A major report looking at the health of the Derwent over the past five years has found the condition of the estuary has improved in some areas and declined in others.
The 2015 State of the Derwent Report has been released today at the Derwent Science and Management Symposium in Hobart.
Hobart Lord Mayor Sue Hickey said the report prepared by the Derwent Estuary Program (DEP) provides a watching brief on the state of the Derwent Estuary.
“Hobart is a capital city that boasts swimmable beaches, an extensive network of walking and cycling tracks and opportunities for boating and fishing. This report highlights the health of this highly valued waterway and areas we can work on for continued improvement,” Ald. Hickey said.
Derwent Estuary Program (DEP) Director Christine Coughanowr said the report summarises trends in industrial, sewage and stormwater discharges, monitoring results for swimming beaches, heavy metal levels in sediments and seafood, and the condition of key habitats and species. The report also highlights actions taken to clean-up the Derwent during this time.
Key findings include:
• Recreational water quality at most Derwent beaches and bays is classified as either good or fair;
• An overall increase in nutrient levels across the estuary, particularly in the upper estuary where algal blooms have recently been observed;
• Heavy metals have declined in surface sediments of the middle estuary, but are still well above national guidelines across much of the Derwent;
• Heavy metal levels in Derwent shellfish and bream are also well above national food safety standards and should not be eaten, while flathead and other Derwent caught fish can be consumed in moderation;
• The Derwent’s wetlands, seagrass beds, tidal flats and rocky reefs provide important ecosystem services, filtering pollutants, stabilising sediments, and providing habitat for fish, birds and other species;
• Good progress made towards eradication of foreshore weeds (rice grass and karamu);
• Monitoring and management of the spotted handfish, little penguin and dolphins has continued with good results.
The State of the Derwent Report also summarises management actions, with a combined estimated value of over $150 million over the past decade.
• Implementation of major groundwater remediation and stormwater treatment projects at Nyrstar.
• Construction of a secondary treatment plant at Norske Skog Boyer.
• Construction of over 20 stormwater projects in the Hobart, Glenorchy, Clarence and Kingborough municipalities to capture and treat urban run-off.
• Decommissioning of the Taroona sewage treatment plant, and construction of the Duckhole Dam in by TasWater to improve the storage and reuse of treated effluent on the Eastern Shore;
• Development and implementation of new oil spill prevention plans at Hydro Tasmania’s power stations, including Meadowbank;
• Extension of foreshore tracks, and better promotion of these via the Greater Hobart Trails website
“The information contained in the State of Derwent Report is used by all levels of government, industries and the community to gauge the state of the estuary and the actions being taken to restore our waterway,” Ms Coughanowr said.
Ald. Hickey congratulated the DEP’s industry, State and Local government, scientific and community partners for their long-term commitment to the DEP.
“The resources they have collectively provided to monitor and reduce pollution to the estuary have made a significant and positive difference.”
For a full copy of the report, go to the Derwent Estuary Program website
The Derwent Estuary Program (DEP) is a regional partnership between local governments, the Tasmanian state government, industries, scientists and community-based groups to restore and promote our estuary. The DEP was established in 1999 and has been nationally recognised for excellence in coordinating initiatives to reduce water pollution, conserve habitats and species, monitor river health and promote greater use and enjoyment of the foreshore.
Major sponsors include: Brighton, Clarence, Derwent Valley, Glenorchy, Hobart and Kingborough councils, the Tasmanian State Government, Nyrstar Hobart, Norske Skog Boyer, TasWater, TasPorts and Hydro Tasmania. The DEP has also been supported through grant funding from the Australian Government.