“Water is life” is a common saying, expressed by those who love being in the water, who enjoy diving under its surface, and by those who know life on Earth cannot exist without it. Our living planet depends on healthy waters to sustain it. This includes inland lakes and rivers, the deepest oceans and our tumultuous coastal shallows.
Throughout history, coasts have hosted the world’s largest cities. The modern coastline is home to around 40 per cent of the global human population. In Australia, 85 per cent of the population live within 50 kilometres of the coast, stretching from the northern tropics all the way down into the cool, temperate waters.
Why coastal environments are important
The coasts are hubs of trade and transport. They are the centre of industries such as fishing, aquaculture and tourism. The waters themselves provide vital food as well as protection from storms. And though the coastal ecosystems—mangroves, coral reefs, seagrasses—are directly impacted by climate change, they also play a huge role in mitigating it by absorbing carbon dioxide from the atmosphere.
But the coasts are changing. And so too will the societies, economies and lives that depend on them.
Some changes, such as sea level rise, are obvious to the naked eye. Many changes aren’t—on both microscopic and global scales. The common root of the greatest challenges is human advancement: population growth, urbanisation, coastal development and climate change now not only test the resilience of coastal habitats, but of human civilisation too.
Effective mitigation and adaption responses require a deeper understanding of these changes. To achieve this, scientists rely on long-term data collection and real-time monitoring at all different scales. From the teeny tiny molecular level, the human level and the all-encompassing planetary level. To properly assess the health of the coasts needs a comprehensive approach across all of these scales combined.
From the rocky shallows to the deepest trenches, the seas can be dangerous, murky and fickle. This makes it difficult for humans themselves to physically navigate and explore the seas consistently, to understand what goes on beneath the surface. But CSIRO has a range of multi-scale technologies to help. The national science agency boasts an impressive portfolio of tools to inform better future-focused decision-making for our coastlines, with even more technology on the way.
Beyond what meets the eye
Keeping a human gaze below the water is difficult. Not only because of the nature of the environment but because there’s a lot more going on within the finer details of seawater than the naked eye can see.
In order to paint an accurate measure of biodiversity, scientists previously had to dive into waters themselves, or use video footage, to manually count, collect and identify species. This process puts divers into physically challenging and risky situations. It's also incredibly time-consuming to get results.
CSIRO’s Dr Lev Bodrossy says a new method of sampling can help speed up the process and keep scientists out of hazardous waters.
The species living within an area—ranging from the microscopic all the way through to whales and sharks—can be identified by reading and monitoring levels of eDNA within samples of seawater. eDNA are the genetic remnants of living creatures.
Various eDNA methods developed within the past decade continue to evolve and improve. They are not only rapid and safe, but a cost-effective way to sample marine species—both common and rare—without having to lay a hand on them.
“Tag sequencing or metabarcoding can assess the composition of the entire breadth of the marine community—from bacterioplankton, through the phyto- and zooplankton, up to the fishes,” Dr Bodrossy said.
The data collected from eDNA sampling methods can help monitor how populations of species change over time. For example, how they are affected after a marine heatwave, flood or tropical cyclone. Pest species can be detected and monitored to inform actions to forecast and possibly prevent a population explosion. Rare or endangered species populations can also be monitored, safely and from ‘a distance’.
Microscopic research for macroscopic knowledge
Dr Bodrossy says eDNA methods are especially important for monitoring at the microscopic scale.
“When we talk about protecting the oceans, we really think about protecting what matters to humans: fish to eat, charismatic megafauna to see and clear waters to enjoy,” he said.
“All of these values rely on a healthy, broad community—in particular on the bacterio-, phyto- and zooplankton, which we don’t really put high (or any) value on.”
Dr Bodrossy says if these tiny creatures which form the basis of all marine food webs decline, then so too do the fish, the dolphins and the pristine beaches. And ultimately, humans.
“We need to understand the plankton-level communities, including how they function and respond to the various stresses we expose them to. They underpin everything we value about the oceans,” he said.
“This, in turn, will help us better predict how our coasts will react to human activities and how we can better manage them.”
Other eDNA sampling methods can monitor both the functional makeup and activity of the marine community, as well as count selected species of interest. These are all equally important markers of biodiversity.
A network of sensors connected above and on Earth
CSIRO’s Dr Tim Malthus says CSIRO has a range of technology already in the water, exploring all marine environments.
Autonomous and piloted observation technologies - such as sensory buoys and both aerial and underwater vehicles - roam the seas and send measurements on its chemical, physical and biological properties back to scientists on land.
The autonomous underwater vehicle, Starbug X, can not only power itself around shallow waters but snap pictures and video by itself too. There is now software that can recognise and classify different marine species via these images.
But, Dr Malthus says, integrating the Internet of Things (IoT) and machine learning software can both simplify and speed up the processes of monitoring and data collection even further.
“Computer models have now far outstripped our ability to keep up with feeding data into them,” he said.
“Emerging technologies can help us keep up with missions designed to be very large and continuous bodies of work.”
AquaWatch Australia is one such mission currently in development. It will provide a comprehensive water-quality monitoring system for water managers across all of Australia, using space technology.
The first step is designing and implementing a combined network of Earth-observing satellites and ground-based sensors to measure coastal and inland waters and feed the information back via purpose-designed IoT satellites. These will then deliver real-time updates, predictive analytics and forecast warnings.
“There are still many water quality parameters where we don’t have sensors, which still need to be economically viable,” “Dr Malthus said.
“This is where adopting the IoT approach can help.”
He says the IoT can possibly help make self-operating and self-maintaining sensor networks not only cheaper but easier to operate and more efficient to manage.
More work to be done
“Coastal zones are enormous,” Dr Malthus said. “What we are doing here is collecting and applying vital data - we use it in oceans and climate modelling. It’s still quite a challenge but it is exciting to be contributing to a potential solution.”
Humankind needs coasts to survive. Consistent environmental coastal health assessments are a vital tool to ensure coasts are healthy and thriving. CSIRO scientists have made incredible advancements in developing and using coastal monitoring methods and technology. They continue to work on speeding up the delivery of more accurate coastal information.
"Developing and applying safer, less invasive and more efficient technologies means we can prioritise protecting the precious coastal environments that need it most," Dr Malthus added.
"This will help to ensure humanity also remains protected."