California Water Policy Seminar Series continues with Peter Moyle: The future of freshwater fishes in California

peter moyleThe UC Davis California Water Policy Seminar Series continued on February 11, 2013, with California fish expert Peter B. Moyle, professor and former Chair of the Department of Wildlife, Fish and Conservation Biology as the featured speaker.  Peter Moyle has spent over 40 years studying the ecology and conservation of California’s freshwater and estuarine species, and is an author or co-author on more than 170 publications.  During his speech, Mr. Moyle shared his personal history with the Delta smelt, gave his outlook for the future of California’s freshwater fishes, and discussed what can be done to conserve California’s native species.

Peter Moyle began by showing a picture of the Delta smelt and asking what words came to mind when thinking about the Delta smelt.   Endemic? Controversial?  Yes, it’s all of those things, he said.

The Delta smelt is a small rare fish that’s highly controversial because it’s in the middle of California’s water distribution system.  You can’t do anything with water in California unless you deal with Delta smelt, at least nothing that involves the Delta,” Mr. Moyle said, noting that he had a long history with the Delta smelt.

In the mid 1970s while working on the first edition of his book on California fish, Mr. Moyle went out with the Department of Fish and Game on a few midwater trawls, which was aimed at sampling juvenile striped bass. “All the water decisions, all the decisions were made to favor striped bass because it was the el primo game fish in the system.  That was what people really cared about.  Nobody even knew much about the smelt,” he said, noting that “DFG was concerned that the big pumps that were just getting online in the south Delta were going to affect striped bass populations.”

What impressed me when I got on that boat and noticed the sampling was how many smelt there were in their samples, both of delta and longfin smelt; hundreds at a single trawl,” said Mr. Moyle.  Future of Native fish_Page_02Nobody knew much about the smelt, and thinking it would be good to study it, “I asked Lee Miller who was the biologist in charge, if he could start saving Delta smelt for me so I could do a basic life history study.  So Lee said, glad to do it.  A few months later, a DFG pulls up to my lab and it literally was a 1-ton truck piled high with crates full of smelt: jars and jars full of pickled smelt. … That study resulted in me becoming the world’s expert on Delta smelt – not that anyone at the time really cared,” he said.

From the study, Mr. Moyle discovered that the Delta smelt spends its entire life in the estuary; it eats zooplankton; it spawns in fresh water but lives in brackish water; it doesn’t reproduce at a rapid rate; and it has a one year life cycle:  “It’s pretty remarkable for a fish that lives in that dynamic environment because it means that at any time, the conditions somewhere in the estuary are right for that fish,” he said, noting that the Delta smelt is rarely eaten by other fish, due to its semi-transparency and its behavior that makes it almost invisible

In 1979, Mr. Moyle started his own sampling program studying the fishes of Suisun Marsh, just downstream from the Delta.  “This program involved monthly sampling of fish, and in those samples were Delta smelt,” he said.  “And when I started out, just as in the DFG sampling, Delta smelt were pretty common in our samples.  But then around the mid 1980s, 1985, 86, I started noticing we weren’t getting very many smelt anymore.  This prompted me to start looking at the data from the other sampling programs going on in the estuary, and there I found the same trend.”

The crashing Delta smelt population was coincident with both the long term drought that was occurring at the time and with the steady increase in exports from the pumps in the south Delta, he said.  “So with the help from Bruce Herbold … I wrote up an analysis of the situation and started circulating drafts of a paper.  Then, at the same time, in August of 1989, I took a sabbatical leave to do some serious writing, but instead of writing another version of my book, I wrote a petition to list the Delta smelt as a threatened species under the state endangered species act.”  He did so because felt a personal responsibility:  “I was the world’s expert on Delta smelt at the time so it was my responsibility to let people know that this fish was in serious trouble.“  Figuring the petition could be controversial and since it seemed to be a California issue, Mr. Moyle filed the petition only with the state: “I thought there would be more flexibility in dealing with water issues if it was only under the state act.”

In August of 1990, Mr. Moyle was invited to attend a commission meeting in Sacramento to discuss the petition.  “The decision making body for the petition was the DFG which is made up of businessmen who like to hunt and fish.  These are not biologists, they are political appointees to this decision making body.  Their major interest really is hunting and fishing regulations,” he said.

Mr. Moyle continued: “I walk into this small auditorium and find it’s packed.  Every major environmental group had representatives there, most of the water agencies and interests had representatives there, and I realized at that point that maybe this was a little more than I was asking for.  So I made a short presentation about the biology of the smelt and why I thought it was in trouble.  That was followed by questions and discussion by the commissioners.”

Finally, one of the commissioners asked me if improving conditions for Delta smelt will require changing the operation of the pumps in the south Delta.  And I replied something like, ‘well, yeah, I think it’s likely, there’s an association there.’  The response was almost immediate on the part of that commissioner, he said ‘well, we can’t really list the smelt, can we, because you certainly can’t interfere with the water supply,’” recalled Mr. Moyle.  “The commissioners were all sort of nodding their heads in agreement, and at about that time, the chair of the commission started asking for a vote, and the commission’s lawyer stood up at that point and said, ‘gentleman, you cannot use this as a reason for not listing the species – the interference with export of water from the Delta’. So the commissioners asked the lawyer, ‘well then, what is a good reason?’  And he said, ‘you can say you have insufficient information.’  The commissioners said, ‘that sounds like a good reason,’ ‘all in favor, aye,’ and the decision not to list was unanimous.”

However, three months earlier, the local chapter of the American Fisheries Society had asked if they could file a petition with the federal government to the Fish and Wildlife Service, “so they took what I had written and converted it into the federal format.  I somewhat reluctantly agreed. I really felt this was a state issue and the state should be in charge of handling it, but then in 1993, the delta smelt was listed as a threatened species by the USFWS, and ironically, the DFG turned around and immediately listed it as a state species as well, because they knew they wouldn’t be a player in the game if it wasn’t listed by the state.”

Once listed, Mr. Moyle headed up the team to write the Future of Native fish_Page_04recovery plan:  “During the early discussion on how to do this, I asked if we could make it a recovery plan for declining native fishes in the Delta, because I had noticed that it wasn’t just the Delta smelt that was declining, there were other species out there that seemed to be in trouble as well. So everybody thought doing a Delta native fishes recovery plan was a great idea, and maybe we could prevent the listing of some of these other species,” he said.  The document was completed within a year, turned in to the USFWS, where the document was ‘put on a high shelf in a back office and pretty much ignored.’  “As it turns out that the listing is so important, if the species are not listed, there’s no reason to work on the fish.  The agencies were so busy with listed species, they didn’t have time for the unlisted ones in order to prevent them from being listed,” he said.

Meanwhile, in the Delta, water exports and diversions continued to increase, environmental conditions continued to deteriorate, the smelt continued to decline, and one by one, the species in the recovery plan have been listed, said Mr. Moyle: “I’ve done such a great job saving native fish that the Delta smelt is closer to extinction now more than ever, and the other Delta fishes are waiting in the queue.  I’ve been tempted to create a graph showing my number of publications versus the status of fish in California – I fear there’s a direct negative correlation,” he joked.

The fate of the Delta smelt and other fishes are mostly decided in the courtrooms these days, but the listing has given the FWS considerable control over exports, he said, Future of Native fish_Page_05noting that just last week, a reduction in export pumping was ordered because the number of smelt being killed at the pumps was close to the allowable limit.

So the Delta smelt continues to be controversial and it continues to be a scapegoat for poor water management.  If you go to the Central Valley, it’s regarded as the evil incarnate, the reason why there is not enough water for farming, so some people say.  It does reflect this general problem we have with our water in California,” said Mr. Moyle.

It is the mission of the Delta Stewardship Council to meet the coequal goals of water supply reliability and water for the environment, and really that water for the environment translates to water for fish, Future of Native fish_Page_07because that’s what we know, that’s where the data is, and the fish most emblematic species,” he said.

However, it’s very hard for fish to be coequal, he said.  The fish are mostly in northern California, the water demand is in Southern California and the San Joaquin Valley, and that obviously presents a very difficult situation for the fish.  “We are the society that has this hydrodynamic system that moves water everywhere throughout the state.  It’s really a very amazing system, but it’s very hard on the fish.”

The fish are starting from a low point, especially when you consider how much habitat is now behind Future of Native fish_Page_08dams or levees they cannot get to, or all the wetlands that are no longer available.  “So when you talk about coequal goals, you have to realize that it’s coequal, but not really.  The water users have a lot of water they’ve been taking out of the system, not just from the Delta pumps but from all the diversions, and the fish have always gotten the short end of the stick, so they are starting now from a very low point.”

California has an endemic fauna.  Out of the state’s fishes, 79% are native.  “Most of the fish found in California are only found in California, so these are California problems, and just as most of the water that we distribute around the state originates in the state, the fish are there as well.  So this gives us a special responsibility is one way I look at it,” he said.

Future of Native fish_Page_11Out of the state’s 122 fish species, 23% are already listed, 22% are recommended for listing, and another 28% are vulnerable, meaning they are on the path to being listed.  “Only 27% we regarded as being reasonable secure, or, in other words, 73% of the fish in California are in trouble,” he said.

These declining species are not just species like Delta smelt; they include salmon, trout, and other gamefish in the state, both sport fish and commercial species, Mr. Moyle said. For example, Chinook salmon populations in the Central Valley are highly unpredictable.  In 2008-2009, only 40,000 came back and they closed the fishery.  This year, we’re back up to 820,000 fish returning, he noted.  Future of Native fish_Page_13The official goal of the CVP is to restore salmon numbers back to somewhat close to their historic numbers, that of wild fish, not just hatchery fish.  …  90% of the fish coming back are hatchery fish, and mostly fall run,” he said.

Now you say what’s the problem? Well these hatchery fish are the reason why you see these high fluctuations …  Things have to be just right for these fish; they are domestic animals essentially, we’re sending these fish out to graze in the meadows of the ocean, and those meadows better be in really good shape and have lots of stuff for the fish to eat to survive,” he said, noting that with wild fish, they tend to go out at different times so it’s much less of an issue.

The status and trends of California fishes for the last 35 years is not good.  Future of Native fish_Page_16Back in 1975 [when I finished my first book], about 60% of the fish I regarded as being in pretty good shape.  Today it’s between 15% and 20%.  Nine species were listed in 1975; 28 species being listed today.  Obviously this is not a good trend for the fish populations in California.”  And there have been extinctions: the thicktail chub was last found in 1957, and the bull trout was last tagged in 1975, he said.

There are also a lot of nonnative fishes that have been introduced into the state, and they are part of the problem; there are 50 species of nonnative species, and they tend to dominate in more disturbed environments.

How will climate change affect the fishes?  “Climate change is going to affect fish habitat in lots of different ways.  Three to six degree rise in temperature in the next 50 – 100 years, maybe even more than that … there will be more rain, less snow, more variability in flows.  The snow melt is going to become much more erratic, we’ll have longer droughts and bigger floods, that’s almost for certain, and generally decreased summer stream flow,” he explained, adding “climate change is not good for fish, even without all the infrastructure we have around.”

Mr. Moyle recently finished a study that evaluated the vulnerability of California’s fish species of extinction in the next 100 years due to climate change.  Future of Native fish_Page_21The study showed that most of the native fishes have either critically or highly vulnerability to climate change meaning their probability of extinction in the next 100 years is very high.” He noted that these fish that are in trouble from other reasons as well:  “83% of the native fishes are in trouble, but you’ll notice that only 19% of the alien fishes are in trouble.  That tells you that our aquatic ecosystems are, from a fish perspective, going to be shifting away from native fish and towards nonnative fish,” he said, adding: “we’ll be part of this homogenization of the fish fauna of the United States that we’ve seen already.  The same fish you have in Connecticut you’ll find here, the same fish you find in Spain and Portugal, you’ll find here in California.  There is this worldwide homogenization of the fauna.  It’s pretty boring; it would be nice if we could hang on to our own fish.”

Mr. Moyle continued: “So here are the conclusions: California has this water crisis, and it’s a freshwater crisis. 42% of our fish are extinct or imperiled; 73% of the taxa are vulnerable to extinction, and 83% are vulnerable to climate change.  That’s a pretty depressing picture when you start thinking about what’s going on.  Most native species face severe decline or extinction, and most waterways will become dominated by nonnative fish – if present trends continue.”

I am an optimist and this is what I like to talk about, some of the more optimistic scenarios we have here,” Future of Native fish_Page_25he said, recommending the book he co-authored, Managing California’s Water: From Conflict to Reconciliation, for those who are interested in California water issues.  The book discusses a new approach: “What we have to do to make this work is shift to ‘ecological reconciliation approaches’ which is simply a way of saying that we’ve got to integrate conservation into the places where we humans live and work and play.  Reconciliation means that trying to protect species by setting aside pristine areas is not going to work by itself.  Its part of the strategies, but it’s not enough,” he said, noting that there’s really no such thing as a pristine stream in California anyway.  “They all have nonnative fishes or invertebrates in them; they are all altered to one degree or another.“

The Endangered Species Act, the Clean Water Act, the decline of native species, and climate change; increasing water demand, increasing costs of water, increasing costs of conservation as well as a greater appreciation in California of the value of our native species, all of these are all driving us towards a reconciliation approach. Future of Native fish_Page_27And new realities face us: most of the ecosystems in this state are what you can call novel ecosystems; they are ecosystems that exist in highly disturbed environments with a high percentage of the species being nonnative,” he said.

For example: “The Delta ecosystem today bears almost no resemblance to the historic Delta, not only physically, but also in terms of the flora and fauna.  Most of the fish in the Delta, depending on where you are, are nonnative fish; the dominant aquatic plants are nonnative and the dominant invertebrates are nonnative, so this is a novel ecosystem,” he said.  “It is groups of species that have never occurred together before that are having to figure this out.  How do we be an ecosystem?  How do we work together?  The amazing thing is that critters do figure it out if you can stabilize the system, even a little bit.”

Part of the new reality is that new nonnative species will continue to arrive.  “We should be able to stop it, but we seem to lack the will and the wherewithal to do it.  Zebra mussels and quagga mussels are on their way; they’ll be in the Delta presumably within the next 20 years, no matter how hard we try, and we aren’t trying terribly hard right now,” he said.  And all our ecosystems are dominated by people.  We’re still faced with population growth, which will mean increased demands for goods and services.

However, there’s this growing realization that these ecosystems, even if they are novel ecosystems, provide a lot of services to us, Mr. Moyle said:  “They provide fisheries, they provide clean water, they do lots of things that are good for us and that save us money if we maintain a healthy ecosystem.”

How do we shift to ecological reconciliation approaches?  First, we need to develop a Future of Native fish_Page_29statewide strategy for aquatic conservation, he said, noting that the Watershed Center is hoping to concentrate on this in the next few years.  “It’s something I’ve been working on for decades in many respects.  It involves time, money, and a lot of effort statewide to manipulate environments that people maybe don’t want manipulated,” he said, “but it has to be systematic: we have to have a strategy that protects examples of all major habitats.  Ideally there will be self sustaining populations of native species because we can’t depend on hatcheries to keep everything going.  And we have to think of fish and macroinvertebrates as umbrella species.”

There are a number of places in California that are very nice and worthy of preservation, said Mr. Moyle; they are not pristine, but they are very close to it.  Mr. Moyle has been working with the Western Rivers Conservancy on Blue Creek, a tributary to the Klamath River.  Future of Native fish_Page_31The watershed has been logged; the headwaters are in forest service land and forest service wilderness, and the bottom reaches are gradually being sold to the Yurok Tribe.  The Yurok Tribe wants to make this into a tribal park and salmon sanctuary, and they’ve already declared it as such, he said.  “The idea is to get this entire watershed protected … you can get the trees to grow back and you can recreate, over a fairly long period of time, a fully functioning tributary system to the Klamath River that will have all the species of salmon in it that are currently in the Klamath Basin.  This is a very ambitious project; and if anyone has a few million dollars in their pocket, this is a very good cause.”

Future of Native fish_Page_34
Big Springs, before restoration

Restoration is still part of the toolbox, noted Mr. Moyle, “especially focusing on areas where you can get a lot of bang for your buck.”  One successful restoration project is the Big Springs Area on the Shasta River, another tributary to the Klamath.  “The Shasta River is a spring fed river, and one of the biggest springs is Big Springs.  This is an absolutely an amazing spot; it’s been in private hands until the Nature Conservancy bought it a few years ago.”

Future of Native fish_Page_35
Big Springs, one year later

The stream had been devastated by cows:  “Literally this water is the same temperature all year round, so in the winter, all the cows would move into the water and graze the vegetation in the water because it was warmer in the water than out in the air.  Obviously, that was very hard on the fish and on the habitat.  The amazing thing is here that once the Nature Conservancy acquired it and fenced it off to keep the cows out, within a year, it made a truly astonishing recovery,” he said.  The channel in the middle is deep, it’s full of fish and invertebrates, and the vegetation has come back.  “It’s a very rich environment for fish, fat little salmon … the bottom is just coated with food … big schools of little Chinook salmon, hanging out, growing extremely fast in this environment. This happened in a couple of years,” he said, noting if you do get to the right place at the right time, there’s a lot you can do.

Another thing we can do is change the way we operate dams, Mr. Moyle said.  “The reality is most streams in California are dammed.  If we want to get these big salmon back, we have to reoperate the dams with salmon in mind,” he said, noting that we have a lot of tools around to do this, such as “Future of Native fish_Page_42Section 5937 of the Fish and Game code, which is really a statement of the public trust doctrine … This is what it says:  ‘the owner of any dam shall allow sufficient water at all times to pass through a fishway or in the absence of a fishway, allow sufficient water to pass over, around, or through the dam to keep in good condition any fish that may be planted or exist below the dam.’  This language has been around for 100 years.  It’s pretty unequivocal, and it’s very seldom used.  I think now times are changing so that it is going to be used more. … This is a law that has not been systematically applied in this state the way it needs to be.”

As an example,Future of Native fish_Page_43 Putah Creek, which flows right past the UC Davis campus, was basically drying up, and where it wasn’t dry, it was full of nonnative fish, he said. When Section 5937 was applied to the flows below the Putah Creek Diversion Dam, a very healthy stream system developed, and it took a relatively small amount of water.  “Today it’s mostly full of native fish and at a relatively low water cost to the Solano Water Agency.  So the reoperation of dams has a lot of potential,” he said.

Dam removal is another tool.  There are a lot of worthless and low value dams around, he said, however, these things are never all that obvious.  For example, Daguerre Point Dam on the Yuba River is on everybody’s list of dams to remove.  “Future of Native fish_Page_45And yet when a grad student of mine did a study there a few years ago, he found the dam was the site of an abrupt shift in the fish fauna.  Basically it was salmon, steelhead, and native fishes above the dam, a lot of the same native species below the dam but in fewer numbers and a lot more nonnative fish.  So it may be from an ecological perspective, this is a dam you may want to keep,” he said.  “This is the kind of flexibility we have to be talking about in terms of our management of dams.”

Restoration and management of flood plains is another tool.  The classic example is the Yolo Bypass: “When the Yolo Bypass when flooded, it’s good for salmon and for other native fishes like the Sacramento splittail.”  Another example is the Cosumnes River floodplain, which we’ve been studying for a number of years, he said.  Future of Native fish_Page_46Salmon get much bigger if they are raised on a floodplain rather than in the river; “they hang out longer and they go out to sea at the right times, so restoring floodplains is clearly a big thing in the future.”

We have to fix the hatchery system.  The hatchery system right now is not working; it’s sending all these semi-domestic fish out to sea that are disrupting wild populations and they are unable to respond and unable to adapt to changing conditions.  So somehow we need a major fix in the hatchery system to make it fit wild fish better and to make it a way get a return on our investment,” he said.

And of course … we’ve got to fix the Delta.  “This is the water hub; a changing ecosystem; it’s got precarious levees and it’s full of endangered species, so what actions can we take to improve the Delta for desirable fishes?” he said.  Future of Native fish_Page_50Create a favorable flow regime, reduce the key alien species, improve water quality: “there’s a whole list of things that you can do, but they are all individual actions that have to be coordinated and they tend to be expensive and they have be done in a way that is adaptive so that we really learn from the experiments that we’re doing out there.”

The big question is, should we build this peripheral canal, the tunnel, the pipe, the garden hose, whatever you want to call it?  This is being is sold as the answers to the Delta’s problems because you can separate water diversion from ecosystem services.  You establish your coequal goals, you reach those goals by separating those two functions, the environment and the water diversion.  Future of Native fish_Page_51Whether that will really work or not is anybody’s guess,” he said.

At this point, Mr. Moyle took questions.

Question: What would a new conveyance system do for native fishes?

Mr. Moyle answered:  “It depends upon which water conveyance system you’re talking about.  The present water conveyance system … it’s not very good for native fish; we know that because those things are going on right now and the native fish are in decline.  So some kind of separation of extraction of export of water from Delta functions has to be done.  Whether or not you can do this with a pipe or peripheral canal is really a hard question.

When we wrote our first report on the Delta, what we said the best thing to do for the fish is to shut down the pumps.  Well, that’s not going to happen, so what’s the next best thing you can do.  It seems to be this.  Although when you talk about the pipes or the canal, there’s a lot of trust involve that these structures can in fact work the way some people think they will work, and that if they don’t work very well, that we can find other ways of operating them or so forth.

One of the aspects of these kinds of facilities is that they are a potential source of money for conservation.  You can essentially make it part of the cost of these to have a big chunk of money available as part of the cost for restoration in other parts of the Delta, and that might be good for fish.

The problem is habitat restoration is that you have water that can interact with that habitat.  I don’t have any answers, unfortunately.”

Question: What do you do about nonnative fish?

Answer:  “You can’t get rid of them.  They are here.  In very limited places you can poison them out with special fish poisons, but for the most part, we have to live with them which is why I talk about novel ecosystems.  You try and manage your waterways in ways that favor as much as possible the native species, recognizing the nonnatives are still going to be there.

Putah Creek is actually a good example of that.  The flow regime we designed results in about 80% native fish and 20% nonnative fish for most of the creek.  It was just the opposite before we instituted the flow regime.  A flow regime that includes spring spawning flows, that really gives them a leg up on the nonnative fishes, works pretty well for Putah Creek.  It’s now going to be tried in the San Joaquin River to see if it will work on a bigger scale.

So the only way we can deal with nonnative fishes is to manage the environment in ways that favor the natives and don’t favor the nonnatives, but we have to live with them, no question about that.”


  • Click here to watch Peter Moyle’s speech.
  • Click here for Managine California’s Water: From Conflict to Reconciliation
  • Click here to look for posts of the other speakers in the California Water Policy Seminar Series.
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