The Benefits Of Dredging The Port Hacking River.

[jewgaffer]

QUOTE DAVEMMM

It seems it's all go in the Hacking at the moment between Grays pt ramp, audley weir and now the dredging has started again.........For those that don't know every few years they dredge the main channel and dump the sand off Cronulla beach....... This unfortunately leads to the area that has been dredged becoming an absolute fishing desert. ...........Dave

Hi Raiders.

I have introduced my article on dredging rivers as a new topic because I wish to cover the many aspects of it thoroughly in the interests of the members, and bring into open debate the affects of dredging on fish and marine life and of course the affects of dredging on our fishing.

Thanks davemmm for reporting accurately in the main on this interesting subject and adding that the area dredged will become an "absolute fishing desert"......No doubt those words echo some scientific findings or other and I believe this information whatever its source is inaccurate....In my opinion that statement is another example of what "scientific findings" and numbers can achieve.

What I am about to write is simply another opinion on which members should decide for themselves. Though my fishing methods are different to some others, they conform to a degree with the methods of a very small minority of anglers. I have no desire to be controversial and whenever I write an article I always intend leaving nothing short of a factual account as a legacy, for want of a better word, for readers to reflect on over their fishing years and I always expand on my views and I strive to give members enough headroom to form their own opinions.

My opinion on the subject of dredging a river is re-enforced by my phone call to Ballina today to a lifelong friend of my wife Shirley and myself, Jimmy Bowers, who is a full time hands on fishing expert who passed information on to me this mornimg on the benefits of river dredging, which Jimmy gathered over many years of hands on experience in fishing freshly dredged rivers sections over time and after consultation with others, including professionals and grass roots fishermen, who have no vested interest in fact finding whatsoever.

The Port Hacking Fishway has been completed, the Swallow Rock boat ramp in the process of being re-furbished and dredging has commenced.

FISHWAY:-

Work was finished several weeks ago on the Fishway ladder system to give fish such as Bass and Estuary Perch the opportunity to interact between the fresh water part of the Port Hacking River and the salt water system extending into the sea.

Due to the weir and the causeway, the salt water part of the system is unable to flow into the fresh water section and like the many other rivers are able to, the Port Hacking River cannot gradually taper out and flow until it loses its salinity and then become freshwater. Nor can the freshwater section of the Port Hacking River have the usual affect on the saltwater side as the Port Hacking is an unusual river as there is no connection to freshwater coming down from the mountains.

Saltwater species will not survive in freshwater if they find a way into the series of rocky holes and over the fishway ladder and into the freshwater section or if they go over the weir when the river is in flood.... They may be able go in and quickly return to the saltwater via the fishway I would think, and it may be possible for some saltwater species to adapt to a certain extent to freshwater conditions over time.

The barrier of the weir and the causeway remains and there will still be a sudden change from salt to freshwater only a matter of a few metres away.

DREDGING:-

My knowledge is limited on all the ramnifications of dredging. Thus in order to give members the proper facts on the affects of dredging upon their fishing, I phoned Ballina Fishing Farm this morning and spoke to my above mentioned friend Jimmy Bowers, who holds an honourary qualification in aquaculture, is a Tafe accredited lecturer to conduct fishing classes for children and people from all walks of life, and Jimmy advises and assists University students in work experience in marine biology and aquaculture prior to graduation. Jimmy has also been consulted by members of the N.S.W. Fisheries.

Besides being one of Australia's best grass roots fishermen, Jimmy Bowers is an expert in recreational fishing, commercial fishing and fish farming. His work involves nurturing estuary fish and providing a nursery for the farming of suitable deep sea species from the fingerling stage to adult hood and is experienced in providing highly successful methods in the farming of quality prawns.

Jimmy is very experienced in fishing both newer and older dredged river sections and his comments to me over the phone come from a fisherman's point of view.

I trust the information I am presenting from Jimmy's "hands on point of view" will help our members.

BENEFITS OF DREDGING:-

* Removes acrid river bed growth and provides immediate occupancy of most species for fossicking and exploratory reasons.

*the immediate changes provide fast adaption for new and old occupants

* the fish populations will improve even further from that point as the seasons roll on.

* Improves river hydraulics i.e pulls up and pushes out water and revives mangrove areas, dribbling away stale and smelly deposits .

* Provides a healthy environment in mangroves which are the nursery for baby fry of every natural estuary and some off shore species and further tide cleansing will provide for an ongoing supply of insect lavae and healthy top water and mid water zoo plankton and micro organisms which are an absolutely essential nursery supply for the very survival of our "bread and butter" fish including adult fish partcularly when carrying roe.

* Encourages feeders such as blackfish to frequent the area by paving the way for clean and healthy algae regrowth.

* Removes dead weadbeds, rejuvenates weed and sea grass growth providing cleaner environments for cephalods and other small organisms who cannot survive in dead or diseased wead beds and cannot thrive in sand bound and dying silt choked weed. and dredging also promotes the establishment of a variety of different grasses and other healthiy nutrients that thrive on them.

* By increasing depth, dredging gives bigger fish safe access further up river and allows fish such as big flathead access further within mangroves.

* Gives big fish deeper holes to frequent in cooler conditions during the day.

* Allows the return of missing species that were once prolific in the area.

* Allows jewfish, the estuary kings, access up river without the fear of being stranded.

* Allows deep sea whalers and estuary sharks such as bull sharks revitalised river sections to shake off deep sea parasites which are unsuited by up river conditions. This is a habit of bull sharks in particular, in up rivers areas and has been the case over centuries.

* Provides mullet preparing to spawn in the open sea a better opportunity to fatten up their row in a revitalised up river system by feeding on new moss and healty algae blooms. in up river cul-d-sac with healthy vegetation which is the habit of the mullet species.

The fact that the dredged silt is then deposited after careful consideration into beach areas chosen by the people concerned means we simply have to have faith in their choice of locations and the affects on those surroundings, and I myself believe we should have faith in them to do that.

I trust the information I am presenting from Jimmy Bowers and others who have given a down to earth "hands on point of view" will help our members.

Cheers

jewgaffer

Edited October 2, 2007 by jewgaffer

[DaveD]

Sounds pretty good from all of that, nice to share all the views there mate Hope every member takes something out of it, even if its just a little thought and opinion

[james7]

Interesting info Jewgaffer.

We watched them dump the sand off Cronulla yesterday. Once we drifted right over the dumped area only a few minutes later. We thought something may have been attracted to it but got nothing.

It was amazing to see the depth change from 9m to 2.5m over the dumping zone. I wonder how long before it disperses?

Cheers

Peter

[zook2001]

I used to fish the Belingen River at Urunga back in the early eighties and the fishing was really awesome until the stupid council decide to charge a licence fee to the dredger who promptly quit and the fishing was all downhill from there.

I don’t known if they ever restarted dredging but why does the Hawkesbury produce big fish, it’s obvious good water depth and current flow, the old ports a good place but would be so much better with more depth.

No doubt there is some temporary damage but longterm I think it's good.

Regards Charlie

[Davemmm]

Jewgaffer

There is no doubt that there is long term benefits from dredging for fishing in the Hacking.

As you stated water flow in and out is probably the most obvious along with channel depth attracting a larger range of fish species. The problem is though there is no weed or seagrass present in most of the areas that are dredged. I fished the channel hard last time it was dredged and came up with donuts (of course this may come down to my lack of fishen skills).

At the time I hadnt really fished the Hacking a lot but had consistently targetted flatties in the channel. Following the dredging - nothing. Of course the following summer the flatties had returned.

I think the dredging is a neccesity and certainly improves the river as a whole but in the short term the area that has been dredged has been a wasteland for me. I might just have to change styles rather than perservering with what worked pre-dredging.

Dave

Edited October 3, 2007 by davemmm

[luderick59]

[jewgaffer

narrabeen lake is a good example of what jimmy bowers is saying

after each dredging it takes about 6mths for the blackies and mullet to come back to their normal feeding habits

peter

[jewgaffer

narrabeen lake is a good example of what jimmy bowers is saying

after each dredging it takes about 6mths for the blackies and mullet to come back to their normal feeding habits

peter

[jewgaffer]

hi Zook 2001

Charlie, good one bringing up the Hawkesbury. I've got an idea there's something that doesn't meet the eye in *urban run off (*fancy words I sound like like a sewer scientist, ay)

Hawkesbury has better conditions such as deep water, big river, fast currents, tidal flushout.

The problem is development not adequately monitored.....Where are all the mud crabs and the big numbers of big bream and flathead that used to frequent the still backwaters, that's the issue up there.

Regards

jewgaffer

Charlie there's great fishing the Bellinger ay and the flatheads nests up the Kalang bridge

[Nook]

* Allows deep sea whalers and estuary sharks such as bull sharks revitalised river sections to shake off deep sea parasites which are unsuited by up river conditions. This is a habit of bull sharks in particular, in up rivers areas and has been the case over centuries.

That will be interesting in the Port

I've hooked a couple of (small) bronzies in Gymea Bay in the last 12 months (and have seen a couple of dolphins).

If they start getting bull sharks up there I'll have to rethink my approach to boarding my mates yacht moored out in the middle of one of the bays

[Evets]

Seems there might be someting to Jewgaffers post.

Dredging seems to liven up the river or lake.

Do we remember Gongfishos reports of the flatties he was catching in Lake Illawarra when it was being dredged? I seem to recall at some point he was catching a flattie almost every cast - all in a supposedly barren area.

Evets

[jewgaffer]

Perhaps someone should see where the work's up to when the dredge finishes on Friday and take a look where the clean water hits the cloudy stuff as the tide pushes up to a colour change.

When the tide runs back out, I would say every flathead in the river will be hanging around the point in South west arm and the near corners running into Yowie and Gymea Bay and I wouldn't be surprised if there was a lot of general activity at the base of both those bays from the bottom of the tide up.

Little Jewgaffer says we should go down there and fiddle around with his gulps and the nibble tip rods.

He tells me he's right on the money.

Jewgaffer

Edited October 3, 2007 by jewgaffer

[Davemmm]

When the tide runs back out, I would say every flathead in the river will be hanging around the point in South west arm and the near corners running into Yowie and Gymea Bay and I wouldn't be surprised if there was a lot of general activity at the base of both those bays from the bottom of the tide up.

The silt isn't running that far up. It seems to be dissapating around shiprock

dave

[Big-Pete]

There was an article written years ago about dredging Myall Lakes, everyone tried to stop it but when the work was done the fishing improved out of sight. Big whiting and every other species were showing up in big numbers.

So hopefully removing some of the sand out of the port will make a big difference, what was normally done all the dredged sand was simply heaped up in the middle of the river and over a short period of time wave and wind action would simply push the sand back into the holes created.

It will be good to see if the dredging makes a difference to the fishing and at least to make the river a bit easier to navigate.

Big-Pete