Salmon at River\u27s End: The Role of the Estuary in the Decline and Recovery of Columbia River salmon

The continued decline of Columbia River salmon (Oncorhynchus spp.) populations has long focused concerns on habitat changes upriver, particularly the effects of large hydroelectric dams. Increasing evidence that ocean conditions strongly influence salmon production, however, has raised questions about the importance of the estuarine environment to salmon and whether the hydropower system has affected estuarine-rearing habitats. In response to Northwest Power Planning Council recommendations, we initiated a review of what is known about the effects of the hydroelectric system on the hydrology, habitats, and ecology of the Columbia River estuary. Our goal was to develop recommendations for improving estuarine conditions or to identify research that may be needed before appropriate salmon-management changes can be defined. Our review and analyses addressed four major questions: (1) What habitats and processes support native salmon populations during the estuarine phase of their life cycle? (2) Have changes to the estuary had a significant role in salmon decline? (3) What have been the impacts of flow regulation on the hydrology, habitat, and biological interactions in the estuarine ecosystem? (4) What estuarine conditions are necessary to maintain salmonid diversity in the Columbia River basin

Geographic Variation in Salt Marsh Structure and Function for Nekton: a Guide to Finding Commonality Across Multiple Scales

Coastal salt marshes are distributed widely across the globe and are considered essential habitat for many fish and crustacean species. Yet, the literature on fishery support by salt marshes has largely been based on a few geographically distinct model systems, and as a result, inadequately captures the hierarchical nature of salt marsh pattern, process, and variation across space and time. A better understanding of geographic variation and drivers of commonalities and differences across salt marsh systems is essential to informing future management practices. Here, we address the key drivers of geographic variation in salt marshes: hydroperiod, seascape configuration, geomorphology, climatic region, sediment supply and riverine input, salinity, vegetation composition, and human activities. Future efforts to manage, conserve, and restore these habitats will require consideration of how environmental drivers within marshes affect the overall structure and subsequent function for fisheries species. We propose a future research agenda that provides both the consistent collection and reporting of sources of variation in small-scale studies and collaborative networks running parallel studies across large scales and geographically distinct locations to provide analogous information for data poor locations. These comparisons are needed to identify and prioritize restoration or conservation efforts, identify sources of variation among regions, and best manage fisheries and food resources across the globe

ADF&G-OCS Fish food habits analysis

ADF&

Commencement Bay Aquatic Ecosystem Assessment: Ecosystem-Scale Restoration for Juvenile Salmon Recovery.

The recent Endangered Species Act (ESA) listing for Puget Sound chinook salmon (Oncorhynchus tshawytscha) highlights both the conflicts and the potential to restore estuarine ecosystems of juvenile salmon in Commencement Bay. In order to restore and sustain healthy wild Puyallup River chinook populations, remediation of contaminated sediments must proceed without further jeopardizing the opportunity for these salmon to respond positively to various recovery actions implemented in their natal watershed and Puget Sound. Conversely, under some scenarios remediation of contaminated sediments and associated mitigation actions have the potential to contribute significantly to salmon recovery by enhancing the health of the lower Puyallup River and Commencement Bay watershed, estuarine ecosystems and associated aquatic habitats that support Puyallup salmon production. Unlike many mitigation and restoration actions that have addressed impacts to aquatic habitats in Commencement Bay in the past, responding to the broader ESA mandate demands a more comprehensive, ecosystem-based approach to juvenile salmon requirements in a highly impacted estuarine and lower perennial riverine landscape.City of Tacoma, WDNR, USEP

Juvenile salmonid and baitfish distribution, abundance, and prey resources in selected areas of Grays Harbor, WA--appendices

US

Growth of juvenile coho salmon in natural and created estuarine habitats: a comparative study using otolith microstructure analysis

US Army Corps of Engineers, Waterways Exp. Sta

Otolith microstructure preparation, analysis, and interpretation: a potential habitat assessment tool

US Army Corps of Engineers, Waterways Exp. Sta