An invasive species is an organism that is not native to a particular ecosystem and causes ecological or economic harm to the new environment. These invaders can be plants, animals, fungi, or even microbes.

Non-native vs Invasive

It’s important to distinguish between non-native and invasive species. Not all non-native species are invasive. For instance, many of the food crops grown around the world, including popular varieties of wheat, tomatoes, and rice, are not native to the regions where they are cultivated. These introduced species can coexist peacefully with the native ones.

To be considered invasive, a species must be able to:

• Adapt to the new area quickly: Invasive species are successful at establishing themselves in new environments. They can tolerate a wide range of environmental conditions and find the resources they need to survive and reproduce.
• Reproduce rapidly: Invasive species often have high reproductive rates, which allows them to quickly establish large populations.
• Cause harm: This harm can be ecological, economic, or even pose a threat to human health. Invasive species can:
• Outcompete native species for resources like food and space.
• Prey on native animals, disrupting the food chain.
• Introduce diseases that can harm native plants and animals.
• Disrupt ecosystems and alter habitats.
• Cause billions of dollars in economic damage each year by destroying crops, damaging infrastructure, and reducing tourism.

How Invasive Species Spread

Invasive species are introduced into new areas in a variety of ways:

• Accidental release: Species can be transported in ship ballast water, on cargo containers, or even in people’s luggage. Ballast water is the water that is taken on by ships to provide stability. When ships release this water in new ports, they can unintentionally release aquatic organisms that were taken up in the ballast water from their previous location.
• Escaped pets: Pets like snakes or turtles that are released into the wild can become invasive if they can survive and reproduce in the new environment.
• Intentional release: Sometimes, people introduce species for purposes like hunting or fishing, but these species can escape and become invasive.

The Impact of Invasive Species

The impact of invasive species can be devastating. They can:

• Outcompete native species: Invasive species can be more aggressive or efficient at competing for resources than native species. This can lead to the decline or extinction of native populations.
• Prey on native animals: Invasive predators can disrupt the food chain by preying on native animals, especially if they have no natural predators in the new environment.
• Introduce diseases: Invasive species can carry diseases that can harm native plants and animals, which may have no immunity to these new diseases.
• Disrupt ecosystems: Invasive species can alter habitats and disrupt the delicate balance of ecosystems. This can have cascading effects throughout the food web.
• Cause economic damage: Invasive species can cause billions of dollars in economic damage each year by destroying crops, damaging infrastructure, and reducing tourism.

Here are five examples of invasive species:

Lionfish: These fish are native to the Indo-Pacific region but were introduced to the Atlantic Ocean and Caribbean Sea through accidental release from aquariums. Lionfish are voracious predators that have no natural enemies in these new environments. They have rapidly reproduced and are now a major threat to native fish populations.

Zebra Mussel: This mussel is native to the Caspian Sea but was introduced to the Great Lakes in the 1980s in ship ballast water. Zebra mussels have clogged water intake pipes and disrupted the food chain by filtering out large quantities of plankton.

Burmese Python: Burmese pythons are native to Southeast Asia but were introduced to the Florida Everglades as pets in the 1980s. These large snakes have become apex predators in the Everglades, preying on native mammals, birds, and even alligators.

Brown Marmorated Stink Bug: This insect is native to East Asia but was accidentally introduced to North America in the late 1990s. Brown marmorated stink bugs are agricultural pests that feed on a wide variety of fruits, vegetables, and ornamental plants. They can also be a nuisance pest in homes, as their name suggests!

Cane Toad: In an effort to control the cane beetle infestations, Australians decided to bring in the cane toad. Instead of eating cane beetles and grubs, these toads eat everything but. This toxic toad is now a highly invasive species that has wreaked havoc on Australian wildlife.

By better understanding the impacts invasive species have we can better understand how to control the spread and mitigate further loss or damage to our ecosystem and also lessen the economic impacts therein.