Category Archives: invasive species

Invasives Are Food for Thought, But Not For Growth

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How do invasive species become invasive? There are a number of hypotheses, and sorting them out is vital to wildlife managers trying to lessen the invasives’ impact. One recent study, published in the journal Ecology, found that generalist plant-eaters, in this case insects, grew more slowly when eating a plant that was not native to their continent.

The plant was spotted knapweed, known to have at least one defensive chemical not yet found in plants native to North America. The researchers concluded that when it came to generalist herbivores and spotted knapweed, the “novel weapons hypothesis,” which says the invasives thrive because native predators are vulnerable to their unfamiliar defenses, seems to be the case.

The study is interesting for a bunch of reasons, but particularly because it offers some insight into the role of spotted knapweed in North American ecosystems. There are many implications, but let’s start with the trickle-up effect in the ecosystem of spotted knapweed consumers (moths, grasshoppers) that are smaller, but still abundant. That could really mess with the energy budget of their predators. Also, while we may think of the biggest impacts as coming from the invasive plant not being eaten at all, even when eaten, the sub-lethal effects of consuming spotted knapweed can echo through the food chain.

Read the whole article, and come to your own conclusions. It’s open access: http://www.esajournals.org/doi/full/10.1890/10-1230.1
Photo: A bee on spotted knapweed.
Photo credit: Cody Hough, college student and photographer in the Michigan area.

Banning felt waders

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Maryland, Vermont, and Alaska are the first states to ban felt-bottomed fishing waders in an effort to slow the spread of the algae known as didymo, and other invasive species. (Well, the Alaskan ban doesn’t take effect until next year, but it is on the books.)

Idaho and Oregon tried to ban felt waders, but the legislation didn’t pass, reports this USA Today story on the wader ban. Nevada will consider a ban as part of an invasive species plan, the article says.

Missouri has taken another route. It is using wader washers at the state’s four trout parks. Read all about it in the Missouri Department of Conservation press release. Info about the wader wash stations is half-way down, below the list of phone numbers. One Ozark skeptic opines here, but gives many more details about Missouri’s attempt to slow didymo by educating anglers.

Photo: What’s on your waders? A biologist conducts a fisheries survey in Wyoming. Courtesy US Fish and Wildlife Service

Pick Your Battles With Invasive Shrubs

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Multiflora rose

Think before you raze a stand of autumn olive, multiflora rose, or buckthorn, urged John Litvatis of the University of New Hampshire at a well-attended session at the Northeast Fish and Wildlife Conference this week.

For over a decade, most wildlife management agencies have had a policy of removing invasive species whenever they are found. Sometimes, though, the removal can do more harm than good. For example, the prickly tangle created by a stand of multiflora rose provides good habitat for the imperiled New England cottontail. Take away the rose bushes, and the cottontails might be quickly gobbled by predators.

If there was nothing but multiflora rose as far as the eye could see, though, then that monoculture would almost certainly need to be restored to some sort of balance, Litvatis said. But in many cases the aggressive — and reflexive — suppression of invasive shrubs may not be necessary.

Litvatis knew he was suggesting something against accepted wisdom, so he repeated that he was not advocating planting invasive species, just a more thoughtful approach to their removal, including the idea that sometimes it is best to leave things alone.

Litvatis flashed a slide with the names of other biologists in the Northeast who are with him in urging a more thoughtful approach to the management of invasive species. The audience stayed well into the break after the session, and not a single commenter attacked the idea or dismissed it out of hand. Food for thought.

Photo: Wikimedia Commons. JoJan

Don’t mess with invasive plants in Texas

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Giant salvinia in Caddo Lake

The Texas Parks and Wildlife Department reports that last year’s campaign to increase the public’s awareness of the invasive aquatic plant giant salvinia reached more than half of its intended audience. Of the boaters living within 60 miles of four lakes in east Texas who saw an ad or information about giant salvinia, 96 percent said they were “more likely to clean their boat, trailer or gear….”

Giant salvinia (Salvinia molesta) is a native of Brazil that came to North America as a plant for water gardens. It can grow up to three feet thick, and can double in size in a week. It has plagued the lakes of eastern Texas for over 10 years, and is also found in Alabama, Arizona, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, North Carolina, and South Carolina.
According to a department release, the campaign included floating messages on buoys near key boat ramps, fish measuring rulers with campaign messages, online web banner ads, Twitter and Facebook posts, gasoline-pump toppers, billboard ads near key lakes, and a cute television public service announcement (PSA) that personifies giant salvinia as a doofus hoping to hitch a ride with a boater to cause trouble in other lakes.

The campaign was so successful that the department may try a similar effort for zebra mussels, which are not yet as established in the state as giant salvinia.

Read the full press release here. You can find the press releases, radio spots, a PDF of the ruler, and two versions of the television PSA here.

Photo: Giant salvinia in Caddo Lake, Texas, © Texas Parks and Wildlife Department

Rock snot found in Connecticut

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Photo: Conn. DEP

Didymosphenia geminata, an invasive alga known as “didymo,” or rock snot, was found in the West Branch of the Farmington River in Connecticut on March 18. Several anglers reported the didymo sighting to the Connecticut Department of Environmental Protection. A lab in Vermont confirmed that the alga is didymo, and the department announced the finding on March 29.


Didymo was found in several states in the northeastern U.S. in the summer of 2007, including New York, New Hampshire, and Vermont. This is the first time it has been found in Connecticut.


Didymo is considered an invasive species because it can grow in dense mats that carpet the stream bottom. It’s not clear where didymo originated. It’s been known in streams in northern Europe and northern North America for some time. It was first found in the Southern Hemisphere, in New Zealand, in 2004. Researchers suspect it is being transported from place to place through recreational activities like fishing (on waders), and kayaking.


For more on the Connecticut situation, including prevention strategies and background on the algae, read the article in The Hartford Courant, or the Connecticut DEP press release.

Rock snot found in Connecticut

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Photo: Conn. DEP

Didymosphenia geminata, an invasive alga known as “didymo,” or rock snot, was found in the West Branch of the Farmington River in Connecticut on March 18. Several anglers reported the didymo sighting to the Connecticut Department of Environmental Protection. A lab in Vermont confirmed that the alga is didymo, and the department announced the finding on March 29.


Didymo was found in several states in the northeastern U.S. in the summer of 2007, including New York, New Hampshire, and Vermont. This is the first time it has been found in Connecticut.


Didymo is considered an invasive species because it can grow in dense mats that carpet the stream bottom. It’s not clear where didymo originated. It’s been known in streams in northern Europe and northern North America for some time. It was first found in the Southern Hemisphere, in New Zealand, in 2004. Researchers suspect it is being transported from place to place through recreational activities like fishing (on waders), and kayaking.


For more on the Connecticut situation, including prevention strategies and background on the algae, read the article in The Hartford Courant, or the Connecticut DEP press release.

Invasive plants change, but don’t master all conditions

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Invasive plant species do change more in response to environmental conditions than other plant species, a team of Australian researchers has found. This ability to change has long been considered a key factor in what makes invasive species, well, invasive. In their paper in Ecology Letters, the research team analyzed the published literature on 75 pairs of similar plants, where one of the pair was a known invasive, and the other a non-invasive species. They were able to confirm that the invasive plants had greater phenotypic plasticity.

They also found, however, that the ability to change didn’t necessarily help the invasive plants when times got tough. They found that the non-invasive plants fared better when there was a low or average amount of resources, such as light, nutrients, or water. They point out that invasive species are jacks of all trades, or at least all environmental conditions, but masters of only some.

They note in a very brief section that while the increase of carbon dioxide in the atmosphere generated by human activity favors invasive species, the stressful environmental conditions (such as drought) that the accompanying climate change brings can favor non-invasive species.

The paper in Ecology Letters is open access, and is available here.

Harnessing March Madness – Great Lakes SmackDown

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A great example of how to liven up important conservation information is the Great Lakes SmackDown!, created by two graduate students at Michigan State University. (In the spirit of academia, their work is done for the Great Lakes Echo, a news service that is a program of the Knight Center for Environmental Journalism at MSU. Got it?)

Graphic: John Kalmar. Great Lakes Echo

This March, an invasive species version of the NCAA basketball tournament has a Sweet Sixteen of invasive plants and animals facing off to determine which of the exotic losers is the most destructive to the Great Lakes region. This time the focus is on land-based invaders, and the competitors include the mute swan, the feral hog, and the gypsy moth.

After perusing fighter profiles, participants submit their brackets, then vote to influence the outcome of each bout.

Last October, a similar SmackDown pitted eight aquatic invaders against each other for the title of “most destructive.” The quagga mussel, aka “The Quagmeister” finished on top. Twenty-five people submitted brackets, and there were over 100 votes in the polls. Best of all, the SmackDown received local newspaper and radio coverage.

“The fact that we pulled it together and got very positive feedback from readers, scientists and our colleagues was a success in itself,” said Alice Rossignol, who coordinates the SmackDown with Rachael Gleason. She expects this March’s SmackDown to be even more successful, thanks to public relations assistance from Michigan State University.

While everything about the SmackDown is executed with Comedy Central-worthy humor, you don’t have to be funny to pull off a similar project, the coordinators said.

“If you have a new idea that discusses an issue in a new way, go for it,” said Rossignol. “The project’s character will be shaped for your own effort and how people interact and respond to it.”

“The SmackDown! was funny because it was fun — fun to read, fun to be a part of and especially fun to put together,” said Gleason, . “We wanted to relate to our readers and get them thinking about an important issue in a new way. And who doesn’t love filling out a March Madness bracket? After deciding on that theme, everything else, like the idea to characterize invasive species as cage fighters, fell into place”

Harnessing March Madness – Great Lakes SmackDown

Posted on by
Reply

A great example of how to liven up important conservation information is the Great Lakes SmackDown!, created by two graduate students at Michigan State University. (In the spirit of academia, their work is done for the Great Lakes Echo, a news service that is a program of the Knight Center for Environmental Journalism at MSU. Got it?)

Graphic: John Kalmar. Great Lakes Echo

This March, an invasive species version of the NCAA basketball tournament has a Sweet Sixteen of invasive plants and animals facing off to determine which of the exotic losers is the most destructive to the Great Lakes region. This time the focus is on land-based invaders, and the competitors include the mute swan, the feral hog, and the gypsy moth.

After perusing fighter profiles, participants submit their brackets, then vote to influence the outcome of each bout.

Last October, a similar SmackDown pitted eight aquatic invaders against each other for the title of “most destructive.” The quagga mussel, aka “The Quagmeister” finished on top. Twenty-five people submitted brackets, and there were over 100 votes in the polls. Best of all, the SmackDown received local newspaper and radio coverage.

“The fact that we pulled it together and got very positive feedback from readers, scientists and our colleagues was a success in itself,” said Alice Rossignol, who coordinates the SmackDown with Rachael Gleason. She expects this March’s SmackDown to be even more successful, thanks to public relations assistance from Michigan State University.

While everything about the SmackDown is executed with Comedy Central-worthy humor, you don’t have to be funny to pull off a similar project, the coordinators said.

“If you have a new idea that discusses an issue in a new way, go for it,” said Rossignol. “The project’s character will be shaped for your own effort and how people interact and respond to it.”

“The SmackDown! was funny because it was fun — fun to read, fun to be a part of and especially fun to put together,” said Gleason, . “We wanted to relate to our readers and get them thinking about an important issue in a new way. And who doesn’t love filling out a March Madness bracket? After deciding on that theme, everything else, like the idea to characterize invasive species as cage fighters, fell into place”

“Bad dog!”

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Feral dogs and dogs running loose threaten wildlife by killing them, stressing them, and passing along diseases. You knew that. This paper in the journal BioScience has the data, and some solutions. Mostly it’s a good resource if you need a quick review of the dog issue.

 
The BioScience paper also received coverage in the popular press. Read a sampling here:

Reuters/Mother Nature Network
Yahoo! News
Red Orbit

This article in High Country News from three years ago really brings the issue to life.