Tiny crustaceans known as Spiny Water Fleas (Bythotrephes cederstroemi) are annoying fishermen and worrying environmentalists in Canada and the Great Lakes region. This freshwater species, introduced from Europe and fairly recently discovered in North America, establishes huge populations that are physically disturbed by the dragging of fishing lines. The result is fishing gear covered with a slimy, smelly mess, and the potential of the species being spread in this manner to even more water sources. Another recent Canadian article discusses the negative impacts that this invasion could have on the vacation/real estate markets.
Tuesday, April 30, 2002
Sunday, April 28, 2002
Today I went to pickup my tree seedling from the Quincy Public Works Department. The city has an "Evergreen Program", which I think is a great idea: you drop off your Christmas tree to be recycled, and they give you a coupon to pick up a baby tree in the spring. They're planning on planting 12,000 trees in the city. The letter I received promised me a Bracted Balsam Fir (Abies balsamea), which is native. Unfortunately, when I got home I realized my seedling was a Norway Spruce (Picea abies). It's ironic to me that most of Europe has been reforested with American tree species over the past few centuries, and now we're growing and planting European trees here. While Norway Spruce is not considered invasive in the U.S., it is on the "watch lists" of some groups studying invasive species, and has been identified as a problem species in Canada.
Saturday, April 27, 2002
People are still ironing out the definitions used in invasive species ecology. Specifically, what constitutes an "invasive" species is a subject of contention among scientists and policy makers alike. Some contend that an invasive species has to have been introduced by humans, either accidentally or intentionally.
Of the species that are naturally dispersing into new habitats on a regular basis, there are very few that can do so on a continental scale. (One example that comes to mind is the Sea Beans, a group of plants whose water-dispersed seeds can cross oceans.) Now comes this story from the BBC about marine creatures hitchiking across the ocean on trash. For thousands of years, organisms like mollusks and corals have attached to natural debris that floats on ocean currents. But now surveys show that more than half of the debris found near the Antarctic is man-made. Not only is there a lot more debris than is natural, but it is even easier for organisms to survive on the more-durable artificial materials. So, if one of these species starts spreading aggressively, is it invasive or not? (Story tip from The Daily Grist)
Friday, April 26, 2002
In California, the Department of Fish and Game has found a better way to deal with introduced freshwater fish than poisoning entire bodies of water...they're blowing the fish up!! The northern pike (Esox lucius) introduced to Lake Davis are aggressive predators, and have taken over the lake. After a previous attempt at poisoning the fish affected water quality, caused health problems, and prevented all fishing for months, Fish and Game has turned to a less toxic option. Explosions are set off underwater and dead fish are then scooped off the surface. If the detonations turn out to significantly harm the trout that also inhabit the lake, officials will look into other management options.
Though this method is obviously one of control rather than eradication, it makes sense in this situation. Since the pike were reintroduced intentionally after the lake was cleared the first time, it is likely introductions will continue to occur. Northern pike is a popular game fish, and though it has been introduced by humans to many lakes, its range is considered circumarboreal. You can read more about the effects of northern pike introduction in this .pdf file. (Thanks to a member of the ALIENS-L listserver for posting the link to this story.)
Thursday, April 25, 2002
In an effort to fight the spread of the Asian Longhorned Beetle, New York will be enlisting the aid of fancy new acoustic devices that detect the noises beetle larvae make as they chew their way through tree trunks. The acoustic sensors, which attach directly to the trees, will be accompanied by a wide-scale insecticide treatment program.
Wednesday, April 24, 2002
Used to considering fruit flies as a household and office pest (my office being adjacent to biological labs), I was surprised to read this story in the New York Times about a non-native species causing problems in the western U.S. (NYT requires a user name and password). It turns out that there are many native species of fruit flies whose populations have been in decline since the arrival of Drosophila subobscura, a European native. Unfortunately native Drosophila suffer from a lack of attention due mostly to the fact that they're, well, flies. If you don't want to deal with logging in to the NYT, you can read a similar article from 2000 from the Seattle Post Intellingencer. For more detailed information, check out this book, though it might be in German.
Tuesday, April 23, 2002
A member of the Yahoo! group ma-eppc posted requesting reports on Jetbead sightings. Known by the scientific name Rhodotypos scandens, this shrub should now be coming into flower, though it is probably easier to identify once it has developed its distinctive 4-fruited clusters. Often planted as an ornamental, this Asian native is being monitored in several eastern states due to reports of its escape from cultivation.
Monday, April 22, 2002
The first Global Biodiversity Forum for the Pacific region will be held in the Cook Islands this July. One of the three workshops they are convening is entitled "Invasive Species in the Pacific: Strategies for Countering the Threats." The deadline for submitting abstracts is May 31. General information about the conference can be found here. To find out about past sessions of hosted by the multi-institutional GBF, click here.
Sunday, April 21, 2002
According to this undated story from the ESPN Outdoors website (yes, that ESPN), the New Zealand mud snail (Potamopyrgus antipodarum) has been found in California. Previously seen in rivers in Idaho and Montana, this tiny snail is prolific and very difficult to kill. This is a decent, fact-filled, environmentally-conscious article, with pointers for fishermen on how to avoid spreading this and other invasive species.
Researchers are not exactly sure how the New Zealand mud snail was introduced, although likely vectors include ships' ballast and imports of gamefish (as eggs or adults). Work continues to measure potential effects of introduced mud snail populations, with initial studies suggesting they contribute to the decline of native aquatic invertebrates.
Saturday, April 20, 2002
A paper published in the March 2002 issue of the journal Global Ecology and Biogeography report results of a study done to investigate the dispersal patterns of two non-native bird species in North America. The authors found a correlation between habitat quality and dispersal patterns of the European starling (Sturnus vulgaris) and the House finch (Carpodacus mexicanus).
Further proving that starlings have at least one redeeming quality (i.e. they are fodder for scientific research), this recent press release from Johns Hopkins University (discovered via ScienceDaily) describes a study which found that the singing ability of male starlings is directly correlated with their health, potentially explaining how female starlings choose their mates (Karaoke anyone?).
Now if only someone would do a study to figure out how to get starlings to stop using my car for target practice...
Friday, April 19, 2002
Details are now available for the 7th International Conference on the Ecology and Management of Alien Plant Invasions (EMAPI), to be held at Florida International University (Univeristy of Miami) Nov. 3-8, 2003. I went to the 6th EMAPi conference in Loughborough, England, and it was a great opportunity to meet people from all over the world studying invasive plants. You can see information for all previous conferences here. As Florida has been profoundly affected by non-native plant introductions, I expect there will be some great field trips as well.
Thursday, April 18, 2002
The Associated Press has picked up on a great research project by Lorraine Brooks at the University of Washington. "When Wildflower Mixes Go Wild" demonstrates that wildflower seed mixes often contain native weeds and non-native invasive species, even when they are targeted to a certain part of the U.S. Many of the mixes contained species not even listed on the packaging. (I'll try to link to the AP article as well, once it comes up on a website or newsgroup post.) The project was directed by Dr. Sarah Reichard, who has previously done excellent research on non-native species and the nursery industry.
This project reminded me of an incident that happened back in March, where a small group of highly-motivated people convinced the National Arbor Day Foundation to stop selling the invasive Bradford Pear (Callery Pear, Pyrus calleryana). Read more via the Yahoo! group ma-eppc by going here and here, and see photos of the Bradford Pear here.
Wednesday, April 17, 2002
Is your woodlot crowded with undesirable non-native plants? Well, okay, you probably don't have a woodlot, but consider that those who do must deal with the encroachment of invasive species that threaten the economic livelihood of their business. Visit the Forest Stewardship Library to read about "Control of Nonnative Invasive Plants on your Woodlot". Part of the "Biodiversity of a New England Woodlot Series", this document has practical information about invasive plants, including sections on chemical and mechanical control options. The Weed Wrench gets my vote for coolest tool.
Scientists in Europe have discovered a "supercolony" of ants, stretching thousands of miles from Italy to Spain. Apparently, the ants have lost their ability to recognize family vs. strangers and instead work together in a giant cooperative effort. How did this breakdown of recognition occur? Research points to factors associated with the repeated introduction of these Argentine ants (Linepithema humile) into Europe. You can read the Associated Press' version of the story on ABCNews.com, or if you're feeling adventurous (and have access), you can read the original paper from the Proceedings of the National Academy of Sciences (-Or-, if you're super-patient and don't have access, check back in 6 months and read the article for free.).
This story is getting a lot of press, but the truth is that Argentine ants, regardless of colony size, have become invasive in many parts of the globe, including New Zealand (see link above), Australia, and the U.S., where they threaten horned lizard populations in California.
Monday, April 15, 2002
Someone posted to the ALIENS-L listserver today requesting information about eradicating Robinia pseudoacacia (Black Locust) from a forest. This in itself did not surprise me, but the fact that the request came from someone in Korea did. Seems this U.S. native has gotten out of control in many of the regions into which it was intentionally introduced.
The BBC Nature page has a feature this week called "Space Invaders". It talks about how certain bird species, including the collared dove and the Mediterranean gull, have expanded their range and are now quite common in the U.K. Whether this constitutes an "invasion" could be debated, but the appearance of these birds has certainly had ecological consequences. Doing a Google search for 'Mediterranean gull' will bring up lots of "first sightings" in the U.K. and Scandinavia.
Sunday, April 14, 2002
The Environmental News Network (ENN) has this article from the USDA about the status quo of Longhorned Beetle invasions in the U.S. and Europe. While most people studying invasive species are probably familiar with the Asian Longhorned Beetle (Anoplophora glabripennis), this is the first I've heard of the Citrus Longhorned Beetle (Anoplophora chinensis), which is also native to Asia. Both species are known for the ability of their larvae to destroy trees by burrowing through the wood. And both species continue to be accidentally introduced to the U.S. via wooden packing material and shipments of live trees, including bonsai.
The latest issue of the online journal of news in the life sciences, The Scientist, has an article by Barry A. Palevitz on "The Continuing Saga of Invasive Species." You have to be registered with the site to view the article, which is about the Council for Agricultural Science and Technology's recent report on "Invasive Pest Species: Impacts on Agricultural Production, Natural Resources, and the Environment".
If you prefer, you can link directly to the CAST report, in .pdf form, by clicking here. Published in March 2002, it's mostly a typical introduction to the invasive species issue, i.e. how did they get here, why are they bad for the environment, how much do they cost, etc. The focus on invasive "pests" means it covers viruses, fungi and other pathogens, as well as insects and other animals...no plants here! The report ends with a nice list of policy recommendations, with public education at the top of the list.
The Chicago Botanic Garden is hosting the Janet Meakin Poor Research Symposium October 27-30, 2002, and the subject is Invasive Plants�Global Issues, Local Challenges. Abstracts were due Friday April 12th. You can register to attend starting in July.