Fish sampling in the Coorong, SA.
Images of high-tech drones or satellite trackers might not be the first thing that comes to mind when you think of delivering water for the environment. However, these are some of the cutting-edge technologies being used to track and measure how plants, birds, fish and frogs respond to environmental flows in rivers and wetlands. Here we take a look at some of the technologies that help us decide when and where to release water to get the most benefits for the environment.
Heather McGinness fitting a Straw-necked ibis with a satellite transmitter. Photo: CSIRO
Hitching a ride – backpacks on birds
Every year, waterbirds in the Basin travel vast distances to find food and the perfect nesting site. Improving our understanding of waterbird movements is important so we can better support them (and their habitats) with water for the environment. This is where satellite tracking comes in. Increasing numbers of waterbirds – such as Royal spoonbills and Straw-necked ibis (shown below) – have been fitted with backpack GPS satellite transmitters. These backpacks transmit data back to scientists, showing them when and where the birds are travelling. Water managers then use this information to make sure wetlands are in the best possible condition for birds to feed and breed. Water for the environment is used to keep important habitats wet to prevent nest abandonment, stave off feral predators, and ensure food is available to support vulnerable juvenile birds.
Tracked movements of one Straw necked ibis (Laurie) from 2017 to 2021
Fishing for information - Tagging and tracking
Scientists are also keeping an eye on some of the Basin’s native fish species.
Fish such as lamprey, Murray cod, Freshwater catfish and Golden perch, have been caught and tagged with special tags. As they swim through the Basin’s waterways, their tags are detected by a carefully laid out network of sensors, leaving a trail of information for scientists.
Tagging has provided some surprising insights into where native fish travel to complete their life cycle. Golden perch have been found to swim over 2000 kilometres upstream along the Murray River to lay their eggs. Similarly, lamprey have been tracked moving from the saltwater of the ocean into the freshwater of the Murray, swimming over 800 kilometres up-river. This knowledge has reinforced the importance of keeping rivers flowing at certain times of the year to help fish move about to breed and thrive.
Tagged Murray cod being released into the Namoi River. Photo: DPI Fisheries.
Using a drone to map vegetation along the Goulburn River, Vic. Photo: Neil Sutton.
From bikes spokes to drones – our eyes in the sky
In the past, scientists hammered bike spokes into riverbanks to manually measure bank erosion. Now, with cameras on drones, scientists are able to map much larger stretches of riverbanks more quickly and easily. By analysing drone-images of riverbanks before and after flows are released, scientists can assess changes to riverbank vegetation, map river heights and monitor bank erosion with greater accuracy.
This more detailed understanding of the impact flows and flow patterns have on riverbanks has already changed the way water managers release water into the Goulburn and Edward/Kolety-Wakool rivers. Based on the advice of scientists, the timing and duration of deliveries of water for the environment are now designed to avoid bank damage and even deposit seed-laden sediment to improve riverbank vegetation.
Drone imagery can highlight changes to the riverbank. Image: Streamology.
What’s for dinner? – providing food for hungry fish
Scientists have put in place data loggers, which measure water quality, temperature, dissolved oxygen, and how much food is made in the river for fish to eat. This knowledge helps water managers use water for the environment to get river conditions just right to produce fish food (algae and other microbes) when its most needed. Having more food in the river at the right time means native fish are more likely to breed, juveniles are more likely to survive and grow, and fish are healthier and more resilient if conditions turn bad (such as during drought).
Installing temperature and dissolved oxygen loggers at Collarenebri, NSW. Photo: Eco Logical Australia.
Getting it right with water for the environment
Satellite trackers, tags, drones and data loggers are making it easier for scientists to understand how plants and animals respond to water for the environment. The more we understand about rivers and wetlands, the better our decision making is about where, when and how much water should be delivered to achieve the best possible results for waterbirds, fish, other aquatic animals and plants.
For more stories about how scientists are collecting information to learn how to best use Commonwealth water for the environment, visit the Flow-MER website