There are a lot of eyes on the Coos estuary. This elongated series of sloughs and tidewater streams makes Charleston the biggest Dungeness crab port on the West Coast.
The Port of Coos Bay plans to widen the commercial shipping channel to increase business, while the state wants to protect water quality. The estuary—one of the largest within Oregon—is important to recreationists, researchers and Indian tribes, as well.
David Sutherland, an oceanographer in the UO Department of Geological Sciences, is also focused on the estuary. His research may ultimately support decision-making that seeks to balance competing interests.
Sutherland is developing a computer model of flows, temperature and salinity in the estuary. Once he’s finished, the public will have a hydrodynamic tool that can be used to investigate a variety of scenarios for the estuary, including the ways in which natural and man-made changes affect this important environmental, cultural and socioeconomic asset.
The Coos estuary project, Sutherland said, “is neat because there are so many stakeholders and it’s a great place for students to learn.”
Estuaries are areas where a river meets an ocean. The Coos estuary provides unique opportunities and challenges in Oregon, said Pam Blake, South Coast Basin coordinator for the Oregon Department of Environmental Quality. The estuary is accessible to large ships, and a variety of development proposals seek to capitalize on this asset.
“On the coast of Oregon, Coos Bay is a hot spot of economic opportunity as well as rich and diverse natural resources,” Blake said.
Blake called Sutherland’s estuary model “absolutely critical” because it will allow DEQ to track how pollutants move through the estuary and where they collect. The model could also help the local economy, she added, by helping to identify areas where development can occur while minimizing the damage to natural resources.
Representatives of another project partner, the South Slough National Estuarine Research Reserve in Charleston, said the model will allow for precise assessments of water quality in the estuary. That might allow officials to refine restrictions on harvesting periods for commercial oyster growers, who aren’t allowed to operate when high levels of bacteria are suspected to be in the water.
“The model is of great interest to conservationists and developers alike, who understand that model results may or may not support what they want to do,” said Craig Cornu of the South Slough Reserve.
Working from a boat in the estuary, Sutherland receives most data for the estuary model through stainless-steel cylinders called CTD sensors, which are submerged to measure the water’s conductivity (or saline content), temperature and depth.
Sutherland began the project last fall and could have a working model next year— but only if additional funding is obtained and everyone with a stake in the estuary is satisfied with the accuracy of his model.
Laura Peteiro, a researcher with the UO’s Charleston-based Oregon Institute of Marine Biology, said the project could aid the Olympia oyster, which is threatened but could be commercially harvested if populations increase. She said the model, by zeroing in on estuary dynamics such as current speed and man-made dredging, “will help to predict how variations in the estuary can affect the population.”
The Coos tribe relies on the estuary’s salmon and shellfish as staple foods; preserving them is important to their cultural heritage, said Howard Crombie, director of the Department of Natural Resources for the Confederated Tribes of the Coos, Lower Umpqua and Siuslaw Indians. The department monitors water quality with equipment that collects readings every thirty minutes.
“While we have a piece of the puzzle, and others studying the estuary have other pieces of the puzzle, Sutherland’s project will help show how our piece and all the other pieces relate to one another,” Crombie said.
Like the Coos, the Coquille tribe also relies on the estuary for cultural resources and monitors water quality there.
“Sutherland’s model will hopefully provide valuable information for planners, developers and long-term conservation and restoration efforts,” said Jason Robison, biological and environmental services coordinator for the Coquille.
The ability to fit the estuary model to specific needs is also a strong selling point for Jon Souder, executive director of the Coos Watershed Association. The group wants to use the tool for wetland restoration and water quality projects.
“There have been hydrodynamic models for the Coos estuary but they were not designed to be turned over to the community to use,” Souder said. “(Sutherland’s model) is really a fundamental building block for a lot of other analysis that we would like to do.”
Said Sutherland: “It’s a little daunting. You want to do it right.”
Photo: South Slough National Estuarine Research Reserve