We acknowledge the Traditional Owners of these lands and waters.
World Rivers Day was the fourth Sunday in September.
“Rivers are the arteries of our planet; they are lifelines in the truest sense.” Mark Angelo. https://worldriversday.com/
Jacob, one of our younger Landcare members, has recently written a project (attached to this update) about freshwater fish. One question he poses is, “Why hasn’t research been done in our local rivers on the native (fish) species?”
The good news is that, as a result of the challenges managing impacts of recent high rainfall on water quality during highway construction at the Black Spur, extra monitoring and research of our nationally vulnerable Australian Grayling Fish will be undertaken both upstream and downstream (thanks to our EPBC laws). This may give insights into Grayling breeding habits and will take place when there are significant events or incidents and then each April for two years after road construction is completed.
High sediment loads have been clearly visible and CPB contractors have been putting in a major effort to slow run-off, catch sediment, anticipate where flows will occur and even be prepared to proactively treat water to improve water quality. Under special conditions, they have been allowed limited access to the flood plain. The white protective sheeting to slow erosion made me think of the wrapped cliffs of the artist Christo!
Take extra care on highway and rail trail. There will be more short stoppages as soil is transported from one side to the other. Major Road Projects Victoria (and CPB Contractors) has released an informative community update for October.
Amidst the construction delays and challenges, spare a thought for the original builders of the Great Southern Rail Trail and its bridges - which subsequent 1890 floods washed away. Coral found a newspaper article about it – “How the Money Goes” The Age Saturday 13 1891. It is available online http://nla.gov.au/nla.news-article190625094 . “Fearfully rough country” was mentioned. “About 75% of the timber used was Blue Gums, the remainder being Red Gum, Iron Bark, and Box brought from the Gippsland Lakes” by steamers and schooners to Franklin River.
Our group bird-monitoring walks have resumed in small numbers again after being interrupted by Covid 19 restrictions. A platypus and koala were recent highlights (even though not birds!). It’s also good seeing Black Cockatoos unperturbed by road works and Australian Clematis (Clematis aristata) looking beautiful with their white blossom draped over shrubs. Control of Sweet Pittosporum (recently begun along the Rail Trail) followed by revegetation will assist these species. Unfortunately the Rail Trail Management Plan only specifies removal of 50 % of the canopy over 3 years which, without follow up, will provide only partial and very temporary control.
At Mel and Luke’s wetlands, swans hatched 6 cygnets and they now seem to wander between adjoining Black Spur Wetlands and Sue and Eric’s place. This will be good news to bird watching members of The Blackburn Creeklands https://blackburncreeklands.wordpress.com/ who have been in touch since their visit earlier in the year.
The documents from Nerrena Tarwin Valley Landcare Group’s September Annual General Meeting are on our website. There was a very interesting piece on the Koonwarra Fossils in the Sentinel Times 16 September 2020 https://sgst.com.au/2020/09/ne... . Dr Stephen Poropat is scheduled to present to us on 16th October.
Platypus & Koala photos by Sue Miles Sept 2020
TROUT - THE FRESHWATER FOXES
The following contribution is by 11 year old Nerrena Tarwin Valley Landcare Group Member, Jacob Tumino.
Trout are not native to Australia. They came from Europe and North America between1864 to 1900 and they brought the ova (fish eggs) in boxes of moss on the ships.
The English settlers brought them out because they were prime fishing stock, so consequently thought that everywhere else should have access to their “best fish”. They tried to “improve” the Australian fisheries by introducing trout and other species.
The English did not think about the consequences of introducing these fish to Australia - just like European carp, rabbits and foxes.
Five species of trout have been imported but the most common are Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss)
Trout eat insects, crustaceans, molluscs, worms and small fish such as Galaxids. Some of these fish that have become endangered because of trout are the Trout Cod from Northern Victorian rivers and the Shaw Galaxias from the northern part of Gippsland.
Regarded by the Victorian Department of Primary Industries as a valuable resource for recreational fishers, they have classified them as a desirable introduced species.
Between 1996 and 2007 14,000 Rainbow and Brown Trout were released into the Tarwin River East Branch, with only 3000 Brown Trout tagged.
Not much is known about the native fish in South Gippsland rivers, maybe there are species which have not yet been identified which could be a risk of extinction due to predatory species.
In Gippsland the Trout have been excluded from the upper reaches of the small creek off the Macalister River in the Alpine National Park. Severe floods and storms in 2010 & 2011 caused the Shaw Galaxias to only live in a 3.00 meters long by 0.3 meter wide creek. A group of environmental organisations worked together to install a permanent predator barrier near a waterfall further down the creek to exclude the trout. Shaw Glaxias were only identified in the past 10 years.
Trout have caused the near extinction of a number of species of fish and invertebrates. In the Murray River system Trout Cod and Macquarie Perch have become endangered due to the introduction of Trout. Trout are a serious threat to Barred Galaxias in the Goulburn River in central Victoria.
I would like to pose the questions –
Why haven't we released native fish to our streams?
Why hasn't research been done in our local rivers on the native species?
Isn't anyone worried about the environmental impact of fish in our streams?
Jacob Tumino
References
https://vfa.vic.gov.au/recreational-fishing/fish-stocking/db/search-by-species-and-water
https://theconversation.com/rabbits-of-the-river-trout-are-not-native-to-australia-14115
North Central Catchment Management Authority – Rainbow Trout & Brown Trout Fact Sheet
Parks Victoria Media Release 9 May 2013 Barriers shore up the future of the rare Shaw Galaxias
http://www.environment.gov.au/resource/trout-cod-blue-nose-or-rock-cod-maccullochella-macquariensis
With thanks to Matt Bowler- West Gippsland Catchment Management Authority
