Tag Archives: invasive species

Invasive hammerhead worms are starting to conquer Europe and Africa

Researchers have described two species of worms sporting a distinctive hammerhead look. The worms, discovered in parts of Europe and Africa, are likely invasive species and could wreak havoc on soil biodiversity.

Humbertium covidum, an invasive hammerhead worm found in Italy. Image credits: Pierre Gros.

As the world is becoming increasingly globalized, species are being brought from one part of the world to the other. These “alien” species have the potential to overrun the new ecosystem they’re brought to, and oftentimes, by the time you realize there’s a problem, there’s little you can do about it.

Oftentimes, you don’t even notice these invasive species unless you’re really paying attention — and this is exactly the case here.

An international team led by Professor Jean-Lou Justine from ISYEB (Muséum National d’Histoire Naturelle, Paris, France) described two new species of hammerhead flatworms. This is the first study of these species, although flatworms have been invading Europe for some time.

“We were surprised at first that some of the species which were invading Europe, a place where biodiversity is supposed to be well known, did not even have a name. That was the case of Obama nungara, a species described only in 2016,” Justine told ZME Science. The researchers did not give it a name at the time, though they did describe it in a 2020 paper with a charming title. The name Obama is formed by a composition of the Tupi words oba (leaf) and ma (animal), a reference to its body shape.

“This is also the case for the two new species described in this paper, they had no names and were never described in their countries of origin.”

Hammerhead worms are predatory creatures, much like their shark namesakes. They can track their prey (typically other worms or mollusks), and bear a distinctive shape on their head region, which helps them creep over the soil substrate.

Diversibipalium mayottensis, an invasive species of hammerhead worm found in Mayotte

A number of hammerhead worms have been described by scientists but, in many cases, the researchers don’t describe them in their land of origin, instead finding them in countries that they have already invaded. For instance, two previously described species (Bipalium pennsylvanicum and Bipalium adventitium) originate from Asia but were first reported from the US. The two newest species follow the same trend.

“I have been working on invasive land flatworms since 2013, when I discovered that gardens in France (and Europe) were invaded by bizarre worms and that almost no scientist was working on this problem. Leigh Winsor, the Australian member of our team, has been working on them since the 80’s,” Justine adds.

The first new species was named Humbertium covidum, as an homage to the victims of COVID-19, but also because much of the work was carried out during the COVID-19 lockdown.

“Due to the pandemic, during the lockdowns most of us were home, with our laboratory closed. No field expeditions were possible. I convinced my colleagues to gather all the information we had about these flatworms, do the computer analyses, and finally write this very long paper. We decided to name one of the species “covidum”, paying homage to the victims of the pandemic.” 

The worm was found in two gardens in the Pyrénées-Atlantiques (France) and also in Veneto (Italy). Although some hammerhead worms can reach up to one meter, this one is small (3 cm) and looks uniformly metallic black — an unusual color among hammerhead flatworms.

These creatures are not easy to characterize based on their morphology alone, so researchers decided to use mitochondrial genetic analysis, which can provide a lot of information about the origin of this species and which other species it is related to. This species appears to have originated in Asia and is potentially invasive. By analyzing the contents of its stomach, researchers also found that it eats snails.

The second species, Diversibipalium mayottensis was only found in Mayotte (a French island in the Mozambique Channel, Indian Ocean). The species is as small as the other one, but instead of a metallic black, it exhibits a spectacular green-blue iridescence. Based on genetic analysis, this species appears to belong to a “sister group” of all other hammerhead flatworms, which means it could help researchers understand how these creatures evolved. Its origin could be Madagascar, but it’s not entirely clear. Presumably, at some point in the past, people brought plants from Madagascar and unknowingly, also brought the worm.

“All land flatworms are generally transported with potted plants,” Justine says. “For the species in Europe, Humbertium covidum, it is likely that the species was transported in recent years, from Asia, with some imported plant. For the species in Mayotte, Diversibipalium mayottensis, it is likely that it comes from Madagascar, but the transport might have happened a long time ago, perhaps even centuries ago, by traditional exchanges between islands in this part of Africa.”

Although finding new species is generally good news, this is not necessarily the case here. These flatworms are probably bad news, especially if they're not in their natural environment. For instance, one study found that one single worm species from New Zealand became invasive in the UK, and when it became established, earthworm biomass declined by 20%.

"All land flatworms are predators of the other animals of the soil fauna, and, as such, can threaten the biodiversity and ecological balance of species in a soil. However, there are only a very few papers in which their impact was thoroughly studied, because these studies are long and expensive," Justine explained in an email to ZME Science.

The study comes with a clear warning: invasive species are probably more prevalent than we realize. In the US alone, invasive species are estimated to cause damage of around $120 billion, and the figure is likely to increase as the world becomes more and more interconnected. Unfortunately, when it comes to dealing with invasive hammerhead worms, prevention is pretty much our only weapon.

"Basically, there is not much to be done once a land flatworm has invaded a country. Prevention is the key, we need to avoid importing new flatworms (that is true for Europe and US)," Justine concludes.

The study was published in the journal PeerJ.

Protected areas are at risk from nearby invasive species, study shows

Invasive (or ‘alien’) species are living close to most almost all protected areas around the world, according to a new study. This poses important risks for local species, and further measures have to be taken to ensure the protected areas remain safe from invasive species.

Credit Flickr

Researchers from the Chinese Academy of Science found at least one established population of a non-native species lives within 10 km of the boundaries of 89% of protected areas.

According to the same study, more than 95% of these protected areas environmentally are suitable for the establishment of the invasive species.

“One of the most harmful ways that people are impacting the natural environment is through the introduction of ‘aliens’ – species that do not occur naturally in an area, but have been taken there by human activities,” said in a statement co-author Tim Blackburn. “These species may kill or compete with native species, or destroy habitats.”

Global biodiversity loss is caused by many factors, with alien species being one of the main problems, Blackburn said. It is becoming increasingly common to find invasive species established in new locations — including protected areas, which are highly important for biodiversity conservation and cover 15% of Earth’s surface. A species is considered invasive if is not native to a specific location, and that has a tendency to spread to a degree believed to cause damage to the environment

Backburn and his team looked at 894 terrestrial animal species, ranging from mammals to reptiles, that are known to have established invasive populations somewhere in the world. They evaluated whether the species could be found near to 200,000 protected areas around the world, such as national parks.

Less than 10% of the protected areas are currently home to any of the invasive species surveyed, which suggests a good level of protection. But that doesn’t mean they are safe, as invasive species can be found within 100km of the boundaries of almost all areas. For 89% of them, invasive species are just 10 kilometers from their limits.

The largest proportion of invaded protected areas was colonized by alien birds (252 species), followed by mammals (91 species), invertebrates (63 species), amphibians (48 species), and reptiles (66 species). Some of the most common invasive species are the Rock Dove (Columba livia) and the Ring-necked Pheasant (Phasianus colchicus)

The study also looked at the common factors among the protected areas that are already home to alien species. They found that protected areas tend to have more alien animal species if they have a larger human footprint index, due to factors such as transport links and large human populations nearby.

The larger and more recently established areas tend to have more alien species, according to the study. Meanwhile, older protected areas tend to be in more remote areas, so they are less exposed to human impacts.

“At the moment most protected areas are still free of most animal invaders, but this might not last. Areas readily accessible to large numbers of people are the most vulnerable,” said in a statement Li Yiming, senior author. “We need to increase efforts to monitor and record invasive alien species that people may bring into protected areas.”

The researchers concluded that while invasive species long been discussed as a threat in protected areas, far more action is required to protect these areas. For instance, the researchers suggest implementing routine monitoring of visitors and vehicles entering protected areas.

There is thus an urgent need to integrate efforts from the scientific community, governments, NGOs, landowners and local stakeholders to develop more effective biosecurity strategies to pre-empt potential further invasions in protected areas under ongoing global change, the researches argued.

The study was published in the journal Nature Communications.

How Pablo Ecobar’s escaped hippos might actually help the environment

 A herd of hippopotamuses swims in a muddy lake at the abandoned country home of the late Pablo Escobar, in central Colombia in Puerto Triunfo. In his heyday in the 1980s, Escobar imported elephants, rhinoceroses, lions, giraffes and other exotic beasts to his lavish Hacienda Napoles ranch as a testament to his fabulous wealth. Credit: FICG.mx, Flickr.

After Pablo Escobar, the world’s biggest drug lord at the time, was killed by police in 1993, the Columbian government seized all of his assets. Among them, his luxurious Hacienda Napoles estate northwest of Bogota, which also served as Escobar’s personal zoo. Most of the exotic animals there were shipped away, but somehow four hippopotamuses — of which Escobar was especially fond — were left behind at the estate’s pond.

The hippos were resourceful enough despite their circumstances and they not only survived — they thrived. No one knows exactly many of them are, wallowing in the mud of Colombia’s main river, the Magdelena. Some believe their population could number as many as 80-100 individuals.

Many local residents close to their habitat are completely horrified.

“We have to lock ourselves inside with the children to try and avoid an accident,” primary school teacher Wilber Quinones told Sky News.

Then there’s their ecological damage. Many scientists have asserted that hippos, as an invasive species, are ruining the native flora and fauna. The water in which they defecate, for instance, causes algae outbreaks in Columbia’s rivers and lakes.

However, a new study published by researchers at the University of Massachusetts Amherst suggests the impact of Escobar’s hippos on the environment might be positive, counteracting a legacy of man-made extinctions.

The hippos aren’t alone, with the study finding many introduced herbivores actually share key ecological traits with extinct species across the world, generally providing balance to ecosystems.

Human impact has significantly altered the ecological landscape across the world over the last 100,000 years. We’ve caused the extinction of many large mammals through overhunting and habitat destruction, but also introduced numerous species to foreign environments often with severely negative consequences for the environment.

But, sometimes, our activity also leads to ‘happy accidents’, rewilding some parts of the world.

In South America, giant llamas once roamed, while the flat-headed peccary was once found all the way from New York to California. Even more mythical creatures once roamed the Earth, such as the tank-like armored glyptodons and two-story-tall sloths. This megafauna appeared millions of years after the demise of the dinosaurs but abruptly disappeared around 100,000 years ago.

Their ecological role has been filled, in some situations, by large herbivores that we’ve later introduced.

“For example, the feral hippos in South America are similar in diet and body size to extinct giant llamas, while a bizarre type of extinct mammal – a notoungulate – shares with hippos large size and semiaquatic habitats. So, while hippos don’t perfectly replace any one extinct species, they restore parts of important ecologies across several species,” study co-author John Rowan, an evolutionary biologist at the University of Massachusetts Amherst, said in a press release.

Credit: University of Kansas/Oscar Sanisidro.

The researchers compared key ecological traits of herbivore species — things like body size, diet, and habitat — that lived before the Late Pleistocene to the present day.

“This allowed us to compare species that are not necessarily closely related to each other, but are similar in terms of how they affect ecosystems,” said Erick Lundgren, lead author and Ph.D. student at the University of Technology Sydney Centre for Compassionate Conservation (CfCC). “By doing this, we could quantify the extent to which introduced species make the world more similar or dissimilar to the pre-extinction past. Amazingly they make the world more similar.”

According to the findings, 64% of introduced herbivores are more similar to extinct species than to local native species. This includes mustangs (wild horses) in North America, which replaced pre-domestic horses that filled the same ecological niche but were driven extinct.

“Many people are concerned about feral horses and donkeys in the American southwest, because they aren’t known from the continent in historic times,” Rowan says. “But this view overlooks the fact that horses had been present in North America for over 50 million years – all major milestones of their evolution, including their origin, takes place here. They only disappeared a few thousand years ago because of humans, meaning the North American ecosystems they have since been reintroduced to had coevolved with horses for millions of years.”

There is a lot of talk about invasive species among scholars — as there should be, since invasive species have been associated with damage to natural parks and 13% of a total of 953 global extinctions recorded thus far. But in some cases, foreign species (at least some herbivores) can rewild ecosystems making the world more similar to its pre-extinction past.

The findings appeared in the journal Proceedings of the National Academy of Sciences. Other researchers who contributed to the study are affiliated with the University of Kansas and the University of California Davis and the Natural History Museum of Los Angeles County in the U.S., the University of Sussex in the U.K., the Universidad de Alcalá in Spain and Aarhus University in Denmark.

Tourism needs to start considering invasive plants

In 1876, the Philadelphia Centennial Exposition featured an intriguing plant from Japan. It was hardy, fast-growing, and good at preventing soil erosion. Kudzu, as the plant was named, is an excellent vine, advertisers said — it’s even edible, as long as you don’t spray it with pesticides.

Fast forward a few decades to the 1940s and kudzu had become a staple in some regions of the US. Hardy and fast-growing it was — but farmers didn’t understand just how fast-growing it was. It expanded its area dramatically, climbing over trees and shrubs and killing them in the process. Where kudzu was planted, it took over the landscape, overrunning it and altering the environment as it went.

Kudzu, the invasive plant, became an ecological disaster.

Like US farmers, we can all be agents that introduce invasive species to pristine environments — and it’s more important than ever to avoid doing this.

Kudzu growing on trees in the US. Image credits: Scott Ehardt.

Invasive species

Invasive species are species that are not native to a specific location, with a tendency to outcompete native plants and cause substantial environmental damage to the environment — as well as the economy, and sometimes, even human health.

Kudzu is hardly an isolated example. Invasive species come in all shapes and sizes — they can be plants or animals, land or sea-based, and can come from a variety of sources. It’s estimated that in the US alone, invasive species cause damage of $120 billion a year.

Take cargo ships, for instance. It’s estimated that 10,000 different species, many of which are non-indigenous, are transported via ballast water each day. Many invasive shells come on the hulls of ships, and get transported all around the world.

In some cases, invasive species can do a world of damage. Take Australia, for instance: it’s one ecological disaster after the next, and much of it is related to invasive species. Starting from rabbits and cane toads, and moving on to foxes, cats, and even cames — when invasive species reach Australia, it’s usually a recipe for disaster. But invasive species aren’t limited to Australia or the US, and they aren’t just related to farming and international trade.

Tourism and invasive species

Tourism involves frequent congregation of people and vehicles, often coming from one part of the world and going to the other. It’s a major pathway for the movement of invasive species, and with low-cost flights, people can travel virtually anywhere, with relative ease.

Understandably, most people want to travel somewhere nice. Whether it’s a beach, a mountainous area, or simply a quiet place with a lot of nature, much of the world’s tourism revolves around protected areas.

The problem is that these areas are particularly vulnerable to invasive species. With invasive species being the hitchhikers they are, they can easily be brought in by unwitting tourists.

Dream-like sceneries are often in protected areas — which are vulnerable to invasive species.

In Antarctica, annual bluegrass (an invasive weed) has become commonplace. Tourists (and even scientists) carry it in, concluded a study published in the journal Polar Research. In New Zealand, anglers and kayakers are bringing in pest species on unwashed gear, leaving the authorities struggling. In Thailand and much of south-east Asia, invasive species are threatening emblematic local species, and much of that damage can be traced back to tourism. In places such as Nepal or Kenya, rhinos and other large herbivores are threatened by invasive species which leaves them little place to forage.

A global assessment found that “that the abundance and richness of non-native species are significantly higher in sites where recreational activities took place” — in other words, touristic activity and invasive species go hand in hand. While tourism is not the main way through which invasive species travel, it is still an important part of the equation and one which is potentially easier to tackle.

But tourism is also a way to bring money into these areas — money which can support sustainable development and even conservation, if used wisely A 2018 study concluded that:

“Tourism provides a crucial and unique way of fostering visitors’ connection with protected area values, making it a potentially positive force for conservation.”

So simply banning tourism is not a solution. But becoming more responsible is.

Of course, much of the responsibility falls on local authorities and how well they care for the ecosystem. But that doesn’t mean we should simply point our finger and rid ourselves of all responsibility. Each of us also needs to act responsibly, both as tourists and in our day to day lives.

Traveling in a remote place? Wash your boots, thoroughly. Wash your clothes before and after traveling, and try to keep them clean of any insects and spores. This is particularly important for fishing gear: you might think it’s clean, but it’s probably not.

The Japanese Beetle is endemic in Japan, but it is an invasive species in the US. Image credits: Robert Thiemann.

Be conscious about bringing invasive plants to your touristic location, as well as from it.

If you’re considering buying seeds and planting them back home, make sure it’s not an invasive species or one that can cause significant damage. If traveling by car, make sure to keep it clean of any insects. The first Japanese beetle found in Canada was discovered in a tourist’s car at Yarmouth, Nova Scotia, and this is a good example of how, unwittingly, tourism can spread invasive species.

Most importantly, we need to be wary of the impact our tourism brings. Native species are particularly vulnerable on islands, and islands tend to be touristic hotspots. Take the Galapagos islands, for instance. At least 1,579 species have been introduced, of which 98% came alongside humans, and more than 70% of these came since the Galapagos became a popular touristic destination in the 1970s.

It’s estimated that, on average, 27 new species are introduced to the Galapagos every year. In the Galapagos and beyond, plants are the most common type of introduced species, followed by insects (often, as a contaminant on plants).

Oftentimes, the tourists aren’t even aware that they’ve become a vector, so this is something we should start considering. Researchers expect that as biosecurity measures grow, the threat of invasive species will decrease, but there’s no substitute for being a responsible tourist.

Invasive species are one of the most overlooked environmental threats. Global trade is responsible for the lion’s share of invasive plant spreading, but tourism also plays a significant role. Clean your travel bags and all its contents before and immediately after the trip, and consider ecotourism as an option. Be mindful of your impact, and travel responsibly — it can make an important difference.

US trees decimated by invasive species

Trees killed by invasive species also affect the atmospheric carbon dioxide, a new study shows.

Image in public domain.

Biological life has its own ways of getting around, but mankind has sent biological movement into overdrive. Globalization doesn’t only affect our society, it affects all ecosystems. Whether it’s mussels attached on a ship’s hull or seeds and plants being brought unintentionally on international shipments, mankind has become a major driver of invasive species — and the consequences are severe.

The United States has traditionally been home to large forest expanses — but that may no longer be the case. Faced with large-scale deforestation, trees have conceded large swaths of land. Now, they’re faced with a new threat: invasive pests.

Some infestations are well-known. The Dutch elm disease and American chestnut fungal disease, for instance, have made headlines with their devastating effects. But many more are causing damage, researchers say. In the new study, the team described thousands of forest plots across the U.S. and the mortality rates due to 15 major tree pest infestations.

Previous studies have already described some 450 invasive tree pests that can damage or kill trees (most of which were brought through international trade or travel). In the new study, the team assessed just how dangerous some of these pests can be.

Around 40% of all forests in the US are under serious threat from invasive species — and the problem shows signs of getting worse year after year. There are also few possible solutions once a tree population has been infected. In most situations, the best thing researchers can do is quarantine the healthy populations to make sure the pest doesn’t spread to them as well.

Not only can invasive pests kill almost half of the US forests, but the damage cascades onto other species. Entire ecosystems can collapse if the trees are killed, and the potential for natural disasters is substantially raised.

It’s not just local, either — the effects can be felt at a global scale. Trees are excellent tools for carbon storage, and the invasive pests kill enough trees to eliminate 6 million tons of carbon atmospheric carbon storage — the equivalent of adding 4.6 million cars on the roads.

Researchers hope that this will raise awareness on this issue and push the introduction of preventive measures.

Journal Reference: Songlin Fei et al. Biomass losses resulting from insect and disease invasions in US forests, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1820601116.

The waters around Galapagos are riddled with invasive species

Ships and vessels are bringing alien species to the Galapagos, posing threats to the pristine environment.

Image credits: Dustin Haney.

The thriving and rare environment on the Galapagos served as an inspiration to Charles Darwin as he was developing his groundbreaking theory of evolution. “Darwin’s Finches,” 12 species of finch on the island that have all evolved to specific niches, served as vital pieces of evidence to Darwin’s theory. But in addition to the finches, the iguanas, and all the endemic creatures, there are also a lot of invasive species in Galapagos.

As humans moved from one part of the world to the other, they brought many other creatures with them — sometimes willingly, sometimes without even realizing it. Regardless, these invasive species have had a massive impact on local fauna. The case of rabbits in Australia is infamous: the rabbits multiplied dramatically in a short period and overwhelmed the local ecosystem. Cats were brought in as predators (or for companionship), and they caused even more damage to the ecosystem. While other examples aren’t quite as dramatic as this one, invasive species have had a massive effect in almost all of Earth’s ecosystems.

Galapagos is no exception. Researchers have noticed for quite a while that invasive species have spread and adapted to the Galapagos, but this is the first study to quantify its extent. Lead author James Carlton from Williams College estimates that over 92% of invasive species were brought in by ships.

“Most of the introduced species treated here were likely brought to the Galápagos by ships,” the team writes in the study. “While we presume that most if not all of the many thousands of vessels arriving in the Galápagos Islands since the 1500s had marine animals and plants attached to their hulls, we hypothesize that the general absence in the Islands of extensive
shoreline structures (in the form of wharves, docks, pilings, and buoys) until the last half of the 20th century may have constrained extensive colonization by fouling species.”

 

The diversity of the invasion was remarkable. The team discovered over 50 introduced species, representing a 90% increase in the previous number known. These surveys were undertaken only around two of the larger islands, so the actual number of invasive species is almost certainly larger — potentially even two times larger, says Carlton.

All the discovered species were invertebrates, ranging from worms and mussels to crabs and moss. Yes, even something as inconspicuous as moss can have a severe impact on the local ecosystem. A simple moss called Amathia verticillata  has been shown to kill local seagrass and cause damage to fishing gears and commercial pipes.

The full extent of the damage has not been thoroughly assessed, but many of the discovered species have been found to cause substantial damage in other parts of the world.

The study has been published in Aquatic InvasionsDOI: 10.3391/ai.2019.14.1.01

 

The brown tree snakes (Boiga irregularis) devastated native populations in Guam. Credit: P Krillow.

Invasive species are responsible for most recent extinctions

When a foreign species is introduced into a new environment, it can wreak havoc on the local ecosystem through competition for resources or direct predation. According to a new study performed by the University College London (UCL), invasive species are the main drivers of extinction in the world, more so than human hunting or agriculture.

The brown tree snakes (Boiga irregularis) devastated native populations in Guam. Credit: P Krillow.

The brown tree snakes (Boiga irregularis) devastated native populations in Guam. Credit: P Krillow.

In the 1950s, brown tree snakes arrived on the island of Guam as stowaways from Papua New Guinea. The only native snake species was a small blind worm-like creature that didn’t bother its neighbors at all. In just a decade, the tree snake had expanded to every part of the island and by 1984, populations of rodents and birds were all virtually extinct. Meanwhile, the tree snake population gained a density of over 13,000 per square mile at the expense of species like the Guam broadbill, which became extinct.

UCL researchers analyzed the International Union for Conservation of Nature Red List — the most reliable database of endangered species — in order to investigate the impact of alien species on native ecosystems. Researchers found that since the year 1500, researchers found that invasive species have been solely responsible for 126 extinctions, representing 13% of a total of 953 global extinctions recorded thus far. Alien species were partly responsible for about 300 extinctions.

In total, 261 out of 782 animal species (33.4%) and 39 out of 153 plant species (25.5%) listed aliens as one of their extinction drivers. In contrast, native species impacts were associated with only 2.7% of animal extinctions and 4.6% of plant extinctions. Overall, the number of extinctions due to alien species is 12 times greater than those caused in part by native species.

“Some people have suggested that aliens are no more likely than native species to cause species to disappear in the current global extinction crisis, but our analysis shows that aliens are much more of a problem in this regard,” lead researcher Professor Tim Blackburn of UCL Biosciences, said in a statement.

“Our study provides a new line of evidence showing that the biogeographical origin of a species matters for its impacts. The invasion of an alien species is often enough to cause native species to go extinct, whereas we found no evidence for native species being the sole driver of extinction of other natives in any case.”‘

Besides alien species, the IUCN Red List identifies 11 other broad categories of extinction drivers, including native species, biological resource use, and agriculture. Biological resource use (i.e. human hunting and deforestation) ranked second on the list behind alien species, having been responsible for 18.8% of lost species.

Among invasive species, the worst offenders were black, brown, and Pacific rats and feral cats. Island habitats were the most vulnerable to invasive species since native species have no alternative home or additional populations.

Plants can also easily drive native species into oblivion. Some have been intentionally introduced for plantations or ornaments for gardens, but once in place, they spread uncontrollably. According to the study published in Frontiers in Ecology and the Environment, foreign plants are several times more likely than native to achieve a maximum cover of at least 80%.

Invasive microorganisms can be just as threatening as more complex organisms. The American chestnut once populated 200 million acres of the eastern United States. However, in the late 19th century, Asian settlers introduced the chestnut blight — a fungus which originally infected the Asian cousin, the Chinese chestnut — and in a matter of decades, all 4 billion trees had been eliminated from the country.

The number of extinctions due to invasive species is likely greater since the origin of some species is unknown, so Blackburn and colleagues assumed that they are native.

“However,” he said, “it is more likely that they are alien. Our results are therefore conservative in terms of the extent to which we implicate alien species in extinction. Also, many regions of the world have not been well studied, and there are likely to be further extinctions that haven’t been captured in these data.”

The findings highlight why biosecurity measures are crucial to preventing the introduction of an alien species, which, in some cases, can be impossible to control once an ecosystem is invaded. Previously, researchers from the Senckenberg Biodiversity and Climate Research Centre analyzed 46,000 recordings of alien animal and plant species that span five centuries, finding 16% of all species have invasive potential. And, let’s not forget that most of these invasive species have been introduced to new environments by humans — ultimately, it is us who are responsible for many extinctions.

Scientists crack genetic code of poisonous, invasive frog

A group of scientists has unlocked the DNA of the cane toad — a toad native to South and Central America, which is invasive in Australia, Oceania, and various islands throughout the Caribbean.

If there’s any place that has suffered from invasive species, it’s Australia. The list of non-native species which have wreaked havoc in the land down under is long and disturbing, ranging from bunnies and feral cats to camels and doves. The cane toad is no exception. It’s now considered a pest and an invasive species, a problem which is made worse by the fact that the cane toad is an adaptable species and a prolific breeder.

But although the cane told is an old species, having been around for over 5 million years, its genetic makeup hasn’t really been thoroughly studied. There was an attempt to sequence its genome a decade ago, but, unfortunately, that project hit a roadblock.

“Despite its iconic status, there are major gaps in our understanding of cane toad genetics, and up until now, no one had put the genome together,” says Peter White, project leader and Professor in Microbiology and Molecular Biology and lead author.

[panel style=”panel-default” title=”Invaders” footer=””]An invasive species is a species that is not native to a specific location but has been artificially introduced and tends to spread to the detriment of native species.

The criteria for defining invasive species remains somewhat controversial and involves some subjectivity, but in general, it is a species that’s doing some kind of harm to the endemic biodiversity.[/panel]

In order to overcome potential problems, the UNSW-University of Sydney team worked at the Ramaciotti Centre for Genomics at UNSW, which has played a role in decoding the genomes of other iconic Australian species, including the koala.

“Sequencing and assembling a genome is a complicated process. By using the cutting-edge sequencing technology and expertise available at UNSW, we sequenced 360-odd billion base pairs and assembled one of the best quality amphibian genomes to date,” says Senior Lecturer Dr. Rich Edwards, lead author of the study.

“We managed to decipher more than 90% of the cane toad genes using technology that can sequence very long pieces of DNA, which makes the task of putting together the genome jigsaw much easier.”

In addition to offering important insight about the cane toad, this also simplifies future genetic studies on other toad species. Essentially, having a draft cane toad genome means that more toads can now be sequenced at a fraction of the cost. Furthermore, the genome will be freely available for everyone to access.

“Future analysis of the genome will provide insights into cane toad evolution and enrich our understanding of their interplay with the ecosystem at large – it will help us understand how the toad spreads, how its toxin works, and provide new avenues to try to control its population,” says cane toad expert and Emeritus Professor Rick Shine from the University of Sydney.

The study has been published in Gigascience.

 

 

A Burmese python found along the Shark Valley Road in Everglades National Park. Credit: National Park Service.

The most popular exotic pets are also the most likely to wind up in the wild

For some people, owning a dog or cat isn’t nearly as exciting as keeping a tarantula or boa constrictor. However, many quickly learn that such exotic pets require far more maintenance than their bargained for. According to a new study, the biggest-selling exotic species are also the most likely to be released by their owners into the wild where they often turn out to be invasive species. In some cases, this can spell an ecological disaster.

A Burmese python found along the Shark Valley Road in Everglades National Park. Credit: National Park Service.

A Burmese python found along the Shark Valley Road in Everglades National Park. Credit: National Park Service.

Julie Lockwood, a professor in the Department of Ecology, Evolution, and Natural Resources at Rutgers-New Brunswick, along with colleagues, tracked the trade of 1,722 reptile and amphibian species in the United States from 1999 to 2016. Because there are no comprehensive records, the team had to combine data from the United States Fish and Wildlife Service on live animals imported into the country as pets and a database that the researchers compiled themselves by scraping websites with records on reptile and amphibians sold in the US. 

The next step involved comparing this information with records of sightings of non-native species, which were gathered from published studies as well as citizen-science programs such as EDDMapS.

The researchers concluded that species with a high probability of being released into the wild were also imported at higher quantities. What’s more, these individuals had a relatively large adult mass and were initially sold at cheaper retail prices than species that were less likely to be released.

“The owners may underestimate the space and costs needed to keep such animals as they grow into adults. Boa constrictors and reticulated pythons grow over 8 feet long. African clawed frogs and Russian tortoises live 30 years or more,” Oliver Stringham, study lead author and a Rutgers doctoral student, said in a statement. “Not wanting to euthanize, owners may resort to releasing them instead.”

Once in the wild, exotic pets can destabilize ecosystems through predation, resource grabs, and disease transmission. Florida, for instance, is overrun by invasive and potentially invasive reptiles and amphibians. One of the most prominent of these new residents is the Burmese python, which appears to be a refugee of the pet trade. Another troublesome non-native is the Red Lionfish, which, according to the Fish and Wildlife Service, has been a direct threat to native saltwater fish in Florida since the late 1980s. It is believed that the root of today’s Lionfish infestation in the Atlantic Ocean resulted from an accidental release of six fish from an aquarium in 1992.

Since the first exotic creature was introduced to the state in 1863, 136 more non-natives have made a home in the Florida wild.

“There are several possible solutions that include everything from banning the import and sale of some species that are likely to be released and become invasive to widespread pet-owner education efforts. Most of these solutions have not been critically evaluated relative to how well they will reduce pet releases, and this is a clear research need going forward. I would recommend that owners seek to adopt out their pets using one of many conduits including ‘amnesty events’ and online pet classified ads. Although a very difficult ethical and personal decision, I would also recommend owners consider euthanasia,” Lockwood told ZME Science.

In many states, Florida included, it is illegal to release a non-native species without a permit. However, the law requires an officer with the Florida Fish and Wildlife Conservation Commission to physically observe the pet owner releasing the animal in order to prosecute them. As I’m writing this, no one has been prosecuted yet for dumping exotic pets into the wild. With this in mind, Lockwood and colleagues hope that a better-educated public — which includes buyers and sellers of exotic pets — will help curb the growth of invasive species in the country.

“Beyond research on which of the many policy solutions may be most effective at preventing pets from being released, I also think there is a need to better understand the role of pet importers and sellers in the production invasive former pets. There is also a need for wildlife agencies to better recognize the threat of released exotic pets to become invasive species. My suggestion to people considering buying an exotic pet is to pay attention to the maximum size and longevity of the species they are buying, and if they are unprepared to take on the care of an animal that reaches a certain size or lives for decades or more; buy another species,” Lockwood said.

The findings appeared in the Journal of Applied Ecology.

France is being invaded by giant, predatory worms

This silent invasion has been taking place for 20 years, but scientists have just now noticed.

Image credits: Pierre Gros.

It’s not every day that an amateur naturalist and gardener publishes a scientific study, but that’s exactly what happened in France. Pierre Gros found some unusual worms in his garden — they were big, predatory, and sported a hammer-like head. He took photos and forwarded them to Jean-Lou Justine of the National Museum of Natural History in Paris.

Justine was annoyed, as he thought someone was playing a prank on him. The worms were obviously hammerhead flatworms (genera Bipalium and Diversibipalium) — the only problem is that hammerhead flatworms are native to the warmer parts of Asia, nowhere near Europe. Gros sent Justin more and more photos, leading the latter to express his frustration to the Washington Post: “The man is bringing back worms from his travels, and he pretends he finds them in his garden!”

But Gros persisted, and after a while, he managed to convince Justine that this was not just a prank. The worms were very much real, and they were very much in France. Shocked, Justine embarked on a four-year survey to see what was going on with the worms, and why they were seemingly thriving in France.

Image credits: Justine et al.

The duo made use of citizen science, asking people to report as many sightings as possible. Observations ranged from Western and Northern France all the way to the South-Eastern corner of the country — even the island of Corsica. At one point, scientists received an email from frightened kindergarteners who thought they had found writhing snakes — but the snakes turned out to be hammerhead worms. Another observation came from a 1999 VHS tape. There was also a Twitter account dedicated to the cause, which sent out photos the team had received.

When the survey was complete, it was revealed that the worms, which can reach up to 27 centimeters (10.6 inches) had invaded France at least 20 years ago, and they were indeed thriving. There are several reasons this was happening: for one, the worms can reproduce asexually, which enables a single individual to produce many offspring immediately. This means that if a single worm somehow arrived in France, it could start a population on its own, something that’s not possible in the case of sexual reproduction. Secondly, the worms also don’t have any natural predators. Thirdly, being so big allows them to overcome competition and fend off other, smaller worms.

Some worms were identified as Bipalium kewenseB. vagum, and Diversibipalium multilineatum. However, two are utterly alien to the stunned scientists and are as yet unnamed.

Of course, worms are an invasive species and they can cause severe problems in their soil ecosystems. France isn’t alone in suffering from this invasion of these worms. Similar cases have been reported in New Zealand, Papua New Guinea, Brazil, and Australia. However, there is surprisingly little scientific literature on the matter.

But how did the worms get there in the first place? Justine admits he is still baffled by this. “I don’t understand how this is possible,” he told the Independent. However, this is not an isolated case — invasive species are becoming more and more common in most parts of the world. Invasive shells can travel the world on the hull of ships, invasive fish can devastate entire streams and lakes, and of course, species can also be released into the wild by humans, often with devastating consequences.

Invasive species also tend to have traits that allow them to out-compete native species

Journal Reference: Jean-Lou Justine, Leigh Winsor, Delphine Gey, Pierre Gros, Jessica Thévenot — Giant worms chez moi! Hammerhead flatworms (Platyhelminthes, Geoplanidae, Bipalium spp., Diversibipalium spp.) in metropolitan France and overseas French territories. PeerJ6:e4672 https://doi.org/10.7717/peerj.4672

Japanese tsunami sent millions of creatures to the US West Coast

Much like mankind, the animal kingdom also has refugees. When their habitats became uninhabitable following the Japanese tsunami of 2011, they fleed as far as they could, even if it meant treacherous journeys on makeshift rats.

These are marine sea slugs from a Japanese vessel in Iwate Prefecture which washed ashore in Oregon in April 2015. Credits: John Chapman.

In 2011, a dramatic 9.1 earthquake struck off the coast of Japan, creating a tsunami which left even more destruction in its wake. Men and animals alike ran, scrambling to escape the ungodly event. Researchers knew that many species escaped as far as North America, and in 2015, they were still hitching rides away from Japan. Now, for the first time, researchers detected entire communities of coastal species crossing the ocean by floating on makeshift rafts. Marine biologists from the Smithsonian Environmental Research Center in Maryland and Oregon State University report that even today, species are still arriving.

When coastal ecosystems are affected by storms or tsunamis, organisms can be rafted across oceans on floating debris, researchers write. However, such events are rarely observed, still less quantified. In this sense, the tsunami generated by the earthquake offered a good research opportunity. It turned out, as co-author John Chapman said, one of the biggest, unplanned natural experiments in marine biology.

Some 300 species arrived in America between June 2012 and February 2017, including some which have never before been seen on the continent. It’s not uncommon for species to drift from one place to another, but the sheer length of this migration is impressive.

“I didn’t think that most of these coastal organisms could survive at sea for long periods of time,” Smithsonian marine biologist Greg Ruiz, a study co-author, said in a statement. “But in many ways they just haven’t had much opportunity in the past. Now, plastic can combine with tsunami and storm events to create that opportunity on a large scale.”

The diversity of the species was also shocking. It’s not like a few species with the same profile escaped, there were all sorts of varied creatures.

“The diversity was somewhat jaw-dropping,” said James Carlton, a marine sciences professor at Williams College, in Williamstown, Massachusetts. “Molluscs, sea anemones, corals, crabs, just a wide variety of species, really a cross-section of Japanese fauna.”

A vessel carried by the Japanese tsunami washed ashore in Oregon, coated in gooseneck barnacles that colonized the boat as it floated across the North Pacific. Image credits: John Chapman.

None of the 289 species that arrived on debris were expected to survive the long journey, especially because the open ocean is considered to be a harsher environment for creatures used to the milder conditions of the coast. Researchers believe that their survival was facilitated by the slower speed of the drifting debris. This slow speed allowed the creatures to gradually adjust to their new conditions. Ironically, ocean pollution might have made it easier for them to survive. Researchers found many species floating on fiberglass or other plastic materials that do not decompose and could easily survive for years and years in the ocean. However, it’s not clear how many others didn’t make it.

They also believe that as more and more plastic accumulates in the ocean, creatures will have more and more rafts to float on and get from place to place — especially in the case of violent storms or tsunamis.

“There is huge potential for the amount of marine debris in the oceans to increase significantly,” added James Carlton, who is also an invasive species expert with the Maritime Studies Program of Williams College and Mystic Seaport in Connecticut.

“In many ways they just haven’t had much opportunity in the past. Now, plastic can combine with tsunami and storm events to create that opportunity on a large scale.”

Journal Reference: James T. Carlton et al. Tsunami-driven rafting: Transoceanic species dispersal and implications for marine biogeography. DOI: 10.1126/science.aao1498

Panda Solar Plant.

Chinese pandas will slash over 2.74 tons of CO2 emissions in the next 25 yeas — because they’re solar plants

Not yet sold on the idea of solar plants? Even if it was as solar plant… shaped like a panda? Thought so.

Panda Solar Plant.

Image via ledpv.com

It’s an undeniably creative advertising stunt, and it’s actually something which will definitely make Shanxi province of China stand out. The brainchild of Panda Green Energy (formerly known as United Photovoltaics) and the United Nations Development Program, the so-called Panda Power Plant has been under construction since November 2016. To get the panda shapes just right, the group used thin film solar cells for the white and gray face and belly and monocrystalline silicon solar cells to ink in the black areas.

Progress on the plant is going quite well. The first phase/Panda of the project has been completed and is currently churning out some 50 MW of clean, adorable energy into the Chinese grid. Once fully completed, the pandas will have an aggregate capacity of 100 MW and are projected to provide 3.2 billion kWh of electricity over the next 25 years — equivalent to 1.056 million tons of coal or 2.74 million tons of carbon dioxide emissions.

But it’s not merely about energy. The Panda project also aims to invest in the future of the communities it serves, and as such, will come equipped with an activity center to educate local schoolchildren about solar energy and its benefits. For a country left struggling with immense climate issues following what may be the biggest industrialization effort ever seen, projects such as the Panda Power Plant are key to a healthier, cleaner future.

Panda Solar Plants.

A way cuter future, to boot!
Image credits Panda Green Energy Group Limited.

Panda Green Energy revealed that more solar farms are planned over the next 5 years as part of their Panda 100 program. These will be built along the Belt and Roads areas that are part of President Xi Jinping’s economic development strategy.

And yes; they will all be pandas.

We’re buying invasive plants on Ebay, and this is bad news

Over a period of 50 days of monitoring,  researchers found 2,625 different plant species for sale on eBay. 510 were known to be invasive in at least one region somewhere in the world and out of that group, 35 are on the International Union for Conservation of Nature’s list of the 100 worst invasive species.

Passiflora edulis, or passionfruit, is an attractive ornamental plant, native to Brazil, Paraguay and Argentina that can easily go invasive in Europe. Credit: Leonardo Ré Jorge / Wikimedia Commons

With the continuous globalization we’re all experiencing, it seems almost unavoidable to also move invasive plants from one place to another. An invasive species is a plant or animal that is not native to a specific location (an introduced species) and has a tendency to spread, damaging local environments and species. Invasive species cause incalculable damage each year, both in economic and environmental terms. The problem, as researchers found, is exacerbated by irresponsible behavior.

Actually, the major contributor to invasive problems is trade, so it was expected that bidding websites are no exception. A group of four researchers at ETH Zurich led by Christoph Kueffer, senior lecturer at the Institute of Integrative Biology investigated the trading of two thirds of the world’s flora on Ebay and nine other online trading platforms.

For 50 days, they tracked what plant was sold, when, and where; they developed a software specifically for this purpose. They then compared the results they got with the list of invasive plants.

“eBay benefits from making sale listings accessible to computer programs that can systematically search for and analyse online content automatically,” says Luc Humair. This is what made the ETH monitoring project possible.

But even so, the software can only monitor the supply side – it can never know whether an actual trade has been agreed upon, and whether or not the plant was actually sold.

“Naturally it would be interesting to factor the destination into the monitoring process,” says Luc Humair. However, that information is personal and can be collected only with the cooperation of eBay or the other providers.

They found that no one really cares whether they are buying an invasive plant or not – almost certainly, most people aren’t even aware of the problems they could cause; once escaped into the wild, an invasive plant can wreak havoc upon local ecosystems.

“To put it briefly, the vast majority of invasive species can be easily obtained with just a click of the mouse,” says Franziska Humair. Rules governing the trade in these plants are half-heartedly enforced, if at all. The dealers don’t care, and even if they did, they have no knowledge over the buyer’s local regulations.

The desert rose is the flowering plant offered most frequently for sale online, but is not yet known to be an invasive species. Credit: Wikimedia Commons

It seems like this problem should be somehow regulated locally, but authorities made no move to intervene.Kueffer continues:

“The only way to contain invasions is by limiting the trade in potential invaders.” The study shows that it is theoretically possible to continuously monitor this trade in order to spot newly traded species, which could signal future invasions. Many countries already have sets of rules and regulations in place with the goal of curbing the spread of invasive species. Switzerland, for example, has a special ordinance on the release of certain organisms, and the EU countries are in the process of drawing up a list of species that are recognised as invaders across the EU. “As online trade blossoms, it makes it even more urgent for the authorities to take action or for responsible large commercial nurseries to adjust their product ranges,” says Kueffer.

Journal Reference: Humair, F., Humair, L., Kuhn, F. and Kueffer, C. (2015), E-commerce trade in invasive plants. Conservation Biology. doi: 10.1111/cobi.12579

Fighting invasive mussels: Lake Havasu offers mussel decontamination for boats

The officials of Lake Havasu have taken a laudable measure: they’re offering free mussel decontamination for boats, in an attempt to stop the spread of a very dangerous species, the quagga mussel.

The spread of quagga mussel in the US. Image via Wiki Commons.

The quagga mussel (Dreissena bugensis) is a species of freshwater mussel named after the quagga, an extinct subspecies of African zebra. A rather interesting creature in itself, the mussel is currently of major concern in the Great Lakes of North America as an invasive species brought by overseas shippers that use the St. Lawrence Seaway.

This is a problem because they are very good at filtering water and taking out the phytoplankton, in turn decreasing the food source for zooplankton, therefore altering the food chain and damaging the ecosystem. Each coin-sized quagga can filter up to a liter of water per day. The mussels can also ruin motorboats and clog engines.

Now, Lake Havasu has taken measures to limit as much as possible the spread of this unwanted species. They’re offering a free service to boat owners. A device inside a shipping container flushes 140-degree water through a boat’s water intake systems, cleaning the boats of mussels. The only downside is that the boats then require about one week to dry.

Kami Silverwood, a Game and Fish aquatic invasive species specialist praised this measure, underlining that we need to stop the spread.

“Other western states are like, ‘Hey, you have the mussels, you need to contain them,’” Silverwood said.

Invasive species still hitch a ride on 2011 Japanese tsunami

The 2011 Japan tsunami was so massive that even today, debris from it keeps washing up in Washington – and that might be a problem. Scientists report that along with the debris, invasive species are also make their way to the USA.

Just one of the boats that the 2011 tsunami sent to the Washington coast. Image via Komonews.

The 2011 earthquake off the Pacific coast of Tōhoku was one of the biggest in recorded history. The earthquake triggered powerful tsunami waves that reached heights of up to 40.5 metres (133 ft), traveling 10 km inland. Even today, we’re still feeling some of its effects – and in more ways than one. The Washington Department of Fish and Wildlife’s aquatic invasive-species unit has recently discovered a barnacle-encrusted Japanese skiff. Three other boats reached the state in the past year alone, and all of them were colonized by dozens of thriving species which have great invasive potential.

“These become their own ecosystems in the ocean,” he said. “What’s not natural is that they’re on man-made objects that don’t disintegrate.”

Invasive species are becoming a greater concern in the modern world, being a rather unforeseen consequence of globalisation. Invasive species are plants and animals not native to a specific location; they’re basically an introduced species with a great tendency to reproduce and overcome native species, causing significant damage to the local environment as well as to human activities and health.

This is an issue that our society, generally speaking, is not prepared to deal with. We have ships traveling from one place to another, bringing with them numerous invasive species, and we even transfer these species ourselves. A 2005 study found that in the US alone, invasive species cause damage of over $138 billion annually, and that number seems to continue to grow.

Invasive Koi Fish – 3,000 Feral Fish Dumped into Colorado lake

Dealing with invasive species is one of the challenges that accompanies globalization and in many areas of the world, it’s becoming harder and harder to tackle this issue. In Teller Lake, Colorado, 3,000 Koi fish (Japanese carp) are now swarming the water, wiping out native species and dramatically altering the environment.

“These are domestic fish actually.These are fish from a store I imagine. They can out-compete the native fish. They may need to drain the lake to remove the goldfish or using electro fishing, where they stun the fish and remove the invasive species. Goldfish are not a native species and are very harmful to the local aquatic ecosystem,” district wildlife manager for Boulder, Kristin Cannon says. “We strongly encourage the public not to dump their unwanted pet fish in our waters. It is bad for our environment, as well as illegal.”

It’s not clear why, when and how the fish popped up in the lake – the explosion of these exotic fish which are not native to North America seems to have occurred three years ago, and authorities suspect that a local pet store is responsible. The fact that all the fish seem to be some three years old seems to be telling for that aspect.

“Based on their size, it looks like they’re 3-year-olds, which were probably produced from a small handful of fish that were illegally introduced into the lake,” Ben Swigle, a fish biologist at the Colorado Parks and Wildlife (CPW), told Live Science.

It should already be well known that dumping fish or any foreign species into a natural environment is forbidden – the consequences can be disastrous. A local ranger estimates that there are now 3-4,000 alien koi fish swimming in Colorado Lake at the moment. As their numbers grow more and more, they will out-compete the local species and potentially drive them out, altering the entire ecosystem.

But even as the fish are successful in taking over the lake, their fate seems to be grim as well. Most of them will likely end up as food at a raptor rehabilitation program. Some residents have contacted park officials, asking to adopt some of the fish, but their requests have been denied so far. It’s not clear exactly what will be done with all these fish.

This isn’t the first time such fish have turned up in high numbers in the area. According to LiveScience, in 2012, some 2,275 koi goldfish had to be removed from Thunderbird Lake in Boulder, after a few were likely dumped there as “unwanted pets” two to three years earlier.

Alien Mussels Threaten U.K. Biodiversity

The single most threatening species to U.K.’s biodiversity is a species of mussels – the quagga mussel. Coming from the Black Sea and the Caspian Sea in Eastern Europe, the quagga mussel came with four other freshwater invaders which have now become a huge danger for Britain’s wildlife.

Quagga mussels. Image via 100th Meridian.

The quagga mussel, scientific name Dreissena rostriformis bugensis, is an invasive species. It is highly adaptive, can thrive in many different conditions and can push out the local wildlife, making way for its own species. The quagga mussel was first observed in North America in September 1989 when it was discovered in Lake Erie near Port Colborne, Ontario, where it also caused a significant loss of wildlife. It’s believed that these mussels travel on the bottom of ships or in the ballast water they use.

Quaggas are prodigious water filterers, removing substantial amounts of phytoplankton and suspended particulate from the water. By removing the phytoplankton, they take out the zooplankton’s main food source – and in turn, affect the entire lifecycle of the area. Each coin-sized quagga can filter up to a liter of water per day, stripping away the plankton that basically supplies the entire food chain. Furthermore, Dreissena has the ability to rapidly colonize hard surfaces, which makes it even more threatening. They can also can clog water intake structures, such as pipes and screens, therefore reducing pumping capabilities for power and water treatment plants. They can also, to some extent, damage boat and harbor structure.

A propeller completely covered by quagga mussels. Image credits: Idaho.gov.

In a new research study, published in the Journal of Applied Ecology, researchers from the University of Cambridge analyzed the most dangerous invasive species in the U.K., and rather surprisingly found that the quagga (the mussel, not the actual quagga which is now extinct) tops that list; and it’s not just biodiversity which is threatened – a reservoir near London Heathrow Airport is also in danger of being ruined. According to a Defra spokeswoman, the cost of the economy that is being threaten by the Quagga mussels amount to 1.8 billion pound a year.

But should the invasion spread, then the risk would be huge – virtually every bit of freshwater and wetland can be threatened.

“Pretty much everything in our rivers and lakes is directly or indirectly vulnerable,” said Dr David Aldridge, co-author from the University of Cambridge’s Department of Zoology, who confirmed the quagga find.

“The invader we are most concerned about is the quagga mussel, which alarmingly was first discovered in the UK just two weeks ago. This pest will smother and kill our native mussels, block water pipes and foul boat.

But it gets even better. Also on that invasive species list is the killer shrimp – dubbed the ‘pink peril’. The killer shrimp’s favorite food is (you’ve guessed it) the quagga mussel – so having huge numbers of quagga mussels will lead to huge numbers of killer shrimps, which will further wipe out the endemic ecosystem, and will further pave the way for other species such as the goby fish. The goby fish haven’t been spotted in the UK yet, but it seems like just a matter of time before that happens. The rate at which the ecosystems are changing is certainly alarming. There are other examples, such as the Netherlands which show just how drastic this change can be – their marine ecosystems are practically unrecognizable now.

‘If we look at The Netherlands nowadays it is sometimes hard to find a non-Ponto-Caspian species in their waterways.’, said Dr Aldridge.

The Killer Shrimp is also an invasive species; among its favorite food is the quagga mussel. A growing quagga population will lead to a growing shrimp population which will alter the ecosystem even more. Image via Superzoo.

Dates and locations of the first British reports of 48 other freshwater invaders from around the world show that 33% emerged in the Thames river basin, making it the UK hot spot for invaders, followed by Anglian water networks (19%) and the Humber (15%). The main cause for this invasion is, if not exclusively than certainly decisively, human activity. The fact that we are transporting things from one place of the world to another seems to inevitably lead to a transport of unwanted invasive species.

“Due to globalisation and increased travel and freight transport, the rate of colonisation of invasive species into Britain from The Netherlands keeps accelerating – posing a serious threat to the conservation of British aquatic ecosystems,” said co-author Dr Belinda Gallardo, now based at the Doñana Biological Station in Spain.

“Cross-country sharing of information on the status and impacts of invasive species is fundamental to early detection, so that risks can be rapidly assessed. A continuing process for evaluating invasive species and detecting new introductions needs to be established, as this problem is increasing dramatically.”

Invasive ant has bear trap-like jaw which can propel it through the air

An invasive ant has been sweeping through southeastern United States; it has a jaw like a bear trap, which close faster than almost anything in nature. Naturally, it packs quite a sting, and if that wasn’t enough, it can propel itself through the air like a rocket.

Photograph by Alex Wild, Visuals Unlimited/Corbis.

“They look like little hammerhead sharks walking around,” said D. Magdalena Sorger.

That amazing jaw is so powerful that you can use it as a surgical staple (when adequate medical equipment is lacking). Especially in military situations, these ants can be quite useful in suturing wounds. But more often than not, their interactions with humans are not pleasant.

There are four species of trap-jaw ants native to the United States, and one of them was the focus of this research.  Odontomachus haematodus is especially aggressive. The species is  found in the tropics and subtropics throughout the world, but in the past 50 years it has grown its populations more and more in the US Gulf Coast. So what changes in the past half century ?

Sorger says population growth and climate change paved the way for this invasion, but the magnificent jaws also helped.

“Trap-jaw ants have little sensory hairs on the inside of their jaws,” said Sheila Patek, a biologist who studies the evolutionary mechanics of movements at Duke University. Patek explained that these hairs are linked directly to the muscles that hold the jaw open. “So they can fire those latch muscles even faster than their brain can process.”

Hey, and as if having one of the strongest bites (per size) in the animal kingdom wasn’t enough, the trap-jaw ants can actually bite the ground with so much strength that it propels them into the air – like popcorn from a frying pan. When a whole army of invasive ants does this at once, it can get a little scary.

“The next thing you know you have this ant flying through the air that you can’t even see, it’s moving so fast, with a big stinger on the end of its abdomen,” she said. “It is really nerve-racking working with them.”

The good thing is that unlike other invasive ants, these ones don’t have colonies, and therefore there’s a much reduced chance of them overwhelming the local flora and fauna – but that doesn’t mean that they won’t have a huge impact. They’re here, and we should be prepared for it.

China battles army of alien invaders

  • Invasive (or alien species) are non-indigenous species that adversely affect the habitats they invade
  • China currently has 550 invasive species, which cause losses of $15 billion yearly
  • This affects the entire world, as China is the main exporter, and invasive species often piggyback exported goods
  • Alien species

    When China opened its borders to international trade, a new age dawned in the country, making them arguably the most powerful economy in the world today. But along with the new technologies and markets that came with this, alien organisms also infiltrated the country. No less than 550 non-native species, from viruses to bugs, fish and mammals, have become invasive in the country, causing estimated losses of $15 billion / year.

    invasive beetle

    The red turpentine beetle has wiped out more than 10 million pine trees in China in the past 15 years.. Image Credits: RUNZHI ZHANG

    “As the volume of international trade has grown exponentially, so has the number of alien species,” said Li Bo, director of the Office for Management of Alien Species in the Ministry of Agriculture, Beijing, at the second International Congress on Biological Invasions in Qingdao last month.

    Since 2000, China has started to improve and tighten its regulations, imposing stricter quarantine regions and limiting the import of plant materials, investing more and more in the research and monitoring of invasive mechanisms. Wan Fanghao, an ecologist at the Chinese Academy of Agricultural Sciences’ Institute of Plant Protection in Beijing is currently finalizing a decade-long project funded by the Ministry of Science and Technology to study invasive species in agriculture and forestry. As he explains, this is a problem that is here to stay:

    “With climate warming, increasing international trade and rapid urbanization, the problem of biological invasions will only get worse,” he says. “We need to keep a close eye on potential troublemakers.”

    CHINESE ACAD. AGRIC. SCI.

    CHINESE ACAD. AGRIC. SCI.

    But with the current admnistrative situation in China, it’s pretty hard to keep things under control; one of the biggest problems is rubbish. Waste disposal is a huge deal in China, and many alien species enter China by piggybacking on imports from other countries. But authorities are throwing the responsibility from one ministry to the other, so it’s almost impossible to take effective measures. That’s the thing with invasive species – it’s often impossible to say that they affect Agriculture, or the Environment, or Health, or whatever – it takes joint efforts from more than one ministry.

    “There needs to be better coordination and more data sharing between them,” says Sun.

    A global problem

    The thing is, what happens in China is no longer just China’s problem – it’s global. Since China is the world’s no. 1 exporter, biological invasions are a 2 way street, explains Helen Roy, an ecological entomologist at the Centre for Ecology and Hydrology in Wallingford, UK. Many of the most dangerous pests in the US and Europe come from China.

    When dealing with invasive species, international collaboration is extremely important – but so far, despite all the efforts, the invasive species seem to have the upper hand, and no large-scale solution is in sight.