Author Archives: Tom Cannon

FISHBIO takes on Stripers – again

Posted on by

In a recent blog post1, FISHBIO again discuss the role they allege that Striped Bass are playing in limiting salmon production in the Central Valley. They bring up the 5-year-old proposal to reduce regulations on the Striped Bass fishery that was soundly rejected by fishermen, resource managers, environmentalists, and scientists alike. They state that despite the fact that anglers spend more than ten times the hours spent fishing for stripers than for salmon, the economic benefit of striper fishing is far below that of salmon fishing.

Well, assuming the raw economic numbers are true:

  1. The State closed the Striped Bass commercial fishery a century ago.
  2. The Striped Bass fishery is year-round and throughout most of the Central Valley, whereas the salmon fishery is seasonal and more localized. There must be some social value in diversity.
  3. The economic status of Striped Bass fishermen is far more diverse than salmon fishermen. There must be some social value in supporting a broader range of citizens.
  4. Many California residents are from the East, where stripers are king and there are no salmon.
  5. Much of the salmon fishery value derives from the ocean fisheries, whereas the striper fishery is focused on Bay-Delta and inland waters. The relative cost of fishing in these regions is very different.
  6. Most of the salmon fishery value (over 90%) is derived from hatchery fish. The Striped Bass supplemental rearing program was closed over a decade ago. The striper effort was ten times higher then, the number of stripers was up to ten times higher in the past, and the economic value was also likely ten times higher.

The other portion of FISBIO’s argument concerns the role of Striped Bass predation in salmon declines.

  • “ During the early 1900s, striped bass thrived alongside salmon, but as salmon declined over the latter part of the century, the impact of these introduced predators took a proportionally greater toll on the salmon population.” There is no evidence to support this statement. Stripers have declined more than salmon. There are still 30-million hatchery smolts for a much smaller striper population to feed on.
  • “Controlling predators to help their prey species is not a new idea; other states have been controlling non-native and native predators with measured success for decades.” No doubt the greatest “predator control” success (over 90%) has been on the Striped Bass population by the federal and state export pumps over the past two decades.
  • “While California has failed to act, some political support for predator control has recently developed at the federal level. Multiple bills currently proposed in Congress include provisions for advancing predator control in the Delta.” These bills were sponsored by San Joaquin Valley congressmen and have little chance of passing.
  • “While these federal actions alone may not be sufficient to produce population increases in some threatened or endangered species, there is evidence that predation is a major barrier to salmon recovery, and the proposed legislation demonstrates a changing mindset toward controlling predation of declining species.” There is no evidence that predation by Striped Bass on wild threatened salmon runs is even in the top ten reasons for their declines. The “mindset change” is to divert attention away from the real reasons for threatened salmon declines, or from having to pay for their recovery.

Finally FISHBIO speaks to “changing mindsets” of anglers: “Perhaps the biggest hurdle to controlling non-native species like striped bass will be changing the mindset of the fishing community that cares deeply about these popular predators.” They mean that anglers should accept the false premise that Striped Bass are the problem and should allow them to be exterminated.

Loss of Salmon in the Sacramento River Floodplain

Posted on by

The loss of juvenile and adult salmon in the Sacramento River floodplain has been a problem for many decades. The problem is largely the result of the construction of dams, agricultural drains, and flood control systems. The problem is acute, and although well documented and quite obvious, little has been done to resolve it. The fixes are not cheap and no one wants to get stuck paying for them. In addition, potential fixes have been hoarded as potential mitigations for large public works projects like the Bay Delta Conservation Plan and its associated Delta Tunnels.

The Problem

Figure 1 is a map of the Sacramento Valley with arrows showing some of the major locations of the problem. Much of the problem is the result of limitation or blockage of fish passage; another major factor is stranding. Adult salmon, sturgeon, and steelhead migrating up the Sacramento River become attracted to the high volumes of Sacramento water exiting the Sutter and Yolo Bypasses (adult fish movement is shown by red arrows in Figure 1), only to be blocked at the high weirs at the upstream end of the bypasses (Figures 2 and 3). Even modest bypass flows in drought years can cause attraction and subsequent mortality (Figure 4).

Young salmon emigrating downstream from upriver spawning grounds pass into the bypasses (green arrows in Figure 1) and adjacent basins in huge numbers. Many become stranded and lost when flows and water levels decline when weirs quit spilling (the river can drop ten feet overnight and quickly cease spilling into bypasses).

Landowners Seek Solution

In one of the areas, the Yolo Bypass, local landowners and stakeholders are seeking a solution. They are addressing three critical issues:

  1. Blockage of upstream migrating fish behind the Fremont Weir at the head of the Bypass.
  2. Blocked fish migrating to their deaths into the Colusa Basin from the Bypass via the Knights Landing Ridge Cut1. Adult migrants are also attracted directly to Colusa Basin Drain outlet even when Fremont Weir does not spill.
  3. Increasing survival of young salmon spilled into the Yolo Bypass by augmenting flows and improving habitats and habitat connectivity.

The first issue often occurs each time the weir spills at flood stage (generally one in three years, although it has not spilled significantly since 2006 because of drought). The bandaid treatment is shown in Figure 2. Stakeholders have advocated a short-term solution for passing fish via a “small notch” in the Fremont Weir to pass fish over the weir into the river; however, long-term agency plans call for a more contentious “large notch” in the weir.

The second issue requires the opposite solution, placing a fish-blocking weir at the outlet of the Knights Landing Ridge Cut to stop adult salmon, sturgeon, and steelhead from migrating upstream into the Colusa Basin. Landowners are working with the California Department of Water Resources and Reclamation toward building such a weir. For now the bandaid is a fish trap and fish rescues such as that shown in Figure 2.

The third issue can be resolved by engineering the bypass floodplain to provide better habitat and connectivity for the salmon including high and longer-sustained flows from the Fremont Weir (via a “notch”). Local landowners have developed an array of actions to provide habitat and connectivity.

In my experience, placing leadership and responsibility for developing and implementing actions in the hands of local stakeholders has worked best to help save fish. “Locals” can be surprisingly adept at coming up with viable solutions to fisheries problems.

Map of Sacramento Valley showing levees and flood control system weirs and bypasses

Figure 1. Map of Sacramento Valley showing levees and flood control system weirs and bypasses. Gray area agricultural basins are generally below the elevation of the river and bypasses. The flood control system was initially designed to convey flood water and historic foothill mining debris through the Valley. Adult salmon (as well as sturgeon and steelhead) are attracted to the high flows entering, passing through, and exiting the Sutter and Yolo Bypasses (such adult migration is shown with red arrows). Many cannot successfully complete their passage either becoming lost or blocked at the upstream end by weirs (located at the blunt end of the green arrows). Many young salmon become stranded in the basins and bypasses after entering in spill over weirs during floods. (Map source: http://baydeltaconservationplan.com/Libraries/Dynamic_Document_Library/Fact_Sheet_-_Sac_River_System_Weirs_and_Relief_Structures.sflb.ashx )

Figure 2. Sturgeon being rescued below a Sacramento River bypass weir

Figure 2. Sturgeon being rescued below a Sacramento River bypass weir

Moulton Weir 1997

High storm flows in late December 2014 into the Yolo Bypass from the Knights Landing Ridge Cut attracted many salmon to the northern end of the Bypass

Figure 4. High storm flows in late December 2014 into the Yolo Bypass from the Knights Landing Ridge Cut attracted many salmon to the northern end of the Bypass. When storm flows receded after several days, hundreds of adult salmon became stranded in winter-fallow fields that had been flooded. Many more salmon likely passed successfully into the Colusa Basin drain system only to find no route to spawning grounds in the upper Valley.

Reclamation continues to threaten Klamath-Trinity-Sacramento Salmon with transfer of Trinity water to Sacramento basin

Posted on by

Minimum carryover storage for Trinity Reservoir is supposed to determine Trinity exports to the Sacramento River basin. In the driest years (certainly 2015 would be considered such a year), exports to the Sacramento are to be minimized to meet minimum instream flow and water temperature requirements on the Trinity River to save Klamath-Trinity salmon from mass die-offs as occurred in 20021. The low probability of refilling of Trinity Reservoir, as compared to Shasta Reservoir, necessitates the restriction. Yet this summer, three-quarters of the 2000-cfs of water being released from Trinity Reservoir is going to the Sacramento River. Low flows in the Trinity and lower Klamath are again threatening Klamath-Trinity salmon, resulting in Reclamation having to triple Trinity River flows as of August 22 (Figure 1). The added water is coming from the already-depleted Trinity Reservoir, while the 1500-cfs export to Sacramento Basin water users continues.

Figure 1

Figure 1. Trinity-Lewiston Reservoir releases to lower Trinity River in mid August 2015. Base required minimum flow is 450 cfs. Flow pulse from August 17-20 was for Hoopa tribal ceremony. New release (1150 cfs) to cool river commenced on August 21.

Reclamation tries to justify the transfer of Trinity water as needed to save Sacramento Winter Run Chinook salmon below Shasta Reservoir, when the transfer actually puts the Sacramento salmon at greater risk2. The transfer water passes through Whiskeytown Reservoir, from which it is released to the Spring Creek Powerhouse to the Sacramento below Shasta. The 50°F water from the Trinity Reservoir cold-water pool transferred to Whiskeytown warms nearly 10 degrees (58.5-59.5°F) before passing through the Spring Creek Powerhouse on Keswick Reservoir. Water from Whiskeytown would be even warmer if not for a floating water curtain installed at the reservoir outlet in 2011 to reduce water temperature of releases to the Sacramento basin (Figure 2).3

Figure 2

Figure 2. Floating boom of water curtain in Whiskeytown Reservoir outlet cove to Spring Creek Powerhouse in Sacramento basin.

The 59°F water entering Keswick Reservoir must be cooled by Shasta 50°F cold-water pool water to meet the 54-56°F required release temperature of the 7000 cfs prescribed release of water into the Sacramento River above Redding. Because Shasta releases are a blend of cold and warm water to meet downstream required temperatures, the added burden of cooling the Trinity water adds to the demands on the critically low cold-water pool remaining in Shasta Reservoir.

The limited Shasta cold water pool has already resulted in the State Board’s weakening of the average daily water temperature standard of 56°F to protect Winter Run salmon eggs to 58°F at Redding. The weakened standard will result in some egg mortality. There remains concern whether the cold water pool releases can be sustained through the summer, unlike last summer when coldwater ran out in early September leading to the loss of 95% of the salmon production.

Further exacerbating the above problems is the continuing operation of all three storage reservoirs (Trinity, Whiskeytown, and Shasta) for peaking power (Figure 3). Releases for peak power demands occur during afternoon hours when reservoir waters are at their warmest (Figure 4). This specific operation pattern has lead to high afternoon water temperatures in Keswick releases to the Sacramento River, and most recently to higher night release temperatures (Figures 5 and 6). The standard remains 58°F average daily water temperature. Egg mortality increases above 56°F.

Figure 3

Figure 3. Release pattern at Shasta Dam in recent days. Peak releases to five powerhouses occurs in afternoon consistent with power demands. Note night releases having virtually been eliminated on August 23 in favor of daytime releases.

Figure 4

Figure 4. Temperature of water in penstocks to powerhouse from Shasta Reservoir. Note warmest water occurs during peak flows in afternoons.

Figure 5

Figure 5. Water temperature of water released from Keswick Dam to upper Sacramento River.

Figure 6

Figure 6. Water temperature of Sacramento River in Redding at CCR gage compliance point. Note average daily temperature approaches 58°F standard. Salmon egg mortality increases above 56°F.

  1. Trinity exports are also to be minimized to save carry-over storage for future Sacramento basin needs. ↩
  2. http://calsport.org/fisheriesblog/?p=384 ↩
  3. To date, the curtain is performing as designed. It achieves an approximate 2 to 4 degree drop in water temperature.
    http://www.fabricatedgeomembrane.com/wp-content/docs/articles/fgi_jan2012_whiskeytown%20temp%20curtain%20pub%20file%20FI.pdf ↩

Reclamation helps Klamath-Trinity Salmon with flow release

Posted on by

Tribal Ceremonial Release

Reclamation recently provided a “ceremonial release” of water from Trinity Reservoir for the Hoopa Valley Tribe’s bi-annual Boat Dance Ceremony1. The release is for the period of August 17-20. The added flow increased the total flow in the upper Trinity River from 450 cfs to a peak of 2670 cfs on August 17 (Figure 1). The flow pulse reached Hoopa at the mouth of the Trinity River on the lower Klamath River one day after the initial release (Figure 2). The flow pulse also had a dramatic effect on the water temperature in the lower Trinity and Klamath Rivers (Figures 3 and 4).

Supplemental Flows

The flow pulse is the first of several anticipated this summer2 to cool the lower Klamath and Trinity Rivers, which have been plagued with high water temperatures (70-80F) this summer due to low water supplies related to the fourth year of drought. Low flows and their associated warm water temperatures are thought to be the cause of salmon deaths. These deaths are attributed to: (1) pathogens Ich and Columnaris; and (2) warm water temperatures, low water velocities and volumes, high fish density, and long fish residence times which likely contributed to the disease outbreaks and subsequent mortalities. Adult salmon crowd into limited thermal refuges and become susceptible to disease.

Figure 1. Release of water from Lewiston Dam into the upper Trinity River near Lewiston from August 10-20, 2015.

Figure 1. Release of water from Lewiston Dam into the upper Trinity River near Lewiston from August 10-20, 2015.

Figure 2. Streamflow at Hoopa on the lower Trinity River from August 10-20, 2015

Figure 2. Streamflow at Hoopa on the lower Trinity River from August 10-20, 2015

Figure 3. Water temperature of lower Trinity River at Hoopa August 10-20, 2015

Figure 3. Water temperature of lower Trinity River at Hoopa August 10-20, 2015

Figure 4. Water temperature of lower Klamath River at Klamath August 10-20, 2015

Figure 4. Water temperature of lower Klamath River at Klamath August 10-20, 2015

Reclamation Jeopardizes Klamath and Sacramento Salmon

Posted on by

By now you have probably heard that Klamath salmon are again threatened by warm water and ICH disease. You may also know that Sacramento River winter run salmon are again threatened with warm water below Shasta at Redding. You may not know that both are related, caused by the US Bureau of Reclamation’s operation of the Central Valley Project (CVP) and in particular Shasta and Trinity reservoirs.

Low flows in the lower Klamath are resulting in warm water and disease, shaping up as having the potential to repeat the massive 2002 die-off of salmon. Water temperatures in the lower Klamath and Trinity near 80°F are killing salmon and blocking their migrations.

Below Shasta on the Sacramento River near Redding, Winter Run Chinook salmon eggs are dying because excessively warm water is being released from Keswick Reservoir near Redding. Water temperatures near or above 60°F occur from Redding down to Red Bluff, the traditional spawning reach of Winter Run Chinook in summer. Egg mortality increases above 56°F.

Here is how the two events are related. The map below shows how the Shasta andTrinity projects are connected as part of the CVP. Trinity Reservoir is presently releasing about 2000 cfs, of which a little less than 500 cfs (52-59°F) is released down the Trinity into the lower Klamath where total flow is 2200 cfs and water temperatures approach 80°F. The other 1500 cfs from Trinity Reservoir is going to Keswick Reservoir via Whiskeytown Reservoir. This 59°F water from Whiskeytown mixes with 5500 cfs of 52°F water released from the Shasta cold-water pool to provide a release of 7000 cfs of 54-56°F water into the Sacramento River from Keswick Dam above Redding. Water temperatures in the Redding spawning reach are 56-60°F.

So the flows diverted from the Trinity are not only contributing to low flows and warm water in lower Klamath, they are also contributing to the water in the Sacramento at Redding that is too warm for salmon eggs. The need to cool Trinity water before it is released into the Sacramento below Keswick is also contributing to the depletion of the limited cold water pool in Shasta reservoir.

Klamath River tribes are asking for more water down the Trinity. Reclamation is offering a small pulse when salmon start to die. A better solution would be to equally split the Trinity release, providing an immediate benefit to the Klamath-Trinity salmon and also saving some of the cold water pool in Shasta. This would require the State Board to reduce deliveries to Sacramento Valley farmers by an additional 500 cfs.

Proposed Actions Reservoirs and Dams