Bird Loss in the Coorong

Saturday 7 December 2002 12:00AM (view full episode)

Earthbeat visits South Australia's Coorong where
bird numbers have plummeted as the mouth of the Murray
River has all but closed.


Alexandra de Blas: On Friday, Federal and State leaders failed yet again to finalise details on a system of national water rights, opting instead to discuss the issue further at future meetings.

At the same time, the water taken for irrigation upstream plus severe drought continues to wreak havoc right along the 2-1/2-thousand kilometre length of the Murray River.

Understandably, there isn't a lot left by the time the river reaches the sea. And yet the final estuary is a key part of Australia's environmental heritage.

It's where thousands of migratory birds gather every spring and summer, and is an area Australia has promised the international community it will protect.

This year the mouth of the Murray is only being saved from complete closure thanks to an emergency dredging program. And a recent bird count had spring arrivals down to a quarter of what they were a year ago.

Annie Hastwell reports from the Coorong wetland near the Murray mouth.

Tom: From one end of the Coorong to the other you could travel and you could see the species of birds from one end to the other. Now you've got to go to certain little spots where all the birds are gathered, because that's the best parts that are left where they're all trying to compete for the little bit of food that's left.

Annie Hastwell: Ngarrindjeri elder Tom Trevorrow is deeply worried about the Coorong, and so should Australia be. South Australia's 110 kilometre stretch of tidal coastline is famous all over the world as one of an elite group of wetlands where birds come to feed and breed. We're signed up to an international treaty to protect its habitat, but with the Murray mouth closing over, the Coorong is suffocating and the birds are staying away.

Tom and his uncle Neville Gollan run Camp Coorong where they take tourists like me out to appreciate their country.

Now we can only see one bird at the moment, a pelican sailing across, and there's a few over there. How much do you notice the difference in birdlife?

Tom: They're very scarce to what they used to be, and the variety of birds that have gone. The curlew is one that was here, never ever came back. And then the snipes, the different variety of snipes coming and going, but they're gone. You look out there, there's some snipes up there, but that's only like one handful to what it used to be those days. Then there was the musk duck. The musk duck splashed the waters, in the fresh water and the salt water, and where we (saw) splashed water it was a good sign of plenty of fish available. So where they were, you went and hunted.

Annie Hastwell: When Neville Gollan was a child, the mouth of the Murray was a dynamic piece of water that actually moved several kilometres up and down the coast from year to year. In 2002 it's stagnant and full of silt. Dr David Paton from the University of Adelaide, has spent 20 years tracking birdlife in the area.

David Paton: The major change has been just a steady decline in the numbers of waders, particularly the ones around the shorelines, and probably in the 1980s there were 50,000 to 60,000 waders using the area. And the last five or so years when we've been going down, it's been consistently around between 5,000 and 15,000. So it has dropped substantially. When looked at historical records, the estuarine areas near the Murray mouth were up to 250,000 small waders going there, now in just that region, the top 20 kilometres of the Coorong, it's probably more like 5,000 to 10,000. So that's like a twentyfold reduction in numbers.

Annie Hastwell: From the waders' point of view, what is it about the Coorong that they don't like now?

David Paton: Well it's not so much a matter of the Coorong they don't like, they can still be there in small numbers, but they're not going to perform as well. And the number of changes that have happened, which is related to how we manage the Murray and the water which comes down the Murray. The first one which has happened at least very prominently recently has been a silting up of the Murray mouth and a silting up of the channels inside the Murray mouth, and this is caused by lack of flows pushing that material out, and the material that's coming in is actually coarse marine sands which come in with sort of storm action and so forth. The dilemma with that sand that comes in, marine sand is coarse and coarse sands, when they deposit on the sediments make it that much harder for the invertebrates that live there to grow well. They make it that much harder for the waders that have got little tiny beaks and have to pick out things about the size of sand grains, to pick the difference between a sand grain and a little invertebrate. So you've got those two factors. And the third factor is that when you start to fill up the system with coarse sands and close off the mouth, you change the tidal flux. Now the tidal flux is the sort of tidal changes in water levels, and if you had an open mouth in the system which is functioning well, you'd expect about a .5 of a metre, half a metre change in water level. Now it's probably down to barely .1, and only over a very small part of that Coorong system, because the rest has all silted up and closed off. That then changes the amount of habitat available for these small migratory waders. Now the migratory waders are short-legged things, they like to feed around the shorelines in water that gets no deeper than about a centimetre or so. If you have no tidal changes in the water inside the system then these poor waders can only forage in a very limited range of mudlfat around the edge. When you have a tidal flux, at least something of half a metre, then they can shift that foraging over the tidal cycle over a much, much wider area of habitat and that makes that system so much more important to them , when you've got a tidal flux.

Annie Hastwell: The South Australian government is taking the Coorong's problems very seriously. Environment Minister John Hill is overseeing a massive 9-month dredging operation at the Murray's mouth which began in October. But he says it's no more than an emergency quick fix.

John Hill: The dredging will just help this year's survival. Our concerns were that if the mouth of the Murray blocked then the Coorong would really start cooking, and it would have a detrimental effect both on the birds but also on the fish that live in that river. The dredging, the channel that we're creating will keep it open so that it'll help this year but it's not a long-term solution. We need more water for the River Murray, that's out big argument, we need probably up to about 3,000 extra gigalitres of water a year. The system currently has extracted something like 73% of its natural flow each year, so we're just really getting a trickle down here at the mouth. Too much water is coming out from the other States and this is not a long-term solution.

Annie Hastwell: We do have Federal environmental legislation as of the last couple of years, the Environment Protection and Biodiversity Conservation Bill; should the Federal government be using that in some way to force the hand of irrigators and so forth further up?

John Hill: Well they've got very strong powers with that Bill, and it would be interesting to explore what they could do with those powers in relation to the River Murray and to keeping the Coorong health looked after. I think part of the problem with the River Murray system in fact, or the political system, is that the Commonwealth chairs it and they've always given the chair to the Agricultural Minister rather than the Environmental Minister, and I think that just really demonstrates that the Commonwealth's view is that this is an agricultural issue rather than an environmental issue. And until they kind of change fundamentally their thinking, I'm a bit worried about the capacity for us to move ahead very quickly.

David Paton: The difficulty here is that there's a lot more to do than that, and the dredging of the mouth is a short-term solution. Ultimately one has to provide the other component of keeping the Coorong alive which is providing more flows out through that system to provide the extra nutrients and the fine sediments, and to actually give that thing a full total flux. We don't want to be spending $2-million every five, ten years to dredge the Murray mouth just to maintain a fabric of what it once is.

Annie Hastwell: If we were to let the wetlands degrade, what implications does that have for our status internationally?

David Paton: That's an intriguing question. I mean one way which will happen here is that the Coorong might get blacklisted, no longer being a suitable, or Australia will get blacklisted as not managing its wetlands to an appropriate level. I think Australia has the potential to be a leader in how it does environmental management. What we need to appreciate is that 200 years ago when we came to this country we came with a European agricultural system that is not suited to the Australian environment. The Australian environment has fragile soils, nutrient poor soils. It also has the sort of vagaries of the weather. We have droughts and so forth. Now they're not designed for the types of intensive agriculture that we currently put on the landscape. We need to be smarter about how we do agriculture to provide a sustainable agricultural system.

Neville Gollan: We know that this talk along the river, why people are saying Why waste fresh water to send down the river so it can flow out through the Murray mouth to the ocean? They say that's a waste of water. It's a part of the cycle, and it's like, how could I put it? everybody knows that what we put into us must come out, what goes in the river and that must go out, and to keep everything clean and fresh and operating effectively, is the same as a body, the land is body, everything must flow out to keep it all clean. If our mouth blocks up, if our Coorong dies and becomes polluted, our lake will die, our river will die, eventually it's going to go upstream and everybody's going to cop it.

Annie Hastwell: When you see the Coorong shrinking like this and when you see the effect on birds in particular, what would you like to see done, what solutions do you see that there are?

Neville Gollan: I'd love to see the Murray River open up and let it flood again, and try and bring it back to where it was. I don't know by what means they could open this up going into the sea, open it all up and let it be what it used to be. Where they were getting sharks up river, stingrays round Murray Bridge, porpoises, you know? You don't see that any more, they blocked it off and when they blocked it off they blocked everything off, and of course the lake dried up. They're just trying to get it back together now, but it's a very, very hard life, and I'd love to see it all come back with plenty of water for everybody.

Alexandra de Blas: Annie Hastwell reporting from South Australia. And John Hill, the South Australian Environment Minister who we've just heard from has just tabled his River Murray Act in the State's Parliament.

And that's it for another Earthbeat, produced by Jackie May and Janita Palmer. I'm Alexandra de Blas. Next week at this time, join Jackie May for a look at the issues facing mountain communities around the world, including our own Snowy Mountains system.



Tom Trevorrow
Ngarrindjeri Elder
Coorong Visitor Centre
Camp Coorong
South Australia
Neville Gollan
Ngarrindjeri elder
Coorong Visitor Centre
Dr David Paton
Senior Lecturer in Environmental Biology
University of Adelaide
John Hill
Minister for Environment & Conservation
Minister for the River Murray
South Australia


Alexandra de Blas
Jackie May
Annie Hastwell