Steelhead, Chinook salmon, lake sturgeon, or suckers are some of the fish species who require migrating to spawning grounds and are particularly susceptible to declines from impassable river obstructions. The very best fish passage is the complete removal of the barrier.
When it is not possible to remove these obstructions, fishways or fish ladders can be installed to allow fish passage over or around the barrier.
Flows, energy dissipation, resting areas, drop between pools (fishway slope), attraction velocities, entrance locations, and space in pools are just some of the factors that need to be considered when designing a ladder.
The Buckley Dam was built in 1911 and is showing its age. Salmon trying to get upstream impale themselves on exposed rebar and damaged planks. Others struggle as they fail to locate or find space in the dams’ outdated fish trap. Even if they make it into the trap, they’re battered and bruised as they wait to get trucked upstream past the dam. The ones who finally make it upriver are so tired and injured that their chances of surviving are much worse than they should be.
The result is hundreds of thousands of dead salmon – including endangered species, like the Chinook. This terrible fish kill could be stopped if the Army Corps modernized the fish passage. Please urge them to stop dragging their feet and fix this old, defective dam.
Come Saturday evening, the five of us are gonna sit down and chat about the various tricks we’ve discovered to getting our askblogs out there. Did you know the best times to publish posts come around 8-10 AM and 2-5 PM Pacific Time? We’ll go into the whys of that and much, much more. The hope is that you’ll leave the panel room ready to bring that neglected askblog out of mothballs, or give your current one some TLC, because you’ve got a story in there that’s worth telling.
Bring your questions with you! We’ll have some time at the end for some Q&A, so long as you don’t ask us silly questions with obvious answers. Most of all, come out and meet us! We want to meet you just as much!
See you all there.
– Couch, DarkFlame, Chocolate Pony, Lovely Laughter, and Fisher
“Here is the full graph of Chinook salmon numbers from rivers from Calif. to Alaska, year by year, produced by the Center for Whale Research from data gathered from all available sources, correlated with Southern Resident orca mortalities year by year since 1976. The correlation is clear - when Chinook runs drop below about 4 million total, orca deaths increase dramatically, and by far the largest decline in salmon numbers is from the Columbia/Snake Watershed since the four Snake River dams began blocking up- and down-stream passage in the mid-1970s.
It’s time to remove the earthen berms beside those dams and let the Snake River run free again and rebuild Chinook runs so So. Resident orcas can survive and grow.
In drought-stricken California, young Chinook salmon are hitting the road, not the river, to get to the Pacific Ocean.
Millions of six-month-old smolts are hitching rides in tanker trucks because California’s historic drought has depleted rivers and streams, making the annual migration to the ocean too dangerous for juvenile salmon.
“The drought conditions have caused lower flows in the rivers, warmer water temperatures, and the fish that would normally be swimming down the rivers would be very susceptible to predation and thermal stress,” said Kari Burr, fishery biologist with the Fishery Foundation of California.
California has been trucking hatchery-raised salmon for years to bypass river dams and giant pumps that funnel water to Southern California and Central Valley farms.
But this year state and federal wildlife agencies are trucking nearly 27 million smolts, about 50 percent more than normal, because of the drought, according to the California Department of Fish and Wildlife.
Each spring, the Coleman National Fish Hatchery usually releases about 12 million smolts into Battle Creek, a tributary of the Sacramento River near Redding. But this year, it trucked 7.5 million of them to San Francisco Bay because the drought had made the 300-mile swim too perilous.
About a month ago I processed a king salmon from the Nushagak River. The tail was pretty impressive so I put it in salt. The bottom photo shows how the tail looked when I pulled it out today. The tail is still pretty oily and not all that desiccated. The most interesting thing to me, though, is how the red molting color has pretty much disappeared and the tail looks as though it came from a salmon before it got too far upstream.
I put the tail back into salt and maybe I’ll check on it again in another month. I wonder if this process will actually let it completely desiccate. Has anyone ever tried this process for fish or any other animal?
Competing Conservation Objectives for Predators and Prey: Estimating Killer Whale Prey Requirements for Chinook Salmon
Published: November 9, 2011
Ecosystem-based management (EBM) of marine resources attempts to conserve interacting species. In contrast to single-species fisheries management, EBM aims to identify and resolve conflicting objectives for different species. Such a conflict may be emerging in the northeastern Pacific for southern resident killer whales (Orcinus orca) and their primary prey, Chinook salmon (Oncorhynchus tshawytscha). Both species have at-risk conservation status and transboundary (Canada–US) ranges. We modeled individual killer whale prey requirements from feeding and growth records of captive killer whales and morphometric data from historic live-capture fishery and whaling records worldwide.
Salmon in America, particularly the Chinook salmon in
California, have long had their natural habitats influenced or destroyed by
humans in one way or another and are now facing extirpation (local extinction)
in California (Zeug et. al, 2011, p. 1). Back during the California gold rush
during the mid-19th century, many miners destroyed and altered the
rivers and stream in search for gold, impacting the home of Chinook salmon
across California (Zeug et. al, 2011). The miners and settlers during the gold rush
destroyed the watersheds and disrupted the ecosystems of the rivers;
over-fishing also posed a problem caused by the miners (Bland, 2015).
long after, during the 20th century, urbanization and development
led to the creation of dams and canals across America, including California.
The building of these dams impacted the natural river runs of Chinook salmon,
creating an unnatural barrier to their migration patterns (Zeug et. al., 2011).
These dams were extremely detrimental to the migration runs of the salmon and
even today pose a problem for Chinook salmon and other fish (Bland, 2014).
Although the dams were built for agricultural reasons, they have dried out many
rivers and blocked salmon from quite a number of their historic spawning areas
(Illustration of gold
miners in a river in California (left) courtesy of DGR News service | A damn
being built in New York (right), courtesy of New York History Blog)
Today, the salmon face
yet another problem: climate change, the California drought, and the allocation
of additional water supplies, which is causing salmon to die by the thousands,
while millions of their eggs are being destroyed each year (Bland, 2015). The
population continues to decline, having already decreased by 29% in the Pacific
Northwest: many streams which was formerly home to thousands of salmon are now
extinct of salmon (Zeug et. al, 2011, p. 7), such as the San Joaquin Valley
(Bland, 2015). A study published in Nature Climate Change predicts that Chinook
salmon “will likely experience ‘catastrophic’ population losses by 2100 to
warming water temperatures”, indicating the problem salmon face (Bland, 2015). Despite
potentially promising numbers in 2014, the data from 2015 is still incomplete
and does not look good for the trend reversing (Kinney, 2015).