Tag Archives: salmon

The Derwent River near Wayatinah town ship

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Salmon hatchery at Wayatinah on the Derwent

Next to the bridge over the Derwent River on Wayatinah Road, an Atlantic Salmon hatchery owned by Salmon Enterprises of Tasmania Pty Ltd trades as Saltas.

According to the Tasmanian Salmon Growers Association the business was established in 1985 ‘after a report to the Tasmanian Fisheries Development Authority concluded that a salmon farming industry could be successfully developed in Tasmania. As a result, in 1984 fertilised Atlantic salmon eggs were purchased from the Gaden Hatchery (Thredbo River, Jindabyne, New South Wales, Australia), which were from stock originally imported in the 1960s from Nova Scotia, Canada. A sea farm was established at Dover in the south of Tasmania and a hatchery was developed at Wayatinah in the central highlands.’

Innotech Controls claims Saltas is ‘Australia’s largest producer of Tasmanian Atlantic Salmon smolt, supplying over 3.5 million smolt each year to the Salmon farm industry.’  Their website provides details about water temperature management using the water of the Derwent River and Wayatinah Lagoon. ‘At Wayatinah, the water used by the SALTAS hatchery is gravity fed from the River Derwent. During the hot summer months, when river flow is greatly reduced, the water temperature can rise by as much as 10 °C in an 8 hour period. Water temperature in excess of 23 °C can be fatal to the fish stock. Located 1km from the hatchery is Wayatinah Lagoon, a man-made lake that forms part of the State’s Hydro Electric scheme. Research showed that at a depth of 6 metres, the water temperature was consistently between 9 and 17 °C. A project was undertaken to utilise water from the lagoon for temperature control at the hatchery and to provide additional water in times of low flow in the River Derwent. The water temperature is monitored at the hatchery where it is maintained at 16 °C +/- 1 by staging the water pumps at the lagoon.’

A thesis by Anna Do offers ‘SALTAS currently operates two hatcheries: Wayatinah hatchery on the Derwent River and the nearby Florentine hatchery‘. When I walked on the north/eastern side of the river upstream from the Wayatinah Power Station last year I could not identify the buildings near the confluence of the Florentine with the Derwent River. Now I understand that I was looking at the second hatchery.  In this thesis on page 8, an aerial photo of the Wayatinah hatchery shows the Derwent River with considerably more water flowing that exists today. Refer to my photos of a stony river bed earlier in this post.

Meadowbank Lake

IMG_3898Dunrobin bridge

Chantale’s photo above shows the north western end (the furthest end from Hobart) of Meadowbank Lake. You can see the trail of Dunrobin Bridge strung across.

Collecting historical information about Meadowbank is not easy, however the information  I have located has added to my store of knowledge.

According to Environmental Flows for the Lower Derwent River Final Report to DPIWE February 2002 Freshwater Systems, Meadowbank Dam is located approximately 107km upstream of the river mouth.  This report divides the lower Derwent into ‘two major sections: 1. The lower River Derwent – the freshwater river between Meadowbank Dam and New Norfolk; and 2. The upper Derwent estuary – the estuary between New Norfolk (in the vicinity of the upstream tidal limit) and Bridgewater.’

A brochure providing information about access to Meadowbank Lake for anglers includes details about Recreational Fishery Management (Meadowbank Lake is managed by the Inland Fisheries Service as a Family Fishery and is open to angling all year round. Regular stocking with brown trout, rainbow trout and trophy sized Atlantic salmon maintains the quality of the angling.); Native Fish Management (The short-finned eel (Anguilla Australis) is stocked upstream of the dam wall. The blackfish (Gadopsis marmoratus), which is native to northern Tasmanian rivers, has been introduced into the Derwent system and may be encountered in the lake.); and Pest Fish Management (Meadowbank Lake has populations of the pest fish species, redfin perch (Perca fluviatilis) and tench (Tinca tinca). If either of these species are caught, anglers are asked to humanely kill the captured fish and dispose of appropriately.)

Discover Tasmania provides information which encourages access to and usage of the Lake and its shores.

Wikipedia gives background information about the Power Station.

The September 2013 LAKE MEADOWBANK PLANNING PROJECT BACKGROUND REPORT  prepared for the Central Highlands Council in partnership with Hydro Tasmania and the Department of Economic Development, Tourism and the Arts includes panoramic photographs of the Lake and explanations of many of its aspects.

Hydro Tasmania provides information about Lake- side facilities and also about changing water levels.

A little history associated with Meadowbank Farm since the 1970s can be read at this site.

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Perched between treed hills sits Meadow Bank dam, roughly 15 kms downstream from Meadowbank Lake’s far western end.   Chantale’s photo shows the start of that water catchment behind the dam wall and the Meadowbank Power Station nestled at its feet.

Green Island – do you know it?

How many islands are green with vegetation? How many blots of land are named Green Island? Probably many thousand.  Tasmania has a few ‘green’ geographical features spread around the state – followers may recall in an earlier walking stage I rounded Green Point on the eastern shore of the River. My walk along the Derwent River last week passed by a green Green Island.

While walking the length of Murphys Flat toward the northern end, across the water of the Derwent River I caught glimpses of a small length of low lying land in the flow of the Derwent River. Green Island was almost invisible from the western shore because the grasses in the Murphy’s Flat wetlands have grown tall.

This small piece of land provides a safe haven in which fish hang about the edges. New Norfolk Anglers Club members and others have enjoyed catching tagged salmon here.

Green Island is looked over by Mount Faulkner on the south western side of the river, and by Mt Terra and Mt Dromedary on the north eastern side.  On the map below, my arrow points to the slim Green Island near one bank of the Derwent River. The Lyell Highway is the yellow line curving through the lower part of the landscape. Murphys Flat is the fat area between the Highway and the River.

Green Island map