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National Geographic's Strange Days on Planet Earth
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INVADERS
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Aquatic Invaders

On the New England coast and in San Francisco Bay, marine ecologist Jim Carlton is tracking the rising rate of destructive aquatic invasive species. He and his colleagues are conducting what is known as a Rapid Assessment Survey (RAS — see link below).

According to Carlton, "Around the world, we've seen tremendous numbers of invasions in the last quarter of the twentieth century and these appear to be unabated as we move into the twenty-first century." Our global system transports plants and animals along with other cargo. Every year brings more volume, more speed and more arrivals. With the relentless growth of global transportation, Carlton believes we may be pushing our luck. "The arrival of every new species is very much like Russian roulette. We spin a new species into the environment and the potential for catastrophic impact to society, to the economy, to the environment is always there."

What do you like best about your profession?
Jim Carlton Carlton: "My career has allowed me a good deal of freedom of travel and exploration and the freedom to pursue a wide range of interests, often well off the beaten track. The more freedom you have in what you want to do when you get up in the morning, the more enjoyable your career..."

See Jim Carlton's full Q&A »

Jeff McNeeley, chief scientist of the World Conservation Union and one of our Strange Days material sources for invasives, agrees that the rise in global trade has greatly increased the spread of invasives. The value of total imports increased from US$192 billion in 1965 to $3.3 trillion in 1990, a 17-fold increase in 25 years (World Resource Institute, 2003). Imports of agricultural products and industrial raw materials — those that have the greatest potential to contribute to the problem of invasive species — amounted to $482 billion in 1990, up from $55 billion in 1965. While this economic performance is impressive it carries with it great hidden costs.

In the words of one of our Strange Days Science Advisors Hal Mooney, a foremost global authority on invasive species: "The biota of the Earth is undergoing a dramatic transformation... Since the beginnings of the Age of Exploration, humans have purposefully and inadvertently moved biological material across barriers that, for recent evolutionary time, have separated the unique biotic realms of the continental land masses. We are now developing a whole new cosmopolitan assemblage of organisms across the surface of the Earth with large consequences not only for the functioning of ecosystems but also for the future evolutionary trajectory of life."

References
» World Resource Institute 2003, Report Series: World Resources 2002-2004: Decisions for the Earth: Balance, voice and power Off-site Link, United Nations Development Programme, United Nations Environment Programme, World Bank, World Resources Institute. 328pp.
 

Rapid Assessment Surveys (RAS) are conducted by teams of marine species experts whose job it is to identify both native and introduced species at selected sites.

For more information
»

MIT Sea Grant Center for Coastal Resources: Marine Bioinvasions Fact Sheet: Rapid Assessment Survey Off-site Link

Next: Termites Invade New Orleans »


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