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 present threats to our environment, economy, human health, and way of life. Preventing the introduction of AIS and stopping their spread is crucial to protecting Washington’s waters, fish, and wildlife.

When free of the natural conditions in their native range that kept their populations in check — such as predators, competitors, parasites, and other environmental conditions — AIS can spread rapidly, displacing native species, degrading habitats, changing water quality, and impacting ecosystems.

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. 

If you find a potential invasive species, report it using the Washington Invasive Species Council webform or the WA Invasives mobile 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.

For AIS information offline, download WDFW's printable AIS brochure (PDF).