Question 1: How do the agencies address spill at the dams?
Spill is a longstanding and fundamental part of the federal strategy to protect fish. The 2014 FCRPS BiOp builds in levels of spill that differ little from what the court ordered in 2005. The BiOp calls for spilling at all eight dams – generally 30 to 40 percent of the flow – from early April through August.
There are two instances, in late May and August, where the BiOp calls for spill operations that differ from operations that have been implemented since 2005. For the spring operation, the agencies are consulting with the regional sovereigns each year to review the latest biological information before finalizing it. In the summer, spill cessation is triggered by numbers of juvenile fish that are still migrating in the river. (Spill could continue through August in this case, too, depending on the timing of the fish migration.) Neither of these operations have been implemented to date.
Question 2: How many fish that return to the Columbia River are hatchery fish? What is the importance of wild fish to the species’ recovery?
The ESA’s goal is to recover wild, naturally reproducing stocks to self-sustaining levels. And while most returning adults – typically about 80 percent – are hatchery-origin fish, for most listed stocks the number of wild fish returning to the tributaries to spawn has also increased since the first listings in the 1990s. To view the abundance trends for ESA-listed fish, click here.
Question 3: What does NOAA Fisheries’ ESA analyses say about the status of listed salmon and steelhead?
NOAA analyzes several factors to assess the status of the fish, including number of returning adult fish (or abundance), productivity of returning adults and population growth rate. NOAA’s most recent analysis showed that abundance has increased at the same time that, for some populations, productivity has declined. Sometimes reductions in productivity follow high abundance years because habitat capacity has been reached – in other words, there is only so much habitat available for fish to use. This is one reason why productivity can vary.
The region is well into a 10-year effort under the 2008 BiOp and the Columbia Basin Fish Accords to implement one of the largest habitat restoration projects ever conducted. Since 2007, the Action Agencies and their partners have re-opened or improved access to over 2,200 miles of rivers and streams that human-made barriers had closed to fish for decades. This is more than the length of the Columbia River.
Question 4: What is the estimated juvenile fish survival through the dams?
The BiOp sets performance standards for average survival through individual dams of 96 percent survival for spring migrating fish and 93 percent survival for summer migrants. In 2012, scientifically designed tests at Little Goose, Lower Monumental, McNary, John Day, The Dalles and Bonneville dams demonstrated that the dams are all on track to achieve these performance standards. The agencies are continuing to assess the improvements for fish passage at the dams.
Question 5: Snake River fish migrate through eight dams and reservoirs. What’s the survival rate through the entire hydrosystem?
In 2013, the NOAA Science Center estimated survival for migrating juvenile salmon through all eight dams and reservoirs on the lower Snake and Columbia Rivers at 52.5 percent for spring chinook and 50 percent for steelhead. (Estimates of 2014 survival are still preliminary.)
Surface passage structures and spill are helping to reduce the time it takes the juvenile salmon and steelhead to travel through all the dams and reservoirs and reach the estuary. NOAA scientists estimate that spill and surface passage have reduced total travel time by 5 days, contributing to increased survival for fish that are migrating in-river. Scientists believe that the timing of juvenile fish reaching the estuary is critical to their health and survival.
Even in free-flowing river segments, such as the stretch of the lower Snake River above Lower Granite Dam, juvenile salmon and steelhead mortality is substantial. NOAA Fisheries calculated, for instance, that in 2011 wild chinook survival ranged from 33.5 (for those fish tagged and released 300 kilometers above the dam) to 94.3 percent (for those fish tagged and released 51 kilometers above the dam).
Question 6: What percentage of juvenile fish go through the turbines when they pass the dams?
With the addition of highly effective fish passage and fish guidance structures in recent years, very few juvenile fish go through the turbines as they pass FCRPS dams on their way to the ocean. The most recent tests – at Little Goose, Lower Monumental and McNary dams in 2012 – showed turbine passage ranging from an average of 2 percent to an average of 8.9 percent, depending on the dam and the species of fish.
These same studies estimate survival through the FCRPS turbine routes at these dams at 77 percent to 93.2 percent, again depending on the dam and species of fish.
Question 7: Can habitat improvements help endangered and threatened fish in the Columbia Basin?
Farming, logging and other human development have severely altered much of the salmon and steelhead habitat in the Columbia River Basin. Years of scientific studies point to the role that habitat restoration can take in helping to improve the survival, productivity and abundance of salmon and steelhead (NRC 1996; Stouder et al. 1997; Lichatowich 1999; Knudsen et al. 2000; Lynch et al. 2002; Montgomery et al. 2003; Wissmar and Bisson 2003). Habitat restoration can also help address potential future impacts from climate change (ISAB 2007-2).
The federal agencies focus their habitat restoration actions on key populations in the Basin that are in greatest need and that can benefit most from habitat improvements. Habitat actions address key “limiting factors” for these populations, identifying specific stream reaches that have reduced flow in the summer, for instance, or culverts or blockages that keep salmon out of spawning areas.
Local expert panels use scientific data from sources such as action effectiveness monitoring, reach assessments and monitoring of fish status and trends to estimate the biological benefits of all habitat improvement projects with Action Agency involvement. A scientifically-designed process for identifying new projects and calculating how they will affect fish abundance, productivity and other indicators of fish health ensures that the projects selected are the ones that will most benefit fish.
Question 8: Were there once annual salmon runs of 30 million fish in the Columbia River Basin?
The most likely estimate is much lower. A two-year review of historic salmon numbers by the Northwest Power and Conservation Council examined all estimates on record and concluded that run sizes ranged from 10 to 16 million fish prior to development. This figure is widely accepted and cited in the literature as the most accurate figure. Of course, run sizes have always fluctuated widely, depending on river and ocean conditions.
Question 9: Can salmon and steelhead access the pristine high-elevation spawning habitat above the Snake River dams?
Yes. All four Snake River dams were built with highly effective adult fish passage facilities. In 2012, more than 280,000 chinook, steelhead and sockeye salmon returning to spawn were counted going past Lower Granite Dam, the last of the four federal dams on the lower Snake River.
Question 10: How does the BiOp consider climate change and its potential effects on salmon and steelhead?
The BiOp recognizes predictions from independent science boards that air temperatures have risen in the Pacific Northwest and that they will continue to rise by .1°-.6°C every decade over the next century. The Action Agencies use those scientists’ recommendations to develop a number of actions in response to the BiOp. For example, cold water releases from upstream reservoirs help cool water during the summer. Planting and revegetation can help provide shade. Reestablishing natural stream channels that meander and placing logs in streams provides cool water refuges during the heat of summer. Because they can help keep water cool and clean, projects like these are an important hedge against the longer term effects of climate change.
Question 11: Is the FCRPS BiOp supported by those in the region?
The BiOp is supported by 3 states, 6 tribes, river users and electricity customers.
Question 12: Can the power benefits of the four lower Snake River dams be replaced with emissions-free power sources?
The energy and capacity benefits of the four lower Snake River dams cannot be replaced with energy efficiency or renewables. Northwest Power and Conservation Council found that replacing the power benefits of the four lower Snake River dams would increase carbon emissions by three million tons per year and require that 437 average megawatts of new natural gas-fired power plants be built. For more information on the power benefits of the four lower Snake River dams, see this Bonneville Power Administration fact sheet.
Question 13: Is predation on juvenile salmon by cormorants and terns a serious problem? What are the federal agencies doing to address it?
Caspian tern and double crested cormorant predation is a major cause of juvenile salmon mortality in the Columbia River Basin. The largest concentration of these birds – and where most of the juvenile fish are consumed – is in the Columbia River estuary below the federal dams. The birds are protected under the Migratory Bird Treaty Act, so management actions must consider these protections.
The Corps has constructed several alternative habitats for terns, attracting more than 1,000 mating pairs away from East Sand Island in the estuary, where the tern population in 2013 was about 7,400 breeding pairs. The Corps has also reduced the size the East Sand Island nesting site by two thirds since 2009. The redistribution protect is expected to protect an estimated 2.4 million to 3.1 million additional juvenile salmon each year.
Cormorant predation has increased in recent years. In 2013, cormorants on East Sand Island consumed an estimated 16.3 million juvenile salmon and steelhead as they migrated to the Pacific Ocean. The Corps recently completed an Environmental Impact Statement to identify alternatives to manage cormorant predation and expects to pursue management actions in 2015.
Avian predation wires installed at dams are an effective deterrent to gulls and other birds that hunt near the tailraces of dams to prey on the juveniles as they pass. Wires installed at John Day Dam in 2010 reduced gull predation by an estimated 76 percent.
Question 14: Do endangered orcas depend on Columbia River chinook salmon for food?
Orcas require abundant Chinook stocks West Coast–wide, likely including stocks from the Columbia River. In the summer, when they are off the West Coast of the U.S. and Canada, NOAA studies have found that more than 90 percent of their diet is Chinook salmon from the Fraser River in British Columbia. Orcas spend about half the year far out at sea, where scientists do not know what they are eating.
Federally funded hatcheries in the Columbia River Basin produce far more chinook than the number affected by the dams, offsetting any reduction in the orca prey base. NOAA has concluded that the dams’ operation is not likely to adversely affect killer whales
Question 15: Do US taxpayers fund the Columbia Basin salmon program?
Most of the funding for Columbia Basin salmon restoration comes from sales of hydropower generated at the federal dams. BPA markets this power to 130 publicly-owned utilities in the Pacific Northwest .
Question 16: What is meant by “delayed mortality”?
Delayed mortality is a term for harm caused when an animal survives one event or circumstance but incurs damage that only shows up much later with illness or death. With Columbia Basin salmon and steelhead, the term is commonly applied in situations such as barging or dam passage of salmon or steelhead smolts. (The term “latent mortality” is generally used to more specifically to apply to the effects of dam passage.) While most or all of the fish might survive the barge or get safely past the dam, the delayed mortality hypothesis holds that a smolt is less healthy than it would be otherwise and therefore less likely to survive in the ocean and return as an adult.
Independent scientists have repeatedly found that it is not scientifically possible to measure the impact of dams on delayed mortality. Instead, scientists say it would be much more productive to focus be on ways to improve smolt survival with the current dam passage and transport systems, which is what the federal agencies are doing.