Originally written by Erin Spencer for Don't Release Me. Visit www.dontreleaseme.org to learn more. More resources to come soon!

Q: What are invasive species? Why are they harmful?

A: According to the National Invasive Species Information Center (NISIC), an invasive species is "plants, animals, or pathogens that are non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause harm." 

Invasive species are wreaking havoc on ecosystems worldwide. Approximately 42% of Threatened or Endangered species are at risk primarily due to invasive species, and invasives cause billions of dollars of damage every year.   

Invasive species threaten native ecosystems, local economies, and human health in a number of ways, including: 

  • Decreasing biodiversity of ecosystems
  • Introducing disease 
  • Preying on native biodiversity 
  • Outcompeting or consuming native species 

Q: Why is it bad to release fish into the wild? 

A: Most fish for sale in aquarium stores are exotic, meaning they are not native to the United States. Each year, nearly 150 million exotic fishes comprising 2,000 different species are imported into the States for the aquarium trade. 

Some pet owners who can no longer take care of their fish will release them into the wild. This is not only bad for the fish (most likely the fish be distressed and/or consumed by native fish), but it's extremely bad for the environment. Exotic fish could introduce disease, prey on native fish, or become established in their new environment.

If exotic fish survive and reproduce, they are extremely difficult to control. Currently, at least 185 different species of exotic fish have been caught in U.S. waters, with 75 of these known to have breeding populations. Over half of these introductions are from people releasing aquarium fish into the wild. (Source: USGS)

Q: Where can I go to learn more? 

A: The following organizations offer helpful resources regarding pet ownership and invasive species management. Visit their sites to learn more: