UPDATE | MAY 2021
Rubicon Rice Grass Project Infomation sheet
Squeaking Point, Port Sorell, Bakers Beach and Narawntapu National Park
Rice Grass is an aggressive and troublesome weed continuing to spread in the Rubicon estuary. The highly invasive weed has the potential to impact on boating, aquaculture, community recreation and the estuarine environment. It out-competes the threatened native saltmarsh community and reduces the area of mud-flats that provide food and habitat for fish, migratory and resident wader birds, shellfish and crabs.
Images: Rice Grass meadow, Red-capped Plover
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This project received grant funding from the Australian Government.
The current Rubicon Rice Grass project ___________________
Cradle Coast Authority, in partnership with Latrobe Council, has secured funding to reduce the Rice Grass infestation in the Rubicon – Port Sorell Estuary. The project will improve the condition and long-term protection of Coastal Saltmarsh. Rice Grass will be treated north of a “containment line” between Squeaking Point and Eagle Point to establish a Rice Grass Free Zone. Rice Grass treatment will continue for another two seasons and this project will end in June 2023.
Future funding for Rice Grass control will be actively sought. In Tasmania, currently the most cost effective and least environmentally damaging herbicide for Rice Grass control is Fusilade Forte. This herbicide does not affect native saltmarsh species or seagrasses, is rapidly absorbed by the plant and quickly degrades and has very low toxicity to estuarine fauna. Permits are required and restrictions on its use apply.
How far has Rice Grass spread in the Rubicon? ____________________________________
Rice Grass has invaded more than 660 hectares of intertidal habitat in the Rubicon-Port Sorell Estuary. Anecdotal evidence suggests that nutrient-enriched water was the catalyst for the explosive expansion in the Rubicon Estuary. It is the largest infestation in the Cradle Coast region and the second-largest infestation in Australia. Rice Grass control has been underway since 1996 and projects have been delivered by Cradle Coast Authority, Tasmania Parks and Wildlife, Latrobe Council, DPIPWE, Rubicon Coast and Landcare, Green Corps and Conservation Volunteers Australia using a range of techniques.
Rubicon Rice Grass project update __________________ Even though wet and windy weather hampered the Rice Grass program this season from February to April, the total area treated this season was more than 436 ha, exceeding our annual target of 405 ha. Weed contractors completed follow-up treatment at Narawntapu National Park and reported a high kill rate of 90% from last season spraying. Initial weed treatment commenced at
North East Arm, Brown’s Creek, Squeaking Point, Thompsons Creek and Panatana Rivulet. Rice Grass control was slow and difficult due to large infestations in creeks and access required through private property. A trial weed treatment of 0.8 ha of a Rice Grass meadow has commenced at Finger Point, in the Rubicon Estuary to monitor sediment movement after Rice Grass removal.
Rice Grass signs _____________ Rice Grass interpretation signs have now been installed at Bakers Beach, Squeaking Point and Port Sorell boat ramps to explain why Rice Grass is a threat to the estuary and the values of saltmarsh, mudflats and seagrass. Coastal Saltmarsh is listed as a Threatened Ecological Community under the Australian Government's Environmental Protection and Biodiversity Act 1999 (the EPBC Act).
Aerial spraying __________________
An application for an aerial spraying permit to the Australian Pesticides and Veterinary Medicines Authority is being submitted by Biosecurity Tasmania, DPIPWE. The aim is to include all aerial options; plane, helicopter and drone, with further planning then undertaken based upon the outcomes of this permitting process.
What are saltmarsh wetlands?
Seagrass _________
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Saltmarsh provides habitat for many plants and animals including crabs, snails, insects, spiders and fish. Along with primary producers (plants and algae), they all form an important part of the marine food web. Saltmarsh wetlands support human use of the estuary and coast for recreational and commerical purposes such as fishing and tourism.
How can the community get involved?
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Boat-users and kayakers can assist in the wash-down of boats and equipment after entering Rice Grass areas to reduce the spread.
Seagrass beds grow underwater and provide important habitat for fish and invertebrates. Like saltmarsh, seagrass is at the base of the food chain, supporting the growth of thousands of fish per year. Seagrass helps keep the water clean, assisting aquaculture and recreational fisheries. It also has a very important role in stabilising sediment. There are five subtidal seagrass species in the Rubicon - Port Sorell Estuary and all are native.
Images: Iona Flett, Margot Oorebeek, Anna Wind
Get in touch For further information or to report Rice Grass in your area, please contact:
__________________________ NRM Project Coordinator Phone: 03 6433 8400 Email: admin@cradlecoast.com
Website: www.cradlecoast.com Resources: www.cradlecoast.com/online-learning-packages