top of page

What Are Aquatic Invasive Species? 


Aquatic invasive species (AIS) grow, reproduce, and spread rapidly in water environments. They are animals, plants, and other organisms (microbes) that are not native to the area and have the potential to cause harm to the economy, human health, our natural resources, and ultimately our quality of life.  They succeed due to favorable environmental conditions, and a lack of natural predators, competitors, and diseases. Aquatic invasive species (AIS) are also referred to as “nuisance” and “exotic” species, and they are one of the most significant threats to our water resources today.


Why Do We Care?


Invasive species are a form of biological pollution; they can be detrimental to the economy, human health, and natural resources. They spread easily in today’s global network of commerce and are difficult and costly to control.  Invasive species can impede industries, damage habitat,  threaten agriculture, and reduce our quality of life.


Introduced species outcompete native plants and animals and alter important ecosystem functions such as food chains, habitat, fire, and flooding.  Invasive species also hybridize with native species, causing complex environmental changes.


The cost to prevent, monitor, and control invasive species is enormous (including costs to crop damage, fisheries, forests, and other resources).  Economic losses are estimated at $137 billion per year, according to the National Institute of Food and Agriculture.


Why Are They Here?


Although there are a number of sources for the introduction of invasive species, such as, wind, water, and animals, most invasive species are introduced by humans. It is important to recognize this is a global issue, as well as a local one. The invasion begins across the world via imported fruits and vegetables, ship ballast waters, vehicles, shipping containers, exotic pet and aquarium trade, and human travel.


Once these non-native species arrive in North America, they spread in many different ways. In some cases, we deliberately introduce new species as garden ornamentals, range forage plants for cattle, and animals and insects used for bio control. Most often they are  introduced  unintentionally through  numerous pathways: travelers, pets and animals, recreational boats and vessels, and the trade of ornamentals.


While the majority of introduced species are not harmful to the economy or the environment, a small percentage are very damaging and need to be eradicated as soon as they are detected.





Eurasian watermilfoil

Quagga/Zebra Mussels

Yellow Flag Iris

bottom of page