Invasive species shift Great Lakes ecosystems – Summit County Citizens Voice

GR:  Invasive species are weakening and eliminating ecosystems around the world. In many instances, people introduced the invasives to increase food production for domestic livestock. In other instances, people introduce the invasives to control other invasives. The search for magic bullets such as pesticides, diseases from the original homeland of an invasive, and introduction of more competitive aliens from the homeland continues, but without much success. Many times, the only effective means to eliminate an invasive species is to apply manual labor: catching, pulling, or mowing.

“The Great Lakes have seen successive invasions by non-native species that alter the ecosystem, including quagga mussels that filter the water and remove nutrients. At least partly as a result of the invasive mussels, Lake Michigan is becoming less hospitable to Chinook salmon, according to a new study led by scientists with the U.S. Geological Survey and Michigan State University.

“The scientists concluded that stocking could help sustain a population of Chinook salmon, but that the lake’s ecosystem is now more conducive to stocking lake trout and steelhead salmon. These two species can switch from eating alewife, which are in decline, to bottom-dwelling round goby, another newly established invasive prey fish that feeds on quagga mussels.

“Findings from our study can help managers determine the most viable ways to enhance valuable recreational fisheries in Lake Michigan, especially when the open waters of the lake are declining in productivity,” said Yu-Chun Kao, an MSU post-doctoral scientist and the lead author of the report.” –Summit County Citizens Voice (Continue: Invasive species shift Great Lakes ecosystems – Summit County Citizens Voice).

Behind New Zealand’s wild plan to purge all pests

Invasive Species

GR:  After 1500 AD, sailing ships and then later on, motor-powered ships began transporting and introducing plant and animal species all over the globe. Freed from the predators and diseases of their homes, some of the introduced species became invasive–that is, they began spreading, replacing native species, and decreasing ecosystem stability and productive. This is not news, of course, biologists have long been aware of the devastation caused by invasive species.

Eradicating invasive species is very expensive and very difficult. National resolve and full public support are required. Eradication is something that we humans, who are responsible for spreading the invasive species, should be about everywhere.

However, it is essential to place greater focus preventing the initial introduction of non-native species. Prevention is cheaper and kinder than eradication. And again, prevention is not a new idea. Natural resource managers have known how to prevent invasions for the past century. In many instances, they just don’t take the necessary steps. Here are some articles on invasive plants.

New Zealand has one of the worst invasive plant and animal problems in the world. The article below describes an ambitious and necessary plan to do something about it.

New Zealand Eradication Plan

New Zealand has three invasive species of rat. The Pacific rat, or kiore (Rattus exulans), was introduced from Polynesia in about the twelfth century; the ship rat (Rattus rattus) arrived in the late 1700s; and the Norway rat (Rattus norvegicus) became established in the 1860s. All three prey on native birds, insects and lizards, and have been blamed for the decline or extinction of a variety of species.

“Razza the rat nearly ended James Russell’s scientific career. Twelve years ago, as an ecology graduate student, Russell was releasing radio-collared rats on to small islands off the coast of New Zealand to study how the creatures take hold and become invasive. Despite his sworn assurances that released animals would be well monitored and quickly removed, one rat, Razza, evaded capture and swam to a nearby island.

“For 18 weeks, Russell hunted the animal. Frustrated and embarrassed, he fretted about how the disaster would affect his PhD. “I felt rather morose about the prospects for my dissertation,” he says.

“Although there was a lot of literature on controlling large rat populations, little had been written about tracking and killing a single rodent, which turns out to be rather important in efforts to completely eradicate a species. “It demonstrated how hard it is to catch that very first rat as it arrives on an island — or, conversely, the very last rat that you’re trying to get off,” says Russell, now at the University of Auckland.

Brushtail possums are among the numerous invasive pests regularly culled in New Zealand.

“Razza’s escape became the subject of a paper in Nature1 as well as a popular children’s book. And now, with more than a decade of successful pest-eradication projects behind him, Russell is taking on a much bigger challenge. He is coordinating research and development for a programme that the government announced last July to eliminate all invasive vertebrate predators — rats, brushtail possums, stoats and more — from New Zealand by 2050 to protect the country’s rare endemic species.” –Brian Owens (Continue reading:  Behind New Zealand’s wild plan to purge all pests : Nature News & Comment)

The harlequin ladybird is a clever little devil

GR:  This is a good example of the unintended harm caused by human efforts to improve nature for human benefit.  Accidental and intentional introductions of plants and animals from one continent to another releases the plants and animals from their native predators and diseases. If they multiply, they can replace whole ecosystems and cause drastic reductions in biodiversity and productivity. After the immediate effects of habitat loss to construction, human-introduced invasive species are the most significant contemporary destructor of nature. As global warming effects grow, surviving humans will probably share the Earth with these species.

“Tricked out in Halloween orange and black, a harlequin moves awkwardly through a micro woodland of moss on the concrete as if it were wandering through an alien world, which in some respects it is. This is Harmonia axyridis succinea, a beetle that began its global travels somewhere in eastern Asia between Kazakhstan and Japan.

“Because its larva has an insatiable appetite for aphids and other small insects it was taken to America in the 1980s for the biological control of crop pests. It was so successful that it has been transported into European agriculture, too. To show its appreciation the beetle, called the Halloween ladybug in the US and the harlequin ladybird in Europe, has had a population explosion.

“This is such a common story of what happens when commerce controls nature for its own ends that it comes as no surprise that a creature pressed into servitude causes fear on liberation. It arrived here in 2004 and in 10 years spread throughout an area that took grey squirrels a century to colonise.

Harlequin ladybirds declared UK’s fastest invading species

“Described as a “voracious invader” with a frightening appetite for other ladybirds and the eggs of butterflies and moths, the harlequin causes understandable alarm, given the threat it poses to Britain’s beleaguered wildlife. By the time the harlequin arrived here it was far too late to do anything about it.” –Paul Evans (The harlequin ladybird is a clever little devil).

Invasive Species and the Bighorn Sheep Die-off in Montana Mountains, Nevada

Invasive Species

GarryRogersGR: Human-introduced animals, plants, and disease organisms have destroyed many species and ecosystems. This aspect of the human impact on nature became a global disaster in the 1500’s as we began crossing the oceans. In the lands we reached, we rampaged about with no thought of the seeds stuck to our boots or the diseases carried by our livestock. Then we developed nature. We cut the soil and filled it with pipes and wires and then we entombed its microorganism ecosystem with pavement. We damned streams, dried up springs, cut the forests, stripped the land with cattle and sheep, and we poisoned the water and air. Now comes our grand slam: We’ve added sufficient greenhouse gasses to the atmosphere to give our climate warmer temperatures, droughts, fires, and stronger storms.

How do we react to all that we’ve done? In the current time of competition between oil producers, for example, the temptation to burn more of the cheaper gasoline doesn’t horrify us, no, we call the lower prices a consumer blessing. Fuels Supplied

And so, in all that we do, our species appears to be striving for maximum destruction of earth ecosystems. Here are a few essays I wrote about how this works with invasive plants.

The following article is by Ken Cole on the Wildlife News website (February 19, 2016).

Bighorn sheep by Ken Cole

Bighorn sheep photo copyright by Ken Cole

“On Sunday and Monday, February 14-15, 2016, USDA Wildlife Services took to the skies and shot the remaining 24 bighorn sheep in the Montana Mountains of northwest Nevada at the request of Nevada Department of Wildlife.

“While the exact source of the disease outbreak is not known, it is not surprising that the bighorn sheep in this area are suffering this fate because there are two domestic sheep grazing allotments – the Bilk Creek allotment and the Wilder-Quinn allotment – in the middle of this area and BLM ignored the disease threat that they pose to bighorn sheep.

“In 2012 the BLM began the permit renewal process for one of the allotments – the Bilk Creek allotment – and Western Watersheds Project submitted comments notifying them of our concern about the risk that domestic sheep posed to bighorn sheep in this area. It is well know that domestic sheep are carriers of pathogens that result in deadly pneumonia to bighorn sheep and that even just one nose-to-nose contact between these related species can result in a disease outbreak that commonly kills up to 90% of a herd and kills the offspring of the remaining animals for up to a decade.

“In 2013 the BLM issued the Final Environmental Assessment that dismissed those concerns . . . . ”  Read more at:  http://www.thewildlifenews.com/2016/02/19/bighorn-sheep-die-off-in-montana-mountains-nevada-is-it-any-wonder.