Invasive Alien Species: Forgotten Environmental Threat

Invasive alien species have been a problem for generations. Find out why a new international study warns that the issue is more urgent than ever.

Farmers around here have been dealing with a pest for several generations. They’re robin-sized, glossy, black birds called starlings.

They may sound innocuous, but they can do significant damage to farms and livestock. They spread disease by carrying germs as well as parasites like mites and fleas. Many of these diseases are life-threatening.

They reproduce rapidly in this habitat, and their flocks can include up to 100,000 birds. Starlings roost together, and they have a nasty habit of making nests in building cavities.

Starlings Don’t Belong in this Part of the World

These birds don’t belong in this part of the world. Starlings’ natural habitat is in Europe, although they can range as far as Africa and Asia.

Settlers from Britain introduced them to Canada in the 1890s. There was a fad at the time. Colonists tried to import all of the birds mentioned by Shakespeare throughout the empire.

Australia had similar experiences. Along with starlings, doves and pigeons, settlers introduced everything from the cane toad to the European rabbit to the dromedary camel.

Alien Species Can Include Plants, Animals and Microbes

Scientists call these kinds of introduced life forms alien species. They can include plants, animals and microbes.

They get introduced by human activity sometimes by chance, like when they sneak onto ships and get carried across the ocean. Other times people do it on purpose, as in the case of our Shakespeare fanatics.

Either way, we unleash these species into native ecosystems where they don’t belong. They often thrive, and then start reproducing uncontrollably, which carries significant risk.

Destructive: Ecosystem, Natural Resources, Public Health

If the new species flourishes expanding beyond its native range, it often leads to destructive results for the ecosystem, natural resources, or public health. As a rule, disrupting the balance of natural habitat has unintended consequences that end up doing more harm than good.

Sometimes humans create vicious cycles with invasive alien species. For example, suppose that introduced mice threaten native species in a local ecosystem.  People might get the bright idea to release foreign predators like snakes to get rid of them.

Then the snakes start causing problems, so we bring in foxes, and on it goes. We can’t seem to leave well enough alone.

Contributing to the Mass Extinction in Our Biosphere

The UN panel on biodiversity, the IPBES, calls invasive alien species one of the five main drivers of habitat loss. They raise it because, even though we often forget about this threat, it’s contributing to the mass extinction that our biosphere is now going through.

According to the IPBES, introducing an invasive alien species “threatens biological diversity, food security, and human health and well-being.”

The panel has also found that “The numbers of invasive alien species per country have risen by about 70% since 1970, across the 21 countries with detailed records.” Globally, invasive species are an ecological threat in the same league as climate change and deforestation.

Threat of Invasive Alien Species is Increasing

The journal Biological Review published a report yesterday that warns that the threat of invasive alien species is increasing. The team of researchers from thirteen countries is calling for immediate steps to check, find and curb ecosystem invaders.

The sheer number of invaders is increasing dramatically. The global list now includes over 18,000 varieties of living things.

Professor Petr Pyšek of the Czech Academy of Sciences and Charles University in Prague is the lead author of the study. He cautioned, “The threats posed by invasive alien species to our environment, our economies and our health are very serious, and getting worse.”

“Threats Posed Are Very Serious And Getting Worse”

Team member Laura Meyerson of the University of Rhode Island explains that a significant cause of the invasion is an increase in the number and types of invasion pathways. By this, she means that creatures are finding new and different ways to travel from one region to another.

One example is the trade in exotic pets. Another is the new tendency for animals to find themselves on a floating piece of plastic that carries them across the ocean.

The research team points to previous studies showing that invasive alien species impact 25% of plants and 33% of animal extinctions, resulting in lost native biodiversity.

Economically, the species we’ve introduced into vulnerable habitats cost the US, UK, Australia, South Africa, India and Brazil over $100 billion a year.

Species Introduced Cost Countries Over $100 Billion a Year

Other drivers of the species invasion include climate change, land-use change and international trade. As temperatures rise, regions become more hospitable to foreign flora and fauna, extending their natural range..

Loss of ice in the arctic has allowed some marine species to begin wandering between the Atlantic and the Pacific. Animals that stow away on ships often flourish now in habitats that would have been too cold for them in the past.

The report is part of a larger project called World Scientists’ Warning to Humanity: A Second Notice. It’s the sequel to a warning that came out in 1992. 

Humans Heading for Conflict with the Rest of Nature

Seventeen hundred distinguished scientists backed the first notice. It cautioned that humans were heading for conflict with the rest of nature.

Then in 2017, a follow-up report with support from 15,000 scientists made it clear that humanity hadn’t made enough progress. They found that many threats to biodiversity were getting worse instead of better.

The authors of this new paper stress that we have a range of practical ways to deal with invasive alien species. One approach is to enhance our customs inspections.

In New Zealand, for example, border crossings now include X-ray machines and sniffer dogs. They’ve managed to cut down on unwelcome fungi that have been damaging native plant species.

”Australia, New Zealand: Biosecurity a National Priority”

Professor David Richardson of the Centre for Invasion Biology at Stellenbosch University in South Africa shared the lead author role. He explained that “Nations such as Australia and New Zealand have made biosecurity a national priority.”

Still, he went on to say, “action is needed more widely at both national and international levels in order to tackle the challenges effectively.” Professor Pyšek emphasized that “Policymakers and the public need to prioritize actions to stem invasions and their impacts.”

Professor Meyerson concluded, saying, “It has been so exciting to see developments in our knowledge and understanding of biological invasions in recent decades, achieved through truly inspiring global collaborations. It is so important that we continue to share our knowledge and engage with relevant stakeholders across sectors and borders.”

We always have more to learn if we dare to know.
Learn more:
International team of scientists warns of increasing threats posed by invasive species
Scientists’ warning on invasive alien species
Mass Extinction Happening Again
Nature Emergency – Time to Make it Official

Biodiversity Always Wins


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