Invasive carp - trapped by their own behaviour

A weir keeper,Alan Williams, has invented a trap which could help to capture a large proportion of the carp which have invaded the Murray-Darling River Basin in New South Wales, Australia.

Native fish species do not jump, but carp do.

Alan's ingenious trap, developed in collaboration with Ivor Stuart from Victoria's Department of Sustainability and Environment, takes advantage of this difference in behaviour.

On entering the trap, carp jump into a second cage and trap themselves - ready for later collection. By contrast, native fish swim straight through the trap, without jumping, and leave unharmed.

In trials, this trap has removed up to 90% of the carp in a stretch of river!

Carp were deliberately introduced to Australia in the 1850s, and have also become serious pests in New Zealand, North America and Europe.

As bottom feeders, carp eat aquatic plants and stir up sediments. The muddy water they produce not only has lower light penetration, less plant growth and reduced oxygen concentrations, but is also less suitable for most native fish.

Prior to this invention carp were very difficult to catch. Fortunately, Alan and Ivor have decided not to patent their invention and to make the trap as widely available as possible.

In 2004, Alan and Ivor won a well-deserved A$10,000 Eureka prize from the Australian Museum.

Australia's Balancing Act...

Australia's CSIRO and the University of Sydney have recently published a report entitled Balancing Act A triple bottom line analysis of the Australian economy.

This report provides an overview of the Australian economy using a set of ten environmental, social, and financial indicators.

The environmental indicators are water use, land disturbance, greenhouse emissions and energy use; the social indicators are employment, government revenue and income; and the financial indicators are operating surplus (or profits), exports and imports.

All effects are referred back to a consumption dollar – roughly the dollar spent by a consumer in everyday life. It also shows that each consumption dollar is quite different – some dollars are positive and create employment, or suck in imports or generate government revenue. Other consumption dollars are less positive through their high use of water or production of greenhouse gas emissions.

It is hoped that this relatively simple presentation of highly complex issues will become a powerful tool for people in industry, government and the community who are interested in sustainability and enable them to make decisions based on a contribution to society, environment, AND the economy.

The report can be downloaded in four very large .pdf files: Parts 1, 2, 3 and 4.

Businesses call for long-term climate change targets

The heads of twelve of the UK's biggest companies, including BP, Shell, HSBC Bank, BAA, John Lewis, Scottish Power have signed a joint letter asking the British government to make firm and consistent commitments to long-term action on climate change.

Between them these firms employ 10,000s of people and have a turnover of £452bn.

To date, few of the encouraging statements made about climate change by the UK government have been backed up by long-term, binding commitments.

The classic example of this short-coming is the Energy White Paper. This policy document committed the government to ensuring that 10% of the UK's energy came from renewable sources by 2010.

Unfortunately, the white paper included only non-binding aspirations for 20% of energy to come from renewables by 2020 and for greenhouse gas emissions to be cut by 60% by 2050.

Businesses, such as those in the energy sector, which plan and invest many years ahead have so far refused to spend money on expensive new technologies and infrastructure until they know for certain that future governments will continue to support their investments.

However, the International Energy Agency has estimated that in order to meeting growing demand the world will spend $16,000,000,000 on energy infrastructure over the next 25 years... and there is clearly money to be made by companies which position their businesses in the right way, and do as much as possible to reduce their exposure to risk.

The authors of this letter therefore offer to work with the government to produce the long-term policies needed for British businesses to shift to low carbon technologies and develop the new industries necessary to meet the government's target of reducing CO2 emissions by 60% by 2050.

At present the government doesn't want to make long-term spending commitments or to become unpopular with voters, by increasing energy bills (if only slightly), and businesses aren't prepared to take unnecessary or unprofitable actions, even when they know it's in everyone's long-term interests to minimise the effects of human-induced climate change...

It is to be hoped that this Catch 22 deadlock can be broken, and Earth Info welcomes this letter is a positive step in the right direction.

An introduction to the photographs below...

A long time ago I promised that I would post some stories on my ecological research and travels in Australia... Below are five photographic stories which attempt to fulfill this promise.

These pictures illustrate the ants I was so fascinated by, the Acacia plants whose pollination ecology I studied, the effects of introduced animals on Australia's ecology, the impacts of roads on Australia's plants and animals and how intensive farming has permanently altered vast swathes of Australia's unique and little-studied ecology.

Unfortunately, although the farmers I met were all very kind and hard-working, they had not yet accepted that the climate and soils of Australia were totally unsuited to the long-term farming of European wheat, sheep and cattle.

In my view, Australia's outback is far better suited to the development of high value and unique crops, based on native flora and fauna. Native Australian species differ in that they have evolved to cope with local conditions, and do not consider every year to be a drought year!

Their limited distributions also mean that they are much less susceptible to fluctuations in global prices, or the weather, and offer many of the best tools for tackling Australia's rampant dryland salinity problem.

Human induced, dryland salinity - the result of excessive land clearance pulling up water tables and ancient sea salts - has already desertified millions of acres of the country's best farmland. It now threatens to make Perth and Adelaide's drinking water undrinkable.

I loved my time in Australia, and even became a citizen while I was out there, but cannot hide that I was very disturbed by the lack of awareness, and concern, about the extent and severity of the environmental problems building up in Australia. Which are mostly out of sight and out of mind! The sooner, and more comprehensively, these problems are tackled, the better it will be for everyone who lives in the countryside or who cares about the state of the environment.

P.S. All of the pictures on this site are protected by copyright and may not be copied without permission.

Meat Ants guarding Lycaenid caterpillars from Bull Ant attack

(1.) An Australian Bull Ant viewed under a microscope


(2.) A Bull Ant foraging on Acacia mearnsii


(3.) A Bull Ant returning to its nest with a Lycaenid caterpillar as prey


(4.) Lycaenid caterpillars at different stages of development


(5.) Meat ants tending and guarding a mature Lycaenid caterpillar.

Meat Ants guard Lycaenid caterpillars against predators such as Bull Ants and birds, and parasites such as wasps and flies. In return for being guarded, the caterpillars offer the Meat Ants nutritious secretions from special organs located at the rear, and along the length, of their bodies. The Meat Ants also appear to direct the caterpillar towards fresh foliage and to herd them around the tree.

The Ecology of Australian Acacia

(1.) The foliage of most Australian Acacia species is bipinnate in juveniles, but phyllodinous in adults. A phyllode, is made from thickened leaf midrib, and more resistant to water loss than normal leaf tissue.


(2.) In Africa and America all the flowers within an Acacia flower head open simultaneously over 1-3 days. In Australia, the flowers within Acacia flower heads often opened in a staggered fashion, over several days.


(3.) The long-lasting flower heads of Acacia melanoxylon change colour as they age. This change in the colour is thought to allow all the flower heads on a plant to attract pollinators from a distance, and then to guide pollinating insects to the flower heads bearing the most pollen once they are close enough to discriminate between different flower heads.


(4.) My PhD research found that hoverflies were more frequent and reliable flower visitors to Acacia flower heads than native bees. It is possible that hoverflies flies, and some beetles, are important pollinators to some Australian Acacia. Unfortunately, large scale land-clearance and pesticide use in Australia have resulted in many pollinators being lost. If the pollinators of more native plants are not discovered, and protected, it will be impossible to conserve threatened species or to revegetate Australia using native plants adapted to local conditions.


(5.) An Acacia pycnantha flower head bearing large numbers of seed pods. It is possible that introduced honey bees, which collect large amounts of pollen from single flower heads and plants, were responsible for the unusually large numbers of seeds being produced on this species. It remains to be discovered whether honey bees are affecting the quality of the Acacia seed bank, due to their collecting and moving pollen between plants in new ways.

Animals that have been introduced to Australia

(1.) An Australian farm dog.


(2.) A feral kitten left in a hollow tree by its mother.


(3.) An anti-fruit fly sign on the border between South and Western Australia.


(4.) Camel grazing on farmland near Nimbin, New South Wales.


(5.) A roadsign indicating that camels are a road hazard over vast areas of Australia. During the 1880s, camels were introduced to Australia in order to transport goods across the dry expanses of Australia. When steam railways made camels uneconomic as a mode of transport the predominantly-Afghan camel herders released their animals into the wild. With no natural predators and plenty of suitable food there are now thought to be up to 500,000 camels roaming around Australia. These numbers can result in heavy grazing and place a strain on water resources which are already scarce.

The impacts of roads on Australia's environment

(1.) Cows crossing in front of two roadtrains. The skid marks on the road suggest road accidents involving animals are common.


(2.) A sculpture inviting drivers to avoid livestock on the road.


(3.) A dead kangaroo found on a road in South Australia. Roadtrains hit so many wild animals that they are usually fitted with roo bars made from huge iron girders. Drivers don't always stop for injured animals, and many dead animals are left on the road.


(4.) A highly endangered Acacia cochlocarpa plant can be seen growing on this roadside verge. South-western Australia has been heavily cleared for farming. Despite the high level of land clearance this region is still one of the most biodiverse regions in the world. Unfortunately, this rare plant is at risk of being bulldozed in order to protect drivers from animals which sometimes stand on the side of the road. With approximately 100 individuals remaining in existence this plant really needs physical protection. This could involve diverting the road or the erection of a fence.


(5.) Travellers often transfer fruit, and the insects living on them, between states. States with large citrus and wine industries can suffer major losses when introduced agricultural pests, such as fruit flies, are moved between states.

The impacts of farming on Australia's flora and fauna

(1.) Land being cleared in southern Australia, with a tree burning in the foreground.


(2.) A forest being cleared for cattle farming in southern Australia.


(3.) Cleared land used for wheat farming in Western Australia.


(4.) Cleared land suffering from dieback as a result of salinity and/or phythoptera (a fungal disease which causes root rot).


(5.) Natural cycles of fire have been disrupted by farming and land clearance. Some plant species struggle to re-establish with more frequent or erratic fires. The seed banks of species which require hot fires to germinate or long periods between fires cannot be replenished if fires are too frequent and/or mild.