03 Aug 2018
The 2018 report card shows an overall decline in grades compared to the 2016 report card. Grades have declined across all zones except for zone 1 (from Launceston to Legana), which remains unchanged with a D grade 'poor ecosystem health'.
The decline in overall grades is most likely due to the extreme weather conditions preceding and during monitoring for the 2018 report card.
The major flood in June 2016 the largest flood in Launceston since 1969, delivered high loads of pollutants including nutrients, sediments, pathogens and metals to the Tamar River estuary.
The decline in the 2018 report card grades has been driven by an increased chlorophyll-a concentrations (indicating increased algal growth) and lower dissolved oxygen levels during autumn and winter.
The 2018 report card illustrates the influence that extreme weather conditions can have on ecosystem health in the Tamar River estuary.