Tag Archives: pests

Weekly salon 23/8

1. The cost of pests

I recall we had some discussion about feral pigs, which rate fifth in a research study by Corey J. A. Bradshaw of Flinders University and Andrew Hoskins of the CSIRO in Pest plants and animals cost Australia around $25 billion a year – and it will get worse:

Shamefully, Australia has one of the highest extinction rates in the world. And the number one threat to our species is invasive or “alien” plants and animals.

But invasive species don’t just cause extinctions and biodiversity loss – they also create a serious economic burden. Our research, published today, reveals invasive species have cost the Australian economy at least A$390 billion in the last 60 years alone.

Our paper – the most detailed assessment of its type ever published in this country – also reveals feral cats are the worst invasive species in terms of total costs, followed by rabbits and fire ants.

Here is how they stack up:

It depends where you are:

Red imported fire ants are the costliest species in Queensland, and ragwort is the economic bane of Tasmania.

The common heliotrope is the costliest species in both South Australia and Victoria, and annual ryegrass tops the list in WA.

In the Northern Territory, the dothideomycete fungus that causes banana freckle disease brings the greatest economic burden, whereas cats and foxes are the costliest species in the ACT and NSW.

2. Humans are the biggest pest

I remember on our trip down the Rhine in 2008 a tour guide explaining that in Europe ‘nature’ had been mostly pushed into the mountains. Last week Gigi Forster and Peter Martin in the ABC RN program The Economists talk about Valuing nature, which economists mostly don’t. They tell us that humans and their domestic animals make up 96% of mammals on earth, with natural mammals squeezing into just 4%. Apparently domestic fowls make up 70% of the bird population. In the program:

A landmark report has urged the world’s governments to come up with a better form of national accounting from GDP, to reflect the value and depletion of nature. Plus, an update on carbon markets and the emerging field of biodiversity offsets.

Here’s the The Economics of Biodiversity: The Dasgupta Review – Full Report.

See also:

Economics’ failure over destruction of nature presents ‘extreme risks’Humans just 0.01% of all life but have destroyed 83% of wild mammals – study

This is what we amount to;

This is what we have done:

We will have to learn to live respectfully in nature, or we’ll destroy our nest. It won’t be easy. There was to be a UN biodiversity summit in 2020 in Kunming, China. This has now been delayed for third time due to the pandemic.

Can we stop the Sixth mass extinction event, the Holocene extinction, found to be accelerating?

Our future depends on what we do in the next little while.

3. Insects in trouble too

Dr Sanchez-Bayo, an honorary associate at the University of Sydney, undertook the first global review of studies of insect decline across the world and the reasons for it. See Insect population and species decline a ‘wake-up call’, scientists say:

“What we found is that 41 per cent on average of all insect species that we know are declining,” said Dr Sanchez-Bayo.

“Among those, a third of all the species are going into extinction. They’re in danger right now. The rate of extinction in insects is about eight times higher than the rate of extinction of vertebrates.”

Most of the studies surveyed were form the US and Western Europe:

One study, in Germany, saw a 75 per cent decline in insect biomass over 27 years. Another study in Puerto Rico reported losses of between 78 and 98 per cent over 36 years.

The rates of decline are so dramatic — up to 2.5 per cent a year — that Dr Sanchez-Bayo claims that at current rates there may be no insects in those regions within 10 years.

4. There is another story beneath our feet

For a long time now farmers and landholders have been told that storing carbon in soil was not only a good thing to do, it was something they could make money from by selling carbon credits.

Problem is that there is no solid science to back this up. Gabriel Popkin tells the story in A Soil-Science Revolution Upends Plans to Fight Climate Change:

One teaspoon of healthy soil contains more bacteria, fungi and other microbes than there are humans on Earth. Those hungry organisms can make soil a difficult place to store carbon over long periods of time.

It’s a long article, but the short story is that the assumption that carbon molecules stored in soil cam remain there for long periods of time. What we know now is that no such molecules can be found. Everything can be munched, although some do stick around.

Climate modellers apparently ‘simplified’ the issue by leaving microbial activity out. Some scientists are :

pushing to replace the old dichotomy of stable and unstable carbon with a “soil continuum model” of carbon in progressive stages of decomposition. But this model and others like it are far from complete, and at this point, more conceptual than mathematically predictive.

Researchers agree that soil science is in the midst of a classic paradigm shift. What nobody knows is exactly where the field will land — what will be written in the next edition of the textbook.

In short, they are in a muddle.

5. Pests found inside a hill in Canberra

Here it is:

Every week Federal parliament is sitting Tony Burke, leader for the opposition in the house, sends around to party members on his mailing list some pithy comments. Last week he told of one of his constituents, a woman who is 102 and lives in:

Western Sydney, which is the epicentre of the current COVID outbreak. She’s been on the pension for 40 years – and yet the government sent her a letter saying she’d be cut off unless she left the house in the middle of the lockdown zone to present proof of age documents she doesn’t actually have.

Luckily Burke’s office was able to get the matter fixed by Stuart Robert’s office. However, it continues the narrative that there is no blunder beyond the capability of this government. Their fiercest critic however is possibly Dennis Atkins, now retired and liberated from writing for the Courier Mail. He is particularly eloquent about their leader:

Where would this man be without pollsters dictating his every utterance?

A good question. Michael Pascoe this morning asks another in a must read piece if you want to understand what is going on with COVID messaging and posturing:

The COVID political ground is shifting – is an election moving it?

Here are some other recent Atkins pieces:

Scott Morrison will weaponise climate crisis in pursuit of re-election

As Scott Morrison tries to ‘get out of Dodge’, Australia needs a political reckoning