Invasive species threaten US biodiversity

Matthew Berger, from IPS, part of the Guardian Environment Network (UK): As 2010, the UN's International Year of Biodiversity, gets underway, a fight against some of the most damaging invasive species in US waterways is heating up. The UN says some experts put the rate at which species are disappearing at 1,000 times the natural rate, and invasive species – which consume the food or habitat of native species, or the native species themselves – are one factor contributing to this acceleration. Climate change is another major factor.

"Often it will be the combination of climate change and [invasive] pests operating together that will wipe species out," says Tim Low of the Australia-based Invasive Species Council. The International Union for Conservation of Nature says that 38% of the 44,838 species catalogued on its Red List are "threatened with extinction" – and at least 40% of all animal extinctions for which the cause is known are the result of invasive species.

But just as invasives are not the only threat to biodiversity, the threat to biodiversity is not the only problem caused by the havoc – ecological as well as economic – wreaked by species that are transported to a foreign habitat, get a foothold there and spread, often voraciously.

The UN Convention on Biological Diversity says the spread of invasives costs 1.4 trillion dollars a year globally in damages and control measures. The US alone loses 138 billion dollars a year in the fight.

The problem can be seen throughout US waterways, from Asian clams in California's Lake Tahoe to snakehead fish in the East Coast's Potomac River. One of the most immediate threats – Asian carp – is currently on the doorstep of the Great Lakes ecosystem, where it could decimate a seven-billion-dollar fishing industry among other economic and ecological assets.

…The concerns over what a carp infestation might mean for the Great Lakes' industries and environment are several-fold. Asian carp are voracious eaters, consuming 40 times their body weight in a day, and females can carry a million eggs and spawn multiple times in a season…..

A cotton-tailed rabbit surrounded by garlic mustard, mugwort (and burdock). None of these invasive species are food for this animal. Image © Sue Sweeney, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License