RANK

SPECIES

IMPACT

DESCRIPTION

1

Burmese Python

Preys on native wildlife and disrupts local ecosystems, particularly in the Florida Everglades.

Originally from Southeast Asia, these large constrictors have become a significant threat to biodiversity in Florida.

2

Asian Carp

Threatens native fish populations by competing for food and habitat, impacting local fisheries.

Introduced to the U.S. in the 1970s, Asian carp reproduce quickly and can dominate aquatic ecosystems.

3

European Starling

Competes with native birds for nesting sites and food, often displacing native species.

Introduced in the 19th century, starlings can drastically alter local avian communities.

4

Cane Toad

Preys on native species and is toxic to predators, causing declines in native wildlife.

Introduced to control pests in sugarcane fields, cane toads have become a significant ecological threat in Australia.

5

Norway Rat

Competes with native species, spreads disease, and preys on birds and small mammals.

A highly adaptable species, Norway rats have established populations worldwide, often leading to declines in native fauna.

6

Japanese Knotweed

Outcompetes native plants, leading to a reduction in biodiversity and destabilization of soil and riverbanks.

This fast-growing plant is difficult to eradicate and can cause significant damage to infrastructure.

7

Purple Loosestrife

Displaces native wetland plants, reducing habitat for native wildlife.

Originally introduced as an ornamental plant, purple loosestrife can dominate wetlands, leading to ecosystem collapse.

8

Water Hyacinth

Blocks waterways, disrupts ecosystems, and outcompetes native aquatic plants, leading to reduced biodiversity.

This floating plant can rapidly cover lakes and rivers, causing issues for local ecosystems and fisheries.

9

Zebra Mussel

Causes significant ecological and economic damage by outcompeting native mussels and clogging water intake systems.

Introduced via ballast water, zebra mussels rapidly reproduce and spread, leading to infrastructure problems.

10

Africanized Honeybee

Outcompetes native bee species, can hybridize with local bees, and is more aggressive than native species.

Also known as "killer bees," they can negatively impact local bee populations and human safety in areas where they are established.