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).

Plastic-eating bugs? It’s a great story – but there’s a sting in the tail

GR: People have often tried to import species to solve problems or increase productivity. Many times, unintended consequences have proven disastrous as the imported species spread beyond the objective and replaced local plants and animals. [Here’s an example from my research.] The story below gives another example for a current problem.

You’d need an awful lot of Wax Moth caterpillars to make a significant dent on the plastic waste problem. The UK alone discards almost 2m tonnes of the stuff every year.’ Photograph: Federica Bertocchini/Paolo Bombe/PA

“Caterpillars that can munch up plastic bags have just been identified, fuelling excited speculation that this could one day eliminate global pollution from plastic waste. The chance discovery, initially made by a scientist and amateur beekeeper whose plastic bag had been eaten through by the moth caterpillars, was reported this week by researchers at Cambridge University and the Spanish National Research Council.

“How thoughtful of nature to provide bugs that eat our rubbish. Is this the end of landfill, turtles with plastic-congested stomachs, and trees adorned with tattered ribbons of shopping bags?

“Well, it’s never that simple, is it? Attempts to commandeer nature to do our dirty work never seem to turn out as hoped, whether these take the form of planting trees to soak up carbon dioxide, or introducing invasive species for pest control, or using microorganisms to clean up oil spills. Remember the Australian cane toad debacle? The toads were introduced in the 1930s to control crop pests but instead gorged themselves on other local wildlife and spread across the country.

“These creatures, the larvae of the greater wax moth (Galleria mellonella), can devour polyethylene, which along with the closely related polypropylene is the main type of plastic found in waste. But you’d need an awful lot of them to make a significant dent on the plastic waste problem. The UK alone discards almost 2m tonnes of this stuff every year. At the rate of consumption reported by the researchers – one worm gets through about two milligrams of plastic a day – you’d need billions of caterpillars eating constantly all year round to deal with that.

“Quite aside from how and where you’d farm all these bugs, there’s something about them that news reports have failed to mention. Wax moths, which are found throughout the world, are so-called because they eat wax. Specifically, they love to eat the wax from which bees make their honeycombs – and so they can devastate bee colonies. The two common species of wax moth, of which Galleria mellonella is one, are thought to cause more than £4m worth of damage annually in the United States alone.” –Philip Ball (Continue: Plastic-eating bugs? It’s a great story – but there’s a sting in the tail | Philip Ball | Opinion | The Guardian)

With bee populations already under severe stress, we might want to think twice about breeding one of their common airborne enemies in huge numbers. Photograph: Peter Komka/EPA

 

 

 

Species Introductions Are Accelerating

GR:  Invasive plants and animals are destroying native ecosystems. Some species that we take from their homes and release in other regions explode across the new habitat. Free from their natural competitors and diseases, the species are like Superman freed from Krypton’s light. Local species cannot compete and are replaced.  I’ve studied some of the plant species that do this. You can read what I’ve learned here.

My work focuses on invasive plants, but animals can be equally destructive. The Eurasian Wild Boar is a good example of the hundreds of species impacting North American ecosystems. Here’s a brief review of the history of its introduction and spread in the U. S.

Feral Eurasian Wild Boar

Feral Eurasian Wild Boar

Invasive species are second only to complete habitat destruction by roads and buildings as destroyers of nature. Global warming will take their place over the next few decades, but that doesn’t mean that we can ignore invasives. Protecting nature requires that we tend to all our destructive behaviors. My articles include suggestions and references to other resources for invasive plant control.

The article below from the National Geographic Society Blog reports that the invasive species problem is growing. Humans really began spreading species 500 years ago when they began crossing the oceans. It surprises me that we’ve left anything behind, but apparently we left enough invasive species behind to continue and even accelerate this form of the human impact.

“A study released this month has illustrated that the rate of species introductions to locations outside their native range is increasing faster than ever. Hanno Seebens and many others used the date of first records of introductions to plot the total number of new non-native species records every year since 1500. They show that this is not only increasing, but accelerating, with no signs of saturation. The increase was particularly marked since the 1800s. This global exchange of species is not good news, as although it increases species richness at the regional scale, globally the species richness of our planet declines as species go extinct.

Global temporal trends in first record rates (dots) for all species (a) and taxonomic groups (b–q) (Source: Nature Communications)

“New Zealand was singled out as one country whose trend was negative compared to the rest of the world. As any traveller to New Zealand will have encountered, the biosecurity importation laws and policing are rigorous and every passenger is screened. In tandem with a ‘white-list’, where only certain non-native species are automatically permitted entry, and all others must be assessed, has clearly assisted in protecting New Zealand’s biodiversity and primary industries from the global trend in accelerating species introductions.” –James Russell (Continue reading:  Species Introductions Accelerating – National Geographic Society (blogs).)

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)