Category Archives: Bay-Delta

It is time to save the Delta Smelt

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Causes of the Decline of the Endangered Delta Smelt

There are multiple threats to the Delta Smelt population that contribute to its viability and risk of extinction. Chief among these threats are reductions in freshwater inflow to the estuary; loss of larval, juvenile and adult fish at the state and federal Delta export facilities and in urban, agricultural and industrial water diversions; direct and indirect impacts of the Delta Smelt’s planktonic food supply and habitat; and lethal and sub-lethal effects of warm water and toxic chemicals in Delta open-water habitats.

Temporary urgency change orders by the State Board have allowed reduced Delta outflow and increased Delta salinity. This has moved the Low Salinity Zone further upstream (eastward) into the Delta, thereby increasing the degree of each of these threats. During the past few drought summers, remnants of the population have been confined to a small area of the Low Salinity Zone where water temperatures barely remain below lethal levels. The change orders are an obvious and direct threat to the remnants living in the Low Salinity Zone. Further allowing these weakened standards to be violated is a direct disregard for the remnants of the population. It places them at extraordinary risk by bringing them further into the zone of water diversions, degrading their habitat into the lethal range of water temperature, further degrading their already depleted food supply, and increasing the concentrations of toxic chemicals being relentlessly discharged into the Delta.

Saving the Delta Smelt

The following are measures necessary to save the remnant Delta Smelt population:

  1. Keep the low salinity zone (LSZ) out of the Delta as prescribed in State water quality control plans over the last several decades. This can be readily accomplished by meeting already defined flow and salinity standards and restrictions on Delta exports. The LSZ on the Sacramento channel side should be in the wide open reach of eastern Suisun Bay between Collinsville and the west end of Sherman Island (location of Emmaton standard). It must be kept out of the Emmaton-to-Rio Vista reach just upstream in the west Delta, because this reach is confined and continually degraded by reservoir releases and warm water passing through the North Delta via Three Mile Slough to the interior of the Delta and south Delta water diversions. On the San Joaquin (south) side, the low salinity zone belongs in the wide Antioch–to-Jersey Point reach as prescribed in standards. This can be accomplished in spring and summer of dry years by maintaining prescribed flows, salinity standards at Jersey Point, installation of the False River and Dutch Slough Barriers, and opening the Delta Cross Channel (which results in positive net outflow from the mouth of Old River downstream to Jersey Point in the Central Delta). Maintaining the net positive flows in west Delta channels helps tremendously in getting salmon, steelhead, sturgeon, striped bass, and smelt from upstream freshwater spawning areas to their downstream rearing area target, the estuary’s LSZ. Keeping the LSZ in eastern Suisun Bay, as has always been an objective Delta Water Quality Plans, has huge indirect benefits as well, including greater plankton production, lower non-stressful water temperatures (conducive to growth and survival of all the Delta fish including smelt and salmonids), higher turbidity levels in the LSZ (reduced predation on and improved feeding for Delta smelt), lower invasive Asian clam concentrations in eastern Suisun Bay (which siphon off plankton and larval fish), and lower concentrations of toxins in the LSZ.
  2.  Improve the physical habitat of the LSZ. Habitat in eastern Suisun Bay, though far better than that of the west Delta, has been continuously degraded over the past century. Fortunately, there are few levees along the north shore of the Sacramento side. However, the wave-swept shores along Antioch Hills have lost all riparian vegetation except pockets of invasive Arundo. Hillside windfarm and shoreline erosion have filled in shoreline shoals, shallows, bays and alcoves that provided rearing habitat for smelt and salmon (salmon fry are the most abundant fish in these shallows through the winter). Miles of shoreline bays, inlets, and tidal marshes east of Collinsville have been lost. On the south side of the Sacramento channel are the remnants of historic Delta marshes and islands of West Sherman Island and Sherman Lake. Gradually the riparian shoreline and shallow waters are washing away as a consequence of wind as well as ship-wake erosion. Lack of interior marsh channel circulation has also led to grand infestations of invasive non-native submergent, emergent, and floating aquatic vegetation. Like the north shore, the south shoreline of West Suisun Bay on the San Joaquin side is not leveed. Likewise, shoreline and shallow water habitats are degraded, but from industrialization. Large areas east of Antioch to Big Break are degraded much as in the area of Sherman Lake. Both the north and south East Suisun Bay channels are degraded by dredging of the two deep-water ship channels, which has resulted in the loss of shallow shoal, bay, and mudflat habitats. Virtually none of the habitats mentioned above were addressed in the grand BDCP restoration plans for the Bay-Delta. Though some of the areas have been prescribed for restoration in various mitigation plans, virtually no progress has been made toward their restoration in the last several decades.
  3. Stock hatchery raised smelt in the LSZ. The agency-sponsored Delta Smelt conservation hatcheries could be upgraded to production status to provide juveniles to be stocked in the LSZ in late spring and summer. The population is so low now (zero 20-mm and Townet survey indices) that stocking would be helpful if not necessary.
  4. Provide a spring pulse flow into and through the Delta to help smelt fry transport from freshwater spawning areas downstream to the LSZ. This could include passing some Sacramento River flow through the blocked entrance to the Deepwater Ship Channel at the Port of West Sacramento. Delta inflow pulses could be provided by reservoir releases coordinated with infrequent natural flow pulses through the Delta.
  5. Manage tidal flows and Delta hydrodynamics, as well as water quality, on a real time basis to help maintain the LSZ in east Suisun Bay and to stimulate and sustain plankton blooms. Real time management is possible because of the many satellite-accessible data recorders in the Delta, as well as the many frequent biological monitoring surveys being conducted throughout the Bay and Delta. Active adaptive management is possible with the many flow controls available on diversions, reservoir releases, and flow splits (e.g., Delta Cross Channel).

More on Longfin Smelt

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Longfin Smelt have declined as other pelagic fish species have over the past two decades. The species was listed in 2009 under the California Endangered Species Act. In a previous blog1 I described trends in their abundance and distribution in the upper Bay and Delta. Below is a chart depicting the long-term trend in another standard CDFW survey, the San Francisco Bay Midwater Trawl Survey. The index is the average catch for the April and May monthly surveys at a basic array of 28-44 standard stations from San Francisco Bay upstream into the central Delta. Yearling smelt are dominant in the April surveys, while young predominate in the May surveys.

Longfin Smelt Average Catch Apr-May Baay Mid-water Trawl Surveys

As in other surveys, the index pattern clearly shows a sharp reduction in average catch since 2007. The average catch is particularly low in the last three years. There was no May survey in 2008. Similar patterns were evident in the Fall Midwater Trawl Survey, Summer Townet Survey, Winter Kodiak Trawl Survey, 20-mm Smelt Survey, and the Larval Fish Survey.

Longfin Smelt Update – They’re Gone

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Back in April, I questioned whether Longfin Smelt, a state-listed endangered fish, are going extinct in the Bay Delta1. The June surveys are in. The Bay Midwater Trawl, the Bay Otter Trawl, the Townet, and the 20-mm Survey show Longfin are at record lows with only a few caught in the Bay2. One only has to compare 20-mm Survey results for June over the past three years to see the trend. Going, going, gone.

Longfin Smelt Survey 2013

Longfin Smelt Survey 2014

Longfin Smelt Survey 2015

Listen to the River

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In 1992, the Central Valley Project Improvement Act (CVPIA) was enacted by Congress and resulted in the development of an Anadromous Fish Restoration Program (AFRP) to double the anadromous fish populations in the Central Valley by 2002. Astoundingly, after twenty-three years and more than $1,000,000,000 spent, extensive monitoring studies and the use of alleged “adaptive management”, the salmon runs have not only not doubled in size, but have declined. Most notably, there is no measureable progress toward delisting any of the threatened or endangered anadromous fish, and the fall-run Chinook, the most abundant among the four salmon runs, have now dropped even further from historical levels. Some individuals have even recently suggested that the fall run may warrant listing as an endangered species (Williams 2012) … not exactly a glowing success story for salmon restoration (or an efficient expenditure of money).

Because of this poor track record, an independent peer review (“Listen to the River”) of the CVPIA fisheries program was conducted in 2008 and was highly critical of the government agencies’ implementation of the anadromous fish restoration efforts. For example,

“Yet it is also far from clear that the agencies have done what is possible and necessary to improve freshwater conditions to help these species weather environmental variability, halt their decline and begin rebuilding in a sustainable way. A number of the most serious impediments to survival and recovery are not being effectively addressed, especially in terms of the overall design and operation of the Central Valley Project system.” (Cummins et al. 2008)

In particular, the review criticized the failures of implementing an effective, scientifically valid adaptive management program:

“The absence of a unified program organized around a conceptual framework is one of the reasons the program appears to be a compartmentalized effort that lacks strategic planning and decision-making. As a result the program is unable to address the larger system issues, has a disjointed M&E [monitoring and evaluation] program, exhibits little of the traits expected from effective adaptive management, and is unable to effectively coordinate with related programs in the region. An uncoordinated approach also creates boundaries to the free flow of useful information and program-wide prioritization. We observed that most researchers and technicians seemed unclear how or even whether their local efforts related to or contributed to the overall program.” (Cummins et al. 2008)

The “Listen to the River” report provided numerous recommendations to improve implementation of the CVPIA AFRP. Included among those suggestions was development and utilization of an effective adaptive management program. Surprisingly, it has now been seven years since the review panel’s report and all proposals put forth remain unimplemented by the involved agencies. When a newspaper reporter recently queried Bob Clarke, fisheries program supervisor for the U.S. Fish and Wildlife Service (USFWS), concerning the lack of progress and excessive funds expended in the AFRP, the response was that officials are still working to change the way they prioritize restoration. Clarke said: “It’s a process, unfortunately it’s not a process that allows you to get your results immediately,”1 Seven years? … It should have been done in seven months. A subsequent Redding Record Searchlight Newspaper Editorial2 on the topic responded that “those responsible have offered excuses, not explanations” and maybe what the AFRP needs “are fewer administrators and more field work”. It’s hard to disagree with that opinion. In an astonishing example, an examination of a portion of the annual AFRP budget in 2014 revealed that a total of $2,794,625 was expended on state and federal staff. Most of those funds were spent on so-called “Habitat Restoration Coordinators”.

AFRP Org ChartIt’s difficult to comprehend how one individual could work 52 weeks a year “coordinating” very few, if any, actual restoration projects in such small regions. Furthermore, with redundancy in the AFRP, both USFWS and the California Department of Fish and Wildlife have “Habitat Restoration Coordinators” overlapping within the same watersheds. Frankly, some of these efforts could probably be handled by an experienced individual during Saturday afternoons and serve as a “facilitator” to expedite projects, instead of a “coordinator” impeding progress with an added layer of bureaucracy. A suggested alternative approach would be to reorganize the program as shown below. This one example would allow more than $2,000,000 to be reallocated to actual salmon habitat restoration projects every year. Many more examples exist.

Proposed AFRP Org ChartDick Pool, President of Water4Fish and a long-time promoter for salmon restoration, recently summed up the problem: “The CVPIA program needs a major restructuring. For the last ten years, the salmon industry, Congress and many others have advocated the money be spent on ‘On the Ground’ projects in the river and in the Delta which deal with the real problems. So far there has been no change in the program.” After 23 years, it is time to listen to the river, implement a new approach, use true adaptive management, and place the needs of the salmon in front of building larger state and federal bureaucracies.

References

Arthur, D. 2015. “$1 Billon Later, Salmon are Still in Peril”. Redding Record Searchlight, May 17, 2015.

Redding Record Searchlight Editorial. 2015. “Agencies finally getting it – fish need cold water.” June 5, 2015.

Cummins, K., C. Furey, A. Giorgi, S. Lindley, J. Nestler, and J. Shurts. 2008. Listen to the River: An Independent Review of the CVPIA Fisheries Program. Prepared for the U.S. Bureau of Reclamation and the U.S. Fish and Wildlife Service. December 2008. 51 p. plus appendices.

Williams, J.G. 2012. Juvenile Chinook salmon (Oncorhynchus tshawytscha) in and around the San Francisco estuary. San Francisco Estuary and Watershed Science 10(3). October 2012.

  1. “$1 Billon Later, Salmon are Still in Peril”. Article by Damon Arthur, Redding Record Searchlight, May 17, 2015. ↩
  2. June 5, 2015 ↩

Splittail – Native Delta Minnow

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Splittail – Native Delta Minnow

Splitail Indices Graph

Splittail, formerly listed as threatened under the federal Endangered Species Act (1994), were delisted in 2003 after nearly a decade of wet years that brought about apparent recovery.1 Dr. Moyle’s recent warnings about other Delta native fish2 after nearly a decade of drought surely apply to splittail. Once the most abundant fish in late spring and early summer salvage collections at the south Delta export facilities, splittail are now rarely collected3. Once common in dry periods (1987-1992) and prone to abundance in wet periods (1993-2001), they are now rare in dry periods (2007-2009, 2012-2015). Because they live 5-8 years, they are able to spawn successfully in infrequent flood years, 2011 being a good example. The modest production from 2011 will be five years of age in 2016. One can only hope that 2016 will be a wet year.

I argued at a January 2001 CALFED workshop on splittail4 for retaining the listing of the species as threatened; however the consensus was “statistical power to detect real population trends in the past 30 years is low, thereby undermining confidence in any estimates of extinction risk based on abundance”. The 15 production years since the workshop have clearly added to the “statistical power”. I would argue for relisting splittail, if only for the reason they are now far less abundant then they were prior to the original listing, and to ensure something is done to protect them over the next several years so they indeed do not go extinct.