Invasive species pose a severe risk to the natural environment. They can cause significant harm and devastate ecosystems, resulting in substantial economic impacts.
According to the World Conversation Union, invasive species are the second most significant threat to biodiversity after habitat loss. Approximately 42% of threatened or endangered species are at risk because of invasive species.
The following article will explore invasive species in more detail and unpack why they are dangerous to the environment.
What are Invasive Species?
An invasive species is an animal or plant organism that has the potential to cause ecological or economic harm in a new region or environment where it is not native and does not belong.
With that said, not all non-native species are invasive. For example, most food crops grown in the United States, such as wheat and rice, are not native to the region.
There are specific characteristics that make a species invasive.
To be invasive, a species must easily adapt to its new region or environment, reproduce quickly and harm property, the economy, or native plants and animals.
In their new ecosystem and environment, invasive species often become predators, competitors, parasites, hybridizers, and diseases to native plants and animals.
Hence, they are difficult to control and contain because they are free of predation and disease, two of the significant factors that keep native plant and animal populations in balance.
Invasive species can completely disrupt the food chain, related ecosystems, and the natural environment.
Common characteristics of invasive species include:
- High reproduction rate
- Rapid growth and maturity
- High dispersal ability
- Few natural predators
- Ability to thrive in distinct habitat types and climate regions
- Ability to out-compete native species
- High cost to remove or control
Why are Invasive Species Dangerous to the Environment?
Invasive species are dangerous to the environment. They represent one of the most potent, persistent, and widespread threats to the natural environment.
Invasive species can harm natural resources (fish, wildlife, plants, and ecosystem health) because they disrupt natural communities and ecological processes and threaten human use of resources. This can cause substantial economic impacts and the distribution of ecosystems.
For example, if an invasive plant species is introduced, this can lead to several problems for existing crops.
Invasive plant species can introduce new diseases and attract new crop pests, which can cause a reduction in crop yields and require an increased need for pesticides. Invasive plants can interfere with regeneration and growth.
This can cause serious harm to native species within that ecosystem because they are suddenly competing with new species for the same resources (food, water, shelter). Invasive species typically thrive under these conditions because they have no predators, unlike native species, to help maintain the population.
When invasive species are introduced, the ecosystem often becomes much less diverse. A less diverse ecosystem is far more susceptible to further disturbances like diseases, climate change, and natural disasters.
Once an invasive species become established in its new environment, it becomes very costly and challenging to eradicate. This can lead to irreversible impacts on the local ecosystem.
Invasive species have a range of impacts that affect the environment, society and economy, and biodiversity.
Invasive species can cause immense damage to the natural environment.
Environment impacts can:
- Leading to the extinction of native species (plants and animals)
- Negatively impact biodiversity
- Permanently alter habitats
- Lead to native species competing for limited resources
- Cause species extirpation
- Cause soil degradation and erosion
- Alter fire cycles
- Displace native plant communities
- Disrupt the food chain
- Destroy the quality understory habitat in forests
- Decrease the quality and amount of range for wildlife
- Introduce parasites
Invasive species can potentially be a significant threat to the income and livelihood of the local people. They can also impact human health.
Social impacts can:
- Cause disease
- Cause human or animal suffering
- Reduce land and water recreational opportunities
- Lead to reduced income
- Increase food insecurity
- Pose a risk to human and animal health
- Increase social challenges
- Reduced water quality and quantity
- Loss of traditional food and medicinal plants
- Export and import trade restrictions imposed
Invasive species affect the economy in several ways, such as agriculture, forestry, and fishing. According to Environment and Climate Change Canada, the estimated annual cumulative lost revenue caused by just 16 invasive species is between $13 and $35 billion dollars.
Economic impacts can:
- Lead to a higher cost of controlling and managing pests, weeds, and diseases
- Reduce productivity in forestry, agriculture, and fishing
- Cause export and import trade restrictions
- Reduce land and property values
- Lower crop productivity
- Harm livestock
- Degrade soil quality
Why are Invasive Species Introduced?
Many invasive species are introduced into their new environment by accident. However, that is only sometimes the case, as some species are purposefully introduced.
The accidental introduction of invasive species usually occurs through ship ballast water, recreational boaters moving between bodies of water or pets that escape or are released into the wild.
Most of the time, invasive species are introduced on purpose as a form of pest control, while other times, they are brought in as pets and are accidentally released, or plants are brought in for decorative purposes (e.g. in a garden).
When invasive species are introduced intentionally, the ramifications are not considered or anticipated. It is hard, even for scientists, to know how a species will adapt to a new environment.
Example of Accidental Introduction
Zebra mussels are an invasive species that are native to freshwater environments in Eurasia. In the Great Lakes of North America, Zebra mussels are now considered an invasive species. In their new environment, they filter out algae that native species need for food and attach to and incapacitate native mussels.
They essentially out-compete with other filter feeders and starve them. Zebra mussels were accidentally introduced to North America via ships that traveled between the two regions.
Example of Purposeful Introduction
In 1949, five cats were brought to Marion Island (South Africa) in the Indian Ocean as a form of pest control. The idea was that the cats would help control the mice population. However, by 1977 over 3,400 cats were living on the island. Since cats hunt more than just mice, the local bird population was at risk.
How do Invasive Species Spread?
Invasive species are most commonly spread through the movement of people. More than ever, especially because of globalization, people and goods travel worldwide at a high rate, and occasionally they pick up uninvited guests along the way.
Invasive species can enter a ship’s ballast water or attach themselves to the propellers of a smaller boat.
Another way invasive species spread is through equipment used at different sites in various regions.
Climate change will also enable invasive species, predominantly plants, to move into new areas.
How Can You Help?
It may not seem like it, but there are a few simple ways to help combat invasive species at an individual level.
Volunteer at your local park, refuge, or other wildlife areas to help identify and remove invasive species. This is also an excellent opportunity to learn and educate others about the risks associated with invasive species and how to stop the spread of invasive species.
Purchase plants and flowers for your home or garden that are not invasive. An even better environmental decision would be to buy plants that are native to your region.
Never release pets or non-native species into the wild. If you own an exotic or non-native pet, take measures to prevent an accidental escape.
Ways to Prevent the Spread of Invasive Species:
- Clean your hiking and fishing gear when moving between regions and bodies of water
- Don’t move firewood between ecosystems
- Fish using native bait
- Clean your boat thoroughly before changing bodies of water
- Don’t take animals, plants, shells, or food from different ecosystems
- If you see something unusual, report it
- Check your pet’s paws
Governments and conservation authorities are working diligently to educate the public about invasive species to prevent the accidental transportation or introduction of new species.
Have you ever wondered why border agents and customs officers are so strict about plants, fruits, and meats at the airport? Invasive species are one of the main reasons.
Governments want to prevent any introduction of new species, seeds, plants, or related diseases as they pose a massive threat to the environment, society, and economy.
Given the potential impact, environmental groups and government agencies are concerned about the harm that is being done by invasive species.
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