5 July 2017

From Ridge to Reef – a story of connections and friendship

By Dr Moritz Müller

“We are tied to the ocean. And when we go back to the sea – whether it is to sail or to watch it – we are going back from where we came.” These words by the late John F. Kennedy have never rung so true.

Oceans are a significant source of oxygen for our planet and are instrumental in regulating Earth’s climate. The study and conservation of our oceans is critical to our survival as a species on this beautiful planet. Just like us humans, planet Earth is also a wondrous network of connections (friends, enemies etc.) and one cannot study one system on its own without looking at its connections and impacts towards other systems. What happens on land and in the rivers for example, has a major impact on the coastal ocean and is equally important in saving our oceans.

The breathtakingly beautiful coral reefs along our coastlines are not only a habitat for various organisms but also provide a protective barrier for our coasts, mitigating the impacts of waves and coastal erosion.

Unregulated discharge from agriculture into rivers can lead to an increased amount of nutrients in coastal waters which will then lead to uncontrolled algal blooms which can damage the coral reefs (among many other negative side effects).

So, bad practices on land can in fact lead to the destruction of coastal ecosystems which are extremely important for the physical protection of said land. Destruction of coral reefs along coast lines has been shown to expose the coast to the unrelenting power of tsunamis which can destroy our cities and towns.

The understanding that what happens on land has a direct impact on what happens in the water is elemental to the “Ridge-to-Reef” concept.

Anything that happens in the mountains (on land) affects the rivers and eventually, the Ocean. In terms of their importance and role in climate change, most scientists considered rivers as “passive pipes” until only five years ago. What goes in comes out at the end.

It is now clear though that rivers do in fact play a very important part in the global carbon cycle and the amount of carbon dioxide (CO2) released into the air from rivers is approximately the same as from the Ocean. Areas where the soils surrounding rivers are very rich in organic matter (which is eventually converted to CO2) are of particular global importance for this process. Three areas are of particular concern globally; the Amazon, Africa, and Southeast Asia.

Our Southeast Asian peat soils store huge amounts of carbon and are currently undergoing severe disturbances due to deforestation and agricultural practises. Our peatlands release their carbon either directly to the atmosphere or via rivers due to these factors.

Together with the University of Bremen, our team at Swinburne Sarawak measured CO2 concentrations and release from several rivers in and around Maludam National Park in Sarawak, and found that the amount released is surprisingly three times lower than recent estimates.

What we are trying to figure out now is what happens to all the organic matter released into the rivers (but not converted to CO2). Does it end up in the Ocean? Does it become new sediment (soil)? If it ends up in the Ocean, where and how far does it get transported?

To get a better understanding of the “bigger” picture, we have begun several collaborative projects with colleagues from UNIMAS, Singapore, Australia, China, and the National Oceanography Centre, UK in the field of Oceanographic research.

One of the biggest ambitions that we have is to be able to use satellites to follow the flow of the organic matter and microbes into the coastal waters and see what happens to them and where they end up. This will allow us to combine and up-scale all the information collected on the ground during our various expeditions to the whole of Sarawak and Borneo, providing much needed information to the global scientific world as well as local authorities.

Dr Moritz Müller is an Associate Professor with the Faculty of Engineering, Computing and Science. He is contactable at mmueller@swinburne.edu.my.