BROWNSMEAD Calm tidal channels in the Gnat Creek Watershed are where juvenile coho, steelhead and chinook can grow and protect themselves from predators before making their trip out to sea.
To further reconnect existing channels, on land no longer in agricultural use, Columbia River Estuary Study Taskforce (CREST) has begun establishing five breaches along a levee in Brownsmead.
During high tide, the increased access for fish traveling to the other side will lessen the force of water at existing openings, allowing them to get in and out much easier.
Defunct tide gates were already breached along the levee, allowing water at high tide to pour into the important channels, but with grant money from the Lower Columbia River Estuary Partnership and the Bonneville Power Administration, CREST hopes to enhance the flow of water to these areas.
The organization worked on restoring 20 acres of Oregon Department of Forestry land last summer not far from the current worksites.
Madeline Dalton, habitat restoration project manager with CREST, said the restoration is needed in order for a more complete system.
The excavation for the project, unlike one year ago, is being partly conducted by barge. Henderson Land Services of Lake Oswego could have reached the sites by land, but it would have had an impact on the existing wetlands, Dalton said, and the narrow levee presented a safety concern for excavator operators.
Marv and Nancy Autio and members of the Eikren family own the land that CREST is opening up and partnered with the Astoria-based organization. By the end of the month, CREST is hoping to have completed what it started last week. Three breaches have already been completed and secured.
Tidal marshes once dotted large swaths of the Columbia River system, but Dalton said about 80 percent have disappeared. CREST has ongoing restoration projects along the river to address the loss of historic wetlands.
Were working throughout the estuary from Bonneville Dam down through the mouth, said Matt Van Ess, CREST's habitat restoration program manager. "There's been quite a bit of restoration happening right here in the Knappa and Brownsmead area.
The levee is covered in invasive blackberry bushes. CREST is planting native vegetetaion on both sides of the excavated sites, which is where the removed dirt is being dumped.
What were doing with those invasives is burying them at the bottom and then putting the dirt on top so that theyre less likely to re-sprout, said Dalton.
Logs 20 feet long are being placed in the water on both sides to keep the breaches in place and slow the tide. The existing openings on the levee allow fish to swim further into the network of channels, but also make it difficult to go back and forth.
Because there are so few of them, when the flow really comes in and out, it creates a velocity barrier for the juvenile fish to come in and out, said Dalton.
The breaches in the levee will match the same level as marsh on the other side. Were not cutting channels, but just taking out (sections of) the levee as if it never happened, said Dalton.
The breaches, which will be part of 70 acres of wetlands, are destined to help coho, steelhead and chinook, but could be a location for chum from Big Creek Hatchery upstream.
Theres a possibility there could be some strays from that overtime, she said. Theres definitely a variety of different species here. Places like these are really important because the currents and the tides are really pulling them out toward the ocean before theyre ready for it.
Not only will the openings allow for fish to get in to the tidal channels, but bugs that fish feed on are able to get out, too, Denise Lofman, director of CREST said, spreading throughout the wetlands and eventually out to the Columbia River.
If you can open up into wetlands, with more native vegetation, then the food web is more complete, too, Lofman said.
Natural channels exist on the other side of the former levee, but the organization is hoping that agricultural channels will eventually become more naturalized along with them as water flows through at high tide.
The ecological and economic benefits of the restoration could impact fish further up the Columbia as well.
What were finding is when we open these places up were finding fish from the Willamette (River) or up above Bonneville Dam, said Lofman.
In the winter, CREST will come out and reassess the native vegetation that has been planted. At the breaches that were created last summer, Van Ess said its hard to tell anything was ever removed.
To see it now, its like we were never there, he said.