Riverine ecosystems
Key Messages
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Healthy riverine ecosystems in Queensland are vital for sustaining biodiversity, regulating water quality, and supporting ecological balance. They provide essential habitats for fish, birds, and other aquatic life, while also playing a crucial role in nutrient cycling, sediment transport, and flood regulation. These ecosystems also supply clean water for communities, agriculture, and recreation. Degraded river health can result in habitat loss, declining water quality, and disruptions to food webs, threatening both species and ecosystem stability. Protecting and restoring riverine ecosystems helps maintain biodiversity, enhances waterway resilience, and safeguards the long-term health of connected freshwater, estuarine, and marine environments, benefiting both nature and people.
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The condition of riverine ecosystems is monitored and reported in the GBR Catchment and Southeast Queensland by two distinct initiatives - the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef program) and Reef Water Quality Report Card and the regional report card program. These show that overall, freshwater floodplain wetlands in the GBR catchments are under moderate pressure from catchment land use, pest species, loss of native vegetation and changes to water flow patterns. Estuarine wetlands in the GBR catchment have a range of chronic and acute pressures, such as, excess nutrients and sediment, pesticides, loss of connectivity, changes in hydrology, coastal development and climate change, including sea level rise.
Key Facts
State
- Condition of riverine ecosystem health
The Burdekin, Fitzroy, Mackay Whitsunday and Wet Tropics regions have generally improved, ranging from moderate to good waterway condition. The Wet Tropics Daintree sub-catchment is an exception and has remained in very good condition. Southeast Queensland waterway conditions have generally remained stable or improved, except in four sub-catchments (Bremer, Lockyer and Upper/Lower Brisbane).
Pressure
- Pressures affecting riverine ecosystem health
Overall, the common drivers affecting Queensland's monitored waterway catchments are climate change, climate variability, population growth and economic growth.
- Invasive non-native freshwater fauna species
Non-native fish, turtles and snakes can damage Queensland's freshwater ecosystems and displace native species. The best way to minimise their impact is to prevent them from entering our waterways.
- Invasive non-native freshwater flora species
Non-native water plants can harm Queensland's rivers, creeks, lakes and wetlands. Restrictions on the import, post-border sale and possession of these plants are vital to reducing their impact on our waterways. Several invasive non-native aquatic weed species have naturalised in Queensland.
- Volume and load of sewage treatment plants
The combined volume of treated sewage released to Queensland coastal waterways has been relatively steady since 2010 at around 290 gigalitres per year, except for 2021 and 2022, due to significantly above-average annual rainfall in Southeast Queensland (SEQ). A significant increase to over 1,500 tonnes of nitrogen was observed from 2020 to 2023 mainly due to significantly high rainfall as well as increased release volumes in the SEQ. A substantial decrease in phosphorous load has been observed since 2015, largely attributed to improved treatment from both SEQ and Great Barrier Reef catchment treatment plants, except for an increase in 2023.