Insights from the 2023 Waterways Report Card: Climate
“Climate conditions are critically linked to the dynamics of our waterways and catchments,” says Kara-Mae Coulter-Atkins, Executive Officer of the Dry Tropics Partnership for Healthy Waters.
“When we have years of increased air temperatures, our waterways tend to show increases in turbidity and reduced dissolved oxygen, and warmer temperatures can promote the growth of macro-algae in our waters.
“At the same time, rainfall and its flushing function has many impacts, pushing sediment and nutrients around our catchments and affecting whole ecosystems.
“From litter accumulating in our creeks, to rates of coral growth on our reefs, climate affects our waterways in every way. Awareness and understanding of this relationship must grow so that waterways management can be increasingly resilient in the face of climate pressures.”
The 2023 Waterways Report Card shows that for the reporting year 2021 to 2022:
1. Our region received average rainfall, but it seemed dramatic
Both the Ross and Black Basins received average rainfall over the 2021-2022 year, despite some months being very dry (‘very much below average’) and others very wet (‘highest 1% on record’).
2. Air temperatures were warmer than average
Monthly air temperatures in the Ross and Black Basins were the same or warmer than average.
Annual air temperature averaged 25.4°C in the Ross Basin, and 24.9°C in the Black Basin, exceeding the long-term annual mean in both basins. The Dry Tropics region experienced multiple heatwaves, but no major floods or tropical cyclones, and there was no change to the La Niña event.
3. Sea surface temperatures were notably high
The annual average sea surface temperature was 27.1°C, higher than the long-term (37-year) average of 26.3 °C. Monthly average sea surface temperature was ‘very much above average’ or ’the highest 1% on record’ for 10 out of 12 months of the year.
4. Risks of coral bleaching were raised
Risks of coral bleaching in our region were above average and ranged from ‘possible’ to ‘highly likely’.