Biological Invaders – Salvinia

Biological Invaders – Salvinia

Music; Ambience: dawn chorus, Australia

It’s usually a bad idea to introduce a foreign species into a new ecosystem, but sometimes there may be no better alternative. I’m Jim Metzner, and this is the Pulse of the Planet. Moving to a new ecosystem may allow a species to survive without restriction, because it has no natural predators. And when a species begins to damage the ecosystem that it’s moved into, one solution is for scientists to bring in a second species that has the ability to control the population of the first. Well, such was the case with Salvinia, a plant that invaded Australia in the 1970’s.

Lonsdale: Salvinia is a floating fern from South America which invaded waterways in Australia and throughout Southeast Asia.

Mark Lonsdale is an Australian ecologist specializing in invasive species.

Lonsdale: Salvinia, came in as an aquarium plant in the first instance. People like to move plants around. They want attractive plants, which they often think they can’t find in the native flora.

Once Salvinia plants were dumped from an aquarium into local waterways, it was only a matter of time before they grew out of control, crowding out other species of plants. Scientists knew that something had to be done.

Lonsdale: We discovered by returning to South America and studying very carefully the weed in its native range – we discovered a weevil which chomps its way through the roots of this floating fern. The weevil doubles in numbers every few days and manages to cause the weed to sink. And having introduced it in the early ’80’s to Northern Australia, and then into other countries in the South Pacific, we’ve seen this particular weed just melt away almost overnight.

The Salivinia control project was deemed a success in Australia, but it was the result of years of careful research to make sure that the release of the weevils wouldn’t create any unforeseen results. Pulse of the Planet is presented by the National Science Foundation.

Biological Invaders - Salvinia

Moving a species to a foreign environment may ultimately require importing another species to control the first.
Air Date:10/23/2001
Scientist:
Transcript:

Biological Invaders - Salvinia

Music; Ambience: dawn chorus, Australia

It's usually a bad idea to introduce a foreign species into a new ecosystem, but sometimes there may be no better alternative. I'm Jim Metzner, and this is the Pulse of the Planet. Moving to a new ecosystem may allow a species to survive without restriction, because it has no natural predators. And when a species begins to damage the ecosystem that it's moved into, one solution is for scientists to bring in a second species that has the ability to control the population of the first. Well, such was the case with Salvinia, a plant that invaded Australia in the 1970's.

Lonsdale: Salvinia is a floating fern from South America which invaded waterways in Australia and throughout Southeast Asia.

Mark Lonsdale is an Australian ecologist specializing in invasive species.

Lonsdale: Salvinia, came in as an aquarium plant in the first instance. People like to move plants around. They want attractive plants, which they often think they can't find in the native flora.

Once Salvinia plants were dumped from an aquarium into local waterways, it was only a matter of time before they grew out of control, crowding out other species of plants. Scientists knew that something had to be done.

Lonsdale: We discovered by returning to South America and studying very carefully the weed in its native range - we discovered a weevil which chomps its way through the roots of this floating fern. The weevil doubles in numbers every few days and manages to cause the weed to sink. And having introduced it in the early '80's to Northern Australia, and then into other countries in the South Pacific, we've seen this particular weed just melt away almost overnight.

The Salivinia control project was deemed a success in Australia, but it was the result of years of careful research to make sure that the release of the weevils wouldn't create any unforeseen results. Pulse of the Planet is presented by the National Science Foundation.