World's eels on slippery slope EU launches action plan to save threatened fish. 30 September 2003
TOM CLARKE
The world's eels are disappearing fast and need protection before it's too late, fisheries
scientists announced last week. Tomorrow the European Commission releases its 'Eel Action Plan'
urging the European parliament to safeguard the region's threatened fish.
But eels' mysterious life-cycle and unappealing image - suspected as major reasons for their decline
- may make protection tough.
"It's a global problem," says fisheries expert Håkan Wickström at Sweden's Institute of Freshwater
Research in Drottningholm.
European eel (Anguilla anguilla) numbers have dropped 99% since 1978, Wickström told the annual
meeting of the International Council for the Exploration of the Sea in Tallinn, Estonia. And
American eels (A. rostrata) and Japanese eels (A. japonica) have experienced similar declines.
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Ancient eruption marks today's tortoises Genes of Galapagos giants record volcano history. 3 October
2003 BETSY MASON
The genes of some Galapagos tortoises bear the stamp of a volcanic eruption 100,000 years ago that
nearly wiped them out1.
Each of the five volcanoes on Isabela Island at the western edge of the Galapagos archipelago hosts
a different giant tortoise. The residents of Volcano Alcedo have far less genetic variation than
those on the other volcanoes, Luciano Beheregaray and his colleagues have discovered.
"It's surprising because this is the largest population of giant tortoises in the Galapagos," says
team member Jeffrey Powell of Yale University in New Haven, Connecticut. "We expect larger
populations to have more variation."
The team calculates that the few existing gene variants evolved from a common ancestor around 88,000
years ago. "It's very unusual," says conservation geneticist, Hampton Carson of the University of
Hawaii in Honolulu who studies the effects of Kilauea Volcano on fruit fly genes. "It means
something big must have happened to reduce the population."
nature.com030929 11.htmlOpen ↗
Plants detonated Cambrian explosion Global cooling may have allowed complex animals to flourish. 1
October 2003 JOHN WHITFIELD
The first land plants might have triggered a rush of animal evolution. German researchers are
proposing a controversial theory that the plants cooled Earth, making it conducive to complex life1.
The idea is a new twist on the Gaia hypothesis that living things influence the global
environment. "During the evolution of the Earth there was a decrease in temperature, and higher
life forms have lower temperature limits," says Werner von Bloh of the Potsdam Institute for
Climate Impact Research.
Many researchers think that rising, not falling, temperatures lit the fuse for the Cambrian
explosion, the biological Big Bang 540 million years ago when most modern animal groups appear in
the fossil record.
There is genetic evidence that simple plants, such as algae and lichens, colonized the land 800
million years ago. But no plant fossils from this time have been found.
It's also unclear whether there was a slump in temperatures, and whether such a drop would have
favoured complex life. Says palaeontologist Robert Riding of Cardiff University, UK: "Nobody knows
what's right or wrong, but it sounds odd to me".
But the link between temperature and life deserves further investigation, argues geochemist David
Schwartzman of Howard University in Washington DC. "The global emergence of certain types of
organism could be tied to their optimum temperature," he says
Kind Regards, Robert Karl Stonjek.