Jennifer Marohasy

a forum for the discussion of issues concerning the natural environment

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Cattle Killing the Macquarie Marshes?

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I started the week exploring the wetlands of Kakadu National Park in Northern Australia. I have ended the week exploring the wetlands of Central New South Wales (South Eastern Australia) with my friend Gill Hogendyk.

Gill, a trained vet, has always had a particular interest in bird watching. After moving to Warren (just north of Dubbo and south of the Macquarie Marshes) in 1990, Gill started taking a particular interest the birds of the Ramsar listed Macquarie Marshes.

Gill is increasingly concerned that the almost exclusive focus on environmental flows and water use by irrigators (her partner grows cotton) has distracted attention from the potential impacts of grazing on wetland environments including in the Macquarie Marshes.

This aerial photo taken earlier this year of the Marshes, shows the dramatic impact of grazing. The fence is the line of demarcation between an overgrazed private property and ungrazed nature reserve. The impact of grazing here is obvious and dramatic.

Over recent years there has been a focus on Australia’s intensive agricultural industries (eg. horticulture, cotton, sugar) and their environmental impacts with most of these industries undertaking environmental audits and developing codes of practice to address issues of community concern.

The grazing industry has had to contend with bans on tree clearing and been excluded from areas including the High Country, but there seems to have been limited interest in promoting best practice and addressing issues of overgrazing.

In the 1940s and 1950s there were restrictions on grazing and burning in the Macquarie Marshes including:

1. Reeds shall not be burned except with the written consent of the district surveyor,
2. Stock shall be excluded from all (reed) regrowth until 3 foot high, and
3. Rookeries (for bird nesting and breeding) will be completely enclosed with a sheep and cattle proof fence.

I understand that there are currently no such conditions on grazing in the Marshes.

It seems incredible that the flood-plain graziers of New South Wales are screaming so loudly for more water and attracting considerable media attention and yet the issue of overgrazing is being ignored by all.

Aerial photograph showing impact of grazing on the Macquarie Marshes.

The website mantained by the local Marsh management committee explains that The Macquarie Marshes is a large non terminal wetland in central west New South Wales and covers approximately 200,000 hectares, 88 percent of which is privately owned. The Macquarie Marshes Nature Reserve makes up the remaining 12 percent and is managed by the NSW National Parks and Wildlife Service.

UPDATE 24TH OCTOBER 2005

I have received some offline emails assuming that the main problem for the marshes is low flow because of Cubbie Station. The Macquarie Marshes are NOT downstream of Cubbie and the Condamine Balonne system.

Rather as detailed here: The Macquarie River is formed by the joining of the Fish and Campbell rivers near Bathurst. The Turon, Cudgegong, Bell, Little and Talbragar rivers join the Macquarie River as it travels north-west. Near the township of Warren, the Macquarie becomes a complex system of effluent creeks, wetlands and floodplains connecting the Macquarie, Barwon and Bogan rivers. The Macquarie Marshes are the wetland and marsh country of this area, consisting of about 40,000 ha of core wetland with up to 220,000 ha inundated during major floods.

The climate of the lower Macquarie River catchment is semi-arid. Rainfall and altitude decrease from east to west, while temperature increases. The marshes are less than 200 metres above sea level and receive approximately 400 mm of rain per year, although flooding occurs in most years due to rainfall in the headwaters of the catchment and occasionally locally (for example, as happened in 1983 and 1995).

Two sections of the marshes are separated by an isthmus and lie on early Tertiary alluvium. The southern section consists of open water linked by anabranches of the river, and contains reed swamps and other emergent vegetation. The northern marshes consist of more prominent braided channels and more extensive reed swamp and river red gum woodland.

Greenpeace Backs Desal Plant!

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I was interested to read at ABC Online yesterday, that Greenpeace has thrown its support behind ambitious plans for a solar powered water desalination plant in Whyalla, South Australia.

I have previously only heard environmental groups criticise such projects – generally suggesting we should just consume less water. Has there been any support for the wind-powered desal plant that I understand will be build for Perth? How advanced is this project?

According to the ABC Online report Whyalla Local councillor Eddie Hughes says desalination plants usually use huge amounts of power and generate greenhouse gases, but solar power would stop this from happening.

He says the plan already has substantial backing from the private sector and would have many benefits for the local community.

“Those benefits would be enormous. This would be the first plant of its type in Australia and if the pilot plant is successful it will demonstrate an environmentally friendly way of not just generating electricity but also providing desalinated water,” he said.

“Greenpeace has used this, what we’ve proposed for Whyalla, as an example of the sort of approach that we should be taking nationally and internationally.”

Whyalla is the largest provincial city in South Australia and the northern gateway to the Eyre Peninsula. It is known for its heavy industry, particularly the enormous iron and steel works.

Cows in Kakadu

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I spent yesterday in the Northern Territory’s Kakadu National Park. It was a truly magnificent experience.

I was surprised to learn that in the wet season 75 % of the park becomes covered in water much of it runoff from the Arnhem Land escarpment. I was also surprised to learn that about 75 % of the park is burnt each year.

And I was surprised to see cattle grazing in the park, view image (about 70 Kbs).

When I asked a local about this beast I was told “We would prefer they weren’t here, but these cattle are owned by one of the traditional owners and she lets them come out”.

I understand there were once 300,000 buffalo in the area but this number has been reduced to 1,000.

With the reduced number of buffalo, I am told the water is not so muddy and so there are a few more water birds. I saw a tremendous diversity yesterday including sea eagles,view image (about 70 kbs)and magpie geese.

My favourite was perhaps this comb-crested Jacana, view image (about 70kbs) – also know as a Jesus-birds because their 8 cm long toes enable them to almost walk on water.

Interestingly it is the male jacana that looks after the eggs – usually on a lilly pad. When danger threatens Dad has been know to tuck a few eggs under a wing and run somewhere safe. Mum may mate several times during the one season, leaving a few males each with a clutch of eggs to raise.

So Many Crocodiles

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There were once only about 5,000 crocodiles in the Northern Territory. The population was decimated in the late 1940 and 1950s by hunters. A ban was placed on hunting and the exportation of skins in the early 1970s. Croc numbers have bounced back and are now estimated at 70,000.

I took this photo of a crocs eye today in Darwin –
view image. My image editing software is not on this computer and thus this image is rather large at 450 kbs and might take a little while to download.

Dr Grahame Webb was involved with the program to rebuild croc numbers. He told me the following three principles were promoted:
1. public education;
2. a program to contain problem crocs including trying to keep crocs out of Darwin harbour;
3. ensuring crocs had a commericial value – so landholders saw them as an economic asset rather than a pest.

About 20,000 eggs and 600 crocs are harvested from the wild each year under a permit system. Eggs sell for about $40 each while crocs sell for perhaps $500.

Many locals wish there weren’t so many… so they could swim at the beach again.

Tim Flannery on Hockey Sticks

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In his new book the ‘The Weather Makers’ (Text Publishing, Melbourne, $32.95) Professor Tim Flannery suggests that the medieval warm period was unique to Europe with “a survey of global temperature records (from ice-cores, tree-rings and lake deposits) showing that, if anything, Earth was then overall slightly cooler (0.03C) than in the early and mid twentieth centuries”. This according to Flannery shows that the “idea of a global Medieval Warm Period is bunk.” (pg 44)

The real bunk is perhaps Flannery’s claim that the world’s leading science journals are telling us that species are vanishing right now as a consequence of climate change. (pg 6)

He is a good writer though, and there is some interesting stuff in the book including his comment there are three agents of change:
1. shifting continents,
2. cosmic collisons and
3. climate-driving forces such as greenhouse.
Flannery writes that while they all act in different ways, they drive evolution using the same mechanisms “death and opportunity”. (pg 46)

Close Down the IPCC

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The US Senate Committee on Environment & Public Works continues to hear testimonials on climate change and related issues.

Earlier this week Lord Nigel Lawson from Britian’s House of Lords told the Americans what he thought:

“I am grateful for your invitation to testify before you today. I am aware that you have been provided with the Report of the House of Lords Select Committee on Economic Affairs on The Economics of Climate Change in advance of these proceedings, so I intend simply to summarise our key findings and to provide some commentary of my own.

By way of background, the Economic Affairs Committee is one of the four permanent investigative committees of the House of Lords, and fulfils one of the major roles of our second chamber as a forum of independent expertise and review of all UK government activity. It is composed of members of all three main political parties. Its climate change report, which was agreed unanimously, was published on 6 July 2005, just ahead of the G8 summit at Gleneagles in Scotland.

In summary, the Committee concluded that:

1. The Government should give the UK Treasury a more extensive role, both in examining the costs and benefits of climate change policy and presenting them to the public, and also in the work of the Intergovernmental Panel on Climate Change (IPCC);

2. There are concerns about the objectivity of the IPCC process, and the influence of political considerations in its findings;

3. There are significant doubts about the IPCC’s scenarios, in particular the high emissions scenarios, and the Government should press it to change its approach;

4. Positive aspects of global warming have been played down in the IPCC reports: the IPCC needs to reflect in a more balanced way the costs and benefits of climate change;

5. The Government should press the IPCC for better estimates of the monetary costs of global warming damage and for explicit monetary comparisons between the costs of measures to control warming and their benefits;

6. A more balanced approach to the relative merits of adaptation and mitigation is needed, with far more attention paid to adaptation measures;

7. UK energy and climate change policy appears to be based on dubious assumptions about the roles of renewable energy and energy efficiency, and the costs to the UK of achieving its objectives have been poorly documented, and the Government, with much stronger Treasury involvement, should review and substantiate the cost estimates involved and convey them in transparent form to the public;

8. Current UK nuclear power capacity should be retained;

9. International negotiations on climate change reduction will prove ineffective because of the preoccupation with setting emissions targets. The Kyoto Protocol makes little difference to rates of warming, and has a na