February 27, 2003

Pimentel Study Shows Alien Species Terrorizing Economy

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Prof. David Pimentel, author of Biological Invasions: Economic and Environmental Costs of Alien Plant, Animal, and Microbe Species, spoke to approximately 50 students and professors at Mann Library yesterday as part of the library’s Chats in the Stacks lecture series. Pimentel presented research illustrating the damage caused to local ecosystems as a result of the introduction of outside species.

Of all the extinctions in the United States, Pimentel said, 40% are caused by invasive species, organisms which are not native to an environment and whose presence creates an imbalance in the ecosystem. As travel grows easier and more efficient, the transport of species from one environment to another grows more likely as well.

“There’s no question that [invasive species] are increasing, and increasing rapidly, with more people traveling, more people available to travel, and more global trade,” said Pimentel.

In addition to causing problems within the environment, introduced species such as feral pigs in the southern United States and wild cats across the country cause severe property damage. Over $137 billion worth of damage is estimated annually by Pimentel and his fellow researchers.

The problem of invasive species is not just limited to animals. “Plants are the worst culprits as far as having ecological effects,” said Pimentel. “When you introduce some of these plants, they spread and dominate the ecosystem and this eliminates the number of native plants or reduces them significantly. And because there are large numbers of insects, microbes and other animals which depend on these native plants, the invasive plants can have devastating impacts.” Invasive species also include microbes such as flu, tuberculosis, and AIDS.

Invasive species require the use of pesticides to protect plants from new threats. “We apply about 1 billion pounds of pesticide annually, and the largest quantity of this is used against invasive species.” Pimentel said. “Then you get the side effects. There are 72 million birds killed annually from pesticides.”

Pimentel also commented on the danger of global warming and the effect it is already having on populations. Species movement to more northern environments has been recorded in the United States, leading to increased instances of ecosystem change. “Global warming really intensifies this whole problem.” Pimentel said.

Pimentel noted that introduced species can have positive effects as well. Some species which have been introduced to new environments as biological controls on other organisms have met with some success. In addition, over 99% of the food supply of most countries is derived from introduced plants or livestock.

When asked what type of solution he envisioned for the problem of invasive species, Pimentel advocated awareness of the issue. “If you really want to get at this problem you need to educate the public. I’m not against legislation and public policy but I really think that there are so many people traveling who don’t understand the problem. It’s not only legislation you need, but education.”

Pimentel’s talk was well received by his audience.

Benjamin Wolfe ’03, who is assisting Dr. Pimentel’s research, said “I find his work interesting and I think it’s a good attempt at figuring out how these species are impacting our ecosystems and what they’re costing us. I also think there are a lot of limitations as far as the numbers and estimates that are given.”

Janet McCue, director of Mann Library, said “I was very happy with the event. The goal of our Chats in the Stacks is really to bring together a community of students, faculty, and members of the Ithaca community to hear the latest research and let faculty member’s talk about their most recent publications.”

Pimentel has been involved in the publication of over 560 papers and 23 books.

“I think that Dr. Pimentel is a very distinguished scientist and educator, and its a very important and interesting topic that he is dealing with. These invasive species are an incredible problem, it’s a huge issue. We have many scientists in the college who are investigating these topics and Dr. Pimentel is certainly a major leader among them,” said Susan Henry, dean of The College of Agriculture and Life Sciences.

Archived article by Jeff Sickelco