Unbuild It and They Will Come: The Initial Stages of Salmon Recolonization In the Elwha River

McMillan, John; Moses, Raymond; McHenry, Mike; Ward, Larry; Frick, Kinsey; Brenkman, Sam; Crain, Pat; Kennedy, Phil; Hugumin, Heidi; Stefankiv, Oleksandr; Pess, George

Before the 1900s, the Elwha River supported one of the most diverse and abundant populations of salmonids on the Olympic Peninsula, including all five species of Pacific salmon, resident rainbow trout and steelhead, coastal cutthroat trout, and bull trout. However, in the early 1900s, the Elwha Dam (river-mile (R.M.) 4.9) and the Glines Canyon Dam (R.M. 13.5: Figure 1) were constructed without fish passage facilitiies (Duda et al. 2008). Limited to the lower five miles of river, the anadromous portion of the salmonid population dramatically declined in abundance, distribution, and diversity. Then, after almost 100 years and decades of political and legal wrangling, deconstruction of both dams began in the late summer of 2011 and the former Elwha Dam site was passable by fish in late April 2012 (Figure 2). Removal of these two dams opens over 70 miles of high quality habitat towards the goal of recovering the salmonid runs of the Elwha River (Pess et al 2008). As part of the recovery process the Lower Elwha Klallam Tribe (LEKT), National Oceanic and Atmospheric Administration/National Marine Fisheries Service (NOAA?NWFSC), Olympic National Park (ONP), Washington Department of Fish and Wildlife (WDFW), United States Fish and Wildlife Service (USFWS), and the United States Geological Survey (USGS) - hereafter referred to as the 'partners' -- collected and relocated adult coho salmon and adult winter steelhead into the middle Elwha River valley, which is located between Elwha and Glines Canyon Dams (Figure 1). The objectives were two-fold. First, the partners wanted to initiate recolonization above Elwha Dam prior to full restoration of anadromous access. Second, deconstruction released sediment stored behind the dams that resulted in elevated turbidity levels in the main-stem Elwha River that were stressful-to-potentially-lethal. To mitigate this, the partners wanted to move a proportion of the fish into two tributaries in the middle Elwha that were directly unaffected by the sediment release, including Indian Creek and Little River. After release, the partners conducted weekly foot surveys to count redds and follow up with summer snorkel surveys. We also radio tagged a subset of the fish to better understand movements prior to, during, and after spawning. Here we describe some of the preliminary findings of those colonizing salmon and steelhead.