In this issue

	ECOS Issue 60

Problems ahead for penguins?
Penguins like kangaroos and koalas, are unusual creatures to many of our international visitors. To ensure our penguins are safely conserved, we need to know more about their feed requirements throughout the year, and where they forage for their food - mainly fish, squid, and krill - when in the wild. Then we can assess what impact commercial fishing may have on them, for human fisheries and penguins may sometimes compete for resources.
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Matching trees to climate
In many poor countries where firewood is in short supply Australian trees planted for fuel are helping people cook the food they have. But, for every successful fuelwood plantation, there is a need for hundreds more. United Nations studies report that this lack of fuelwood has reached a crisis. In countries where most of the people depend on firewood as their chief source of fuel, natural forests and woodlands close to homes have been cut down and villagers now walk many kilometres to gather what they need to cook their food. The immediate practical solution is to grow more fuel closer to home. Australian trees can make a significant contribution to alleviating the fuelwood shortage.
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Lead surprise - in via the skin
Lead is toxic; hence, the shift to lead-free petrol, a move indicative of a growing concern about inadvertent poisoning by a widely-used element. Health authorities and employers are generally aware of the dangers of lead in the environment. They have acted to reduce the risk of poisoning from eating food high in lead or from breathing in lead-rich dust. Less often considered is a third route of entry, the skin. Skin usually forms a fairly efficient barrier to the entry of chemicals and microorganisms. Certain compounds, especially if they are fat-soluble, can pass across it.
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Getting it clean with aquatic plants
Wetlands, swamps, call them what we will, they're probably not the place most of us would look for an ecologically sound way to treat our wastes. Yet in the struggle to live in that halfway house between the terrestrial and the aquatic, many swamp plants have developed some remarkable qualities that make them particularly suitable for cleaning up our dirty water.
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Farming the sea
For thousands of years humans have cultivated useful plants and animals in large numbers and thereby enjoyed the benefits of agriculture. However, virtually all of this has taken place on the Earth's land surface. In the western world, the idea of aquaculture (marine agriculture) has only come about in the last century. Aquaculture is the controlled rearing, at high density, of marine animals (and occasionally plants) of commercial value. Following considerable investment, Australia now possesses an important new area of primary production, worth more than $105 million a year.
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More news on nuclear winter As long as the threat of a large nuclear war continues to exist, the possibility of resulting drastic changes to the atmosphere, and thereby Earth's climate, also remains. Our knowledge of the specific effects of such a 'nuclear winter' are being refined as research continues on what is still a relatively new idea. Download Article

Caring for Campbelltown's koalas
At the turn of the century, Sydney's southern Campbelltown district had plenty of koalas. But records indicate that early residents shot most of them for their pelts. Before their rediscovery in the area in 1986, koalas had not been seen in the region for about 50 years. When rediscovered, local residents formed a protest group to preserve a koala colony near Campbelltown. An independent survey of the koalas was conducted and an assessment made of the potential effects of a development proposal.
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When water meets an underground hole
Conventionally, the question of whether water seeps into caverns, tunnels, and other underground holes is answered by a simple yes or no: yes, if the soil surrounding the hole is saturated with water; no, if it is not. Recently it has been shown that this is not always true: water in unsaturated soil can indeed enter holes. The larger the hole the more vulnerable it is to water entry, shape too is very significant. Other things being equal parabolic shapes provide the largest possible seepage-free storage volume or floor area under given conditions.
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The march of the Maoris
Most archaeologists have believed that, true to Maori legend, Maoris first landed in New Zealand somewhere in the North Island and slowly spread southwards. Examination of data from Carbon-14 dating of remains from all the known sites of the moa hunting settlers has led to the suggestion that the Maoris first landed on the north-eastern coast of the South Island. They then moved south down the coast and reached the North Island later, moving only slowly at first.
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