A crayfish never before found west of the Rockies is now invading rivers and streams in Oregon. But this invasive species can’t be blamed on anglers or their boats. Instead, Oregon school children and their teachers are responsible. Tune in to OREGON FIELD GUIDE on Thursday, June 23 at 8:30pm on the stations of Oregon Public Broadcasting to learn more about this new silent invasion. Also a look at lichen, Heritage Trees and some dogs working for conservation.

Crayfish Invasion - Five years ago, non-native rusty crayfish were found in the John Day River. It was the first time the species was spotted west of the Continental Divide, but here they were, 2,000 miles from their native habitat in the upper Ohio River drainage. They arrived by a unique pathway – elementary school classrooms. They were shipped to schools for biology classes and then released where they don’t belong by well meaning children or their teachers. The shipments of live classroom specimens violates state wildlife laws but state authorities have chosen not to aggressively enforce the ban. Now the aggressive rusty crayfish have colonized 30 miles of the John Day where they are threatening native signal crayfish and making their way to the Columbia River.

Lichen - Next we join two researchers on a crane 200 feet high in the Gifford Pinchot National Forest getting a bird’s-eye view of lichen. What could possibly be inspiring about that green stuff covering Oregon’s trees? Owls and squirrels make nests from it, elk eat it, and people make antiseptics and even poison from it. But perhaps one of the most interesting uses is what it tells us about the quality of the air we breathe.

Heritage Trees - Portland’s Heritage Tree program started in 1993 to recognize trees of special importance to the city. A tree can be granted the designation for size, or botanical or historic significance. FIELD GUIDE joins the committee considering trees nominated for designation to see how the process works.

Working Dogs for Conservation – One woman has learned to turn a dog’s keen sense of smell into a tool for conservation. See what dogs are doing or the preservation of rare wildflowers in the Willamette Valley.

Videos of the stories featured on FIELD GUIDE are available at opb.org/programs/ofg/ or watch entire programs at watch.opb.org.

Check out the FIELD GUIDE blog at blogs.opb.org/fieldjournal/ or follow us on facebook at facebook.com/oregonfieldguide.


In its 22nd season, OREGON FIELD GUIDE remains a valuable source of information about outdoor recreation, ecological issues, natural resources and travel destinations. OREGON FIELD GUIDE airs Thursday evenings at 8:30pm on the television stations of Oregon Public Broadcasting and repeats on Sundays at 1:30am and 6:30pm. In the Mountain Time zone of Eastern Oregon, the program airs at 9:30pm Thursdays, and at 7:30pm Sundays.

About OPB

OPB is the largest cultural and education institution in the region, delivering excellence in public broadcasting to 1.5 million people each week through television, radio and the Internet. Widely recognized as a national leader in the public broadcasting arena, OPB is a major contributor to the program schedule that serves the entire country. OPB is one of the most-used and most-supported public broadcasting services in the country and is generously supported by 120,000 contributors.