It is 50 years today since the Wetlands of International Importance Convention was signed in Ramsar, Iran. Since then, World Wetlands Day has been celebrated every year on 2 February.
In the Wet Tropics, wetlands are extremely important – as filters for pollutants running off the land to the Great Barrier Reef, as nurseries for fish, buffers to reduce the impacts of flooding and homes for a wide range of plants and animals.
They include swamps and mangroves, billabongs, seagrass meadows, mudflats and, in some cases, even coral reefs.
The goal of the Ramsar Convention was to stop the loss of wetlands around the world and to build international cooperation on conservation and management of our remaining wetlands. It encourages areas with rare or unique wetlands that are important for biodiversity to be added to the Convention’s List of Wetlands of International Importance. A management framework is then established to ensure future protection.
Australia has 66 Ramsar sites covering more than 8 million hectares. While none of these are in the Wet Tropics region, wetlands ecosystems play an essential role in the health of our local waterways and many people are working hard to restore and rehabilitate our wetland areas.
About 6% of land in the Wet Tropics is wetlands, mostly estuarine, palustrine (swamps) or riverine. Of these, palustrine wetlands have been the most affected by land clearing for agricultural and urban use since settlement, with almost 50% estimated to have been cleared. About 40% of riverine wetlands are estimated to have been lost and 7% of estuarine.
Our wetland ecosystems are vulnerable to threats including:
- Alterations to the flow of water e.g. from construction of weirs and dams, extraction of groundwater etc.
- Loss of vegetation
- Pests and weeds e.g. the ponded pasture hymenachne,
- Water quality and pollution.
Community groups throughout the Wet Tropics are engaged in restoring and rehabilitating wetlands areas. Examples include:
- Mungalla: The Nywaigi people in Ingham have taken over the management of Mungalla Cattle Station and have begun restoring the wetlands on the property, bringing back birdlife. Read more.
- Fig Tree Lagoon: Mulgrave Landcare has planted over 5000 trees at Fig Tree Lagoon, which used to be under sugarcane production. Read more.
Constructed wetlands are even being trialled as a water quality treatment mechanism on farmland in the Tully and Johnstone basins to reduce nutrients entering the Great Barrier Reef. This is part of the Wet Tropics Integrated Management Project. Read more.
Because of the role that wetlands play in waterway health, the Wet Tropics Report Card includes an indicator score for wetland extent, which is derived from mapping undertaken every four years. It doesn’t currently assess wetland condition by catchment – this information is only available at a regional level and is included in the Great Barrier Reef Report Card.