I’m a Vector, You’re a Vector Too

Several years ago, I was on an autumn larch hike led by Clayton Antieau, a past-President and long-time board member of the Washington Native Plant Society. Several of us on the hike had lugged our copies of Hitchcock and Cronquist up to the subalpine meadow in our day packs. These well-worn volumes had weighted down many a hike before.

Once we arrived in the meadow, we cracked open our floras to start the delightful tedium of keying out plants in habitat. Out fell plant remnants from previous field trips. Oops.

Clay noted that we were jeopardizing the health of the place we had trekked so far to enjoy—carrying in plant material from elsewhere in the very instrument of our education and appreciation.

I thought of this incident the other day, when I was talking with Wendy Brown, the Executive Coordinator of the Washington Invasive Species Council, about the prevention protocols that the council has developed.

The protocols are designed to help field staff and others (field trip participants, for example!) prevent the inadvertent spread of invasive species.

Pants with seeds attached

Certain types of clothing transport invasive species easily. Photo: California Invasive Plant Council

Invasive species can be spread in numerous ways. For example:

  • When you drive to a field site (or trailhead), you can move soil embedded with seeds or plant fragments in the vehicle’s tires or undercarriage. New infestations can begin miles away when the seeds and fragments drop off elsewhere.
  • When you move gravel or soil to a new site, say when you are gardening or carrying out restoration or construction activities, you run the risk of transporting seeds and other propagules. Before long, the seeds germinate, and the new site is infested.
  • If you spend time in a water body infested with invasive plants, animals, or pathogens, you can move them via your boots, nets, sampling equipment, or boats (and, I assume, via your swimsuit, aqua shoes, or water wings) to another aquatic environment.

What can you do?

The Washington Invasive Species Council has developed two sets of protocols, one for activities on land and one for activities in water. While designed for field workers in state agencies, the protocols provide useful guidelines to all of us who love to spend time outdoors.

The major difference between the water and land protocols is that when you spend time in the water, it’s necessary to decontaminate in a way that tackles immature stages of invasive animals as well as pathogens such as viral hemorrhagic septicemia (VHS), a fish disease that sounds very icky indeed.

The protocols boil down to three common-sense steps:

  • Bring backups. In other words, if you are going between two sites, you can avoid transferring invasive organisms by changing your clothes and your shoes, and by using different field equipment or tools.
  • Minimize contact. This means to stay on the trail, avoid walking through seed-laden weed patches, and know what invasives are out there so you can avoid them.
  • Inspect and clean. Take a look at yourself, your clothes, your pets, and your car at the field site. Remove any seeds, dirt, algae, or critters (!) you see. If you or your equipment have been in the water, they recommend Clean, Drain, Dry.

The full text of the protocols is available here: Invasive Species Council Prevention Protocols

Other agencies have their own invasive species prevention and decontamination recommendations. These tend to be more detailed and tailored to each agency’s specific mission and operations.

Washington Department of Ecology

Washington Department of Fish and Wildlife

U.S. Forest Service – Noxious Weeds

U.S. Forest Service – White-Nose Syndrome (bats)

See more information on preventing the spread of invasive species.

Nowadays I try to practice good field hygiene. I have brushed out my copy of Hitchcock and Cronquist, so that it no longer sprinkles plant fragments whenever I open it.

I clean the mud out of my boot treads, inspect my insoles, and pick seeds off my shoelaces, pant legs, and fleece jacket. And I fervently hope to avoid any water bodies containing viral hemorrhagic septicemia.

How do you avoid being a vector of invasive species?