.
But it wasn’t until after finishing school, when Komugabe was living in another land-locked country, Austria, that the siren call of the deep blue sea became irresistible.
Komugabe applied for the Summer Scholar program at ANU and began a project with the Research School of Earth Sciences looking at black corals of the deep ocean.
"One week into the program, my supervisor realised that I had no idea if coral was a plant or an animal. He sent me away with a pile of books - and I was hooked. I fell in love with these carnivorous creatures that are popularly known as the ’rainforests of the sea’."
This new romance inspired her to move to Canberra to continue studying these tree-like corals. Three years on, Komugabe has reached the mid-point of her PhD on the deep sea corals of south Tasmania. These black corals are revealing how ocean currents have changed over the past 5,000 years.
"Climate change is inextricably linked with regional ocean circulation. For example, studies have shown that the East Australian Current (EAC) has intensified in the past half century due to a multitude of things, one of them being increased atmospheric carbon dioxide levels. That’s why we’re so interested in the changes in ocean currents and water masses."
The EAC has been extending further southwards. As it penetrates into east Tasmanian waters, it brings warm, low-nutrient waters into a region where cold, nutrient-rich Antarctic waters are typically present. This is causing a shift in the ecosystems along the east coast of Tasmania. Fewer local fish species can survive in the nutrient-poor waters, whilst tropical fish larvae are now being found further south.
"At present, all the records of ocean movements and temperatures are from instrumental records dating back only 60 years, not long enough to indicate whether these events have happened before, and how the natural system reacted.