News Room
Office of Communications, Education & Outreach
1807 13th Street, Suite 104
Sacramento, CA 95811
(916) 322-8911
Facts on Common Topics
Salmon Fishery Changes - News & FAQ
Articles
- DFG Using State-of-the-Art Technology to Tag and Track Salmon
- Marine Management News: Collaborative Research Improves Management of California's Chinook Salmon
- Acoustic Tagging in San Joaquin River Seeks to Solve Salmon Mystery.
News
- October 30, 2009
DFG Announces Limited Central Valley Recreational Salmon Opener - June 10, 2009
Notice of Refund of 2009-2010 Commercial Salmon Fishing Fees (PDF) - May 28, 2009
Catch and Release Salmon Fishing No Longer Allowed in the Central Valley Basin - May 5, 2009
Federal Register: NMFS Final Rule for 2009 Ocean Salmon Fisheries (PDF) - April 23, 2009
Summary of 2009 California Ocean Salmon Seasons - April 21, 2009
The California Fish and Game Commission voted unanimously to prohibit commercial and recreational salmon fishing in state ocean waters, which extend three miles off the coast, through August 28, 2009. There will be a 10-day ocean sport fishery in the Klamath Management Zone (Horse Mountain to the California-Oregon border) from August 29 through September 7, 2009. All ocean salmon fishing will be closed after September 7 for the remainder of the year. The Commission took this action to protect Sacramento River fall run Chinook. At this meeting, the Commission also adopted Central Valley and Klamath-Trinity river recreational salmon seasons. - April 8, 2009
PFMC Sets 2009 Salmon Seasons (PDF) - March 31, 2009
PFMC to Host Public Meeting on Salmon Season Options- Hearing Summary (PDF)
- March 12, 2009
PFMC Chooses Options for 2009 Salmon Season (PDF) - February 25, 2009
PFMC Releases Salmon Abundance Forecasts for 2009 Fishing Seasons (PDF) - February 23, 2009
DFG to Host Public Meeting on Salmon- Agenda and Meeting Materials (PDF, includes calendar of events and contact information)
- February 18, 2009
Ocean Salmon Season Setting Process Begins: Estimates of 2008 Sacramento River Fall Chinook Escapement At All Time Low
For 2009 salmon management news, visit the
Pacific Fishery
Management Council (PFMC) website.
Frequently Asked Questions
- GENERAL FISHERY MANAGEMENT
- What are the California salmon seasons in 2009?
- Why are salmon seasons restricted again this year?
- Who sets ocean salmon seasons off the California coast?
- Who sets river salmon seasons in California?
- Why is it so complicated to set a simple salmon season?
- Why do I have to pay full price for a license when there is only a limited sport salmon fishery?
- What can I do to help salmon?
- OCEAN SALMON
- RIVER SALMON
- What are the salmon seasons for the Sacramento River system?
- How many fall Chinook returned to the Sacramento River system last year?
- What are the salmon seasons for the Klamath and Trinity River systems?
- Will everybody go to the Klamath River to fish for salmon, creating a crowded situation and potentially over-harvest those fish?
- How many fall Chinook returned to the Klamath and Trinity River systems last year?
- LAWS & ENFORCEMENT
- TRIBAL FISHERIES
- SALMON BIOLOGY
- What is a “run” and what Chinook salmon runs are in the Central Valley?
- What are the primary mortality factors for young fish going out to the ocean?
- What are the primary mortality factors in the ocean? What is the main mortality factor affecting their return?
- Where can I find information on Delta health issues and salmon smolt outmigration?
- CONSERVATION EFFORTS
- HATCHERY PRACTICES & GOALS
- What are the DFG's hatchery Chinook salmon production goals?
- Is DFG meeting production goals for both mitigation and enhancement for Chinook salmon?
- What are mitigation fish and what are enhancement fish?
- What are acclimation net pens and why are we using them?
- Why can't young salmon be held in the hatcheries until there is net pen space available?
- Why can't the DFG make more salmon at hatcheries?
- Have there been any changes in salmon hatchery practices?
- POSSIBLE FACTORS IN THE DECLINE OF SALMON
- What are the possible factors in the decline of salmon?
- How did this situation get so dire?
- Why are the Central Valley Chinook salmon more affected than salmon from other areas?
- Is there a relationship between other species population declines and the salmon decline?
- Is some of the decline related to smolts not making it out of their juvenile river habitat?
- Are stripers eating all of the young salmon before they can make it out of the river system?
- Is the health of the Delta a factor?
- Could sea lions be to blame for the decline? If so, are there any means to control them?
- Did poaching cause this decline?
What are the California salmon seasons in 2009?
Sport and commercial ocean salmon seasons are closed through August 28, 2009. There will be a 10-day ocean sport fishery in the Klamath Management Zone (Horse Mountain to the California-Oregon border) from August 29 through September 7, 2009. A limited in-river salmon season was considered by the California Fish and Game Commission at the May meeting, and it decided to leave open the Sacramento River between the Hwy 113 bridge near Knight's Landing and just below the Lower Red Bluff (Sycamore) Boat Ramp from November 16 through December 31. Available data suggest that this fishery will target Sacramento River late-fall Chinook and will have negligible impacts on Sacramento River fall Chinook. The Klamath-Trinity River Basin will have a salmon sport fishing season for Klamath River fall Chinook salmon that begins August 15. Check the regulations booklet for specific fishery regulations.
- DFG Regulations Web page
- DFG Ocean Salmon Seasons Web page
- Central Valley Rivers Sport Fishing Regulations
- Klamath-Trinity Rivers Sport Fishing Regulations
Why are salmon seasons restricted again this year?
The closures are aimed at conserving Sacramento River fall Chinook salmon. Historically, this stock has made up the bulk of the salmon caught in California's ocean salmon fisheries and within the Central Valley. At least 122,000 to 180,000 adult salmon must return to spawn in the Sacramento Basin rivers on an annual basis to ensure the sustainability of the stock and to meet the egg-take needs of state and federal salmon hatcheries. Approximately 122,050 Sacramento River fall Chinook adult spawners are projected to return in the fall of 2009.
Who sets ocean salmon seasons off the California coast?
The California Fish and Game Commission sets the salmon seasons in all California waters, including all coastal waters extending three miles offshore. The National Marine Fisheries Service sets all seasons beyond the three-mile limit out to 200 miles. California is a member of the Pacific Fishery Management Council (PFMC) and presents data and information for review during its season-setting process. The PFMC makes recommendations to the National Marine Fishery Service for ocean salmon seasons. Once the federal season setting process is completed, the California Fish and Game Commission normally adopts a similar set of regulations for state waters.
- PFMC Salmon Management Page
- California Fish and Game Commission Policy on Salmon
- Pacific Coast Salmon Plan
Who sets river salmon seasons in California?
The California Fish and Game Commission sets the salmon seasons in all California waters. DFG recommends seasons to the Commission. California's river salmon seasons follow conservation goals and harvest guidelines established by the Pacific Fishery Management Council and any restrictions under the Endangered Species Act.
Why is it so complicated to set a simple salmon season?
The life cycle of salmon is complex which makes setting a fishing season complex. Salmon are affected by a wide variety of factors in the ocean, rivers and streams, including ocean and climatic conditions, dams, habitat loss, urbanization, agricultural and logging practices, water diversion, and predators (including humans). Since salmon migrate long distances in the ocean, managing the ocean salmon fisheries is an extremely complicated task. Different stocks of salmon mix at different times and locations further complicating management issues. Federal legislation enables the Pacific Fishery Management Council to address fisheries management issues and recommend seasons to the National Marine Fisheries Service.
This year ocean salmon seasons are drastically reduced off the California coast to protect the Sacramento River fall Chinook salmon. These fish make up the bulk of salmon caught off the California and Southern Oregon coast and need protection based on low returns of adult salmon the last two years and predicted low returns for this fall.
- Pacific Coast Salmon Plan
- PFMC Sets 2009 Salmon Seasons (PDF)
- Stock Abundance Analysis for 2009 Ocean Salmon Fisheries
Why do I have to pay full price for a license when there is only a limited sport salmon fishery?
At this critical time, funding from the sale of sport fishing licenses is vital to the management and protection of California's salmon resources. Funding from license fees is used to employ wardens and biologists, and to operate hatcheries; thus any reduction in license revenue could hinder the DFG 's ability to manage and protect our salmon resources, potentially causing further damage to the salmon population.
While salmon seasons have been drastically reduced in the ocean and Sacramento River Basin, the Klamath and Trinity rivers are still open to salmon sport fishing. The DFG understands the frustration of California salmon anglers, but these temporary closures will help to ensure the future of salmon fishing for present and future generations.
Many other fishing opportunities still exist for California anglers with a fishing license. California's steelhead and trout fishing remains to be some of the best in the West and there are numerous lakes and streams that have great black bass fishing. There are other unique opportunities such as sturgeon and striped bass fishing in the Delta, in addition to halibut, rockfish and lingcod fishing in marine waters. When you add in Dungeness crab, abalone, clam, scallop, and spiny lobster sport fisheries, a California fishing license is still one of the better values on the Pacific Coast.
What can I do to help salmon?
California's salmon are managed through open, public processes that are guided by many state and federal laws. One way to help our salmon is to get involved by learning how salmon are managed. There are many other ways to get involved, including attending meetings, writing letters, or talking with your Council representative.
Ocean Salmon
What are the California ocean salmon seasons in 2009?
In April 2009, the Pacific Fishery Management Council (PFMC), the National Marine Fisheries Service, and the California Fish and Game Commission adopted a limited sport ocean salmon season north of Horse Mountain to the California-Oregon border. The fishery will open August 29 for all salmon except coho, and continue through September 7. The minimum size limit is 24 inches total length, with a two fish per day bag limit.
Ocean salmon fishing south of Horse Mountain is closed to protect Sacramento River fall Chinook.
In 2010, the area south of Horse Mountain is scheduled to open for sport salmon fishing on Saturday, April 3. Please check the 2009 California Sport Fishing Regulations Supplement for specific fishery regulations.
Why are fishery restrictions still needed?
In 2008, approximately 66,200 Sacramento River fall Chinook adults returned to spawn in the Sacramento River Basin. This is the lowest return of Sacramento River fall Chinook on record and is well below the annual conservation objective of 122,000-180,000 adult spawners required by the PFMC's Salmon Fishery Management Plan.
With only 4,000 Sacramento River Fall Chinook age 2 fish (also known as jacks) returning in 2008, fishery scientists forecasted approximately 122,200 Sacramento River fall Chinook adults (ages 3-5) remaining in the ocean during 2009. Thus, even without any additional ocean and in-river fishing in 2009, the ocean abundance of Sacramento River fall Chinook salmon was only a couple hundred fish above their spawner goal.
Since Sacramento River fall Chinook salmon contribute significantly (generally 80 to 90 percent) to California's ocean sport and commercial fisheries, as well as to Oregon's fisheries south of Cape Falcon (60 to 80 percent), the PFMC, National Marine Fisheries Service and Fish and Game Commisson have severely constrained ocean salmon fisheries in California and much of Oregon to protect Sacramento River fall Chinook.
- Pacific Coast Salmon Plan
- Historical Record of Spawning Escapement (PDF)
- Stock Abundance Analysis for 2009 Ocean Salmon Fisheries
Which salmon stocks are caught off the coast of California?
The majority of salmon caught off the coast of California are Central Valley Chinook (fall and late fall runs). There are also small numbers of Sacramento River winter Chinook (endangered), Central Valley spring Chinook (threatened), California coastal Chinook (threatened), Klamath Basin Chinook (fall and spring run), and northern Chinook stocks from Oregon and Washington caught in California's fisheries. Generally, the closer the fishery is to the mouth of the Klamath River, the higher the contact rate (the fraction of the population brought to the boat) with Klamath Basin stocks. Contact with Oregon and Washington salmon stocks generally increases as you move north.
Ocean salmon 2009 preseason process: Calendar of events and contact information
- 2009 Ocean Salmon Fisheries Management (Calendar and Contact Information)
River Salmon
What are the salmon seasons for the Sacramento River system?
The California Fish and Game Commission approved a limited sport fishery for late-fall Chinook salmon on the Sacramento River with a two week delay compared to last year's fishery. The open area is from Highway 113 at Knight's Landing to the Lower Red Bluff (Sycamore) Boat Ramp from November 16 to December 31. There is a one salmon bag and possession limit during this time. Also new for 2009, catch and release fishing for salmon is now illegal when salmon fishing is closed for all Central Valley areas. This new measure and the two week delay increases protection for Sacramento River fall Chinook salmon. Available data suggest that this fishery will have negligible impacts on Sacramento River fall Chinook.
How many fall Chinook returned to the Sacramento River system last year?
In 2008, approximately 66,200 Sacramento River fall Chinook adults returned to spawn in the Sacramento River Basin. This is the lowest return of Sacramento River fall Chinook on record and is well below the annual conservation objective of 122,000-180,000 adult spawners required by the PFMC's Salmon Fishery Management Plan.
With only 4,000 Sacramento River Fall Chinook age 2 fish (also known as jacks) returning in 2008, fishery scientists forecasted approximately 122,200 Sacramento River fall Chinook adults (ages 3-5) remaining in the ocean during 2009. Thus, even without any additional ocean and in-river fishing in 2009, the ocean abundance of Sacramento River fall Chinook salmon was only a couple hundred fish above their spawner goal.
- Historical Record of Spawning Escapement (PDF)
- Stock Abundance Analysis for 2009 Ocean Salmon Fisheries
- Pacific Coast Salmon Plan
What are the salmon seasons for the Klamath and Trinity River systems?
The forecast of returning Klamath River fall Chinook is more than are needed to meet conservation and reproduction goals. Since the ocean and Sacramento River Basin salmon season is very restricted, the Klamath River fall Chinook return will provide fishing opportunity in 2009. The fishery opens on August 15, 2009. Please check the 2009 California Sport Fishing Regulations Supplement for specific fishery regulations.
Will everybody go to the Klamath River to fish for salmon, creating a crowded situation and potentially over-harvest those fish?
The Klamath River fishing is closely regulated with a harvest quota, and fish checkers sample angler's catch each day. It will not be over-harvested by sport anglers, but it may get crowded. Boat launches and spots on the river with good fishing access are expected to fill up. Access along highways and side roads is limited. Boat launching facilities can be packed during peak steelhead season, and will likely be full during this year's salmon season.
How many fall Chinook returned to the Klamath River system last year?
The Fishery Management Plan requires that at least 35,000 Klamath River fall Chinook adults return to spawn in natural areas. Since this conservation objective was not met in 2004, 2005, or 2006, the Pacific Fishery Management Council adopted a rebuilding strategy that requires the natural area spawning objective be increased to 40,700 adult Klamath River fall Chinook.
In 2008, approximately 30,900 adults returned to the Klamath River Basin to spawn in natural areas, well below the rebuilding conservation objective. However, the total jack return (age 2 fish) was over 25,300 fish.
- Historical Record of Spawning Escapement (PDF)
- Stock Abundance Analysis for 2009 Ocean Salmon Fisheries
- Pacific Coast Salmon Plan
Laws and Enforcement
What laws guide salmon fishery management?
Chinook salmon fisheries are managed using an open, public process that is directed by several federal and state laws. The Magnuson-Stevens Fishery Conservation and Management Act, a federal regulation that governs ocean fisheries in U.S. waters (3-200 miles, the Economic Exclusive Zone), was first adopted in 1976. This law required the development of a “Salmon Fishery Management Plan” based on the best available science, and established the Pacific Fishery Management Council – a coast-wide representative group that helps guide ocean fishery management decisions.
In addition to off-shore ocean fishery regulations, there is a public process for developing near-shore ocean and in-river salmon fishery laws. The California Fish and Game Commission is a representative group appointed by the Governor that is responsible for managing all in-river fisheries, as well as fisheries from California's ocean shoreline out to 3 miles.
What law enforcement efforts are used to protect salmon?
Law enforcement efforts related to salmon in California's anadromous rivers (inland waters accessible to salmon migrating from the ocean) peak in the spring and in the fall. In the late summer and fall, adult salmon are migrating into California's anadromous waters to reproduce and continue their life cycle. These migrating fish represent the breeding stock and future of the salmon fishery. California's game wardens must focus much patrol time to prevent poachers from reducing their numbers. In the spring, juvenile salmon have hatched from the eggs laid by their parents in the prior fall, and are attempting to swim back out to the ocean. They are targeted by poachers to use as bait to catch other fish such as striped bass and sturgeon. Use of salmon for bait is illegal.
Tribal Fisheries
Will Tribal fisheries be allowed on the Klamath and Trinity River systems?
Yes. The Hoopa Valley and Yurok tribes have federally-protected rights to harvest salmon in the Klamath and Trinity Rivers (Department of Interior Solicitor Opinion, 1993). Klamath River fall Chinook harvest allocation is based on equal sharing of harvestable Chinook among tribal and non-tribal groups. The Federally recognized tribal harvest of Klamath River fall Chinook is 50 percent in any given year. The non-tribal 50 percent is divided between ocean fisheries and in-river sport fisheries. If Klamath River fall Chinook ocean impacts are reduced to minimize ocean impacts to Sacramento River fall Chinook, the number of Klamath River fall Chinook allocated to the Klamath River Basin in-river sport fishery will increase.
- Tribal Fishing Rights (PDF)
Salmon Biology
What is a “run” and what Chinook salmon runs are in the Central Valley?
There are four races, or runs, of Chinook salmon in the Central Valley: fall, late-fall, winter, and spring. The name of each run indicates the time the salmon return to the river. The life history patterns, including how much time the fish spend in the ocean and in frestwater, varies greatly for each distinct run. Fall Chinook are the most abundant in the Central Valley today, while the winter- and spring-runs have been placed on the Endangered Species List.
What are the primary mortality factors for young fish going out to the ocean?
Juvenile salmon face many challenges on their way to the ocean, and most mortality of Chinook salmon occurs in this vulnerable life stage. These factors can also act in combination, resulting in increased juvenile mortality. Chinook salmon require cold, clean water with sufficient flow to thrive. Some mortality factors include:
- Unsuitable water temperatures or flows,
- Poor water quality conditions,
- Entrainment in water diversions,
- Predation,
- Disease, and
- Lack of food supply
What are the primary mortality factors in the ocean? What is the main mortality factor affecting their return?
Chinook salmon spend the majority of their life in the ocean, and the right marine conditions are needed for their survival. Food supply at the right time and place is a major factor influencing salmon's survival. The Chinook salmon's diet changes as the fish grows, from tiny crustaceans like copepods to small fishes such as anchovies and sardines. This food supply is reliant on ocean upwelling and surface temperatures. Mortality factors in the ocean environment are complex and diverse, but can include:
- Upwelling strength and timing,
- Ocean temperatures,
- Lack of food supply,
- Disease,
- Natural predation, and
- Fishing
Where can I find information on Delta health issues and salmon smolt outmigration?
U.S. Fish and Wildlife Service - Stockton Fish and Wildlife office.
Conservation Efforts
What is the DFG doing to help restore Chinook salmon populations?
- DFG has participated in several of the following programs to help restore Chinook salmon populations in the Central Valley:
- CALFED Ecosystem Restoration Program - Over $500 million has been spent to date on ecosystem restoration projects in the Central Valley. Fish screening and passage projects received the highest level of funding.
- Central Valley Project Improvement Act programs have provided over $2.8 million/year for Chinook salmon restoration projects since 1993.
- Habitat restoration project types in the Sacramento River Basin include:
- Fish screens
- Fish passage
- Riparian restoration
- Floodplain acquisition
- Flow modification
- Gravel restoration
- Multi-million dollar annual grants to restore habitat
- Total grant monies nearing the $200 million mark
- Tracking salmon produced in central valley hatcheries
- Multi-million dollar state-of-the-art computerized trailers purchased to mark fish
- New technology allows massive marking to provide more data on salmon
- The “Constant Fractional Marking” program was instituted in 2006. The goal of this program is to place coded wire tags in 25 percent of the production of Sacramento River Fall Chinook at four DFG hatcheries and the Coleman National Fish Hatchery. Further, all spring-run Chinook are 100 percent coded wire tagged at Feather River hatchery. Tagging data is submitted to the Regional Mark Processing Center operated by the Pacific States Marine Fisheries Commission, and is publically available. Tags are recovered in the commercial and sport fisheries and from fish returning to spawn at the hatcheries and in the rivers. The first year of data available for these “Constant Fractional Marked” salmon is 2008.
- Development of the Sacramento Index and Sacramento Harvest Model
- The DFG participated in the development of a new method to estimate the impacts fisheries will have on the number of Chinook returning to spawn. This model is a significant improvement by including data from river fisheries and from Chinook caught north of Horse Mountain, CA.
- Fishery managers can now evaluate the effects of proposed fishing regulations, and determine the expected ocean and river harvest and number of Sacramento River fall Chinook expected to return to spawn.
- See also, Acoustic Tagging in San Joaquin River Seeks to Solve Salmon Mystery and Marine Management Newsletter: Collaborative Research improves Management of California's Chinook Salmon. Photos provided.
Hatchery Practices and Goals
What are the DFG's hatchery Chinook salmon production goals?
- Feather River Hatchery: 6 million fall Chinook for mitigation, 2 million fall Chinook for enhancement and 2 million spring-run Chinook.
- Nimbus Hatchery: 4 million fall Chinook for mitigation.
- Mokelumne River Hatchery: 3.4 million fall Chinook for mitigation and 2 million fall Chinook for enhancement.
- Merced River Hatchery: 1.4 million fall Chinook.
Is DFG meeting production goals for both mitigation and enhancement for Chinook salmon?
DFG Central Valley Hatcheries have achieved overall mitigation goals in eight of the last ten years and mitigation plus enhancement goals in six of the last 10 years.
The Central Valley hatcheries have released over 30 million young salmon the last ten years. Each hatchery has specific goals. State and the Federal (Coleman Hatchery) hatcheries work to make to meet the overall goal. State hatcheries are expected to release 18.6 million smolts this year and Coleman is shooting for 12 million plus.
Here is a breakdown by hatchery:
- Feather River and Nimbus Hatcheries are on line to meet both mitigation and enhancement goals for 2009.
- Due to reduced run size, Mokelumne River Hatchery will only reach 75 – 80 percent of its goal and Merced River only approximately 15 percent of its goal.
What are mitigation fish and what are enhancement fish?
- Mitigation fish are produced to replace Chinook salmon that historically spawned in areas and habitat which have been lost due to human constructed dams or other barriers.
- Enhancement fish are raised to provide additional fish intended for commercial and sport fisheries.
What are acclimation net pens and why are we using them?
The acclimation net pens are temporary holding areas which allow salmon smolts, which have been trucked from the hatchery to San Pablo Bay, to make their final adjustment to the temperature and salinity in the bay without being subjected to predation by fish or birds. Fish are moved into deep water and released after they have adjusted or “acclimated” to bay conditions.
Why can't young salmon be held in the hatcheries until there is net pen space available?
Once young salmon are ready to leave the hatchery they must be moved in a relatively short time. Growing bigger by the day, they simply out grow the space available. Coming in behind each group of fish is another new crop of fish to take over the raceway space they live in. Labor, food, materials and transport trucks have to be scheduled in advance to move millions of these young fish. This involves millions of fish from several installations, so it requires considerable planning and coordination.
Why can't we make more salmon at DFG hatcheries?
DFG hatcheries are producing Chinook at maximum capacity. Increased production of fish would require building new rearing areas at the hatcheries. Additionally, producing more salmon than the hatcheries currently produce may not help restore salmon populations, and could end up being a detriment to the overall health of the population.
Have there been any changes in salmon hatchery practices?
There have been no significant changes in hatchery practices over the years which would have adversely affected the current year class of fish. To help better understand what is happening to young salmon making the journey out to sea, a new program marking 25 percent of the 32 million Sacramento fall Chinook smolts should provide excellent data on hatchery fish contribution to the fisheries in the near future. The new information will help salmon managers consistently track returns of salmon.
Possible Factors in the Decline of Salmon
What are the possible factors in the decline of salmon?
In 2008, a multi-agency scientific panel was formed to investigate possible factors in Sacramento River fall Chinook salmon decline. A list of possible factors affecting salmon populations was created and each of these factors was carefully reviewed by the scientific panel. The panel found that unusually poor ocean conditions in 2005 and 2006 resulted in very low survival of juvenile salmon. When these fish entered the ocean, water temperatures were unusually warm and upwelling was very weak, resulting in low food availability. The panel also highlighted long-term poor river conditions as a major factor influencing Chinook salmon survival.
In April 2009, the panel presented their draft report on the possible causes of the Sacramento River fall Chinook population decline to the Pacific Fishery Management Council:
- Report on the causes of Sacramento River fall Chinook salmon decline
- NMFS presentation on Sacramento River fall Chinook salmon decline
How did this situation get so dire?
Sacramento River fall Chinook salmon spawning returns to the Sacramento River system have been declining since 2002, but the returns dipped below the escapement goal in the Salmon Management Plan only in 2007 and 2008. The proximate cause of this dramatic decline is the result of poor ocean conditions, combined with continued poor freshwater conditions.
Why are the Central Valley Chinook salmon more affected than salmon from other areas?
Chinook salmon spawning in many west coast rivers was lower than expected. Additionally, coho salmon spawning has been reduced in recent years. Chinook salmon spawning in the Central Valley are at the southern most end of their range, and are more vulnerable to changing conditions.
Is there a relationship between other species population declines and the salmon decline?
Delta smelt and many other species live in the Sacramento-San Joaquin Delta, but these species use the habitat much differently than do Chinook salmon. Delta smelt, and the other species that spawn and rear in the Central Delta, are highly dependent on habitat conditions in the Central and South Delta. Chinook salmon pass through the Delta, but generally do not have access to the interior Delta because the Cross Channel gates are closed during their out-migration period. Chinook salmon appear to be less vulnerable to the effects of changes within the Delta than delta smelt and similar species.
Seabird populations with diets similar to juvenile salmon, such as Cassin's auklets, also experienced severe population declines. Many birds abandoned their nest because they could not feed their chicks. Additionally, scientists noted emaciated gray whales and found sea lions foraging far from shore. Numbers of juvenile rockfish and anchovies, common salmon prey items, were low during the same time as the Sacramento River fall Chinook salmon decline.
Is some of the decline related to smolts not making it out of their juvenile river habitat?
Salmon undergo a physiological change called “smoltification” to prepare for life in the ocean. Evidence from trawl surveys at Chipps Island suggest that normal numbers of smolts entered the San Pablo Bay. Additionally, normal numbers of Chinook were released by the Central Valley hatcheries. The majority of these fish are released into the bay, bypassing the rivers altogether. Mortality of Chinook salmon is usually very high when they are juveniles. Predation on out-migrating smolts normally occurs throughout the Sacramento River system, but there is no evidence that predation has increased significantly in recent years. Increased predation cannot explain the magnitude of the recent decline.
Are stripers eating all of the young salmon before they can make it out of the river system?
Predation on out-migrating smolts by striped bass does occur. However, the striped bass population has been stable, and there is no evidence that predation has increased significantly in recent years. The failure of salmon stocks on the west coast is across a broad spectrum. Increased predation impacts cannot explain the magnitude of the recent decline.
Is the health of the Delta a factor?
At the time Sacramento River salmon are out-migrating through the lower Sacramento River, flows and gate closures are conducive to continued movement through the mainstem river, bypassing the interior Delta. Water exports from the Delta have reached record highs in recent years, but occurred after the majority of Sacramento River fall Chinook had left the Delta and entered the ocean.
Could the sea lions be to blame for the decline? If so, are there any means to control them?
Several marine mammals feed on salmon, including sea lions, harbor seals, and killer whales. Sea lion and harbor seal populations have increased since the 1990's, but have been relatively stable in recent years. Sea lions were observed foraging much farther from shore in 2005, suggesting they had a lower impact on salmon than normal. Sea lions are not thought to be a key contributor in the decline, and it is highly unlikely that the magnitude of the recent decline is due to sea lion predation. Sea lions are protected under the Marine Mammal Protection Act and control measures are a federal issue.
Did poaching cause this decline?
The system wide decline in fall Chinoook indicates large factors were acting on a wide range of salmon stocks in California and portions of southern Oregon. Poaching cannot explain the dramatic decline in the population.
