Invasive Species Policies

From Stateline.org comes this politically-oriented perspective on invasive species issues. The article touches on one of the main problems with invasive species, which is that people tend to want proof that a non-native species will causing damage before outlawing it, yet information is difficult to come by until the species has already caused the damage. Included are some specifics from Florida, possibly the number one state for plant invasions.

Spotting Knapweed

Greg Moore has written a nice piece for the Idaho Mountain Express about Blaine County's dealing with the invasive Spotted knapweed (Centaurea biebersteinii, formerly C. maculosa). The county is waging a constant battle against the weed, which often quickly re-colonizes places it is eradicated from. A lack of funding doesn't help matters, forcing the county to spend all its time and money in an attempt to prevent new populations and spray large ones to keep them from spreading; there is rarely a chance to shrink current populations.

Child's Play

Are you a fifth grader, or do you think like one? Even if you don't fit into either category, you may be interested in checking out the free activity book "Understanding Invasive Aquatic Weeds." Developed by the Aquatic Plant Management Society, the book is full of information and activities to help kids learn about aquatic weeds. You can download the acticity book for free, but if you don't have a good printer, you can also order paper copies and pay only the cost of postage.

Thanks to a member of the ALIENS-L listerserver for posting information about this topic.

Natural Disaster Opens Gateway to Invasion

Hawaiian officials are concerned that last weekend's Supertyphoon Pongsona will increase the risk of the brown tree snake (Boiga irregularis) invading Hawaii. According to this story in the Star Bulletin, many of the fences around the airport in Guam were destroyed during the storm, meaning that more snakes could be hitchiking over to Hawaii on airplanes. Even with strict prevention and inspection procedures, four brown tree snakes were found in cargo flown to Hawaii last year.

Island Invasion

In the field of invasive species ecology, time is limited and funds are scarce, making it hard to do those intensive, long-term studies that would really let us know how a non-native species is affecting the ecosystem. As a result, the fact that very few species have been shown to have gone extinct due to the introduction of a non-native species is sometimes presented as evidence that invasive species are not really a problem. But as reported at Science Daily, a new study being published in the journal American Naturalist demonstrates that non-native birds and plants are establishing on islands in great numbers, pushing up tallies of local biodiversity while increasing global homogenization. There is evidence that this massive influx of species is influencing the ecosystem regardless of the fact that native species aren't disappearing. You can read the article abstract by going here and scrolling down the page.

Fighting one invasive species with another

As reported in the Austin-American Statesman, the invasive aquatic plant hydrilla (Hydrilla verticiallata) has invaded Lake Austin, and the state of Texas wants to introduce invasive grass carp (Ctenopharyngodon idella) to keep it under control. Hydrilla is an extremely pervasive aquatic weed that causes ecological damage to the flora and fauna of the lake and also impedes recreational activities like boating and swimming. At first glance, the grass carp may seem like the ideal biological control for a closed freshwater system like Lake Austin. But as fishermen pointed out at a public hearing on the subject, there's no way to control the grass carp once they're introduced; if they eat more than just hydrilla they could be reducing food sources for other fish in the lake. I'm a little skeptical about the claims made by officials that testing showed that they can keep the carp in the lake, given the risk of flooding, but it is likely that they will be using functionally sterile triploid carp, reducing the risk that populations would establish in the wild.

Thanks to D.V. for sending in the link to this article.

Check you ballast at the door

Researchers at Portland State University and the Smithsonian Environmental Research Center have joined together to develop a system to monitor ballast water exchange, according to this article from The Columbian. The scientists are interested in creating standards that will allow them to determine whether a ship has exchanged ballast water mid-ocean. While this is considered to be better for invasive species prevention than dumping ballast in port, it is not a perfect solution, and the search continues for technology that will prevent all non-native species introductions.

Thanks to the Protect Your Waters web site for posting a link to this article.