Aquatic invasive species

A hand holds a European green crab with its claws outstretched.
Photo by WDFW
European green crab. 

Aquatic Invasive Species (AIS) are organisms that have spread beyond their native range and, now free of the natural conditions that kept their populations in check like predators, competitors, parasites, and their native environmental conditions, can spread rapidly displacing native species, degrading habitats, and changing water quality. 

Threats to our environment, economy, human health, and way of life make preventing the introduction of AIS and stopping their spread crucial to protecting Washington’s waters.   

Prevention is our best defense. AIS are often introduced and spread through human activity, either purposely released or accidently transported on aquatic plants, gear, equipment, and watercraft. 

Infested boat propeller
Photo by National Park Service
Invasive mussels encrusting an outboard motor. 

For AIS information offline, download the printable AIS brochure (PDF). 

If you find a potential invasive species, report it using the Washington Invasive Species Council or the WA Invasives app (available in the Apple and Google app stores). Questions? Call WDFW's Aquatic Invasive Species hotline at 1-888-WDFW-AIS or email ais@dfw.wa.gov.