The Barred Owl, an invasive species in Washington forests


Ever since humans started going to different places, there have been other organisms traveling with them, and moving into new habitats. Sometimes, this may be a good thing, and the ecosystem stays the same, or even improves from before. But much of the time, this ruins the habitat of the organisms that are native to the area. These are called invasive species, and they truly do live up to their name; invaders. 

Here in the Pacific Northwest, there are tons of species that aren’t native, many of which are doing harm to our beautiful environment; the greenest of green coniferous trees, the large variety of animals and plants and the gorgeous terrain are endangered by invasive organisms. You may have heard about the Asian Giant Hornet nests, which are massive, attack the bee population, and can easily kill a grown, healthy human. Or maybe you’ve heard of the seemingly innocent butterfly bush, which can be ignored by those who do not know that it is invasive. You may have not paid as much attention to Viral Hemorrhagic Septicemia (VHS), which is a virus that kills fish. Either way, here are some of the most common invasive species (and viruses) that can be found in Washington State. 

Image courtesy of Wolfgang Hasselmann


In the Spring of 2020 there was a lot going on, including the pandemic (which caused much of the country to go into lockdown), as well as… Killer Bees??? Asian Giant Hornets were turning up in Washington; headlines showcasing the news. They are somewhat easily distinguishable from native species, with their 3 inch long wingspan, 1.5 inch long length, yellow/orange and black striped bodies, and yellow/orange heads. They are a threat to many species, especially honeybees (as well as the honeybee industry). These “Murder Hornets” are also perfectly capable of killing a healthy adult human, which is another cause for concern. The USDA is currently trying to eradicate all of them in the Pacific NorthWest area, which means that any sightings are recommended to be reported immediately. You should also not attempt to remove it unless you a professional or are aided by an expert’s help. You can report sightings to the Washington Invasive Species Council (and through the app). 


As mentioned earlier, the Butterfly Bush is an invasive plant commonly found wreaking havoc in much of Western Washington State. It can grow up to fifteen feet up high, and is a shrub with deciduous, arching branches. Branches and leaves can have hairlike qualities, with lighter colors below and blue-gray/green above. Leaf stalks are shorter, but still have the hairs, and are sometimes directly on the stems. Flower clusters are between 4 and 10 inches in length, and flowers come in a purple-scale ranging to nearly white to the deepest of purples. They are a cause for concern because they are often found replacing native vegetation, and ironically, horrible for butterflies, which harms the ecosystem as a whole. They also resprout easily, making it hard to remove them from an area, and are Class B Noxious Weeds here in Washington (in need of control in many places). These perennial shrubs are mostly commonly found around rivers. Some ways to get rid of them include replacing them with native plants, deheading them, and more. You can also report a sighting using the same resources provided in the section regarding the Asian Giant Hornets.


Butterfly Bush, Image courtesy of Micheile Henderson 


Viral Hemorrhagic Septicemia (VHS), is a deadly blood vessel virus commonly found in fish. The IVb variant is found in freshwater much more often than in saltwater. IVa is in marine water ranging from Southern California, all the way north to Alaska. This virus is highly contagious, and can negatively affect many different types of fish. The WA state department of fish and agriculture takes great measures to keep it out of the area, and recreational management monitors for the virus, as well as other things such as zebra/quagga mussels. A fish may be infected if they show hemorrhaging on the body, congestion of organs, damage to the blood vessels, a darker appearance, a distended abdomen, and more (see more in sources). Report if you see a fish with any of these symptoms.


As mentioned multiple times earlier in the article, if you live in Washington State, you can report any sightings to the Washington Invasive Species Council and learn how to prevent more from establishing in your community. You should also remember to continue to make sustainable choices, and stay safe during these hard times! We also recommended that you check out the sources below for a more in-depth understanding of invasive species here in Washington. 


Sources: (you can see a picture of a butterfly bush here)