Environmental Science students analyze a river reborn
In 2011, the National Park Service began the removal of the Elwha and Glines Canyon dams, the largest dam removal project in the world. Today, the effects of these dams on the lifeforms around the Elwha River, and the benefits of the dams’ removal, are still being studied and discussed.
In 2018, a group of Western students in the John McLaughlin field camp conducted a study to analyze effects of the dam removal on the local ecosystem. The field camp consists of four outdoor courses where students camp, cook meals, study, conduct field research and travel together. The study focused primarily on the altered distribution of birds, drained water reservoirs, changes in vegetation and return of the salmon population.
The effect on the salmon population is also of concern to the Lower Elwha Klallam Tribe. The placement of the Elwha and Glines Canyon dams blocked migrating salmon from reaching the tribe, who relied on the fish for consumption.
“In addition to blocking the passage of salmon upriver, the dams were blocking the downriver transportation of trees, branches, and root wads. In healthy rivers and streams, large woody debris accumulates naturally and provides habitat for fish,” the Lower Elwha Klallam Tribe official website states.
Ethan Duvall, a fourth-year studying environmental science, was thrilled to play a role in the Western study.
“My study specifically focused on river-dependent birds…how the removal affected the abundance and distribution of these birds, and habitat characteristics that were important to them,” Duvall said.
Duvall explained that when the dams were removed, Lake Aldwell and Lake Mills were drained, which exposed the sediment of 250-acre lake beds. This resulted in the replacement of lentic, or still water, lake habitat with lotic, or continuously flowing, river habitat. The removal dramatically altered the existing habitats and many species were adversely affected depending on their habitat preferences, he said.
Randy Jones, another fourth-year studying environmental science who worked alongside Duvall in the study, conducted a water-dependent bird abundance survey on the lower stretch of the Elwha River.
“Previously, the Elwha system was starved of the substantial amount of nutrients that the salmon acquire while out at sea and then deposit into the ecosystem after they spawn and die,” Jones said. “The removal of the dams has allowed for the return of this vital nutrient source that is increasing in volume every passing year since the removals occurred.”
Jones said how dams have negative ecological impacts on river systems, because they impede important sedimentation processes, decrease water quality and prevent anadromous fish, who migrate up rivers from the sea, from reaching freshwater breeding grounds.
According to an article by The Revelator, several species of fish like sockeye salmon and bull trout have returned to the river and salmon have quickly moved into places they haven’t been in over 100 years. The once carved-away river mouth is no longer deprived of sediment like it was when the dams existed, which showed researchers how essential rivers are in the transportation of sediment.
Another key effect of the dam removal is the estuary recreation. Relocated at the mouth of the river, the estuary now provides salmon and other fish with new habitats.
After much data collection and the use of statistical methods to compare multiple data sets, the students found that the response of the river-dependent birds was extremely positive. With the help of McLaughlin, students found that the abundance of targeted species increased overall. If these dams weren’t removed, the situation would continue to wreak havoc on the existing wildlife habitats.
Duvall said the next step people can take toward a healthy environment starts with personal growth and change.
“It starts with us as individuals being more conscious of what we do because it’s easy to get caught up in the way our society works with consumerism,” he said.
Jones explained that while hydroelectric power created by dams may be a carbon-neutral energy form, its ecological, economic and cultural side effects outweigh its benefits.
“As a society, we need to move past this notion of viewing hydroelectric power as being a ‘clean’ source of energy,” Jones said. ”We must look to hydro not as the future, but just as a bridge fuel while we figure out the intermittent problems that are disallowing us to switch fully to the cleanest forms of energy production like wind and solar.”