Invasive species

It is estimated that at least nine non-native species of marine plants and 83 species of marine animals have been introduced into Puget Sound. Some of these were intentionally introduced, such as the Pacific oyster and Manila clam, to substitute for the loss of native shellfish species. Other animals have arrived through ship ballast water and other accidental introductions.

Sources:

Sound Science 2007

Addition resources:

Encyclopedia of Puget Sound list of invasive speciesWashington Invasive Species CouncilUSGS non-indigenous aquatic speciesWA Noxious Weeds Control BoardWDFW prohibited aquatic animals species list

Overview

Non-native species are those that do not naturally occur in an ecosystem. A non-native species is considered invasive when it is capable of aggressively establishing itself and causing environmental damage to an ecosystem. Plants, animals, and pathogens all can be invasive. 

The invasive tunicate Styela clava. Photo: WDFW

Related Articles

A September 2016 report from the University of Washington Puget Sound Institute provides an overview of key products, results, and recommendations presented in three previous reports reviewing 50 projects from the first four years of the Puget Sound Marine and Nearshore Grant Program.

Invasive species are considered a top threat to the balance of ecosystems worldwide. New discoveries of non-native green crabs in Puget Sound have highlighted that concern here at home, but invasive species can impact more than just the food web. Some introduced species can produce toxins that accumulate in shellfish or by directly infecting the human body.

Another European green crab has been spotted in Puget Sound prompting concern that the species may gain a foothold in the region. 

Gaps in regulations could allow invasive species to hitch a ride on ships and boats. We report on some of the potential impacts, and how state and federal agencies are trying to solve the problem. 

Concerns over the potential arrival of the European green crab have inspired a small army of volunteers. A search is underway for early signs of an invasion.

Almost twenty years ago, volunteer biologists began an intensive survey for invasive species in the marine waters of Puget Sound. In a little over a week of hunting, they found 39 such species, including 11 never before seen in the region.