Gone Fishing

One of the most common recreational uses of rivers is fishing and in this, the Barwon and its tributaries are no different to most. What is caught and where varies from river to river and location to location and there are multiple websites which give detailed descriptions of what fish can be caught where and when, such as the Department of Environment and Primary Industries site which includes the Barwon and more.

Fisherman at Barwon Heads

During my meanderings up and down the Barwon I've come across several species of fish which call the river home and come across all sorts of people fishing along its length, from families fishing off the William Buckley footbridge at Barwon Heads or on the banks amongst the mangroves to the retirees fishing off the platforms through Geelong.
On a recent paddle up from Baum's Weir we met a guy paddling a fully-equipped Hobie Cat upriver to spend the day fishing for redfin (aka English perch) in the quiet section of river above Merrawarp Road. He claimed to have caught over fifty of the fish in the river over the past two weeks, which is good news for the Barwon as they are an introduced species which impacts native fish populations. Fortunately, they also make good eating (the reason they were introduced by settlers in the 1860s). Whilst they have been declared a noxious species in New South Wales, this is not as far as I can tell, yet the case in Victoria, however anglers are strongly encouraged not to return redfin to the water once caught.
Other problem exotic species I have come across in the Barwon are mosquito fish and of course carp, all of which I mentioned in an earlier post. It has been noted that since the introduced carp population took hold in the 1960s, that stocks of redfin have reduced, however the carp themselves cause serious damage to native fish populations and our waterways.


Carp in the Barwon at Breakwater

On the other hand however, I did come across a native species on a recent fishing excursion to the Moorabool River. We took the kids (along with the rods they received for Christmas) to a relative's property where we used to fish as kids too. I can't say that the haul was huge however, there were several good bites which resulted in a catch of one short-finned eel and a redfin fingerling, which had the misfortune of catching its tail on the hook.

Short-finned eel taken from the Moorabool

Like redfin, short-finned eel make good eating and are particularly popular as an export to Japan. They are found in many of our waterways, extending from the South Australian border along the east coast. They are also found in New Zealand and almost as far north as Fiji. Their ability to draw up to 50% of their oxygen through their skin, means young eels are able to move short distances between bodies of water such as lakes, river pools, swamps and dams over moist ground, where they stake a territory of around 400m. Males are somewhat smaller than females, reaching maturity at around 14 years as opposed to females maturing between 18 and 24 years.
Short-finned eels were also an important source of food for the local Wathaurong tribes who used the rocky parts of the riverbed - such as the anabranch at Fyansford - to create traps to catch the eels as they swam downstream.

Anabranch, Fyansford

Whilst there are a number of other species of native fish common to the Barwon and associated waterways, I have yet to spot them.

Invasion forces

Not all of the flora and fauna to be found along the Barwon River is native in its origin. Of course, there are plenty of eucalypts and wattles, kookaburras and cockatoos, but there are also many foreigners.

Common Starling

Some of the most obvious introduced species are birds. Through the urban areas of Geelong, the Common Myna is regularly seen as are Common Blackbirds, Rock Doves (aka feral pigeons), Spotted Doves, Common Starlings and House Sparrows. All were introduced to Australia in the mid to late 19th century from Asia or Europe and have made themselves very much at home.
Blackbirds, starlings, sparrows and mynas have all become pests, affecting crops and urban gardens across the eastern part of the country whilst nesting pigeons can create unsightly messes on and around buildings.

Rock Dove aka Feral Pigeon

Another species which has been introduced to Australia and to the environment of the Barwon is of course the rabbit. This was introduced to the district in 1859 by Thomas Austin of Barwon Park near Winchelsea as I mentioned in a previous post.

Rabbit on the banks of the Barwon

It took barely a decade before the rabbit population exploded, causing soil erosion and untold damage to native plants. It has been suggested that the rabbit is the largest contributing factor to the loss of native wildlife in the country. Over the last century and a half, various measures have been taken to control the rabbit population including trapping, hunting, destruction of rabbit warrens, the erection of a rabbit-proof fence and in the 20th century, the introuction of the Myxoma virus in 1950 and then in 1995 the calicivirus.

Carp at Breakwater

Unfortunately, none of these measures has been successful in eradicating the rabbit population and in recent years, the return of sufficient rainfall to end the drought and increase food supplies has of course resulted in a huge upsurge in the rabbit population across Victoria. This is also true along the banks of the Barwon and its tributaries. Measures are currently being taken to cull them with baits laid along the river, however there still seem to be plenty of them to be found.
Other pests which are not so easy to see can be found in waterways throughout the country. Carp are common in the Barwon and are often caught by fishermen as are redfin. Both are introduced species which compete with native fish for resources. Carp are omnivorous, eating plants, insects, zooplankton and other small organisms. Significant reduction in the levels of zooplankton can leave rivers susceptible to algal blooms. Redfin eat other smaller fish and the young of larger fish, reducing the numbers of native fish and putting strain on their food supplies.

Mosquitofish in the Moorabool River at Fyansford

Another tiny immigrant which has found its way into the Barwon river system is the mosquitofish. These fast moving little fish form schools which swim close to the water's surface making them relatively easy to spot. They were introduced in the north of Australia in 1925 in a bid to control mosquito numbers, however as with many such introductions, the mosquitofish has done more harm than good and its effect on the mosquito population has been negligible. It is now believed that some native species of fish do a better job than the mosquitofish for which mosquito larvae form only a portion of their diet. In addition to the larvae they also consume algae-eating zooplankton with the result mentioned above and a variety of insects and beetles, reducing food supplies for other native species.
Mosquitofish are aggressive, attacking other fish causing injury and infection, they breed prolifically, are resistant to many of the toxins and chemical pollutants found in waterways and can survive in a wide range of temperatures and salinity levels enabling them to out-compete almost any other species of fish.