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NPD hazard. Salvinia outbreak.

rayke1938

By rayke1938
in Freshwater

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rayke1938 Experienced

rayke1938

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Please be aware that there is an outbreak of salvinia weed in the North Pine Dam.It is a dark green coloured with leaves around an inch across.

Please make certain that you clean off your waders before fishing other waters as the salvinia is very aggressive and fast growing and if not eliminated will completely choke the waterway. Under optimal growing conditions it can double itself every 24 hours.

I have seen small clumps around Forgans and Bullockys but apparently it is widespread in the upper reaches.

The rangers are about to commence a spraying program but in the meantime please take care not to accidentally trans-locate any of it to other waters as it is extremely difficult to eradicate.

Cheers

Ray

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rayke1938 Experienced

rayke1938

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Animals & Livestock

Crops & Pastures

General Farming

Horticulture

Landcare Groups

Soil & Water

Trees & Native Vegetation

Weeds

Biological Control

This is off a victorian government website unfortunatly i do not know how to copy the photos across but if you google salvinia there is heaps of info about it.

Cheers

Ray

Banner: Information Series Printer Friendly Version

Salvinia: State Prohibited Weed

LC0283

Keith Turnbull Research Institute, Frankston

February, 1998

To view the Adobe Acrobat file, you will need the Adobe Acrobat reader. LC0283.pdfPDF 256 kb

Common Name

Salvinia

Botanical Name

Salvinia molesta D.S. Mitchell

Status

Salvinia is one of only fourteen weeds proclaimed as State Prohibited Weeds in Victoria. This is the highest category to which a noxious weed can be allocated and means that salvinia is to be eradicated if possible from the State.

Origin

Salvinia is native to south-eastern Brazil. It has been distributed worldwide and probably throughout Australia by use in aquariums.

Description

A perennial aquatic fern with most leaves floating on the water surface, forming mat-like growths. The plant has different forms depending on its density. The leaf stems, which are rhizomes, and modified leaves which act like roots, are submerged, but they both float and do not “take root†in any substrate.

Stems - up to 30 cm long, 1 to 2 mm thick, multiply branched. Stem length decreases with increasing plant density. In dense infestations the stem length between leaves is very short.

Leaves - are of two kinds, emergent (floating) and submerged. Emergent leaves have two leaflets growing on opposite sides of the leaf stem. There is significant variation in size and shape of floating leaves depending on the growth stage of the plant. Leaves of isolated plants are oval to heart-shaped, flat and as small as 10 mm by 5 mm. In dense infestations the leaves are crowded together, oblong in shape, deeply keeled, and up to 3 cm by 6 cm wide when opened flat. The floating leaves are green, non-wettable on the upper surface and have complex waxy hairs about 1 mm long. The submerged modified leaves which act like roots are short brown hairy stalks ending in hairy filaments up to 50 cm long which look like wet hair.

Roots - absent.

Being a fern salvinia does not produce flowers. Ferns generally reproduce by spores but salvinia is a sterile hybrid. It produces spore capsules on submerged stems but any spores produced are incapable of germination.

Life Cycle

Reproduction of salvinia is vegetative and results from buds shooting at stem nodes and the continual creation of daughter plants. Daughter plants are the invasive form of salvinia. In order to grow they require nutrients and an area of clear water surface amid, or on the edge of the infestation.

Photo: Invasive growth form of salvinia

Figure 1. Invasive growth form of salvinia

Photo: Dense infestation of salvinia

Figure 2. Dense infestation of salvinia.

Dispersal

As salvinia only reproduces vegetatively by division, dispersal is by invasive growth or physical transfer of parts of the plant. Daughter plants break away from the parent and may be moved with water currents and the wind. Careless disposal of aquarium contents could result in salvinia being deposited in freshwater and must be avoided. Salvinia has also been used as an ornamental in garden ponds.

General

When conditions are suitable salvinia can spread very rapidly and completely cover water surfaces. Its growth can block waterways including irrigation and drainage systems and smother dam and reservoir surfaces. Masses of salvinia carried by flood waters can destroy fences and other structures. Dense infestations significantly decrease water quality and reduce penetration of sunlight. Masses of decaying salvinia de-oxygenate the waters on which they are growing, resulting in the death of fish and other aquatic fauna. Infestations also increase the rate of water loss, because the plants use water faster than it normally evaporates. Access to water by stock and wildlife can be restricted. Infestations have occurred in rice fields overseas.

Distribution in Victoria seems to be limited to aquariums and garden ponds. In other states salvinia has become a major problem in water storages and rivers.

Control

Salvinia plants found in aquariums should be dried and burned or buried so they cannot enter the storm water system. Tanks which contain the weed should be emptied onto lawns and gardens, not into sinks, drains or waterways. Mechanical removal of large infestations is extremely difficult. Early detection of this weed is therefore very important.

Chemical Control

Under Victorian legislation there are controls on various aspects of the uses of agricultural chemicals. Some particular uses are prohibited and some require permits. Users of certain agricultural chemicals are required to obtain an Agricultural Chemical User Permit (ACUP) or work under the direct supervision of an ACUP holder. Additional restrictions on the use of some herbicides apply to particular geographic areas known as Chemical Control Areas (CCA).

It is the responsibility of chemical users to familiarise themselves with these controls. See Agriculture Note: Agricultural chemical user permits (ACUP) and chemical control areas(CCA) for further information.

Contact the Regional Chemical Standards Officer of the Department of Natural Resources and Environment if further advice is required.

You should read the product label and follow all label instructions carefully before using any herbicide.

Use a product containing the following active constituent that is registered for use in Victoria to control salvinia in the particular situation in which you need to use chemical control. Consult the product label for detailed information.

* DIQUAT DIBROMINE MONOHYDRATE

This list of chemicals is based on information supplied to the Department of Natural Resources and Environment by the National Registration Authority for Agricultural and Veterinary Chemicals (NRA). The State of Victoria through the Department of Natural Resources and Environment has not assessed or checked the accuracy of the information supplied to it from the NRA as that responsibility rests with the NRA.

Important

Any person who believes they have located an infestation of salvinia, regardless of the area, please notify a Catchment Management Officer at a local office of the Department of Natural Resources and Environment.

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Tom B Newbie

Tom B

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i was there this arvo and according to some guys at the forgan cove carpark there is another hazard at np. Acoording to them they used to hunt wild dogs or dingoes as they quoted years ago around the shores of np and kuwongbah.

they reckon that they have spoken to the rangers about it recently and were told they have been spotted and are the reason behind the no fishing at night and the designated recreation areas. they also made a good point about there being a lack of kangaroos and wallabies in the area

needless to say it had me looking over my shoulder every 30 seconds or so but i was a bit sceptic to wether he was telling the truth or not

so maybe just a heads up to not fish alone around sunset incase these guys arent far off the truth

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Dinodadog Rising Star

Dinodadog

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Yes from the boats as Ray said dingoes,pigs,roos,red belly blacks trying to get in the boat with you, even had butcher birds that used to land on your rod while you were trolling,spiders would also drift with the wind and land on your rod, plus heaps of koalas in the trees close to the shore. Who needs the zoo we had the lot out there ha ha

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