Ecosystem Response to the Removal of the Elwha River Dams
Вставка
- Опубліковано 21 сер 2024
- Joint Committee home: units.fisherie...
Joint Committee Webinars page: units.fisheries.org/fishpassagejointcommittee/activities/webinars/
Webinar Essentials:
Ecosystem Response to the Removal of the Elwha River Dams
George Pess, Ph.D., Program Manager, Watershed Program at the United States National Oceanic and Atmospheric Administration (NOAA) Northwest Fisheries Science Center (NWFSC)
Tuesday, December 6 2022
One ecosystem restoration technique that can have a large-scale effect is dam removal. This single action allows for the re-connection of ecosystem processes such as upstream and downstream organism movement, the rapid transformation from lentic to lotic conditions in former reservoirs, rapid shifts in community structure and food webs, and accelerated habitat creation through sediment deposition.
Worldwide stream and watershed restoration efforts cost billions annually. These projects are typically local-scale activities that do not have a measurable effect on ecosystem function or services. In this webinar, George will present the results from the largest dam removal ever undertaken, and the measurable ecosystem changes which include:
-The release and subsequent downstream transport of tens of millions of metric tons of sediment from former reservoirs and the transformation and rebuilding of estuarine and riverine habitats.
-The resumption of free passage for aquatic organisms and re-established anadromous fishes to areas that have been void of such species for 100 years, and the rapid increase in salmonid life history diversity.
-Short-term effects due to large changes in sediment supply which temporally resulted in reductions in Chinook salmon productivity.
-Increased marine-derived nutrients entering the food webs and altering the migration patterns and fecundity of an aquatic songbird.
George has worked in fisheries since 1989 (A.B. in Economics and Environmental Science, Bowdoin College 1987, an M.S. in Forest Science, Yale University 1992, and a Ph.D. in Aquatic and Fishery Sciences, University of Washington, 2009). His primary research interest has been the examination of natural and land-use effects on salmon habitat and salmon production and his current research includes the ecosystem response to the removal of the Elwha River dams. A program manager for the watershed program at the United States National Oceanic and Atmospheric Administration (NOAA) Northwest Fisheries Science Center (NWFSC), he is also an affiliate professor at the University of Washington School of Aquatic and Fishery Sciences.
The Joint Committee on Fisheries Engineering and Science hosts a free webinar series as part of its mission to engage scientists and engineers on topics related to fish passage. The Committee consists of members of the American Fisheries Society Bioengineering Section (AFS-BES) and the American Society of Civil Engineers Environmental and Water Resources Institute (ASCE-EWRI). It was established in January 2011 to foster communication between the two groups, provide opportunities for engineers and biologists to share relevant knowledge and learn from one another, and to collaborate on projects related to fish passage.
For job announcements, resources on fisheries science and engineering, and more, please visit our website at units.fisherie...
Great to see the Elwha recovery and removal of antiquated dams. It will be interesting to see the restoration of the Klamath.
Outstanding presentation, question and answer session...there is so much we don't know yet but the trend is clear how quickly a river-riparian system will reboot after dam removal...I am most impressed with the Chinook salmon strays returning after the sediment flows have subided
Appreciate any insights, the Webinar, and your analysis, it will help to redefine Analysis, variable factors, recruitment Status of studied Species, that is great!
Great job
Great job, and more flora means more bees and honey.
Steelhead are the best jumpers, can return to saltwater after freshwater spawning, so that is excellent news ir Research.
Did they make a LIDAR scan of the area before and after the dams were removed? If you have scans, it may help you compare sediment movement over time.
True.
Sediment is not always a bad thing, but I do share some of those worries. Klamath Dam Removals will do similar factors, yet for the removals.
❤
Turbidities do exist, and help to hide fish, salmonids for example. Clear water can be hard to fish as the fish may see you.
Good, would expect Hatchery fish to do so as I personally daw the lower Elwha and how complex those "Hatcheries" are, so hopeful.
WOW
I wonder has there been any consideration reintroducing beavers to the river? They could be especially useful in the areas where the dams used to exist restoring riparian habitat, slowing water and creating environments for fish to breed.
Love the name -
In '72 I was at Elkhorn camp 11 miles in on the Elwha trail and there was a logjam full width of the river. Probably 80 - 100 feet across. It was huge. Beaver in smaller streams maybe.
Beaver, also, are very able to introduce more woody debris into river channel creating more substrate for many invertebrates life cycles. This will improve aquatic insect populations as they make use of submerged woody debris, leaf matter, sheltering options, and substrate to anchor to. Beaver actively bury cut limbs, branches in the muddy bottom for winter feeding purposes leading to increase cover and feeding opportunities for juvenile fishes of all species.
Were salinities being taken before the dams were removed, that would be an excellent series for prior data to exam.
Does the birth stream marker in pink salmon stay in the fish for shorter than salmon or steelhead? Smaller returns could be from lost markers?
What of the definition of an estuary? Seems like saltwater intrusion from the river mouth proves Salinities in the lowest part of the river went up. This would benefit juvenile anadromous fishes, organisms, and saline tolerant plant Species, I would guess.
Many plant species would not be very tolerant to saltwater intrusion, and I do know sharks( dogfish) appeared in lower Elwha.
Skallam Tribe does hire many Biologists, and those Hatcheries must have had active Scientists, so I am just staying my personal knowledge. Was in area when dams wete being removed, hearing complaints of loss of hydropower, though not unsympathetic, but must guess if any co-generation of electricity being used now.
Pinks would ne almost always spawning in the lower reaches, as they rarely spawn in th mid to upper reaches, according to WA, Ca, and OR populations, north in Canada and Alaska inland lakes or other options pinks may move up furyher for other reasons.
I have done some bed score analysis on the Trinity River where cobbles, spawning strata we're put into the river to improve spawning areas known to be suitable in the Mid(!)- Trinity below Burnt Ranch. The Trinity River in CA, does have at least Lewiston Dam upstream of Burnt Ranch.
Above 23 ' C, most salmonids, trrout, whitefish, etc. cause Hazards for these Species as they are not tolerant of warmer water.
Fisheries engineering 😂😂😂 nature engineers fisheries not socially awkward humans.
I think they should remove ALL DAMS!. Or at least, let the fish back upstream! What were they thinking? Dams were made to starve out the undesirable people, downstream. Man made lakes cover Native American Villages. I see this in Lake Mead, Shasta, Folsom, Oroville, and many other man made lakes. The drought really exposed the truth. I love the dam removal. Nature really needs the water to flow. Fish can not spawn, unless they can get upstream. Dams ruin the ecology, for generations.
Well Grandma, I bet you can't even carry a bucket of water from a river much less live off the land. Perhaps you should give up all modern conveniences instead of benefiting from things that wouldn't exist without dams?