Yesterday Sarah Morely of NOAA/NWFSC Watershed Program, Fish Ecology Division gave a 40-minute synopsis of the “Elwha River Dam Removal – Past, Present, Future.” My notes are appended and the NOAA site has an abstract with recommended references (also appended in case the link breaks).
A small (fall) Elwha chinook (dated Oct 4, 2010)
The most interesting aspect of the talk from the perspective of the southern resident killer whales is that no one in the audience, including Mike Ford, offered a clear articulation of the strategy for recovering the Elwha’s chinook salmon — and particularly the possibly extinct spring chinook of 50-kg fame. Given their strong preference for big chinook (Hanson et al., 2010), the southern residents would presumably benefit most from the fast recovery of the biggest Elwha chinook, but Sarah only indicated that her impression was that the return of salmon to the Elwha was going to more “natural” than managed. With large salmon and a combined species population potential of ~400,000 fish, we ought to be very clear as a community about the chinook recovery strategy!
That led one audience member to wonder whether the spring run is really extinct and, if so, how long it might take the fall chinook population to naturally fill the spring niche. He asked whether 25 years might be a good guess for natural recovery of the spring chinook runs if adults are not moved above Glines Canyon dam to facilitate their re-colonization of the upper Elwha and tributaries (as is currently being done at Condit Dam on the White Salmon), but Sarah didn’t volunteer a confirmation or an alternative estimate. The audience member’s suggestion of possible extinction is echoed on the National Park Service’s web page on the historic range of Elwha chinook:
Very few, if any, spring-run Chinook remain in the Elwha.
This made me realize that I (or some other southern resident stewards) need to dig into the EIS and figure out if the spring chinook are being managed in an optimal way from the perspective of the salmon-eating killer whales. If they are not, then perhaps we should all make it a priority to change the situation.
In sleuthing around for details on the Elwha chinook runs, I did start to answer a different long-standing question: “Why were the Elwha chinook so big?” I had heard 2 compelling hypotheses: (1) velocity and vertical barriers are more substantial on the Elwha than on comparable (Olympic) rivers and selected for fish powerful enough to surmount them; and, (2) stream bed gravel size in the Elwha is much larger than on comparable (Olympic) rivers and only bigger salmon could dig in it to build their redds.
The second is refuted by Sarah’s response to a question I asked her after her talk: How does the sediment size distribution in the upper Quinalt compare with that in the upper Elwha? She said the upper (east?) fork of the Quinalt was chosen as a comparison site because the river bed sediment size distribution is similar to that in the upper Elwha. Yet the Quinalt does not host gigantic chinook… But perhaps it has bigger velocity and vertical barriers than the Elwha?
The first hypothesis is addressed in Brenkman et al., 2008 (special issue of Northwest Science). They describe the velocity and vertical barriers on the Elwha:
The 7.9 km of main stem habitat currently available to anadromous salmonids in the Elwha River will increase to 71 km following dam removal. Possible seasonal velocity barriers exist in three main stem Elwha River canyons during periods of high river flows (Figure 2)—Rica (rkm 26.1 to rkm 27.3), Grand (rkm 31.1 to rkm 35.3), and Carlson Canyons (rkm 53.0 to rkm 54.5). Rica Canyon consists of bedrock, large boulders, and high-velocity water with several cascades and falls up to 1.8 m in height. The upstream portion of Grand Canyon contains several cascades and low waterfalls, and the lower 2.4 km of Grand Canyon contains approximately 15 cascades and falls. Carlson Canyon has a single waterfall that is 2 m in height (Washington Department of Fisheries 1971).
Seasonal velocity barriers in the Elwha River occur where the river channel is constrained by steep canyon walls and boulder- and bedrock- dominated substratum. Canyon reaches have channel gradients that are up to two times steeper (2% in Rica, Grand, and Carlson Canyons) than the average gradient for the entire 69 km of the main stem river (1%). High-flow events resulting from early winter storms and spring runoff create high-velocity cataracts that may constitute seasonal migration barriers to salmonids moving upstream. In contrast to these steep canyons, other sections of the Elwha River are much more gradual, with gradients of 0.3% from the mouth to Elwha Dam, 0.8% from Elwha Dam to Glines Canyon Dam, and 1.4% from Glines Canyon Dam to the headwaters of the main stem.
While salmon are generally capable of jumping 1.8-2m barriers, their ability to do so is limited by the pool size (particularly depth), relative position of the pool and the hydraulic jump, and degree of aeration in the pool. I’ve yet to find these details, but if they don’t exist, I know what I’m doing on my next hike up the Elwha drainage!
MY NOTES ON THE TALK:
Sept 16 was beginning of deconstruction of dams. Deconstruction will take another 2-3 days. Salmon recovery is expected to take decades.
Global distribution of dams and reservoirs is extensive in termparate regions. Global Water System Project Database, 2011 (McGill University)
Poff & Hart, 2002, Bioscience: increased dam removal over last 30 (now 40?) years is due to replacement generally being more expensive than removal, BUT most removed dams have been small.
Imminent NW removals – Elwha, White Salmon, Sandy River, Marmot Dam on Little Sandy River, Rogue, Calapooia (Umpqua), Kalamat
Lower Elwha (190? 1913) and Glines dams (1932? 1927) reduced sediment, river movement, woody debris, as well as salmon populations. They will be removed concurrently in controlled increments over 2-3 years (to minimize impacts of sediment to fish as well as benthic organisms.
Link to web cam of sediment plume? (Bureau of Reclamation is managing erosion of 18 M m^3 of sediment, 50% fine, 30% coarse, suspended sediment concentrations of >10,000 ppm)
Monitoring efforts and objectives
Objectives: 1) Establish baselines (advanced) and 2) evaluate response to dam removal (just getting started)
Research areas: Former reservoirs, Nearshore (consortium of Fresh/Kagley/+), River ecosystem
Nearshore (slides from Kurt, but also USGS+ collaborators)
- Monthly sampling (Mar-Sep) since 2006; 37m beach seine plus environmental data
- Community composition doesn’t change much between years, but is a little different between their reference areas and the area expected to be impacted by sediments.
River ecosystem (Floodplain dynamics, aquatic foodwebs, fish recolonization [enumeration, distribution, predicted movements, genetic work])
Floodplain dynamics Pess, Beechie, LEKT, USGS, USFWS
- Channel age, connectivity, distribution
- Riparian vegetation diversity
- Kloehn et al 2008, Influence of dams on river-floodplain dynamics in the Elwha River, Washington. Northwest Science 82.
- Trout dominate surface water channels; Coho dominate in groundwater channels.
- George snorkels to measure residual pool depth, pebble counts and spawnable area and fine sediment sampling.
- 14 monitoring sites (7 below Elwha, 7 above Elwha; 2 mainstem, 2 tributaries, 10 floodplain)
- Morley, Coe, LEKT, USGS
- Nutrient Limitation, primary production, benthic invertebrate, marine derived nutrient transfer
- Morley et al. 2008. Benthic invertebrate and periphyton in the Elwha River basin: current conditions and predicted response to dam removal. Northwest Science 82.
- Duda et al., 2010. Isotope patterns.
- River is nutrient limited in non-winter months by nitrogen and secondarily phosphorous
- Elwha Fish Weir (species, sex, length, Tags (CWT, ?), scales, fin clip
- Blue View (Keith Denton and 1 other) is helping with enumerating Coho when fish weir is non-functional in high flow periods.
- Genetics of O. mykiss (resident rainbow and steelhead): see 3 gene pools or distinct populations: 3 native, 1 non-native (lower, resident, Trout Lake); no hatchery influence upstream of dams.
- McMillan looking at resident rainbows vs anadromous steelhead metrics.
- Kinsey Frick: Spawning movements of adult salmonids during dam removal. Catching fish in weir, tagging with radio tags, and releasing above
- 20 chinook released above dam; relocated 3-4 that had found spawning habitat in lower Elwha while some returned to spawn below the dam. Plans to tag more chinook as well as other salmonids.
11:45 — QUESTION AND ANSWER SESSION:
- Do you have plans to monitor hatchery stock status and impacts? At recent symposium, Norm Dicks mentioned that Chambers Creek (non-native steelhead) may be an issue, plus it is also focus of current law suit.
- There used to be spring and fall chinook. The spring were the big ones and likely are extinct. Will spring chinook be brought in or are fall chinook expected to fill in that gap?
- Me: How will chinook recovery be managed? Why was this approach taken, while more direct facilitation was done on White Salmon?
- The Condit removal is supposed to take 3-5 days; why should the Elwha take so much longer?
Big Elwha salmon (from LEKT?)
Questions I didn’t ask:
- What is evidence of 100 lb chinook? Have all sources of evidence been pursued? (Middens? Interviews? Historic photographs? Written accounts? Inference from tree ring growth rate and/or isotope ratios?) What is the source and story of the photo in your title slide (shown at right and credited to LEKT = Lower Elwha Klallum Tribe)?
- Are sediment size distributions similar in Quinalt to in the Elwha? Are such distributions governing invertebrate community structure?
- Why is recovery expected to take decades? (Urgency is lent by the SRKW’s need and preference for chinook.)
Follow research to do:
- Frick re plans for upper Glines?
- Is “out-planting” mentioned in the EIS?
- Ask Eric Anderson how long fall chinook would take to fill niche of spring chinook.
- Surely there are studies of how fast adaptation occurs from other removals or mitigation efforts?
- How much sediment is behind Condit?
Clipping from the NWFSC talk announcement web site:
|Date and Time:
||October 06, 2011, 11:00-12:00 Pacific Time Zone [Check U.S. Time clock for your local time]
||NOAA Northwest Fisheries Science Center (NWFSC) (2725 Montlake Boulevard East, Seattle, WA 98112; Map to NWFSC), Room: Auditorium.
||Sarah Morley (Research Ecologist, Watershed Program, Fish Ecology Division, NOAA NWFSC)
|OneNOAA Seminar Sponsor:
||NOAA NWFSC Monster Seminar JAM
||The removal of the Elwha River dams on the Olympic Peninsula of Washington State is a unique opportunity to examine ecosystem recovery on a watershed scale, and has spurred collaborative research efforts among divergent groups. For the past century, the two dams have blocked the upstream movement of anadromous fish to over 90% of the watershed, and restricted the downstream movement of sediment, wood, and other organic materials to the lower river and estuary. Populations of all five Pacific salmon species and steelhead in the Elwha are critically low, habitat complexity decreased in the middle and lower river, and downstream coastal habitats are sediment starved. Simultaneous deconstruction of the two dams began in September 2011 and will take three years to complete. During and after that time, researchers are examining dam removal effects in three geographic regions: the soon-to-be former reservoirs, across the river floodplain, and in the nearshore environment. Short-term (< 3 years post dam removal) monitoring is focused on the projected downstream transport of approximately four million cubic meters of fine sediments accumulated in the reservoir deltas, associated peaks in river and estuary turbidity levels, and re-vegetation of the reservoir themselves. Longer-term effects of dam removal (> 5 years) to be evaluated are the delivery of gravels and cobbles to the lower river and nearshore, the re-establishment of a natural wood delivery regime, the re-colonization of the upper watershed by anadromous fish, and the associated effects on aquatic and riparian foodwebs. This talk will provide an overview of the Elwha restoration project, but particularly highlight the research of NWFSC researchers examining river floodplain dynamics, salmon re-colonization, and aquatic foodwebs. The removal of the Elwha Dams has been long awaited by the Lower Elwha Klallam Tribe and others and will provide ongoing learning opportunities for future dam removal efforts across the United States and elsewhere.
|About the Speaker:
||Sarah Morley is a field ecologist whose research focuses on biological assessment-using biota to evaluate the condition of a place and better identify the causes of degradation. Within this broad framework, she has conducted research on the effects of urbanization on the health of Puget Sound streams and evaluated the effectiveness of restoration actions on streams and rivers across the Pacific Northwest. Recent projects include examining the effects of shoreline armoring on the biota of the Duwamish River estuary, the effectiveness of green stormwater management strategies in improving urban stream health, and aquatic foodweb effects of dam removal on the Elwha River. Sarah holds a B.S. in Environmental Science from U.C. Berkeley and an M.S. in Aquatic and Fisheries Sciences from the University of Washington. She has been a member of the Watershed Program at the Northwest Fisheries Science Center since 2000. http://www.nwfsc.noaa.gov/research/staff/display_staffprofile.cfm?staffid=649
- Duda, J. J., H. Coe, S. A. Morley, K. Kloehn. 2011. Establishing Spatial Trends in Water Chemistry and Stable Isotopes (d15N and d13C) in the Elwha River Prior to Dam Removal: A Foodweb Perspective. River Research and Applications. doi:10.1002/rra.1413
- Kloehn, K.K., T.J. Beechie, S.A. Morley, H.J. Coe, and J.J. Duda. 2008. Influence of dams on river-floodplain dynamics in the Elwha River, Washington. Northwest Science 82: 224-235.
- Morley, S.A., J.J. Duda, H.J. Coe, K.K. Kloehn, and M.L. McHenry. 2008. Benthic Invertebrates and Periphyton in the Elwha River Basin: Current Conditions and Predicted Response to Dam Removal. Northwest Science 82:179-196.
- Morley, S. A., P. S. Garcia, T. R. Bennett, P. Roni. 2005. Juvenile salmonid (Oncorhynchus spp.) use of constructed and natural side channels in Pacific Northwest Rivers. Canadian Journal of Fisheries and Aquatic Sciences, 62:2811-2821.
- Pess, G. R., S. A. Morley, J. L. Hall, R. K. Timm. 2005. Monitoring floodplain restoration. Pages 127-166 in Roni, P. (Ed.) Methods for monitoring stream and watershed restoration. American Fisheries Society, Bethesda, Maryland.