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Marine Sciences Division

Lower Columbia River

Cumulative Effects Analysis

Cumulative Effects Analysis

Restoration projects take place at single sites, but restoration goals for large systems like the Columbia River cover aim for improvement at basin-wide scale. Monitoring the effectiveness and contribution of individual projects to meeting basin-wide restoration goals can be difficult to track, and measures are lacking to evaluate net improvement. Programmatic evaluations should include cumulative effects assessment because restoration occurs at multiple sites and the collective effect is important to ecosystem function and species recovery. Ecosystem and species responses to restoration occur through multiple pathways and can take decades to materialize. The most important aspect of this challenge is to be able to programmatically evaluate the cumulative effects that multiple site-specific actions have in aggregate.

MSL scientists are using an evidence-based assessment methodology that includes causal criteria to synthesize evidence for and against a cause-and-effect interpretation of cumulative effects. Evidence is obtained from field evaluations, remote sensing data, modeling and meta-analysis designed to test tiered hypotheses regarding physical and biological responses, which are developed from an ecosystem conceptual model.

MSL scientists applied the evidence-based assessment approach to evaluate the effect of the Federal Columbia Estuary Ecosystem Restoration Program (CEERP) on ESA-listed salmon and steelhead stocks. Two main hypotheses were that habitat-based indicators of ecosystem controlling factors and structures show positive effects from restoration actions, and fish-based indicators of ecosystem processes and functions show positive effects from habitats undergoing restoration. Monitored indicators for the ecosystem response hypothesis were water surface level and temperature, sediment accretion/erosion rate, vegetation, and export of prey and organic matter from wetlands to the main-stem river. Monitored indicators for the fish response hypothesis were presence, residence time, survival, prey, diet, fullness, and growth. Based on the evidence, we concluded that the habitat restoration activities occurring by CEERP are likely having a cumulative beneficial effect on juvenile salmon directly during access to restored shallow-water areas and indirectly during active transit of main-stem river habitats.

Wetland Science

Wetland Science

Sea level fluctuations as a result of climate change in the Pacific Northwest could be between -2 and +48 cm on the floodplain of the Lower Columbia River and Estuary (LCRE). When combined with hydroelectric demands and the expected changes in snowmelt, concerns are emerging as to whether there will be sufficient streamflow to sustain threatened and endangered salmon and trout.

Ongoing research by MSL scientists has indicated the tidal wetlands in the LCRE region occupy a vertical elevation band of only 2 m relative to the Columbia River Datum. Therefore, anticipated sea level changes are likely to have serious impacts of the amount and distribution of wetlands in the LCRE.

In an ongoing project, MSL scientists are studying tidal wetlands in the LCRE region to determine the vegetation type and cover of herbaceous plants. Results from this study indicate that the magnitude and duration of the annual inundation accounts for much of the distribution patterns of vegetation. These results can then be used to estimate the impacts of climate change on vegetation in the LCRE.

Restoration Science

Restoration Science

Habitat restoration projects are frequently performed despite high levels of uncertainty. Most projects must balance multiple objectives, socioeconomic impacts, and the competing values of stakeholders. Adaptive management (AM), a systematic process of learning while acting and using information to improve future decisions, can improve outcomes when resource management decisions must be made despite uncertainty.

MSL scientists have developed and applied AM programs at multiple sites representing diverse types of aquatic and terrestrial ecosystems. Commonly used tools in AM include structured decision making, conceptual and numerical models, monitoring programs, and stakeholder engagement to develop and implement programs. Expertise gained from past experiences has helped make MSL a valuable independent contributor to multi-agency teams implementing new AM programs across the country.

An ongoing example of MSL contribution to AM programs is the participation in the Bonneville Power Administration (BPA) and USACE Portland District'Ss effort to establish the Columbia Estuary Ecosystem Restoration Program (CEERP). The CEERP seeks to implement ecosystem restoration actions and research, monitoring, and evaluation (RME) in the 235-km lower Columbia River and estuary (LCRE). Since 2002, MSL scientists have worked with BPA and USACE in a variety of ways including:

  • Participating in expert technical groups that provide science-based assessments of proposed restoration projects
  • Designing plans for ecosystem-based restoration
  • Developing a programmatic AM framework
  • Applied research on controlling factors, structures, processes, and functions in LCRE wetlands
  • Develop conceptual and numerical models to establish and test hypotheses concerning CEERP actions.

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