Difference between revisions of "Coho Salmon Crisis in the Central California Coast ESU"

From CCoWS Wiki
Jump to: navigation, search
(New page: A watershed-related issue examined by the ENVS 560/L Watershed Systems class at [http://csumb.edu CSUMB]. == Summary == Marin County's Lagunita Creek Watershed, o...)
 
(→‎Links)
 
(80 intermediate revisions by 8 users not shown)
Line 2: Line 2:
  
 
== Summary ==
 
== Summary ==
−
Marin County's Lagunita Creek Watershed, once held out as a statewide model for fisheries restoration, is now hanging in the balance with an unprecedented 90% decline in coho salmon returning to spawn so far this year. Fisheries and watershed biologists say that several years of exceptionally reduced winter rainfall have contributed to the worst coho salmon return in recorded history.
 
−
 
−
The lack of rain this winter has contributed to what fisheries biologists say is, so far, the worst return of coho salmon in the recorded history of Marin County's Lagunitas Creek watershed, one of California's most critical ecosystems for the endangered fish.
 
  
−
Only a smattering of coho were spotted and only 20 egg nests, or redds, were seen in the two main tributaries - Lagunitas and San Geronimo creeks - during the annual winter survey of fish, watershed biologists said this week.
+
=== Current Issue ===
  
−
The paltry showing of redds represents an 89 percent drop in the number of returning offspring of parents that gave birth in the lush western Marin watershed three years ago. Last year at this time, 148 redds had been counted, then the lowest number in the 14 years that records have been kept, said Paola Bouley, the conservation program director for the Salmon Protection and Watershed Network, or SPAWN.
+
Marin County's Lagunitas Creek Watershed, once held out as a statewide model for fisheries restoration, is now hanging in the balance with an unprecedented 90% decline in coho salmon returning to spawn so far this year<ref name="fimrite">Fimrite, P. 2009. Crisis Situation for Marin's coho salmon. San Francisco Chronicle. 01092009 Section B1</ref>. The primary reason for the decline of coho salmon in Lagunitas Creek appears to be due to the construction of the Kent and Nicasio Reservoirs, which restricted the fish to the lowermost portion of the creek. Construction of the reservoirs has prevented recruitment of new gravel into most of the system resulting in a streambed dominated by relatively large and angular particles. Most spawning now takes place in San Geronimo Creek, an unregulated tributary, and the region immediately downstream of its confluence with Lagunitas Creek.<ref name="Status">Brown, L.R., Moyle, P.B. 1991. Historical Decline and Current Status of Coho Salmon in California. North American Journal of Fisheries Management http://www.russianriverwatershed.net/docManager/1000000622/brown1991.pdf</ref>
 +
In addition, fisheries and watershed biologists say that several years of exceptionally reduced winter rainfall have contributed to the worst coho salmon return in recorded history. The decreased rainfall translates as reduced creek flow which prevents salmon from effectively swimming upstream and being more vulnerable to predation in the open ocean.
  
−
"It's just frightening, actually," Bouley said. "We were expecting 70 redds, which is still a 63 percent decline. It's definitely a crisis situation."
+
=== History<ref name="Brown">Brown, L.R., Moyle, P.B. & Yoshiyama, R.M. 1994. Historical Decline and Current Status of Coho Salmon in California. North American Journal of Fisheries Management 14.2:237–261</ref> ===
  
−
The waterway, which winds its way through the picturesque San Geronimo Valley on the northwest side of Mount Tamalpais, typically supports the largest wild run of salmon left in the state, historically about 10 percent of California's coho population.
+
Lagunitas Creek Watershed offers unique spawning grounds in that it is in the midst of a developed area. While historic Coho salmon runs numbered in the thousands a hundred years ago, subsequent redwood logging operations followed by road and housing construction reduced the original salmon habitat to 40% of its original size.  The seven dams  spread throughout the area also significantly blocked off historic salmon habitat while also reducing gravel needed for spawning while also increasing creek sediment. In the early 1980s, restoration efforts started with the lobbying of a [[Trout Unlimited]] to the county make efforts to halt the salmon fishery decline.
  
−
During the first winter rains, the spawning fish swim 33 miles from the open ocean into Tomales Bay and up the creek through the redwood-studded valley to lay their eggs and die. The females lay their eggs only after they've found the place where they were born three years before. The decline this year is alarming given that 190 redds were counted in 2005 when the parents of these coho laid their eggs.
+
===Significance===
  
−
The plummeting coho numbers exacerbate a near catastrophic decline in the overall population of salmon along the West Coast. So few chinook salmon returned to spawn in the Sacramento-San Joaquin river system last year that ocean fishing had to be banned in California and Oregon.
+
This unprecedented decline is particularly troublesome because the Lagunitas Creek Watershed is considered one of California's most critical ecosystems for endangered coho salmon<ref name="noaa">NOAA Fisheries Office of Protected Resources http://www.nmfs.noaa.gov/pr/species/fish/cohosalmon.htm</ref>. Historically the Lagunitas Creek Watershed has supported California's largest wild salmon run, regularly supporting  10% of the state's Coho Salmon population<ref>http://sfbay.sierraclub.org/yodeler/html/2009/09/winter5.htm</ref>. The Lagunitas Creek watershed salmon population is also considered considered critical for the coho salmon population of the entire central California coast <ref name="Brown"/>. Salmon have been regularly taken from this watershed to supplement populations in regional watersheds There are now probably less than 5,000 native coho salmon (with no known hatchery ancestry) spawning in California each year, many of them in populations of less than 100 individuals. Coho populations today are probably less than 6% of what they were in the 1940s, and there has been at least a 70% decline since the 1960s. There is every reason to believe that California coho populations, including hatchery stocks, will continue to decline. The reasons for the decline of coho salmon in California include: stream alterations brought about by poor land-use practices (especially those related to logging and urbanization) and by the effects of periodic floods and drought, the breakdown of genetic integrity of native stocks, introduced diseases, over harvest, and climatic change. This local scale salmon decline is consistent with the recent plummeting of statewide salmon populations that prompted the chinook salmon fishery collapse and subsequent closure along the west coast.
−
 
+
−
The number of coho eggs throughout the state declined about 70 percent last year. The low number of coho in the Lagunitas watershed in 2007 was shocking given that a record 496 redds were counted in 2004, the year they were born.
+
−
 
+
−
"We had our best year class in 2004," Bouley said. "What happened is our best year class turned into our worst year class."
+
−
 
+
−
'''This year is looking even worse.'''
+
−
 
+
−
Fisheries biologists believe the primary cause is the unusually dry weather in Northern California, which has prevented salmon from swimming up the creeks. The rains in December were barely enough to breach sandbars on most beaches, forcing salmon up and down the coast to circle in the open ocean where they are vulnerable to sea lions and other predators.
+
−
 
+
−
"It's not looking good," said Sean Hayes, a National Marine Fisheries Service biologist who monitors salmon in Scott Creek, the southernmost coho run in California, north of Davenport (Santa Cruz County). "The fish have been hammered a couple of years in a row now. If it doesn't rain, there could be a spawning failure this year, which would be catastrophic."
+
−
 
+
−
'''Threat of extinction'''
+
−
 
+
−
Bouley said a big rainstorm could turn things around, but hardly any rain is expected in the next two weeks. If things don't improve, she said, this year's cycle of fish may go extinct.
+
−
 
+
−
The lack of salmon in Lagunitas Creek is a major concern, she said, because the watershed is a statewide model for fisheries restoration. The first winter rains normally bring schools of coho wriggling up the creeks, drawing tourists, schoolchildren and naturalists to watch the fish leap from the foaming rapids.
+
−
 
+
−
"The Lagunitas population is critical to the viability of the entire central California coho population. It is the keystone watershed along the coast," Bouley said. "Fisheries agencies look to Lagunitas as the key to the recovery for neighboring watersheds. We won't have any streams left to seed them if this one is gone."
+
−
 
+
−
The watershed is unique in that the primary spawning grounds are in the middle of developed communities. Since coho were listed as endangered in 2005 under the Endangered Species Act, many residents have taken a proprietary interest in the fish. Schools have become involved, organizing work parties and teaching children about the historic coho migration.
+
−
 
+
−
More than a century ago, about 6,000 coho spawned in the system of streams every year. At that time, the salmon swam from Tomales Bay virtually to the top of Mount Tamalpais, spawning in tributaries all along the way. But industry started taking a toll almost from the day Joseph Warren Revere spotted the valley in 1846 and saw "a copious stream, fed by mountain brooks."
+
−
 
+
−
The redwood forests surrounding the creek were logged between 1860 and 1900. Subsequent homes and roads built along the waterway removed about 60 percent of the original riparian habitat.
+
−
 
+
−
The first major dam, which created Lake Lagunitas, was built in 1873. Six more dams were constructed over the next century, the largest being Peter's Dam at Kent Lake, finished in 1953 and then raised 42 feet in 1982. The dams blocked 50 percent of the historic salmon habitat, reduced the amount of gravel and increased sedimentation in the creeks.
+
−
 
+
−
But the decline was slow. Old-timers told how they used to spear fish from decks or garage hatches overlooking the creek. In 1959, when the habitat was already in serious decline, the largest recorded coho in state history, a 22-pounder, was fished out of Lagunitas Creek.
+
−
'''Lobbying the county'''
+
−
 
+
−
The restoration effort began in the early 1980s when a group called Trout Unlimited began lobbying the county to stop the decline of the fishery.
+
−
 
+
−
SPAWN, which was created in 1996, sponsors salmon-watching creek walks during spawning season and has saved more than 15,000 juvenile salmon and steelhead from drying pools during the summer. The Marin Municipal Water District, which is required by the state to help the coho as mitigation for raising Peter's Dam, started counting coho redds in the early 1990s and now works with SPAWN to monitor releases from the dam, install woody debris in the creeks and replant vegetation.
+
−
 
+
−
"This is the beacon of hope for the California watershed," Bouley said, but "the fish are missing. They are gone."
+
−
 
+
−
E-mail Peter Fimrite at pfimrite@sfchronicle.com..
+
  
 
== Location ==
 
== Location ==
  
−
Lagunita Creek Watershed is located in Marin County, California.
+
Lagunitas Creek Watershed winds through San Geronimo Valley on the northwest side of Mount Tamalpais in Marin County, California<ref>http://en.wikipedia.org/wiki/Lagunitas_Creek</ref>. The Lagunitas Creek Watershed coho salmon are part of the Central California Coast Evolutionarily Significant Unit <nowiki>(ESU)</nowiki> that extends from Punta Gorda in northern California south to and including the San Lorenzo River in central California<ref>http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Coho/</ref>. This ESU status was designated 1999<ref name="noaa"/>.
  
 
== Resource/s at stake ==
 
== Resource/s at stake ==
  
−
The endangered Coho Salmon are threatened with extinction for the year.
+
Fishery biologists fear that the severe decline in returning Coho Salmon may result in a spawning failure and possible extinction for the year. Biologically speaking, diminished population size can negatively effect the genetic diversity of the population and reduce fitness or viability for the future. Genetic diversity is a significant concern with with most native spawning coho salmon  populations consisting of less than 100 individuals<ref name="fimrite"/>. Economically, reduced salmon numbers can negatively impact human communities that have relied on salmon fishing for income and tourism.
  
 
== Stakeholders ==
 
== Stakeholders ==
−
 
+
* '''[http://www.spawnusa.org/ SPAWN (Salmon Protection and Watershed Network)]'''
−
...Who are the stakeholders in the watershed? e.g. agencies, non-profits, associations...
+
** Created in 1996, SPAWN sponsors salmon-watching creek walks during spawning season and has saved more than 15,000 [[Salmonids in California's Central Coast Region: Salmon, Trout, and Steelhead | salmonids]] from  diminishing summer pools.
−
 
+
* '''[http://www.tu.org/site/c.kkLRJ7MSKtH/b.3022897/k.BF82/Home.htm Trout Unlimited]'''
 +
**Trout Unlimited- lobbyists
 +
* '''[http://www.marinwater.org/ The Marin Municipal Water District]'''
 +
**Required by the state to help coho salmon to mitigate any negative impacts of Peter's Dam, started counting coho redds (salmon spawning 'nests')in the early 1990s and now works with SPAWN to monitor releases from the dam, install woody debris in the creeks and replant vegetation.
 +
* '''[http://www.nmfs.noaa.gov/pr/ National Marine Fisheries biologists]'''
 +
** Are interested in monitoring and studying salmon populations.
 +
* '''[http://www.nmfs.noaa.gov/pr/species/fish/cohosalmon.htm National Oceanic and Atmospheric Administration (NOAA)]'''
 +
** Study and monitor endangered species.
 +
* '''Area Residents'''
 +
**Community members and schools organize programs to inform students and other community members about the historic coho migration.
 +
*''' Regional Fishers & Fish-related industry'''
 +
** Many communities rely on the fish as a source of income.
  
 
== Laws, policies, & regulations ==
 
== Laws, policies, & regulations ==
  
−
...What laws, policies, and/or regulations are involved?...
+
* In 2005 coho salmon were listed as endangered under the United States Federal Endangered Species Act<ref>http://www.nmfs.noaa.gov/pr/laws/esa/</ref>
−
The CFG,
+
  
 
== Systems ==
 
== Systems ==
  
−
... What elements of the biophysical system are/were involved?...
+
* Climate change may be contributing to warmer and drier winters with less rainfall. The resulting creek flow limits salmon ability to navigate to the spawning grounds.
 +
* The salmon form part of the food web that with their disappearance may become deranged
 +
* The Coho salmon habitat and watershed integrity were negatively impacted by logging and development which reduced available habitat, stream connectivity and flow<ref name="Brown"/>. The resulting decreased creek gravel and increased sediment contribute to reducing critical spawning habitat <ref name="Status"/>.
  
−
== Science ==
+
== Scientific questions ==
  
−
...What scientific studies are or would be relevant / already completed?...
+
* Examining whether restoration efforts actually improved the watershed conditions?
 +
* Examining whether reduced creek water flow is more due to changes in weather patterns alone or a combination of weather patterns in conjunction with development in the watershed reducing its capacity or decreasing flow.
  
−
== Tools ==
+
== Relevant scientific tools ==
  
−
...What analytical (e.g. modeling) tools were or could be used?...
+
* Fish could be tagged and tracked, but that might be difficult considering life span and size.
 +
* Fish that are assisted out of drying ponds could be monitored for survival rate with GPS tracking information.
 +
* Weather models could be implemented to predict required rainfall patterns.
 +
* Genetic tools to investigate genetic diversity of coho salmon population and what percentage is "pure wild type" versus those with stock ancestry.
  
 
== Future research ==
 
== Future research ==
  
−
...What knowledge gaps remain?...
+
* Given unlimited money the remaining population's genotype could be assessed to deem if there is sufficient diversity remaining for re-population. If so, a breeding program that tracks  and pairs individuals could be started to increase genetic diversity. Especially important if this population was used to restock other locations. Also genetic analyses could be done to test whether distinct morphotypes reflect genotype diversity.
  
−
...Suggest a CWSP MS thesis topic that could contribute to the issue...
+
== Notes and References ==
  
−
...Suggest a topic for a hypothetical study that had unlimited resources...
+
<references/>
  
−
== References ==
+
== Links ==
  
−
...Proust, M. 1901. Poetica nausea. ''J. Nauseum''. pp 1-9999.
+
* Other [[Watershed Issues]]
 +
* [[Anadromous Fishes of California's Central Coast Region]]
 +
* [[Salmonids in California's Central Coast Region: Salmon, Trout, and Steelhead]]
  
 
== Disclaimer ==
 
== Disclaimer ==
  
 
This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of [[CSUMB]], its staff, or students.
 
This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of [[CSUMB]], its staff, or students.

Latest revision as of 13:18, 9 April 2020

A watershed-related issue examined by the ENVS 560/L Watershed Systems class at CSUMB.

Summary

Current Issue

Marin County's Lagunitas Creek Watershed, once held out as a statewide model for fisheries restoration, is now hanging in the balance with an unprecedented 90% decline in coho salmon returning to spawn so far this year[1]. The primary reason for the decline of coho salmon in Lagunitas Creek appears to be due to the construction of the Kent and Nicasio Reservoirs, which restricted the fish to the lowermost portion of the creek. Construction of the reservoirs has prevented recruitment of new gravel into most of the system resulting in a streambed dominated by relatively large and angular particles. Most spawning now takes place in San Geronimo Creek, an unregulated tributary, and the region immediately downstream of its confluence with Lagunitas Creek.[2] In addition, fisheries and watershed biologists say that several years of exceptionally reduced winter rainfall have contributed to the worst coho salmon return in recorded history. The decreased rainfall translates as reduced creek flow which prevents salmon from effectively swimming upstream and being more vulnerable to predation in the open ocean.

History[3]

Lagunitas Creek Watershed offers unique spawning grounds in that it is in the midst of a developed area. While historic Coho salmon runs numbered in the thousands a hundred years ago, subsequent redwood logging operations followed by road and housing construction reduced the original salmon habitat to 40% of its original size. The seven dams spread throughout the area also significantly blocked off historic salmon habitat while also reducing gravel needed for spawning while also increasing creek sediment. In the early 1980s, restoration efforts started with the lobbying of a Trout Unlimited to the county make efforts to halt the salmon fishery decline.

Significance

This unprecedented decline is particularly troublesome because the Lagunitas Creek Watershed is considered one of California's most critical ecosystems for endangered coho salmon[4]. Historically the Lagunitas Creek Watershed has supported California's largest wild salmon run, regularly supporting 10% of the state's Coho Salmon population[5]. The Lagunitas Creek watershed salmon population is also considered considered critical for the coho salmon population of the entire central California coast [3]. Salmon have been regularly taken from this watershed to supplement populations in regional watersheds There are now probably less than 5,000 native coho salmon (with no known hatchery ancestry) spawning in California each year, many of them in populations of less than 100 individuals. Coho populations today are probably less than 6% of what they were in the 1940s, and there has been at least a 70% decline since the 1960s. There is every reason to believe that California coho populations, including hatchery stocks, will continue to decline. The reasons for the decline of coho salmon in California include: stream alterations brought about by poor land-use practices (especially those related to logging and urbanization) and by the effects of periodic floods and drought, the breakdown of genetic integrity of native stocks, introduced diseases, over harvest, and climatic change. This local scale salmon decline is consistent with the recent plummeting of statewide salmon populations that prompted the chinook salmon fishery collapse and subsequent closure along the west coast.

Location

Lagunitas Creek Watershed winds through San Geronimo Valley on the northwest side of Mount Tamalpais in Marin County, California[6]. The Lagunitas Creek Watershed coho salmon are part of the Central California Coast Evolutionarily Significant Unit (ESU) that extends from Punta Gorda in northern California south to and including the San Lorenzo River in central California[7]. This ESU status was designated 1999[4].

Resource/s at stake

Fishery biologists fear that the severe decline in returning Coho Salmon may result in a spawning failure and possible extinction for the year. Biologically speaking, diminished population size can negatively effect the genetic diversity of the population and reduce fitness or viability for the future. Genetic diversity is a significant concern with with most native spawning coho salmon populations consisting of less than 100 individuals[1]. Economically, reduced salmon numbers can negatively impact human communities that have relied on salmon fishing for income and tourism.

Stakeholders

  • SPAWN (Salmon Protection and Watershed Network)
    • Created in 1996, SPAWN sponsors salmon-watching creek walks during spawning season and has saved more than 15,000 salmonids from diminishing summer pools.
  • Trout Unlimited
    • Trout Unlimited- lobbyists
  • The Marin Municipal Water District
    • Required by the state to help coho salmon to mitigate any negative impacts of Peter's Dam, started counting coho redds (salmon spawning 'nests')in the early 1990s and now works with SPAWN to monitor releases from the dam, install woody debris in the creeks and replant vegetation.
  • National Marine Fisheries biologists
    • Are interested in monitoring and studying salmon populations.
  • National Oceanic and Atmospheric Administration (NOAA)
    • Study and monitor endangered species.
  • Area Residents
    • Community members and schools organize programs to inform students and other community members about the historic coho migration.
  • Regional Fishers & Fish-related industry
    • Many communities rely on the fish as a source of income.

Laws, policies, & regulations

  • In 2005 coho salmon were listed as endangered under the United States Federal Endangered Species Act[8]

Systems

  • Climate change may be contributing to warmer and drier winters with less rainfall. The resulting creek flow limits salmon ability to navigate to the spawning grounds.
  • The salmon form part of the food web that with their disappearance may become deranged
  • The Coho salmon habitat and watershed integrity were negatively impacted by logging and development which reduced available habitat, stream connectivity and flow[3]. The resulting decreased creek gravel and increased sediment contribute to reducing critical spawning habitat [2].

Scientific questions

  • Examining whether restoration efforts actually improved the watershed conditions?
  • Examining whether reduced creek water flow is more due to changes in weather patterns alone or a combination of weather patterns in conjunction with development in the watershed reducing its capacity or decreasing flow.

Relevant scientific tools

  • Fish could be tagged and tracked, but that might be difficult considering life span and size.
  • Fish that are assisted out of drying ponds could be monitored for survival rate with GPS tracking information.
  • Weather models could be implemented to predict required rainfall patterns.
  • Genetic tools to investigate genetic diversity of coho salmon population and what percentage is "pure wild type" versus those with stock ancestry.

Future research

  • Given unlimited money the remaining population's genotype could be assessed to deem if there is sufficient diversity remaining for re-population. If so, a breeding program that tracks and pairs individuals could be started to increase genetic diversity. Especially important if this population was used to restock other locations. Also genetic analyses could be done to test whether distinct morphotypes reflect genotype diversity.

Notes and References

  1. ↑ 1.0 1.1 Fimrite, P. 2009. Crisis Situation for Marin's coho salmon. San Francisco Chronicle. 01092009 Section B1
  2. ↑ 2.0 2.1 Brown, L.R., Moyle, P.B. 1991. Historical Decline and Current Status of Coho Salmon in California. North American Journal of Fisheries Management http://www.russianriverwatershed.net/docManager/1000000622/brown1991.pdf
  3. ↑ 3.0 3.1 3.2 Brown, L.R., Moyle, P.B. & Yoshiyama, R.M. 1994. Historical Decline and Current Status of Coho Salmon in California. North American Journal of Fisheries Management 14.2:237–261
  4. ↑ 4.0 4.1 NOAA Fisheries Office of Protected Resources http://www.nmfs.noaa.gov/pr/species/fish/cohosalmon.htm
  5. ↑ http://sfbay.sierraclub.org/yodeler/html/2009/09/winter5.htm
  6. ↑ http://en.wikipedia.org/wiki/Lagunitas_Creek
  7. ↑ http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Coho/
  8. ↑ http://www.nmfs.noaa.gov/pr/laws/esa/

Links

Disclaimer

This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of CSUMB, its staff, or students.

Retrieved from "http://ccows.csumb.edu/wiki/index.php?title=Coho_Salmon_Crisis_in_the_Central_California_Coast_ESU&oldid=26577"