This is one in an ongoing series of posts by artist Elizabeth Conner, artist in residence on the Tolt River. Elizabeth is working with scientists who are monitoring the river in the aftermath of a recent restoration project near Carnation.…
On a warm day in July, I meet Dan Eastman and Josh Latterell under a bridge over the Snoqualmie River at Chinook Bend. They prepare for “edge mapping,” a repeat of a 2009 sample survey that was done at the same flow level, equipped with a GPS device and a velocity meter, which they load into an inflatable. I observe from shore, since I am not trained for water activities.
Edge-mapping measures the amount and distribution of slow water: good habitat for juvenile salmonids. This activity helps answer two questions:
• At what flows is edge habitat most limited?
• Do restoration projects increase the amount of edge habitat overall, especially at flow levels when edge habitat is scarce?
As the river becomes more complex following restoration, more slow-water areas should appear, assumed to be good for juvenile fish. The team has been sampling fish in different edge habitats to make sure this assumption is correct. Chinook Bend, and the confluence of the Tolt and Snoqualmie, both underwent restoration two years ago, so the monitoring activities are related. However, the scale of the Chinook Bend landscape is completely different.
“I feel like an ant when I’m here,” Josh remarks. He and Dan locate the boundary where water is moving at 0.45 meters per second, a low velocity that enables juvenile fish to easily hold their position in the current without expending energy needed to grow. These edge habitats may also provide some shelter from larger predatory fish that live in deeper water. Fish achieve their own segregation by size, and they can exist safely within three feet of schools of predatory fish that have chosen deeper water.
High-precision GPS units are used to trace two lines on every bank: the wetted edge of the river, and the location where the current exceeds 0.45 meters per second. Josh explains that GPS units are used as space-age crayons, accurate to within an arm’s length, to trace a giant cartoon of the limits of slow-moving fish habitat.
I think about how artwork that relates to this project might engage in its own “edge-mapping,” exploring variations on Josh’s early remark to me that “the forest is fish habitat.” What are the “edges” between urban and rural, people and fish, past and present, high-tech and low-tech, words and images? Can some of these edges, which might appear to be fixed, become more permeable? Josh and I talk about how this blog, a new experience for both of us, has been useful in developing shared languages that might help dissolve the perceived edges between subjectivity and objectivity, science and poetry. What would a moving and changing version of this slow process of change look like?
On another summer day, at the end of August, I join Josh Latterell, Laura Hartema and Cody Toal on the Tolt, just upstream from the Snoqualmie. This team is measuring median size of pebbles over time, to test the effect of restoration on spawning gravels. The “gravel survey” is a monitoring activity I have eagerly anticipated, because it sounds so baffling.
“You have to warm up. You gotta stretch,” says Laura. Cody and Laura stand back to back midway between one of several sample points established in 2008, every 100 meters along the “wetted edge” of the river. They walk slowly, heel to toe, a designated number of steps, then stop and, eyes closed, place the tip of a yellow wooden 2B pencil into the gravel at the tip of their front boot. They measure and call out the diameter of the rock touched by the pencil point. Josh records this on a data sheet containing 100 squares, for 100 measurements of 100 randomly selected pebbles. This collection of measurements will be used to describe the size distribution of rocks in the river, to help understand how restoration projects are affecting the river’s ability to reshape itself, and the suitability of the streambed for spawning.
At the command “turn and mark,” Cody and Laura mark their locations with a little cairn of larger rocks, turn to face each other, and retrace their steps, repeating the choreographed labor-intensive pencil and boot measuring activity. Josh explains that the pencil is used in order to obtain an unbiased sample. “If you use your finger to point to a rock, you will already have a “tendency to bias” against pebbles smaller than the end of your finger,” rather than making a random selection. “The more you can reduce biases, known and unknown, when you are measuring nature, the more accurate you will be.”
“Elizabeth, want to do the next one?” I am happy to participate, but immediately understand why Laura advised stretching exercises. This is hard! I lose my balance and work much more slowly than my partner. This necessitates some additional scientific controls to mitigate the work of a rank amateur, who now has a much more direct understanding of what monitoring looks like, and how it feels to do this work.
Photos by Elizabeth Conner