From Yahoo! News comes this article about Buddhists in Hong Kong, and the unintended consequences of one their religious practices. Many who follow Buddhism believe that they are morally bound to free any trapped animal, and the act of doing so will increase health and well-being. Buddhists in Hong Kong will often buy animals from the markets and then release them into the wild. This is so common that there are entrepreneurs who trap common wild animals, such as sparrows, sell them to people, and then recapture them once they are released. Unfortunately, this religious practice can have unintended consequences. One is that well-intentioned Buddhists sometimes release animals into the wrong habitat, where the animals cannot survive. Another is that non-native animals, including turtles and frogs from North America, are becoming established in the wild, threatening native Asian species.
Sunday, June 30, 2002
Saturday, June 29, 2002
The World Environment web site has a link to this story from the North Jersey News about the newest member of the USDA inspection team at Newark Airport: a beagle. Scroll down past the cute stuff about the beagle sniffing people's luggage to learn more about the species inspection officials are most concerned about entering the U.S., including the Asian longhorned beetle (Anoplophora glabripennis). The battle to prevent both accidental and intentional introductions of plants, animals, and pathogens via people entering or re-entering the country is neverending.
The Water Hyacinth (Eichhornia crassipes) has become quite prolific in Uganda, to the point where the Egyptian government has generously pledged to give almost $14 million to the African nation to combat the infestion of Lake Kyoga. You can read more about the battle with this aquatic plant incountries in Africa and the Middle East from this page and this one.
Thanks to a member of the ALIENS-L listserver for posting a link to this story.
Thursday, June 27, 2002
Check out the Gambusia Control Homepage. Dedicated to explaining to the world the problems caused by Mosquitofish, which has been used as a method of controlling mosquito larvae, the page points out that this genus threatens native biodiversity in Australia and New Zealand, and coyly renames the fish "damnbusia." The U.S. is also dealing with this problem genus, which is actually native to the southeastern states. Ironically, Mosquitofish do not even do a good job of mosquito larvae control.
Tuesday, June 25, 2002
A pack of Wild Boars (Sus scrofa) has been terrorizing a neighborhood in Marion County, Florida, according to this story from Local 6 News (Be sure to click on the link to watch the video footage). The animals, as is their habit, are tearing up turf and otherwise causing distubance in the yards of residents. Wild Boars are invasive all over the U.S., and are hunted in many states for sport.
Monday, June 24, 2002
The Toronto Star printed this story about the invasion of the Hawaiian islands by a frog known as the Coqui (Eleutherodactylus coqui) (5 bonus points to The Toronto Star for using the scientific name!). The islands were frog-free before several species in this genus were introduced, and the cacophony of frog calls during the night is driving some people crazy.
Sunday, June 23, 2002
I've just added a set of pages about the invasive plant Perennial Pepperweed (Lepidium latifolium) to my web site. There are photos for use in identification, information about populations in Massachusetts, and links to other sites with information about the species.
Saturday, June 22, 2002
A study done in northern Australia on the invasive tree Prickly acacia (Acacia nilotica), published in the June 2002 issue of the journal Austral Ecology (link to abstract), looks at the possible explanations behind the preference of the species for riparian habitats. Prickly acacia, native to Africa and Asia, has been been planted worldwide as a fodder plant...unfortunately grazing animals eat this leguminous tree's pods and disperse the seeds in their feces.
Friday, June 21, 2002
Since I found the Canadian ladybug site, I've been trying to find a ladybug in the field that wasn't the introduced Southern beetle (Harmonia axyridis). I was happy when I saw a different species today at Wollaston Beach Reservation (see image below), but a check at the identification site indicated that it was the Seven-spotted lady beetle (Coccinella septempunctata), another species imported for insect control.
Thursday, June 20, 2002
In the latest issue of the online journal Conservation Ecology, you can read an article by Perrings et al. entitled "Biological Invasion Risks and the Public Good: an Economic Perspective." It's a very interesting discussion piece on the major role economics plays in the spread and management of non-native invasives. While the article does focus mainly on diseases, it makes policy recommendations that can be applied to all organisms (my favorite: insurance for importers of non-native species). Also in the same issue is an article by Graeme Cumming about modeling invasions, "Habitat Shape, Species Invasions, and Reserve Design: Insights from Simple Models"
Wednesday, June 19, 2002
The Plant Conservation Alliance, which is part of the Bureau of Land Management, has created a set of "Celebrating Wildflowers" coloring books. From their Northwest Coloring Book you can download the pictures to color, along with color guides, for such invasive species as Purple Loosestrife (Lythrum salicaria), the not-actually-from-Canada Canada Thistle (Cirsium arvense) and Scotch Broom (Cytisus scoparius). The web pages that list the species have no information other than the common and scientific names, but the coloring book pages themselves do have a little "Noxious Weed" note opposite the "Celebrating Wildflowers" logo.
Monday, June 17, 2002
Back in January, the National Geographic News posted this story about the indirect benefits of a new method of preventing rust in ballast tanks. The ballast tanks of ships, filled with water and/or soil to provide balance, have been traced to the accidental introduction of many non-native species, including such invasives as the Zebra mussel. Now scientists have found that removing the oxygen from ballast water not only helps prevent the tanks from corroding, but also kills a large percentage of some non-native invertebrates. Results of the research were published in the January 2002 issue of the journal Biological Conservation.
Saturday, June 15, 2002
From the St. Louis Post-Dispatch comes this article about the war against invasive plants in Missouri. It features profiles of several people involved and lists some ways in which they have changed the way gardeners and nurseries think about invasive plants, as well as their hybrids and cultivars. There's also this article from the same newspaper, which suggests native alternatives to invasive plants. If you are from Missouri and want more information, you can visit the Harmful Exotic Species Program web site, from the Missouri Department of Natural Resources.
Thursday, June 13, 2002
A member of the Yahoo! newsgroup ma-eppc posted a reference to this article about a proposal by the San Diego City Council to "ban the sale, distribution and cultivation" of four well-known invasive plant species: Pampas grass (Cortaderia jubata), Tamarisk (Tamarix sp.), Giant reed (Arundo donax) and German ivy (Delairea odorata or Senecio mikanioides) (Would have been be nice to have the scientific names in the article!). The proposal is similar to the restrictions put into place by Palm Beach County, Florida. The minutes of the Council meeting may eventually posted here.
Wednesday, June 12, 2002
Investigators have shown that visitors making their way into the Antarctic are bringing foreign strains of bacteria with them on their boots. As reported in this article, introduction of new types of bacteria and other disease-causing organisms could be potentially devastating to the Antarctic ecosystem. Since seawater has turned out to be ineffective at removing the bacteria, researchers are recommending that the environmentally friendly disinfectant Virkon be used to wash boots before entering the region.
Tuesday, June 11, 2002
Utah is determined to rid itself of Dyer's Woad (Isatis tinctoria), an invasive plant introduced to the state over a century ago, and -everyone- is getting involved. If you're a kid and you live in Box Elder or Cache county, you can earn $10 per bag of Dyer's Woad (sorry, there's a 2 bag limit!). Mormons led camping trips during the late 1990's during which participants pulled the weeds or sprayed them with herbicide. Dyer's Woad, as its name implies, can be used to make a dye, comparable to indigo. It has become a pervasive part of the landscape in Utah and surrounding states.
Monday, June 10, 2002
The "IPM and Biological Control in Florida" web site has updated information about a weevil released in the late 1990's in Florida to control the invasive Melaleuca tree (Melaleuca quinquenervia). The goal is not to eradicate Melaleuca, only to decrease its ability to flower and thus spread by seed.
Sunday, June 09, 2002
Continuing a study that spans over a decade, Svata Louda and Charles O'Brien are releasing new information about the impact of the introduction of Eurasian weevils as a biocontrol for the invasive Canada thistle (Cirsium arvense, incidentally not native to Canada!) in the U.S. This sanctioned introduction has gone on to be the best known case against biological controls; the weevils have moved on to native thistles, some of them rare. Organizations like CABI Bioscience have since become a lot more cautious about approving new species introductions to combat invasives.
Friday, June 07, 2002
Hurray for the Galapagos Islands! Declaring one of their largest islands finally free of feral pigs, conservationists can congratulate themselves for winning a hard battle in what will probably be a long war. Feral pigs (Sus scropha) are very destructive, and there are several native species that will benefit from their absence. But there are still other pig-infested islands in the chain, and as the list at the end of the article shows, there are many other invasive plants and animals that must be dealt with.
Thursday, June 06, 2002
From The Guardian of London comes this article about the problems caused by invasive species, the difficulty in predicting the next "big thing", and issues regarding what is native and what was introduced a really long time ago. A nice piece covering a lot of ground, focusing mainly on America though it's in a British paper. The author does gloss over the bit about why species are invasive, attributing it to the absence of predators; there are many other reasons a species might be invasive when introduced to a new habitat, and this is only one of them.
Wednesday, June 05, 2002
Scientists at CSIRO in Australia have genetically modified the Carp (Cyprinus carpio) to make all individuals turn male, according to this Reuters article. Apparently the gene sequence used, called "daughterless", is found naturally in the carp genome. The hope is that if these modified carp are released into bodies of water, over the next several decades they will breed with wild carp, resulting in many fewer females, and theoretically fewer carp offspring. Since carp interefere with the ecosystems they are introduced to by competing with native species for food and polluting the water, this could be a good thing. If you want to know more, you can check out this information sheet (.pdf) from CSIRO's website. There is also a great web page about Aquaculture Genetics .
Tuesday, June 04, 2002
The Florida Aquarium, located in Tampa, recently debuted its new exhibit "Invaders! Florida�s Most Unwanted Species." They should have lots of information; Florida has been the site of over 20,000 non-native species introductions, and has been particularly devastated by invasive species. There doesn't seem to be a link on the website to info about the new exhibit, but if you want more details, you can read the press releases.
The Minnesota Department of Agriculture has issued a press release again this year, asking the public to report infestations of Garlic mustard (Alliaria petiolata) and remove the species when possible. Unfortunately, they don't include a good link to a page with more information on how to identify the plant or control it; you can go here for more information.
Garlic mustard is a biennial, meaning that it does not flower in the first growing season, making identification more difficult. The leaves do emit a strong odor of garlic when crushed, but after making the mistake of doing this with what turned out to be very early growth of Stinging nettles (Urtica dioica), I recommend you use something besides your hands to crush the leaves. Since Garlic mustard flowers early in the spring, to remove second-year plants before they set seed you'll have to attack within the next few weeks. It's unclear exactly how the seeds are spread, but I suspect humans play some role in their distribution when they tromp through infested areas.
Sunday, June 02, 2002
Today I found this great website created by the Canadian Nature Federation as a part of their 1995 survey of Ladybugs (also known as Lady Beetles or Ladybird Beetles). They have pictures and descriptions of 16 different species that exist in North America. Using their guide, I was able to determine that these photos (from a previous blog entry) are most likely of the same species, the Southern beetle (Harmonia axyridis). Also known as the Asian Lady beetle, this species has been repeatedly introduced to North America since the early 1900's.
Saturday, June 01, 2002
What can be done when an invasive plant is taking over a lake? Removing it is often not an option; many aquatic invasives spread vegetatively, which means that if you break up stems you aren't killing the plant, you're just increasing the potential for the species to restablish in a new area or cling to a boat and find refuge in a nearby body of water. There are rarely any options for eradication that won't cause serious disturbance to the rest of the lake's flora and fauna. Often a decision is made to wipe out almost everything in the lake and "start from scratch".
South Australia is taking the herbicide route, using a combination of chlorine and copper sulfate to rid the West Lakes of Caulerpa taxifolia, according to this story from news.com.au. Some parties are concerned about the major impact this could have on all lake life, but after reading how aggressive Caulerpa can be, I don't blame them for making this decision. You can read more about aquatic plant management here.