William J (BJ) Miller, Ph.D.

Consulting Engineer

San Luis & Delta-Mendota Water Authority

Testimony

Before the Subcommittee on Water and Power

Committee on Resources

United States House of Representatives

*Extinction is not a Sustainable Water Policy:*

*The Bay-Delta Crisis and the*

*Implications for California Water Management*

July 2, 2007

**Introduction**

Madam Chairman and members of the Subcommittee, my name is BJ Miller,
and I am a consulting engineer working on behalf of the San Luis &
Delta-Mendota Water Authority. I appreciate the opportunity to testify
today regarding "*Extinction is not a Sustainable Water Policy: The
Bay-Delta Crisis and the Implications for California Water Management."*

For the past 26 years I have been a consulting engineer focusing on
California water problems. Prior to becoming a consulting engineer I was
a member of the California State Water Resources Control Board from 1978
to 1980. For many years I have taught a one-day course, "The Management
of Water in California" for the UC Berkeley Engineering Extension and
elsewhere on request. My primary focus has been on the Sacramento-San
Joaquin Delta because of its importance for California water management.

Since approximately 1992 I have worked primarily on issues related Delta
fisheries because of the relationship between actions to protect Delta
fisheries and operations of the State Water Project ("SWP") and Central
Valley Project ("CVP") operations. With my colleague, Thomas Mongan,
Ph.D., a licensed civil engineer with a doctorate in physics, and
others, including Bryan Manly, Ph.D., one of the world's foremost
statistical ecologists, I have conducted numerous analyses of factors
affecting fish in the Delta. Most of our efforts have focused on delta
smelt, the small, native fish listed as threatened under both the State
and Federal endangered species acts.

**Summary**

To date, virtually the entire effort to recover the delta smelt has been
focused on operations of the SWP and CVP. However, there are no valid
statistical analyses showing that exports from the Sacramento-San
Joaquin Delta or entrainment of delta smelt at the export pumps have
important effects on abundance trends of delta smelt. Several analyses
show a strong relationship between the decline in delta smelt abundance
and significant declines in the densities of the zooplankton (small
floating animals) delta smelt prey upon, especially in spring. Reliable
analyses indicate routine management of Delta exports to minimize
entrainment ("take") of delta smelt is a futile attempt to prevent
extinction or achieve recovery. Certainly exports should be managed to
prevent the rare, unusually high incidences of take. Beyond that, the
key to saving the delta smelt is to find out what affects their food
supply and, if possible, do something to address those limiting factors.

**Decline of the delta smelt**

As you know, the abundance of delta smelt has declined sharply in recent
years. The graph below shows the key measurement of smelt abundance, the
Fall Midwater Trawl index. This index measures abundance of sub-adult
delta smelt. I compared this index to the population index for spawning
adults in winter, derived from the highly efficient Kodiak trawls that
began in 2002. There is an excellent relationship, indicating the FMWT
index is not only useful because of its length of record (since 1967),
but also because it appears to be a good indicator of the following
winter's spawning adult population.

![](media/image1.wmf){width="5.995138888888889in"
height="2.7979166666666666in"}

The hearing today is largely because of this graph, so I would like to
point out a couple of things about it. First, there has obviously been a
decline in delta smelt abundance. It began in 1999 and was especially
sharp after 2001. The 2005 index was the lowest of record. The 2006
index was higher, but still very low. Second, note the variation from
year to year. Since 1996, the average change (up or down) in this index
has been about 60%. So, if we want to figure out what happened to delta
smelt, and possibly a few other pelagic fish whose abundance has
declined, we should look for factors capable of causing a change of
about 60% per year. We should also look for factors that changed at
about the same time as delta smelt abundance did, that is, factors that
changed for the good from 1996 to 1999, and for the bad thereafter.

It is possible that factors with subtle, long-term effects control delta
smelt abundance in complicated ways. However, most (about 95%) delta
smelt live for only one year. For a fish with a one-year life cycle, the
most likely factors controlling abundance are those with important
effects each year.

This is a data-rich estuary, so we have long-term data on many factors
that might affect delta smelt. For example, we have long-term data on
exports from the southern Delta, daily flows into and through the Delta,
salvage of delta smelt at the export pumps, distribution and abundance
of delta smelt throughout their one-year life, densities and location of
delta smelt prey, and turbidity, salinity, and temperature of Delta
water. We also have data on the prey found in the guts of delta smelt.
We have long-term data on the zooplankton (small floating animals) on
which delta smelt feed, as well as on the phytoplankton (small, floating
plants) consumed by zooplankton. That is not to say we have all the data
we need, but as estuaries and fish problems go, we have lots of data.

**Searching for export effects**

Numerous analysts have worked for years to determine if there is a
relationship between delta smelt abundance and operation of the SWP and
CVP export facilities. I\'ll summarize the analyses most relevant to the
delta smelt question.

-   Dr. Bryan Manly (independent consultant) and Dr. Mike Chotkowski
    (Bureau of Reclamation) searched for river flow and export effects
    on delta smelt abundance. They found a statistically significant
    relationship between rates of exports and delta smelt abundance, but
    they concluded that this relationship could account for a very small
    percentage in the variation of smelt abundance. In other words, the
    effect was small and unimportant relative to the trend in delta
    smelt abundance. Dr. Manly summarized the relationship as follows:
    "I can sum up my conclusions from the analyses that I have done over
    the past few years by saying that so far it appears that river flows
    and exports cannot account for most of the downward trend in delta
    smelt numbers in recent years. Some other change to the system seems
    to have happened in about 1999 to cause the decline. What is
    therefore needed now is further work to better understand the system
    and to identify any important variables that are not currently being
    considered to account for the decline." This finding is important
    for two reasons: First, an effect of exports was found. This
    indicates the analyses were capable of finding such effects. If no
    effect at all were found, one might wonder if the proper analysis
    had been carried out. We would expect *some* effect of exports.
    After all, delta smelt are entrained at the export pumps, and
    because of the fragile nature of this fish (unlike salmon and
    striped bass), few of those salvaged can be returned to the Delta.
    Second, the effects turn out to be unimportant relative to the
    changes in abundance of delta smelt. Manly characterizes the effects
    as one percent or so per year.

-   Subsequently, I analyzed whether export effects were not found
    because exports only affect delta smelt abundance in some years but
    not in others. If this were the case, analyzing data from all years
    could obscure effects only occurring in some years. Delta smelt
    spend most of the year near the confluence of the Sacramento and San
    Joaquin Rivers, 30+ river miles from the export pumps. Smelt migrate
    upstream to spawn in winter. Sometimes a significant fraction of
    their population migrates toward the export pumps, and sometimes
    they do not. So, I searched for export effects only in years when
    delta smelt were closer to the export pumps. I (and Manly) found no
    such effects.

-   Pelagic Organism Decline (POD) studies noted that salvage of delta
    smelt was high in the years of the decline. They assumed this
    coincidence (high salvage, low delta smelt abundance) indicated
    entrainment of delta smelt at the export pumps could be an important
    cause of declining delta smelt abundance. However, finally, POD
    analysts checked for statistically significant relationships between
    any measure of salvage and the subsequent FMWT. They found no
    statistically significant effect. I conclude from this that high
    salvage and low delta smelt abundance were coincidences, rather than
    indication of a cause and effect relationship. This conclusion is
    reinforced by the importance of food limitation to delta smelt
    abundance, described below.

-   Drs. Wim Kimmerer (SF State University), Pete Smith (USGS), Mongan
    and I all independently estimated the percent of the total
    population of delta smelt entrained each year at the export pumps.
    All of us estimated percentages in the range of 30-40% in one year.
    However, no one has been able to find statistically significant
    relationships between annual estimates of percent entrainment and
    subsequent FMWT index or annual changes in the index. These analyses
    suggest two conclusions: First, the estimates may not be correct.
    There are uncertainties inherent in each of them. Second, because
    they might be correct, it would be prudent to assume high
    entrainment events, although unusual, can occur and should be
    prevented.

-   Several representatives from environmental organizations and state
    and federal resource agencies have presented analyses purporting to
    show a relationship between exports and the subsequent FMWT
    abundance index. All of these correlations are spurious for the same
    reason: They do not consider the important effect of "regime
    changes" affecting delta smelt abundance. These correlations result
    from stretching the analysis over all years, both before and after
    the delta smelt decline that occurred in 1981. Such analyses violate
    a fundamental assumption in regression analysis. The fundamental
    assumption necessary to draw reliable conclusions from regression
    analyses is that the models considered include all of the important
    variables in the system, with no important hidden variables. If
    there is a change in the system at some point in time due to unknown
    causes, the effects of known variables can be analyzed either by
    fitting separate models before and after the change, or by including
    terms for changes in the mean level of the response variable and
    changes in regression coefficients. Clear change points can be
    detected from patterns in regression residuals. Failure to allow for
    change points can lead to spurious conclusions about the effects of
    variables. In other words, if delta smelt abundance underwent a step
    decline in 1981, for reasons having little or nothing to do with
    exports, and if this step change is not accounted for in the
    regression analysis, any factor that tended to be high (or low)
    before the step change and low (or high) after the step change may
    show a correlation with delta smelt abundance, even if this factor
    had little or nothing to do with abundance of delta smelt. Exports
    were generally low before 1981 and generally higher after 1981.
    Hence, the spurious correlations.

-   Dr. Bill Bennett (UCD) proposed a "Big Mama" theory hypothesizing
    that high exports before mid-April entrain early hatching delta
    smelt larvae that, if not entrained, would grow into larger spawners
    the next winter. Larger female delta smelt produce more and better
    eggs. This theory has been popular among those who believe exports
    must have important effects on delta smelt abundance. However, the
    theory has two problems. First, long-term data on delta smelt size
    in December show a step decrease in size that has no relationship
    with the recent decline in delta smelt abundance. It occurred around
    1990; the smelt decline began in 1999, when the December size was
    level. Second, the theory does not account for the demonstrated
    importance of food limitation in determining the size of spawning
    delta smelt. Put another way, there are two ways to become a Big
    Mama: hatch early and grow for a longer time or eat well after you
    hatch. Well-fed delta smelt at the delta smelt culture facility grow
    so fast that they spawn in October rather than waiting until March.
    So, besides the evidence of food limitation discussed below, we know
    from actual data on delta smelt that food is important to spawning
    size.

-   Dr. Ted Sommer, and associates (Department of Water Resources), in a
    study conducted for the Pelagic Organism Decline effort, looked for
    declines in residence time of water in the Delta during the period
    of the recent decline in delta smelt abundance. Residence time could
    be affected by exports. They did not find evidence of a major shift
    in residence time. In fact, they observed that residence times may
    have increased slightly in the San Joaquin River.

**Implications for managing exports**

Taken together, these analyses indicate the following principles for
managing exports with regard to delta smelt:

1.  No rigorous scientific analysis indicates entrainment of delta smelt
    at the export pumps caused the recent decline in delta smelt
    abundance. Moreover, there is no scientific analysis that
    demonstrates that controlling exports will contribute to the
    prevention of extinction or achievement of recovery of the species.
    Therefore, routine management of exports or river flows to minimize
    entrainment (or take) of delta smelt as a means of preventing
    extinction or achieving recovery is futile.

2.  Because analyses indicate that unusually high entrainment events
    have occurred in the past, exports and other water project
    operations should be managed to prevent such occurrences in the
    future. This should be done by real-time monitoring of the
    distribution of sub-adult, spawning adult, and larval-juvenile delta
    smelt, coupled with judicious use of mathematical Particle Tracking
    Models and close monitoring of river flows and turbidity related to
    entrainment.

**The importance of food**

If exports or entrainment did not cause the decline in delta smelt
abundance, what did? I summarize below recent analyses related to this
question.

-   Dr. Bill Bennett "autopsied" 100+ delta smelt and found most of them
    were food limited in the summer.

-   Mongan and I, keying on Bennett's finding, analyzed the
    co-occurrence of delta smelt and their primary prey (the two alien
    zooplankton, *Eurytemora affinis* and *Pseudodiaptomus forbesi*) in
    July. We found a good correlation for the period 1981-2006 between,
    on the one hand, July co-occurrence of delta smelt and density of
    the two zooplankton and, on the other hand, the subsequent FMWT
    abundance index. This was the first correlation with an obvious
    explanation (delta smelt must feed to survive) ever found between
    any factors and the subsequent FMWT.

-   Dr. Anke Mueller-Solger, Department of Water Resources, noted that
    after 1996, the FMWT index depends solely on July delta smelt
    abundance. That is, the co-occurrence with prey was not necessary in
    recent years. She concluded from this and other analyses that food
    limitation was not the problem. However, this conclusion rests on
    the questionable assumption that delta smelt feed equally well on
    yet another recently introduced alien zooplankton, *Limnoithona
    tetraspina*, as they do on their established favored prey,
    *Eurytemora* and *Pseudodiaptomu*s. Without this assumption, there
    is a clear drop in prey densities. *Limnoithona* now occur at
    extraordinarily high densities in July in delta smelt habitat.
    However, *Limnoithona* were not found in the guts of delta smelt
    examined in 2005, when Limnoithona levels were merely high, but were
    found in 2006 when they were extraordinarily high. Individual
    *Limnoithona* are much smaller than both *Eurytemora* and
    *Pseudodiaptomus*, so more energy is required by delta smelt to
    capture *Limnoithona*. It is possible that, rather than being a good
    source of food for delta smelt, *Limnoithona* are starvation rations
    that may interfere with survival by being so numerous and requiring
    so much more energy to capture.

-   We attempted to find out what determined delta smelt abundance in
    July. We discovered an even better correlation between late-April
    co-occurrence of delta smelt and their primary springtime prey,
    *Eurytemora*, and the subsequent FMWT abundance index for 1997-2005.
    This is the period when July abundance determines the FMWT index. As
    mentioned above, the FMWT index is closely related to subsequent
    winter spawning abundance. Using the relationship developed for
    1997-2005, we can predict the FMWT abundance index from the previous
    year's index and the co-occurrence of delta smelt and *Eurytemora*
    in late April. Predicted and actual FMWT index values are shown
    below. The predicted line uses only one estimate of delta smelt
    abundance, the FMWT index of 1996. From that index and annual
    late-April densities of *Eurytemora* and distribution of delta smelt
    (not their abundance), the next nine years of FMWT indices can be
    predicted. Exports and entrainment of delta smelt at the export
    pumps is not a factor in this prediction. It is solely determined by
    *Eurytemora* densities in areas where delta smelt are in late April.
    I conclude from these analyses that the problem with delta smelt is
    a significant drop in the densities of their prey, initially in the
    summer and, in recent years, in the spring. Why this drop occurred
    is a mystery. If it were caused by exports, exports would show up as
    an important factor affecting delta smelt abundance, but the data do
    not support that possibility. Something else must be affecting the
    zooplankton that delta smelt prey on. If we could identify those
    factors and do something about them, we might be able to save the
    delta smelt. No reliable, statistically significant analyses suggest
    we can save delta smelt or cause their recovery by managing exports
    or entrainment.

![](media/image2.wmf){width="5.991666666666666in"
height="3.816666666666667in"}

**Conclusion**

One might reasonably ask how it is possible that so much emphasis is put
on exports as the cause of the delta smelt abundance decline if there
are no reliable analyses supporting this belief and several analyses
indicating that food is the problem. An answer can be found in the
report of outside experts, the Review Panel for the Pelagic Organism
Decline Program. These panelists are listed below.

> Mark D. Bertness, Brown University
>
> Stephen M. Bollens, Washington State University Vancouver
>
> James H. Cowan, Louisiana State University
>
> Ronald T. Knelb, University of Georgia Marine Institute
>
> Parker MacCready, University of Washington
>
> Russell A. Moll, California Sea Grant College Program
>
> Paul E. Smith, Scripps Institution of Oceanography
>
> Andrew R. Solow, Woods Hole Oceanographic Institution
>
> Robert B. Spies, Applied Marine Sciences

Their first conclusion concerning "weaknesses" of the Pelagic Organism
Decline Program in their December 2005 report is as follows:

> "The program relies too heavily on local perspectives and resources
> for problem analysis, research and solutions. This can give rise to a
> culture of common assumptions that impedes alternative possibilities."

I agree with this conclusion. The belief that exports have important
effects on delta smelt and other fish has been a fundamental tenet of
Delta water project management for years. It has proven to be an
unfounded belief for striped bass and salmon, and many analyses of the
wealth of data in this estuary indicate it is also unfounded for delta
smelt. Nevertheless, as evidenced by the title of this hearing, it
remains a powerful paradigm, contrary to the science, and to the
detriment of delta smelt.