Conservation targets too small to stop extinction

[OKIsItJustMe]

http://www.adelaide.edu.au/news/news36022.html

Conservation targets too small to stop extinction

Monday, 12 October 2009

Conservation biologists are setting their minimum population size targets too low to prevent extinction.

That's according to a new study by University of Adelaide and http://www.mq.edu.au/">Macquarie University scientists which has shown that populations of endangered species are unlikely to persist in the face of global climate change and habitat loss unless they number around 5000 mature individuals or more.

The findings have been published online today in a paper `Pragmatic population viability targets in a rapidly changing world' in the journal http://www.elsevier.com/wps/find/journaldescription.cws_home/405853/description#description">Biological Conservation.

"Conservation biologists routinely underestimate or ignore the number of animals or plants required to prevent extinction," says lead author Dr Lochran Traill, from the University of Adelaide's http://www.adelaide.edu.au/environment/">Environment Institute.

"Often, they aim to maintain tens or hundreds of individuals, when thousands are actually needed. Our review found that populations smaller than about 5000 had unacceptably high extinction rates. This suggests that many targets for conservation recovery are simply too small to do much good in the long run."

A long-standing idea in species restoration programs is the so-called `50/500' rule. This states that at least 50 adults are required to avoid the damaging effects of inbreeding, and 500 to avoid extinctions due to the inability to evolve to cope with environmental change.

"Our research suggests that the 50/500 rule is at least an order of magnitude too small to effectively stave off extinction," says Dr Traill. "This does not necessarily imply that populations smaller than 5000 are doomed. But it does highlight the challenge that small populations face in adapting to a rapidly changing world."

Team member http://www.bio.mq.edu.au/about/people/staff/rf.html">Professor Richard Frankham, from Macquarie University's Department of Biological Sciences, says: "Genetic diversity within populations allows them to evolve to cope with environmental change, and genetic loss equates to fragility in the face of such changes."

Conservation biologists worldwide are battling to prevent a mass extinction event in the face of a growing human population and its associated impact on the planet.

"The conservation management bar needs to be a lot higher," says Dr Traill. "However, we shouldn't necessarily give up on critically endangered species numbering a few hundred of individuals in the wild. Acceptance that more needs to be done if we are to stop `managing for extinction' should force decision makers to be more explicit about what they are aiming for, and what they are willing to trade off, when allocating conservation funds."

Other researchers in the study are http://www.adelaide.edu.au/directory/corey.bradshaw">Associate Professor Corey Bradshaw and http://www.adelaide.edu.au/directory/barry.brook">Professor Barry Brook, both from the University of Adelaide's Environment Institute. The paper is online at http://dx.doi.org/10.1016/j.biocon.2009.09.001

[Oregone]

1. Im done with humans

Maybe itll come before humans learn how to colonize planets and become the scourge of the universe. We can only help. All I am saying, is give other life a chance.

[SPedigrees]

2. I totally agree with you.

Of course the new dominent life forms will probably be algae and cockroaches, but at least they won't be likely to create another multi-acre floating island of plastic trash in our oceans or nuclear bombs, so it will still be an improvement over human life IMO.

[YoungAndOutraged]

3. I've pretty much accepted that most things will be extinct by the time I die.

Our population will continue to climb and unfortunately, most animals are very likely to be extinct by the time the imbalance corrects itself. I would like to hope that one day, humanity will gain the technology to simply create life and thus be able to bring back any species we've destroyed, just like I would like to hope that we'd survive long enough to develop the technology needed to explore space, but it seems like we're destined to just fade away into oblivion, and at our own doing, too. I can only hope I'm wrong.