Coos Bay, located on the southern Oregon Coast, is the largest estuary between the Columbia River and San Francisco Bay. Palouse and Larson Creeks in the northern section of Coos Bay are the two most productive streams for coho salmon. Such productivity occurs despite the pressure salmon habitats have experienced through a long history of anthropogenic alterations, and continue to face from the region’s robust industrial economy, including recreational and commercial fisheries, agricultural production, and forestry. Restoration efforts since the 1980s have helped mitigate environmental impacts, but the turn of the century brought a new era of coordinated research, monitoring, and restoration. Forming a multi-stakeholder partnership with the goal of restoring salmon runs, the local nonprofitnon-profit Coos Watershed Association and its partners worked together to learn about the strategies that coho use to survive in these altered landscapes and apply research findings to restore habitats. Specifically, they examined the most appropriate habitat restoration strategies for various life histories of coho salmon, while working within social and political constraints. As a result, these efforts over the past 35 years have led to a better understanding of salmon populations in Palouse and Larson Creeks and an effective restoration program that continues till today.
Students will gain insights into 1) the complexities of watershed restoration and biodiversity conservation in areas with diverse land ownership and uses, 2) the importance of applied research and monitoring to demonstrate and improve watershed restoration strategies, and 3) the benefits of considering political contexts and working with landowners to sustain research and restoration efforts.
Coos Bay, located on the southern Oregon Coast, is the largest estuary between the mouth of the Columbia River and San Francisco Bay. Palouse and Larson Creeks in the northern section of Coos Bay are the two most productive streams for coho salmon, which are classified as a threatened species under the Endangered Species Act (ESA). Such productivity occurs despite pressures salmon have experienced through landscape alterations in a robust natural resources-based economy, including recreational and commercial fisheries, an international port, farming, ranching, and forestry. Watershed restoration efforts began in the 1980s to mitigate environmental impacts, but the turn of the century marked a new era of coordinated research, monitoring, and restoration through a multi-stakeholder partnership among the non-profit Coos Watershed Association (CoosWA), Oregon State University (OSU), and the Oregon Department of Fisheries and Wildlife (ODFW). With the overarching goal of restoring salmon runs, this partnership researched on how coho use these landscapes and how restoration projects can be responsive to both the needs of the fish and those of landowners. Taking an applied research approach and adapting to constraints posed by political contexts led to better knowledge and a highly effective restoration program over the past 35 years.1
Situated adjacent to each other in the northern Coos Bay estuary, the long and narrow Palouse (43.462110°N; −124.194065°W) and Larson (43.465737°N; −124.189674°W) watersheds are roughly equivalent in size and together encompass approximately 2,800 ha, including 88 km of streams (see Figure 1). Both watersheds contain three geomorphic regions:
Historically, tidally-inundated wetlands covered 1,142 ha near the stream mouths, providing critical fish habitat. These areas are in Drainage Districts (local governmental bodies) authorized to manage streams within their boundaries.
Upstream, broad, low-gradient valleys contain agricultural fields used for grazing and hay production with rural residences located on smaller parcels, sometimes immediately adjacent to the streams.
Headwaters in forested uplands with steep hillslopes actively managed for timber production by public and private landowners .
Beginning in the late 1800s, and accelerating through the twentieth century, both the streams were significantly altered to create pastures and aid boat navigation. After dikes were constructed, the Drainage Districts dredged the streams to improve drainage and reduce flooding of adjacent pastures. Tide gates were installed at the mouths of both creeks in 1918. Tide gates control the flow of water between creeks and estuaries by closing during rising tides to keep the areas behind them free of saltwater and also temporarily impounding streamflow; they then open during ebbing tides to release this impounded water into the estuary. Between diking and channelization, over 90% of historic wetlands in Palouse and Larson Creeks have been lost and fish passage has been adversely affected .
Land use practices in both watersheds significantly affected fish habitat that support coho salmon, the key species of concern, as well as smaller populations of winter steelhead, fall Chinook, chum, and sea-run cutthroat trout .2 Current population of coho salmon is about 10% of their historic size (see Figure 2), which is estimated to be approximately 206,000 individuals for the entire Coos system [3–5]. The peak count of adult coho in both the streams remained mostly below 100 between the mid-1960s and the mid-1990s. Earlier records beginning in 1948 show periodic increase of about 200–300 in Larson Creek (see Figure 3).3 In the mid-1990s and early 2000s, peak counts increased, but then abruptly declined in the mid- to late-2000s—from 280–380 in 2004 to about 20 in 2007. These fluctuations were likely due to changing ocean conditions in the El Niño–Southern Oscillation (ENSO) cycle of cool, productive ocean conditions (La Niña) giving way to above average temperatures and reduced nutrient upwelling (El Niño) in the years prior to the decline [6–8]. Peak counts have since risen again, but still vary between 100 and 50 adult coho in Palouse and Larson Creeks, respectively.
Although coho populations have persisted in Palouse and Larson Creeks, four inter-related conditions threaten salmon habitat, public and private property, and infrastructure: (1) high sediment inputs, (2) elevated summer water temperatures, (3) inadequate shelter from high flows, and (4) impeded fish passage.
Sediment in streams reduces aquatic habitat quality and increases the demand for dredging. Suspended sediment sources vary by region: in the uplands, poor forest road construction and logging practices cause landslides ; and in the valleys, historic channelization has increased stream gradients and bank erosion, exacerbated by riparian vegetation removal, while road surface gravel releases fine sediments. Sediment settles as the stream gradient decreases, which generally occurs in the diked areas under Drainage District jurisdiction. Tide gates further interrupt sediment transport by creating reservoirs that form deltas and fill stream channels.
During summer, solar loading can increase stream temperatures beyond the regulatory salmon rearing standard of 18°C. While the confined upper valleys of both basins remain cool from topographic and riparian shade, the downstream riparian areas are sparsely vegetated. Shallow silt-laden channels spread water across a larger surface area, leading to greater exchange with warmer air temperatures, while tide gates impound warmer water upstream and prevent cooler estuarine inflows.
Winter storms (freshets) cause high flows in Palouse and Larson Creeks, leading juvenile coho to seek refuge in lower velocity areas behind large wood, in deep pools, and in flooded fields. Actions taken to make the valleys suitable for agriculture and habitation removed much of these habitat features. Even the tide gate reservoirs represent a hazard for juvenile salmon not yet physiologically adjusted to brackish water if they are swept through the tide gates into the estuary and cannot return through closed gates. The representation of the three-year life cycle of coho salmon is shown in Figure 4.
Salmon and most other fish volitionally move from poor habitat conditions if possible. Roads, dikes, and tide gates pose physical barriers to juvenile fish migrating downstream to nursery habitat or to the ocean, as well as adult fish traveling upstream to spawn. These barriers prevent fish from fully utilizing important habitat, constraining populations. Eleven road crossings on fish-bearing portions of Palouse and Larson Creeks prevented passage, and many were in poor condition and undersized, potentially causing them to plug and fail during freshets. Tide gates prevent fish passage when they are closed and can create high water velocities and turbulence that inhibit passage of juveniles, especially upstream, which is the case of the Palouse tide gate, as its two top-hinged, wooden doors are in poor condition and provide a small opening window . The former Larson tide gate also posed a fish passage barrier 75 percent of the time . In contrast, the two newer side-hinged metal doors on Larson tide gate open earlier to a wider angle and close later in the tidal cycle, offering better conditions for passage .
Social and Political Challenges to Restoration
Environmental challenges faced by fish and residents of Palouse and Larson Creeks are not easily resolved due to the complex social and political environment. Myriad land uses in these basins generate tension among private timber companies, agriculturalists, rural residential landowners, and agencies, as decisions made in one part of the system have ecological and economic implications in other parts. In particular, a myriad of Federal, state, and county land use regulations are a common source of conflict among stakeholders. While timberland owners are regulated by the 40-year-old Oregon Forest Practices Act (FPA), lowland agriculture owners are less accustomed and express more resistance to oversight, including Confined Animal Feeding Operations (CAFO) regulations (prompting the closure of some dairies), Oregon Senate Bill 1010 agricultural water quality regulations, and §404 of the Clean Water Act requiring dredging permits. Many landowners consider these regulations as an impediment to using their property as they desire. Regulations have also posed problems for wetland restoration, as County Commission and Planning Department staff have historically been resistant to these permitted activities on Essential Farm Use zoned lands.
Successful applied research and restoration on private lands requires cooperation with landowners and working within their constraints. Given the conflict-prone political landscape in these basins, landowners support can be hard to secure and maintain. Penalties from permit violations often make landowners hesitant to voluntarily cooperate with CoosWA and its agency partners. Demographic changes have caused ownership turnover, fraying social networks, and bringing in new residents who are less familiar with managing coastal lands and less willing to support restoration efforts. Furthermore, it is common for landowners, agencies, and restorationists to each have different visions for “restoration,” which is further complicated by scientific developments that have changed restoration practices, sometimes contradicting previous ones.
In the course of research and restoration efforts in Palouse and Larson Creeks, two strategies have been proven to be effective for CoosWA and its partners in navigating these challenging social and political dynamics: 1) actively listening to and incorporating landowners’ interests and concerns into restoration plans, and 2) incentivizing restoration projects by highlighting opportunities to achieve landowners’ goals (e.g., upgrading tide gates).
Efforts to restore fish populations and meet landowners’ needs have used different approaches in three phases: 1) practical but disjointed structural modification in the 1980s; 2) organized ecological improvement in the 1990s; and 3) coordinated, strategic ecosystem-based restoration beginning in the 2000s to present. A comprehensive map of restoration and monitoring activities in Palouse and Larson watersheds is shown in Figure 5. Actions taken during the first two phases were based on a less-robust scientific understanding of stream ecology, and in some cases, they were based on different priorities (e.g., improving drainage) than those of CoosWA and its partners. Therefore, the initial phases of restoration actions made less progress toward restoring salmon runs, and in some cases, they were counter-productive. In the 1980s, individual landowners spearheaded small-scale projects to address drainage and erosion on their agricultural lands. Log jams were cleared after floods in 1981 to enable fish passage and reduce streambank erosion; later in this decade, the first large wood was placed in upper Palouse Creek, representing an evolution in stream restoration. After both tide gates failed during floods in 1984, the Haynes Drainage District (Palouse) and the Larson Drainage District replaced their tide gates in 1985 using emergency funding; their inverts (bottom elevations) were 3 ft higher, which subsequently caused problems with drainage and leakage.
In the 1990s, increased agency involvement led to more organized efforts. While drainage remained a concern, many projects aimed to reduce erosion and improve in-stream habitat. Streams were fenced to prevent livestock from trampling banks, and 63,700 willows and other riparian trees were planted along Larson and Palouse Creeks. Road culverts were upgraded and off-channel ponds were dug to increase floodplain connectivity and create high-velocity refugia for juvenile coho. To improve stream complexity, 300 logs and rootwads were placed throughout both basins, with 15 rock weirs constructed in Palouse Creek, between 1991 and 1996.
Agencies often initiated these restoration efforts in the 1990s, with ODFW partnering with private landowners, the Oregon Department of Forestry (ODF), and the Department of Environmental Quality (DEQ). The newly established CoosWA, founded in 1994, took a community-based stewardship approach to foster cooperative efforts in both basins. Buttressing this increased cooperation was the Oregon Plan for Salmon and Watersheds that expanded the role of watershed councils and provided significant funding after voters in November 1998 passed Measure 66 by a two-thirds majority to dedicate 7.5% of Oregon Lottery profits to direct funding to watershed restoration programs thereby protecting fish and salmon habitat.4
Although restoration efforts in the 1990s were more organized and better funded, they lacked overall coordination, strategic planning, and long-term monitoring. In the early 2000s, cooperation among landowners, agencies, academia, and CoosWA improved, resulting in more integrated monitoring, research, and restoration. Watershed assessments identified population limiting factors, including winter rearing and summer nursery habitat, fish passage, and sediment loading. Winter rearing habitat was expanded with wetland restoration through permanent Wetland Reserve Program easements covering 7 ha in lower Palouse and 30 ha in lower Larson Valleys, along with large wood placements in upper Palouse Creek and Sullivan (Larson) Creeks. Riparian planting helped to reduce solar loading and lower water temperatures to improve summer rearing habitat.
Fish passage was improved by replacing the Larson tide gates in 2001 with two side-hinged metal doors, providing a longer period fish passage through the gate under lower velocity conditions and improving access to 16 km of upstream habitat. In Palouse, eight fish-bearing culvert replacements improved access to 4 km of spawning and rearing habitat. Another 24 non-fish culvert and cross-drains were installed to reduce fine sediment runoff, while riparian projects helped reduce erosion and stabilize streambanks.
Improved Restoration through Applied Research
The success of restoration efforts in Palouse and Larson Creeks since the early 2000s is largely attributable to a better understanding of coho life histories and habitat use, supported by meaningful landowner engagement. Two strategies guiding restoration were 1) long-term monitoring and applied research, and 2) an assessment-based, cooperative approach.
CoosWA partnered with Oregon State University in 2004 for the Life Cycle Monitoring (LCM) project in Palouse and Larson Creeks, a long-term monitoring study to understand how tide-gated streams affect coho salmon. To date, researchers in the LCM project have
demonstrated innovative uses of passive integrated transponder (PIT) tags to show how tide gates impede coho movement and migration by constraining opportunities for upstream or downstream passage ;
monitored juvenile and adult coho movement using PIT tags to show a correlation between higher coho mobility during winter months and lower winter survival, suggesting that a lack of accessible refugia puts fish at greater risk when seeking refuge from high-velocity flows ;
analyzed coho otoliths’ (ear bones) microchemistry to identify rearing strategies, outmigration timing, and growth characteristics that highlighted potential genetic markers for these characteristics ; and
evaluated aquatic food webs to determine coho diet and resulting body condition .
Collectively, the LCM studies advanced the understanding of coho salmon, revealing at least two different life history strategies: (1) remain sedentary during the juvenile rearing period, and (2) be mobile throughout the stream system, likely in response to food availability and stream temperatures, and apparently correlated with greater marine survival . These multiple coho life histories are likely bolstering their resilience in highly dynamic and frequently perturbed systems, as has been found in other cases [15, 16]. Critically, LCM insights have guided watershed restoration efforts by targeting habitats used by these multiple life histories, leading to more effective restoration projects in these and other lowland areas of the Coos River estuary and engaging landowners who have interacted with researchers and seen the work first-hand.
CoosWA’s Lowlands Assessment of 2006 improved its restoration program by identifying and prioritizing projects for both basins. This assessment showed that Palouse and Larson watersheds, respectively, had only 39% and 10% of winter rearing habitat, and needed 25% and 50% of summer rearing habitat to reach their full coho production potential . Lack of riparian vegetation for stream shade was a key factor adversely affecting summer habitat, as were high water temperatures in the tide gate reservoirs, exceeding rearing habitat thresholds (18°C) for approximately 100 days during the summer. The assessment also identified 34 culverts in Palouse and 18 in Larson that were undersized and at risk of improper drainage or failure, potentially releasing an estimated 1,650 cubic yards of fill into each system and preventing fish passage to upstream habitats.
In an effort to secure landowner support and generate co-benefits through restoration projects, CoosWA shared the assessment’s findings with landowners through a series of “coffee klatches,” in which neighbors gathered in each other’s homes to discuss their vision for the future environmental state of their watershed and the land management challenges they faced. To address these challenges, landowners were shown various restoration tools that were being considered by CoosWA, which they were then asked to prioritize based on 1) the ability to meet their land management objectives and 2) acceptability among their neighbors. The landowners’ feedback weighed into the restoration project prioritization. This engagement strategy led landowners in both watersheds to become more engaged and supportive of restoration projects; since the assessment, nearly all projects in both basins have been on private lands. Relationships with landowners have also enabled monitoring and research to continue.
The case of Palouse and Larson Creeks highlights two important principles for watershed restoration in historically altered coastal ecosystems with productive coho salmon populations. First, applied research is a successful approach in understanding coho populations and their survival strategies. Coho life histories were more complex and diverse than commonly recognized, with differences in survival, growth, and recruitment likely determined by the availability and access to desired habitats. Second, using research to inform restoration design leads to more effective projects by better targeting habitats needed by diverse coho life histories. Furthermore, this case illustrates that building relationships with landowners and incorporating their interests into restoration design can facilitate applied research and restoration efforts, especially in contrast to previous eras in which landowner resistance hindered restoration and monitoring activities.
Although significant progress has occurred in Larson and Palouse Creeks, there is still a need for ongoing restoration efforts. Continued monitoring is necessary to provide consistent and high-quality data to state and regional fishery managers, to evaluate the effectiveness of watershed restoration actions, and to improve regulatory regimes. Future research in the LCM project will build off recent work on habitat use and food availability to continue unraveling the full significance of life history variations to coho salmon resiliency . Further analyses will determine whether life history patterns are genetically distinct, which would inform restoration design to increase coho resiliency in the face of climate change. In these endeavors, care must be taken to continue engaging landowners to plan and implement programs that benefit fish and residents alike. A recent breakdown in cooperation prevented sampling in the middle reaches of Larson Creek and required moving the LCM project to a different tributary tide-gated stream (Willanch Creek), illustrating the importance of considering social and political contexts to ensure successful applied research and watershed restoration.
CASE STUDY QUESTIONS
Consider the perspective from which this case is written. What are the authors’ goals and priorities regarding watershed restoration? How might this case be different if it were written from the perspective of a stakeholder with another set of goals and priorities?
How does science and technology support or limit ecosystem restoration? What other factors inform restoration approaches? In the case of Palouse and Larson Creeks, how did those factors shape the strategies that were taken and the outcomes of restoration efforts?
Based on this case, what are some benefits of using applied science to inform restoration projects?
What was the role of landowners in this case? Was their cooperation voluntary?
How did the social and political context in Palouse and Larson Creeks present challenges to research and restoration?
Emily Wright compiled and reviewed CoosWA materials to write the original draft. Both authors wrote and edited the final draft.
This study drew upon several primary efforts. The initial Coos Bay Lowland Assessment, carried out by the Coos Watershed Association, provided a baseline inventory of conditions, provided the context for historic conditions, and summarized the perspectives of landowners in the Palouse and Larson watersheds. Life Cycle Monitoring research was conducted by Arthur Bass, Adam Weybright, Katherine Nordholm, and Kailan Mackereth under the supervision of Dr. Guillermo Giannico, OSU Department of Fisheries and Wildlife and Oregon Sea Grant. The restoration projects and associated monitoring efforts implemented by CoosWA, ODFW, and other agencies in cooperation with individual landowners provided information on the work to restore these critical systems.
Many of the restoration projects that were undertaken in the Palouse and Larson Creeks were funded by the Oregon Watershed Enhancement Board and the Bonneville Environmental Foundation. More details about specific projects and funding sources can be found by contacting the Coos Watershed Association at www.cooswatershed.org.
The authors have declared that no competing interests exist.
DATE ACCESSIBILITY STATEMENT
Data related to restoration projects in Palouse and Larson Creeks are available in the previous publication that provided the basis for this case study, available at www.cooswatershed.org. The current and historic data on stream conditions in basins across the Coos Watershed are also available at this website.