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Coho salmon were once abundant in the coastal rivers of California, including the Gualala River. The large trees that lined the river’s edge helped keep the water cool, a necessity for coho salmon to thrive. Female coho would dig nests in stream beds and deposit their eggs, which were protected beneath gravel and aerated by the constant flow of water. After hatching, the juvenile salmon made their home in deep, cool pools, protected by large woody debris and overhanging vegetation. In the estuary, emergent wetlands– shallowly flooded areas dominated by plants that “emerge” above the water’s surface–offered seasonal shelter from predators and foraging opportunities. Submerged aquatic vegetation provided additional habitat as juvenile salmon prepared for their migration to the ocean. These conditions are critical to the full lifecycle of coho salmon and steelhead. So if the Gualala River was once such a prime habitat, where are all the fish?
The Gualala River is listed as “impaired” under the Clean Water Act. While steelhead are still present–though threatened–throughout the watershed, coho salmon are endangered and now virtually absent. The reasons are multifaceted and date back to at least the 1860s, when clear-cutting of old-growth forests and milling operations dramatically altered the watershed. Increased runoff from deforested slopes carried heavy sediment loads into the river and down to the estuary. Large woody debris was also removed from the river, further simplifying stream channels and altering how the river flows. It’s estimated that over four or five acres of low-elevation wetlands were lost due to channel migration and changes in estuary dynamics. Today, while overhanging willows still line the river banks and a small fringe of wetland vegetation persists along Mill Bend Preserve, they provide only a fraction of the habitat salmon once relied on in the estuary.
Enhancing salmonid habitat conditions in the estuary is a priority for the community and aligns with long-term goals for the California Department of Fish and Wildlife and NOAA Fisheries to increase and enhance estuarine habitat complexity in the Gualala River. In 2022, RCLC completed a Conservation Plan for the 113-acre Mill Bend Preserve, reflecting strong community interest in enhancing estuary habitat conditions to support more robust salmonid populations. Estuaries provide rich feeding opportunities for juvenile fish, maximizing their growth and improving their chances for survival in the ocean. The longer that fish spend feeding in estuaries and lower-watershed wetlands, the more likely they are to thrive in the ocean and return to begin the cycle again. Without a healthy estuary that provides the habitat they need, salmonid populations will continue to decline.
Funded by the California Department of Fish and Wildlife’s Fisheries Restoration Grant Program, RCLC hired environmental consulting firm Prunuske Chatham, Inc. to outline opportunities for improving habitat conditions in the Gualala River estuary. This collaborative plan is supported by multiple state and federal agencies, as well as community organizations committed to the health of the watershed. Initial design proposals will be shared with the community at the Restoring the River: Community Event.
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