Wetland Management
Aquatic Ecosystems and Riparian Zones
Contributor:
Mr Nigel Blake
Northern Rivers CMA
PO Box 618
GRAFTON NSW 2460
October 2006
The rivers, creeks and drains of the Clarence Floodplain are home to fish, crabs, waterbugs and other aquatic animals and plants. All are dependent upon the aquatic zone (the wet bits) and the riparian zone (the riverbank) for their survival. These two zones provide food, shelter, living space and breeding sites. Changes to these zones can have a huge impact on the abundance and diversity of aquatic life.
In the Aquatic Zone snags and logs, water plants, undercut banks, pools and riffles, rocks and gravel beds and tree roots are all places that water plants, bugs and birds, fish, turtles and platypus live, feed and breed.
The Riparian Zone provides shade, food and shelter.
Shade on the water is important because it :
- Limits the amount of light loving water plants and algae that are less palatable to waterbugs.
- Decreases the daily maximum water temperature allowing many plants and animals to survive and keeps Dissolved Oxygen levels higher.
- Creates patchy lighting allowing predators and prey to hide.
Food from riparian vegetation comes as:
- Falling leaves, bark and branches for scavenging and leaf eating fish and water bugs
- Falling terrestrial insects – a significant food source for many native fish
- Nutrients from the falling leaves for uptake by other plants and micro-organisms
Shelter from riparian vegetation comes as:
- Snags, logs and debris that are used for refuge by fish and water bugs.
- Exposed root systems for fish and water bugs to live and hide amongst
- Protruding branches for roosting sites for water birds.
Further Information:
The NRCMA can assist landholders maintain and improve aquatic and riparian habitats. Contact Nigel Blake on 6642 0633.
