This dissertation addresses the relationship between large-scale dam removal and the nearshore ecosystem function for fish. The work is based on almost a decade's worth of collaborative field work in the nearshore of the largest dam removal in the world recently completed on the Elwha River. The data analyzed span seven years prior to, during, and throughout the first year of each dam removal (January 2008 to November 2015). As of September 2015, approximately 2.6 million m3 of sediment material increased the area of the Elwha delta to over 150 ha. Long term study of fish in the estuary reveals fish community response to dam removal, and indicates likely interactions in the nearshore between hatchery and wild fish, including chum salmon critical to watershed recovery. Continued hatchery releases may therefore further challenge chum salmon recovery, and this interaction should be considered when planning for future watershed recovery. Community analysis revealed that, while species richness and taxonomic diversity do not appear to have a significant response to dam removal, functional diversity in the nearshore does respond significantly to dam removal. Three main shifts occurred in the nearshore: large scale and rapid creation of estuary habitats; delivery of large amounts of sediment to the delta/estuary in a short period of time, and; a shift in original habitats from tidally influenced to non-tidally influenced habitats resulted in changes in estuary function. Changes in functional diversity occur disproportionately in the new sites, which have more unstable, and so less resilient, communities. Functional diversity in the original estuary sites appears to be more resilient than in the newly created sites due to the large-scale environmental disruption that, ironically, created the new sites. However, the functional diversity at the original sites may be defined in part by management activities, including hatcheries that could mute/mask/inhibit other community responses. Further, functional diversity at the newly formed nearshore areas is predicted to stabilize as the habitats are vegetated and mature. Principal components analysis of Elwha fish community over the course of this study reveals that the fish communities of the Elwha are predictably grouped, indicating that while a few new species are observed, dam removal has not resulted in observable disruptions in fish community assemblages. And finally, nearshore habitats are critical for many forage fish species, and an emerging topic for large-scale dam removals. Forage fish spawning response to dam removal appears to be complex and may be related to multiple factors including high interannual variability in physical habitat conditions, geographic factors and complex life histories of forage fish. Habitat suitability for forage fish spawning should increase as restored ecosystem processes and newly created habitats mature and stabilize, indicating that time may be an important factor in nearshore restoration for forage fish spawning. It is therefore important to implement long-term monitoring and incorporate nearshore ecosystem process and function for multiple life history stages of nearshore species, including forage fish, into large-scale dam removal restoration and management planning.

"In 2009, Jackson County applied for and received a National Oceanic and Atmospheric Administration (NOAA) Coastal and Marine Habitat Restoration Project Grant under the American Recovery and Reinvestment Act (ARRA) to remove the Gold Ray Dam for the purpose of improving fish habitat and passage. The grant was separated into two phases; a first phase that included conducting environmental and other studies to determine the feasibility of removing the dam and a second phase that included the removal of the dam and associated structures. NOAA released the funding for the first phase of the project to the County but delayed the release of funding for phase two until after the National Environmental Policy Act (NEPA) analysis could be completed. National Marine Fisheries Service (NMFS), as the administrator of the grant, must comply with the NEPA requirements to assess the potential impacts of the proposed action on the natural and human environment. In early May 2010, Jackson County, as the dam's owner, decided dam removal is the best option for addressing their long-term interests as the owner of the dam. NMFS is proposing to release funding to Jackson County, Oregon to improve fish passage at the Gold Ray Dam on the Rogue River near Medford, OR. The dam owner, Jackson County, has been working with NMFS and additional project partners to explore the option of dam removal. The purpose of the project is two-fold: (1) to address inadequate fish passage and improve native fish habitat on the Rogue River at Gold Ray Dam; and (2) to address the short- and long-term financial and liability impacts of the dam to Jackson County, Oregon"--Executive summary.

Over the past dozen years, a number of large dams in the Pacific Northwest have been removed in an effort to restore riverine ecosystems and dependent species like salmon. These dam removals provide perhaps the best example of large-scale environmental remediation in the 21st century. This restoration, however, has occurred on a case-by-case basis, without a comprehensive plan. Yet the result has been to put into motion ongoing rehabilitation efforts in four distinct river basins: the Elwah and White Salmon in Washington and the Sandy and Rogue in Oregon. In all, nine significant dams have been removed, and four more -- in the contentious Klamath Basin of Oregon and California -- are slated for removal in within the next decade. This article surveys both the successful and proposed removals in to draw lessons both within and beyond the Pacific Northwest. We identify a number of factors that determine both the speed and success of dam removal efforts, including the availability of the federal licensing process under the Federal Power Act, the existence and organization of local opposition, the amount and sources of funding, and the support of federal and state resource agencies and well-positioned members of Congress. These factors suggest that the promised removal of the Klamath Dams as well as calls for removing the federal dams on the Lower Snake face significant odds.