Recording. This is Paul, her and Jennifer Sweeney of Arizona State
University interviewing Richard Valdez at the SWC A offices in Salt Lake
City on March 4th 2020. Rich. Thanks for uh interviewing with us today.
Thank you for asking me. Would you just start out by telling us um, the
positions that you've held in the Adaptive Management Program over the
years and the years that you were participating? Yeah. Thank you. I um I
started working um in the Grand Canyon with Glen Canyon Dam operations and
in 1989 that was when it was the Glen Canyon environmental studies. G ce S
under Dave Wagner and the Bureau of Reclamation. And uh at that time, I
was contracted to do a life history and ecology of the Humpback job
through the Grand Canyon. So that was my first time there. And as a result
of that involvement, I also did some other things. I worked some with the
wallaby tribe. So we extended a lot of our investigations below Diamond
Creek all the way to Pearce ferry. So we were doing about 275 280 miles of
the river that we were surveying for fish populations. And with that, uh I
, I then was asked to convene several panels of scientists, one in 1999 to
look at the possibility of a second population of Humpback chub in the
Grand Canyon. And I met with geneticists and biologists to look at ideas
of how to start Humpback job in the Grand Canyon. That was about 1999.
In 2000, I was involved in the low steady summer flow experiment. I did
the fisheries evaluation of that experiment. And then in um in 2003, I was
part of a team of scientists that were looking at the possibility of a
temperature control device for Glen Canyon Dam. And that was being co
ordinated by the Bureau of Reclamation.
And in 2004, I co ordinated a survey of some of the tributaries in the
Grand Canyon with Steve Carruthers. So we looked not only at the main stem
but also fisheries populations in places like Shinan or Bright Angel Creek
or Havasu Creek and some of the others in the system. And then in, in 2010
, I was asked by the,
the Bureau of reclamation to convene a science panel on reintroducing
razorback sucker into the Grand Canyon. And uh and then in, in 2012, I was
asked to convene another science panel by the seven Colorado River Basin
States to evaluate possible alternatives that would become part of the
2016 temp eis temp was of course the long term experimental management
program for the Glen Canyon Dam. And then, and then most recently, uh, I
was, uh, asked to be a member of the Brown Trout management team, looking
at options of how to manage brown trout, worked with, uh, Mike runs and
Charles Yule to look at the options of how to manage brown trout and
reduce predation by brown trout on, uh, on Humpback chub and on other
trout species in the system, especially in the tail water. So it's pretty
much banned from about 1989 to here. Most recently, 2019. It's a nice long
tenure. Um, how much of the work that you did was, uh, say contract
research work with SWC A versus work, um, directly as a participant in the
Glen Canny Dam Adaptive Management Program, like with AM Wig or Twig, can
you? Yeah, most of it was contract work. Most of it was contract work
either either through Biow West or through SWC A. And the Biow West work
was that initial study of fisheries, the life history ecology of Humpback
job through the, through the canyon. And then the subsequent to that, it's
been through Biow West and I was involved in a number of Am Wig and Twig
meetings, but pretty much always as a, as a linkage to one of these two
companies, correct? So let's drill down a bit on, um, the role of the
Humpback Chub in the Adaptive Management program, you're probably gonna be
the most knowledgeable expert we interview on the life history and the
status and the recovery efforts of the Humpback Chub. So, talk a little
bit about how that all got started and developed over time. Yeah, it, it,
it's an important part of, uh, of the Glen Canyon Dam operations because
the Humpback Chub is perhaps one of the keystone species, if not the
keystone species for, for that particular project in that operation. Um
I've been uh the, the recovery team leader for the Humpback Chub recovery
team since 2015. So it's put me close to some of the populations, not only
in the Grand Canyon but in the upper basin as well. But the interesting
part about it is the, the genesis of how the Humpback chub came into the
important and significance that it holds in the Grand Canyon. I started
working in the upper Colorado River basin in 1968 with a fellow graduate
student, he was doing work on the Colorado and Green Rivers and I was
doing work in Alaska. So we would trade trade off helping each other. And
uh after that, then I was um uh I got involved in some of the work earlier
research. Now, this is before the endangered Species Act was passed in
1973. And at that time, um the Humpback chub and the, what was at that
time known as the Colorado squaw fish. It is now called the Colorado pike
minnow. At that time, those species were included under the Endangered
Species Conservation Act, the Preservation Act of 66 and then the
Conservation Act of 69 prior to the passage of ES A. So, uh in 1973 when
uh the endangered species act was, was enacted and signed by President
Nixon, those species then became part of this suite of, of species in this
country that people had to protect somehow but no one, no one knew exactly
how to do it. And so I was in on some of the original uh environmental
impact statements, the eas that affected some of these species uh that,
that, that took place in the uh especially in the upper Colorado River
basin. But it's interesting to note that that in um and I was with fish
and wildlife service starting in 1979
I was hired by the service to start a field station in Grand Junction,
Colorado to do that specifically to evaluate the distribution and
abundance of these fish in the upper Colorado river basin. So above Lake
Powell, basically and in and in and until 1980 from the time that the act
was, was passed in 73 we had these biological opinions that all declared
jeopardy. In other words, that the action would, would likely continue to
jeopardy or continue to jeopardize the existence of the species. Um in
1980 with the, with the amendments to the endangered species Act, that a
concept of reasonable and prudent alternatives was then put into the act
which really opened the door and allowed agencies now to start doing good
things for the species to offset or mitigate those potential bad things.
And that, that became the heart of what became then the Glen Canyon Dam
eis is basically those reasonable and prudent alternatives that were put
forward. Now, the first E I was done, of course, in 1995 when the Humpback
job was, was listed and the biological opinion was under a jeopardy
determination. In other words, it was declared that the operation of Glen
Canyon Dam was likely to jeopardize the continued existence of the species
that changed in 2008
when the service came up with a non jeopardy determination and decided
that instead they would go with conservation measures which were finalized
in 2010. So now we have an agency or agencies, the Bureau of Reclamation
and the Park Service in that case that we're looking at ways to do things
better as a way to benefit, not just to mitigate the potential jeopardy
effects, but also to benefit the species. So, so the Humpback chub
underwent uh a whole, I think evolution of understanding of how that
species worked out with the endangered species Act, how they act was going
to apply to that species specifically. And the Grand Canyon became kind of
the the stage for that to all take place where the Grand Canyon supported
the largest population of Humpback chub known in the basin. There were six
other populations in the upper basin, but they were all smaller. But the
Humpback job was the main driver. I think of a lot of the actions that
took place in that system and actions in terms of modifying dam operations
or actions, in terms of improving habitat or reducing predation, all of
those things, it was all of those things. And initially, as a, as a fish
biologist, my first reaction to seeing a uh a large dam put in the middle
of a river that used to be occupied by these, these fish was that of
course, that dam, first of all backed up Lake Powell for about 200 miles
and that meant there was 200 miles of river that were under a lake. So it
eliminated that habitat to the species. And these are not lake dwellers
except for the Razorback sucker. Uh the Humpback chub and the pike minnow
don't do well in lakes or reservoirs. So that eliminated that habitat. But
also what the dam did is it was now drawing water from the, from the
depths of the reservoir. What is known as the Hypo Limn and that's the
coal region. So you had coal releases going downstream that we all knew
was not good for the warm water native fish like Humpback chop. So our
first reaction was to and then I I talk II I say that collectively for
most fish biologists was to say we're going to somehow need to offset that
cold water coming out of the dam by some kind of temperature control
devices. So the T CD became a pretty important and controversial. I might
say uh proposal starting in about 2002 or 2003 where some of us were
advocating to have the dam modified to allow warmer water, warmer, more
surface water to be released and warm the water downstream. For the
Humpback chub.
In retrospect, as it turns out, that probably was
a lack or a not a good enough understanding by the biologist to really
know what was going on. As it turns out, it could be, it could very well
be that the coal releases have been part of the savings grace for the
Humpback job in Grand Canyon. So in that those coal releases now prevent
or at least inhibit other non native warm water fish that are predators or
competitors to the Humpback job from entering and coming into the system.
And in addition to that, the Humpback chub in the Grand Canyon has been
using the little Colorado River which is a seasonally warm system for
spawning. So it made and and still does. It makes for an ideal situation
for that fish to be able to live as adults in the main stem and then
migrate annually into the little Colorado River and spawn in warmer water.
And then they're young, then descend down into the main stem. So that's
the way, that's the way the situation is today. And, and we didn't know
that. Of course, at that time, many of us were advocating to have a
temperature control device. And in fact, uh we had a series of meetings
with the bureau of reclamation and many scientists and in fact,
reclamation even did a, a rough estimate of what it would cost to put in a
a uh uh a select what's known as a selective withdrawal temperature
control device, which would mean that that the uh the gates at the pen
stocks where the water leaves the reservoir and goes through the dam, the
gates would be modified with elevators so that they would, you'd have the
op the option of basically withdrawing water from any level that you want
within a given range. So you could mix it warm with cold and get target
temperatures. The only problem was that the estimated price tag was about
$100 million
and that of course, raised many eyebrows and caused much concern as to how
serious we really wanted to get about that proposal. Mhm.
So um
so one of the lessons we learned, I think as scientists in, in going
through Glen Canyon Dam and evaluating the effects and sitting to sitting
down together and coming up with different alternatives was that in the
end, uh it's Mother Nature that really drives everything. And as we were
considering a temperature control device, of course, the elevations of
both Lake Powell and Lake Mead were dropping and with a decline in
elevation of uh of Lake Powell, we now started to see warm water being
released from the reservoir by warm. I mean, what had been 10 °C 8 to 10
°C releases were now 1213, 14, maybe even up to 15 or 16 °C. But that,
that warm water was coming out in October and November in the fall. And
the reason for that is that um in the fall, the reservoir overturns there
is what is known as a fall overturn and as that warmer surface water is
mixing with a lower water, it comes in contact with the those pen stocks
where water is being withdrawn through the dam. And so that's why we see
that warmer water at that time. Well, it just so happens though that that
was not what the Humpback chub necessarily needed because the Humpback
chub is a spring spawner. So we were not seeing warmer water in the spring
, we were seeing warmer water in the fall, but we were seeing warmer water
nevertheless.
So that was one thing that we didn't fully understand and expect or
appreciate when we started talking about a temperature controlled device.
Now, ironically, if you look at the system in the Grand Canyon. Uh If you
, if one were to consider the continued trend or pattern of the lowering
reservoir elevations and more warm releases, one might even go as far as
to say that maybe we do need a temperature control device, but in fact, to
cool it,
um, can I ask you a question rich about the, um Humpback chub spawning in
the, uh LCR? Is that something that's always occurred or is that uh
something that developed after the, after the dam was built as far as we
know, it's, it's always occurred or at least uh in recent history. The
there were two brothers, the Cole Brothers who are famous for their
explorations in the Grand Canyon and their photography in the Grand Canyon.
And we have historic photographs of the Cole Brothers going down to the
little Colorado River at about the time that the fish would be spawning
and talking about that there were a lot of fish in that system and they
took their uh their, their fishing poles and caught all they wanted for to
eat. The earlier studies that were done in about the 19 seventies also
show that the fish were using that system that way. So it's probably part
of the historic use of the species that is the little Colorado River. But
we also suspect there was spawning also occurring in the main stem of
Colorado as well. That is prior to closure of Glen Canyon Dam and in the
sixties and then the releases of cold water. So if anything did change, it
was probably Humpback chub could no longer spawn in the main stem, but
they were still using the little Colorado and that was providing the young
to sustain the population. So the the changes in the elevation of Lake
Powell was one little bit of a surprise for Mother Nature. The other which
is somewhat related to that was also declining reservoir elevation in Lake
Mead which now increase the length of the Colorado River into the Lake
Mead Basin between about separation rapid or separation rapid, which is
where the uh the Powell historically and the Howell Brothers historically
left or abandoned the Powell expedition between there for about uh some 65
or so 70 miles all the way down to Pearce ferry. And so now uh what was
under uh Lake Powell and, and I surveyed that area in the, in the nineties
when it was in fact under Lake Powell at the time. And there was a very,
do you mean Lake Mead, I'm sorry, Lake Mead, excuse me. Thank you. And
there was a thick layer of sediment in there that was the deposits of uh
of, of Lake Mead. Now, uh with the receding levels of Lake Mead, the
Colorado River has carved out its original channel and much of that
historical habitat has been restored. And in fact, the most um productive
population that we have a Hump of Humpback chub is probably in that what
we referred to as the western Grand Canyon, which is downstream of Diamond
Creek and all the way down to about Pierce ferry. So that area is, uh, if
you go down to that area now and sample some of the backwaters in that
area, you, you'll catch primarily native fish, not just Humpback chub, but
flannel mouse suckers and blue head suckers and speckled dace, The other
species that are also there. And so that has been another unexpected uh
twist from mother nature, like I said, uh where one can sit and plan all
the things that you anticipate are going to happen. But there's some
things you just don't expect that that will occur and take place.
Um The other thing that you brought up that I found fascinating is not
only does nature surprise us, but um when we make
science is a practice of developing a hypothesis, doing some research,
developing a kind of a limited knowledge base. And then in adaptive
management, we go do a management action, try to monitor it and find out
if the response is what we expected. So it's constant learning and what
you with the, the stories that you were telling us is about how fisheries
biologists come up with a hypothesis and then do some experiments and then
learn that that's part of the story. But it's more complicated and we're
constantly developing a knowledge base over time. That's, and, and it
takes that opportunity to be able to get involved at the, at the, at the
beginning of planning something like uh Glen Canyon Dam Eis and trying to
structure those alternatives and doing intense analysis of all the
available data and testing of hypotheses to try to anticipate or predict
the response by resources, the different management actions or scenarios.
But it takes that opportunity and then to go back years later and, and
looking to see how right or wrong we were. And, and it emphasizes that
concept of Carl Walter's adaptive management, whereby it's all a learning
process. If one were to believe that you could structure something in a
way that's definitive with predictable results and responses, that of
course is not true at all. You learn as you do, you learn as you go. And
so that was that to me, that was the biggest lesson from this, not only
the way that resources responded to the things that we predicted were
going to happen, but also this, this these tricks from Mother Nature also
Mother Nature throwing little things at us like climate change and
lowering reservoir elevations or different volumes of water coming down at
different years or perhaps uh bigger floods or smaller floods out of the
Peria River or the little Colorado River that delivered different amounts
of sediment into the system. There was always something going on that one
somehow cannot always anticipate or or make sure you cover as you're
working on this. And so it really does, especially as you get involved in
a, as one gets involved in a project from the beginning and you think
you've really got this right? And then you start looking at the responses
down along the road a few years later and then look back at it 20 or 30
years later and you realize, wow, we learned a lot, we got some things,
right? We got some things not so right. And there were some absolute
surprises.
So in addition to the surprises related to the role of temperature, river
, temperature on the viability and health of the chubb uh population.
There's also been some interesting surprises in the role of predation.
Some of our other interviewees talked about how early hypotheses about
predation evolved over time as we learn more. Can you talk a little bit
about that? Yeah,
the the the Colorado river um is an historic, an historical river in that
it was it has been isolated from other river, other surrounding or nearby
river basins for probably the last uh 3 to 4 million years or more. The
historical river in the upper basin is very much like it has been for
about that period of time through the Grand through the Grand Canyon. Of
course, we know that more recently as the plateau rose and the river
carved its way through the canyon and captured some of the streams in the
lower basin, we know that's AAA little bit younger uh geologically.
But because the Colorado River has been isolated for so many years, the
diversity of fish species in the system has always remained quite low. And
in fact, if you look at the main Colorado river, not, not including the
species that would be marine species or that would use the estuary, not
including those, there's only about 14 species that are native to the
entire Colorado River basin. And if you compare that to, for example, the
Mississippi or the Missouri, where you have hundreds of species, you can
now begin to understand that you have a very, very different, very unique
evolutionary scheme that has taken place in these systems, a situation
where you have few predators and therefore have few adaptive traits to be
able to cope with predators. If they get introduced into the system, alien
predators from other systems, the the species in the Colorado River are
and, and all you have to do is look at them and you can tell these are
special, very, very special fish. They are very uniquely adapted. You look
at something like the Humpback chub. It is a species that is very torpedo
shaped to deal with high velocity current. It is a species that has large
falcate fins to be able to soar in that current, not to necessarily swim
into it at high velocity. In fact, the Humpback chub is a very poor
swimmer in laboratory experiments. They're not even as good a swimmer as
any salmon species or striped bass or any river and species. But they're
smart, they know how to deal with these high currents by finding small
eddies or small pockets of low velocity. And, and III, I am fortunate
enough to have been in the, I worked with the species in the upper basin
and to work with the species in the lower basin in Grand Canyon where the
water was clear and I could now see the fish and it's fascinating to watch
Humpback chub. Uh and how that fish is able to maneuver through currents
in the Grand Canyon. And I, and I'd like to, to equate that somewhat to a
raptor that is soaring on the edge of a cliff or a rim and is using those
thermals to maintain its position. And all you see is it tweaks one wing a
little bit or a feather and it's able to stay there with relatively little
energy expenditure. Well, Humpback chub do the same thing except that
they're in a water environment. And in addition, the river also delivers
food to them as they are sitting there with little energy expenditure. So
it's a fascinating species. They have very uh they have deeply embedded
scales. They have thick leathery skins to resist the, the um the scouring
of a sand laden system. They have a flattened rostrum or, or the top of
their head is flattened so that it allows water to pass by. And also they
have that hump, which is, which is the origin of their name. What is the
purpose of that? Hump? Robert Rush Miller that who identified the fish or
described the fish initially taxonomical in 1946
thought. And I, and I think there's a lot to it that they, it's part of
AAA hydrodynamic
uh feature that enables or allows the fish to maintain that position in
the inner river current. There's no bony structure in it at all. It's
simply a fleshy structure. Unlike the Razorback sucker. Razorback sucker
has a in fact, it was also called the Humpback sucker for many years. The
razor back now it's called the Razorback sucker. The Razorback sucker does
in fact have a modified bony structure that forms the razor or the hump,
not so with Humpback chub, the Humpback chub is a fleshy protrusion behind
the head that takes place. So it helps to stabilize. So if you look again
at the different species, you can see these adaptations, you see Razorback
sucker with AAA hump on their back, that if you look at it from the front
appears to be this very nicely designed hydrodynamic uh feature that would
allow that fish to stabilize itself and to maneuver around. It also has a
very thick skin and also has fairly large fins. And so these fish were
very, very specifically and very highly adapted to the environment. That
is the Colorado River. Now along comes uh well in the um
in the 19
starting in the 19 thirties, of course, with Lake Mead and then through
the Colorado river storage projects uh with Glen Canyon Dam in 63 and then
uh Flaming Gorge, 6263. And then Navajo also, the states looked at at the
formation of these reservoirs as a great opportunity for recreational
fisheries. And, and so with that, they started introducing things like
largemouth bass and Croppy and bluegill and green sunfish and bullheads
and fat minnows and red shiners, all kinds of fish. And in fact,
altogether, today, you've got 14 fish that are native to the system and
you've got upwards of about 30 to 35 that are alien or from other river
basins and you have fish that are not, are ill adapted. That is the
Humpback Chub ill adapted to coping with those with those alien predators
or competitors. And there are also vectors for disease and parasites as
well. So, so now we go back to this idea of a temperature control device
and what protections the uh coal water releases out of Glen Canyon Dam
have provided to the Humpback chub. Now we begin to better understand how
that cold water has in fact been a barrier or at least uh uh uh uh
discouraged the invasion of many of these alien fish that could have come
up from Lake Mead or could have come down from Lake Powell. Yes, they are
in the system, but they are not thriving as you might otherwise expect if
it was a warm water system. So, predation is a, is a key issue and it is
in the Grand Canyon. Interestingly enough, though, in the Grand Canyon
predation is not necessarily from warm water. Fish. Predation is
principally from the cold water fish that is rainbow trout and brown trout.
And they were introduced for, uh, fisheries based, uh, rec recreation,
fisheries, recreation. Right? Yeah, the, the, uh, those are not native to
the rainbow trout.
Both the rainbow trout and the brown trout were introduced by the National
Park Service in the 19 twenties into initially into Bright Angel Creek.
And of course, at that time,
excuse me, the, the Colorado River was a warm muddy Turbid River and yet
there was Grand Canyon National Park that had just been established. And
so there was a need to have people have some kind of recreational
opportunity. You wouldn't imagine fishing this dirty warm main stem
Colorado River, but you would gain enjoyment and in fact, the unique
opportunity to fish for trout, literally in the middle of the desert. And
so the side streams in the side streams exactly in places like Bright
Angel Creek and Bright Angel Creek was one of the places. In fact, it was
the main place where trout were brought in by the Park service. They
brought them in and Clear Creek to the, upstream from Bright they did,
they did and in fact, did well, there they did quite well. And in fact,
there was a hatchery facility that was set up at Bright Angel Creek to
culture rainbow trout and brown trout. And I'm curious, we have native
trout in Arizona, like the Apache trout. Um, I wonder, I, I've never heard
anybody say that. Um, there were any Apache trout native in these sides
streams? Were there any trout in the side streams or were they all
imported the, um, the Apache trout and the Gila trout are, are, um, are,
were derived from a, uh,
a fish that was more closely akin to the salmon species as opposed to the
mountain cutthroat trout. The patchy trout and the Gila trout are not in
tributaries of the Grand Canyon. They are, they're native of the
tributaries of the Gila river that eventually does go into the Colorado
river, but further downstream. And so, uh, historically, and even today,
we, we don't have Apache trout or Gila trout in either headwaters of the
Little Colorado River or in Havasu Creek or any of the other, uh
tributaries that come in on that site or for that matter, on the other, on
the north rim, either out of Bright Angel or Shene or any of the other
tributaries there as well. So, those were outside of the system. So the
fish that were introduced were, in fact, uh, rainbow trout from, uh, from
hat trees in California and then brown trout from hatcheries in Michigan
that eventually came from Europe because the brown trout is a European
species.
And, um, you were talking about, um, their role in, in predation on the
humpback chub. Where does that come in? Yeah. And so, um,
the, uh, the, the rainbow trout of, of course, has been concentrated
principally in the tail water, uh, of, of, of Glen Canyon Dam, The 15
miles from the dam down to uh down to Lee's ferry and that of course has
become a world renowned blue ribbon trout fishery. People come from all
over the world to fish there. Uh There have not been many brown trout in
that system perhaps because the water was too cold brown trout
historically or that, that is after the dam was completed in, in uh 1963
brown trout were, were principally concentrated around Bright Angel Creek.
And that's of course where they were introduced originally and there were
some in the main stem as well. We would catch brown trout at the mouth of
the Little Colorado River which is upstream of Bright Angel Creek and they
were moving up there and then evidently moving back and then spawning in
Bright Angel Creek with the increasing temperature
as a result of lowered elevations in Lake Powell and warmer water coming
out of the dam, it has apparently enabled or allowed brown trout to move
around more in the main stem. So they perhaps are not as closely tied to
Bright Angel Creek. For example, as they were historically, they can now
start using the main stem more because they're a warmer water fish species
than say rainbow trout. Recently, we have found brown trout up in Lee's
ferry and in fact, in, in, in sizable numbers and a concern is that brown
trout may in fact be competitors and predators for the rainbow trout at
least very really. And then in 2017,
the GC damp asked to convene a science panel that was headed up by Mike
Runge of the US, GS and Charles E Kulick from GCMRC myself and other
biologists in that program to look at what alternatives might be available
for controlling brown trout, removing them and reducing that predation and
competition threat, not just for rainbow trout in the tail water, but the
potential is that if brown trout were to expand, then they could end up in
prime Humpback chub habitat, which is, uh, which is at the LCR river mile
61. So about 75 miles or 76 miles downstream from the dam. So that's a
concern that we have now is the potential for brown trout being a major
predator in, in that system.
I can remember, um, one of our interviews, uh, somebody mentioned that, uh
, early on the thinking was that both species of trout were probably
eating Humpback chub and depressing the population. And after further
research, it was determined that the rainbow basically weren't and the
brown trout were, is that correct in your mind? There was, did we learn
that? Yeah, there was, there was some excellent work that was done by Mike
Yard on looking at the effects of predation by both species. And it
followed up on some of the work that we had done there earlier when we
were doing the life history and ecology studies on the Humpback chub. And
what Mike found is that, uh, brown trout, both species eat Humpback chub.
They both will prey on them, but brown trout eat them. As I recall,
something like 3 to 4 times more, they'll eat 3 to 4 times more. Humpback
chub than rainbow trout dune. So the pre so for one brown trout, you're
gonna have a fish that would equal maybe three or four rainbow trout in
terms of the numbers of, of Humpback chub that, that fish might eat. So
predation was a, is a, is a real problem, especially with brown trout. Um
, the other species that we're seeing in the system is, is the small mouth
bass and we're especially concerned about smallmouth bass because they in
fact, are a cool water species. They do tolerate cooler water than say
large mouth bass or Cropper blue gills or some of the warm water fish that
fish has now recently gotten into the Grand Canyon. To my knowledge, there
is, there's no evidence of reproduction in that system yet. But it's
certainly a, a river that would be suitable for reproduction by the by
that species. So that's another one, we're kind of keep an eye on our eye
on and you expect them to be predators on humpback. They are, they are
intensive predators. In fact, um, the upper Colorado river recovery
program that manages these, these endangered fish in the upper basin above
Lake Powell currently spends about 40% of its budget, controlling
mechanically removing smallmouth bass and northern pike in the upper
Colorado river, specifically in the northern pike in the Colorado river,
they were introduced by the state of Colorado into Elk Reservoir some
years back and they escaped both northern pike and Small Mount Bass. And
in fact, today, there are guided tours for fishing for northern pike and
the Yampa River. You can hire a guide out of Colorado to take you down the
Yampa river and catch these £20 northern pike out of the Yampa river. Now
, those fish are more aligned with cold conditions, cold water conditions.
You don't see them leaving the Yampa much although we catch them in the
Green River as well, but not as much. But the, the the swam up bass is a
much more uh plastic species in terms of temperature. It can tolerate a
big range of temperatures. And that's one that I that I believe could be a
real problem in the Grand Canyon in years to come because it fills that
intermediate niche between the cold water species and the warm water
species and could probably do quite well in a place like the Grand Canyon.
So, where are we at today? With the recovery of the Humpback chug? I heard
recently that there was talk about down listing it from endangered to
threatened. Um, what's the status now? And where do you think we're going
in the near future? Yeah. The Humpback chub is currently listed, of course
as endangered. Um,
it was brought into, it was grandfathered into the endangered species Act
in 1973. It was included in the original list of endangered species in
1966.
Um And so it has been listed as endangered for, you know, since
fundamental. Yeah. Yeah, since that. Yeah. Right. Half a century. Um
because of the uh expanding numbers of Humpback job that we see,
especially in the Grand Canyon. The, the increased abundance of Humpback
chub in the Western Grand Canyon. And how well the species is doing in the
main ga in the main Grand Canyon. In addition to the fish that are in the
Little Colorado River, there are about oh, about six or seven other, what
we refer to as aggregations. They're small groups of fish that are located
usually in, in springs, warm water, spring areas like fence vault at 30
mile near Vys Paradise or around the Little Colorado River, which is a
seasonally warm system or around, uh, perhaps, um, uh, Havasu Creek. I saw
a bunch of Havasu creek mouth of Havasu Creek and it was clear water. So I
got to take pictures of them while I'm standing kind of over them. And
they're swimming around in that sandy bottom. And in fact, many people who
travel down the Grand Canyon now raft down the Grand Canyon, uh, observe
that one of the most common fish they see is in fact, the Humpback chub,
if there's scraps of food or whatever fall in the river, they're the first
ones there and they often almost are begging like a bunch of little puppy
dogs waiting to be fed. Uh They're very social species, they usually uh
move around in schools as groups of individuals. And so, um that
population of Humpback job is doing quite well. In addition to that, there
are also uh five other populations in the upper Colorado River basin in
Black Rocks, Westwater cataract Canyon, desolation, Gray Canyon and Yampa
Canyon. The Yampa Canyon population has recently been declared as
functionally extirpated. Uh We did a species status assessment for the
Humpback job about two years ago and determined that the numbers of fish
in that population were pretty much gone. We recently convened a uh part
of the Humpback Chub recovery team to look at the prospect of trans
locating Humpback chub back into the Yampa River and establishing a
population there, connected with Echo Park and Whirlpool in the Green
River which is below Flaming Gorge to try to re-establish that population
, the other populations are either stable or perhaps in slight decline. So
they're not doing quite as well, perhaps as the Grand Canyon population,
but they're, they're self sustained. They produce young every year. Uh We
see, you know, good numbers of them in these populations. And so the
service has decided that uh if we examine the, the terms of the Endangered
Species Act and what's defined as an endangered species, one likely to go
extinct within the foreseeable future, that the impact job is, in fact,
probably not that it is an AAA species that faces threats. And so, uh
perhaps the classification of threatened is more appropriate. So the uh US
fish and wildlife service here uh about a month ago, which would be back
in about February sometime 2020 2020. Yeah, of this year, correct, uh
initiated the process of a down list proposal for the species. The
proposal was published in the Federal register about a, about a month ago
, which would be about February 2020 and is open to comment, I think till
the end of March 2020. If it is determined that uh that it's appropriate
to down list the species, the Humpback chub could be down listed within,
within the next year. Uh That would be determined of course, as, as part
of the ruling in the federal register. So that, that's one that's one
prospect. The likelihood I think of that is pretty good. Um Given that the
population is doing so well in the Grand Canyon and given that the
population in the upper basin are holding their own, perhaps a little
decline, perhaps in some years, they go back up. And if we can get fish
into the Yampa River, I think we'll be in pretty good shape, but it
certainly does not meet the definition of endangered if you, if you look
at it that way. Um There is, there is another species that's also being
considered now in the Grand Canyon. And that's the Colorado pike minnow,
Colorado pike. Minnow is also an endangered species. And there is uh there
is currently um an evaluation of, of possibly reintroducing the Colorado
pike metal into the Grand Canyon. It's extirpated from the Grand Canyon
right now. It has been extirpated from the Grand Canyon since about 1975
as a result of the changes in the river due to the construction of Glen
Canyon Dam or something else. Probably all of the above where it was a
highly, it it's a, it's what's known as a PTA species. In other words,
it's highly migratory within a given river system. So we believe that that
Colorado Pikemen at one time probably migrated all the way from, say, Yuma
Arizona, which is where it was warmer and perhaps even went into the
estuary to feed. And uh the evidence is is strong that the fish got to
about 6 ft or so in length and weighed £100. Uh North America's largest
minnow and we've got bone fragments and remains that support that
contention. Now, the biggest fish we see are about 25 maybe £30. Uh So
we're not quite seeing the, the large fish now, perhaps because they're
restricted to the upper basin and perhaps because they don't have the full
uh regime of temperature year round to allow that growth. So we don't have
any below lake uh uh Hoover Dam in Lake. No, there are none below. Um
There are none below Glen Canyon Dam. Ok. At this time, everything is
above Glen Canyon Dam except for the small numbers that were introduced.
They, they're not natural but they were introduced into the Salt and
Verde rivers, tributaries of the Gila and those are known those are now
currently called 10 J populations or experimental non essential
populations in others. They are there just to have them there to maintain
, but they're not part of recovery targets at this time. So the idea is
being entertained right now by A US Fish and Wildlife Service and Arizona
Game and Fish Department and the National Park Service to perhaps look at
the possibility of bringing Colorado Pike Meadow into the Grand Canyon at
least to have them there. The I I think it's questionable whether all the
life history requirements are there for the species to be self sustained.
I don't think so at this time, uh that fish needs uh uh long rivers to
migrate to spawn in clean headwater areas, warm temperatures, the young
drift, uh perhaps many miles up to 5060 miles or more into small sand
backwaters where they can feed and live for most of the, most of the rest
of the year. It's a summertime spawner they spawn in usually about late
June, July. Sometime those, those key life history elements are probably
not present in the Grand Canyon, but I think that that's still being
looked at at least to have the species there to say that they are
someplace in the lower basin. Um
So, so at this point in time, the um again, the Humpback job is, is, is
being proposed for down listing. I think there's information that would
warrant that at this time, we'll see what the public decides and what
others decide as well. If that, if that down listing takes place, it
really would not change much in terms of how Glen Canyon Dam is operated.
The difference between an endangered species and a threatened species is
,
is small relative to section seven of the, of the endangered Species Act.
It can open some opportunities for additional conservation measures. For
example, there is a section in the endangered Species Act called the four
D rule. That is a provision that allows the states now to become more
active and more participant in part of the conservation measures, it gives
, for example, the states the opportunity to define, take what is known as
, take. In other words, how you can take or kill or capture or maintain
these individual individual fish. So it might give some flexibility to
management, which I think would be good. Um Can can you say to what extent
the improved
health of the Humpback chub population in the Grand Canyon is traceable to
the Adaptive Management Program and you know, changes in dam operations. I
mean, how much of it is just serendipity and how much of it is the results
of our efforts to recover the species?
That, that that is a thing of, of uh scientist nightmare.
Uh where one spends a lifetime trying to be smart enough to come up with
the right management actions and then implements a program like Glen
Canyon Dam Ltpis and then looks back upon it 20 years later, whatever. And
again, we're not that far away from it yet, but we're going to be uh and
you realize that many of the things that you did either made a difference
or didn't make a difference, most of them perhaps didn't make much of a
difference. And then the word serendipity is perhaps the most the best
word for that. How many things took place naturally or normally part of
the of the the expanded distribution and abundance of the Humpback Chub is
in fact, due to reoperation of Glen Canyon Dam and the actions that were
put in place by the federal Agencies in Cooper operation with the States
and other stakeholders. Part of that recovery is directly attributed part
of it. However, is in fact serendipitous relative to the changing
elevations of Lake Powell and Lake Mead warmer releases from the dam and
also re excavation of the historic river channel downstream of Diamond
Creek and all the way down to Pierce ferry. Now, specifically, the things
that were put in place that have really helped. I think the Humpback chub
is that um prior to 1995
the Glen Canyon dam operation was um was a
a hydro power generation type facility where hydropower is maximized by
having flows as low as three or 5000 cubic feet per second in the middle
of the night. And then at about four o'clock in the morning, start ramping
those releases up to say 30,000 cubic feet per second, which is the
capacity of the power plant. And you would see then about a 20 ft increase
in the elevation of the river right there below the dam. And this of
course would generate this uh kinematic wave all the way downstream. And
fundamentally, that was almost a daily flushing of the Grand Canyon if you
may, I mean to be a little extreme perhaps, but that was kind of the
effect. And so when I first got involved, that was what was happening is
we had these very, very high fluctuations. And of course, people will tell
stories about when you were down there with the big rafts that you had to
make sure you parked those boats in such a place that you wouldn't be
stranded on the beach for the next day until those flows, you know, came
back up. Um That operation of these very, very large changes in flow and
river elevation were probably um were not beneficial to young Humpback job
that used the shoreline for nursery areas. The fish would come out of the
little Colorado River as four or five month old fish and then they would
hang out along the shoreline, which was the better place for them to
escape predators and to find food with flows going up and down. Even as
far down as the LCR maybe as much as 4 5 6 ft or more, then you would have
displacement of these fish and they would either be displaced downstream
or be displaced away from that cover and be exposed to predation by, by
another fish. So that was good that the idea of what was known as the
modified low fluctuating flow MLFF that came about in, in uh in, in 1995
basically as a result of those, those studies that were done prior to that.
Um That was good that and so that, that made the, the habitat for the
Humpback job a little bit more stable. Now, admittedly, I was one of the
biologists that were saying that was saying at the time, in fact, you have
to try to get those flows even more stable because if you look at
summertime in the Colorado River, except for places where there's
monsoonal storms that would be large enough to increase flow by and large.
The flow of the Colorado River during the summertime was relatively
stable. It didn't fluctuate and low, correct low. And that's what brought
about the low steady summer flow concept, the flow that we had in 2000 to
test that hypothesis. But what we found out and thanks to some of the work
done by Bill Pine and and others is that in fact, the Humpback job was
quite plastic in terms of its ability to be able to move with those flows
and use those tailless slopes. If you look at the at the slopes in Grand
Canyon, for example, downstream of the little Colorado River where you
have young Humpback chub, they are, in fact, slopes of Talus that are
continuous rock and boulder mixture all the way up the slope. So all the
humpback job has to do is just move with the water and it's at a new
interface that is still that boulder tailless habitat where you can still
use those areas for different kind in the back water. You get behind in
the little little eddies and backwaters and little cubby holes in and
between these boulders. So the large fluctuations that we saw prior to
MLFF were probably not good for the humpback job. The more modified
fluctuations have probably helped to benefit the species and in fact
probably do help even stimulate maybe some production along those
shorelines when you have water moving around the way it does. So that,
that, that did help out. The other thing where we think there was quite a
bit of benefit is, is there was, in fact, mechanical predation, mechanical
predator removal in the Grand Canyon. Um, even before the Ltpis, where we
were removing brown trout and rainbow trout from the system, as well as
other species removing channel catfish or carp from the little Colorado
River as well. Are catfish also predators on Humpback? Absolutely. Very
much so that not Carp because, well, carp we know are, are voracious
predators of fish eggs. Oh, ok. And I've watched, uh, uh, red shiners
spawning in Spencer Creek, which is the lower end of Grand Canyon. And
then as the red shiners were spawning early one morning, it wasn't but
five minutes. And here comes a, an entire herd of Humpback, excuse me, of
carp, common carp that came up and just vacuum that entire area for eggs.
So they, they're not native either. That's correct. Yeah. And that's
another species that we may underestimate in terms of their effect to
these native fish is how, how much effect they may have on eggs and on
larvae and, and their predation there as well. So, um so that, so that was
another thing is, is modifying those fluctuating flows, doing some
predator control to reduce the, the the predation on those fish. The other
, the other thing that probably did help Humpback chub was um
was these high flow experiments that provided uh large sandy beaches and
deposits in the large recirculating eddy complexes of the Grand Canyon.
And as part of that recirculating complex, of course, what happens is that
the water is laden with sediment because it, it is a higher volume, higher
velocity. Uh The the the base flows may be at uh 1512, 1510, 15, 12,000
cubic feet per second. With a high flow experiment, you're going up to
45,000, which is the, the 30,000 out of the power plant and then the
15,000 out of the bypass valves. So when you've got 45,000 CFS going down
the system, you are lifting, activating, energizing the sediment in the
system suspending it. And then when it gets to these large recirculating
eddies, it slows down and drops out in the eddy was part of that large
sandy beach. There is the recurrent channel which is that little stream of
high velocity water that goes right against the bank. And behind that
sandbar, that recurrent channel forms a backwater, which is very nice
habitat for fish. And while Humpback chub don't necessarily use those that
often. They are there. Nevertheless. And the high flow experiments do help
to provide that environment for the fish. But also other native species
like flannel mouse suckers and blue head suckers and speckled dace do use
those habitats. So it has helped. So those are some of the things that the
reoperation has done to benefit the fish. But like I said, many of the
others are like you said, serendipitous because they are tied to mother
nature and climate change and availability of water in different years.
That that's great explanation. Thank you. Um You did some studies of the
early high flow experiments to determine whether they were being effective
or not. Can you talk about how the science and our understanding of the
impacts of those high flow experiments has evolved from the, the first one
was sometime in the 19 nineties, right? And that's when you were looking
at that. And you have a couple of publications from 1999 and 2001 on that.
Yes. So how did our understanding of those high flow experiments evolve
over time? Well, the, the first experiment of course was the 1996 control
Flood. We called it The Control Flood through Grand Canyon. And of course
, uh I was fortunate enough to edit a book with uh Bob Webb Jack Schmidt
and Dick Marzo called the 1996 Control Flood in the Grand Canyon. And it's
available through the Geophysical Union. It's available on the internet.
And that archived many of the studies that were done at that time and what
we found out about a high flow experiment. Now, prior to that, it was, it
was called the uh beach habitat building flow BHBF. That was a terminology
that was supposed to be descriptive of what it was supposed to do. And
that was to beach, to build habitat, to build beaches, beach habitat,
building flow. But the history of that is, is, is I think even more
interesting. The na when, when Dave Wagner was uh head of the Glen Kenyon
environmental studies, G ce s, this is all the way back into the um the
mid eighties. He asked the National Academy of Sciences to do a review of
studies and the program G CS in the Grand Canyon. And of course, that was
just after the high flow of 1983 and 84 where the capacity of lake Paul
was practically exceeded. And there were these emergency releases. You,
you can read about it in uh the book by Kevin Fedarko the Emerald Mild,
correct, did an excellent job of documenting what was happening at that
time. But um what the National Academy of Sciences concluded after that,
after that experience with those high flows was that in fact, high flows
are bad for the Grand Canyon because in fact, they transport large amounts
of sediment out, out of the system, correct? And so the initial thought
was oh my goodness, we can't allow these high flows to take place in the
Grand Canyon. A second review by the National Academy of Sciences. A few
years later said, no, there's perhaps more to it than that. Perhaps we can
use certain releases from Glen Canyon Dam to in fact, suspend that
sediment and not transport all of it out of the system. But in fact, and
train some of it in these large recirculating eddies. And it was people
like Jack Schmidt and other scientists that said this is a way perhaps to
preserve sediment, sand in the Grand Canyon as beaches for river runners,
for camping and a substrate for riparian habitat for all the way from
Southwest Willow flycatchers to reptiles and lizards and all kinds of
animals that rely on those riparian areas. And so in the um leading up to
the 1995 EIS, the concept was, was developed uh of beach habitat building
flows bhbfs. And as a result of that, uh the Secretary of Interior
approved a high flow release, which was, which was really significant
because it in fact um was a release that not only involved the full power
plant capacity of 30,000 cubic feet per second but also involved the
bypass valves. Now, the bypass valves are what are known as the jet tubes
do not have hydropower generating facilities. And so there was in fact,
the cost associated with that and the lost hyder power revenue cost do you
mean? Exactly. And so the first uh nine, the 1996 experiment went for, uh
gosh, almost almost two weeks. As I recall, it went for a long period of
time. But again, we learned a lot from it because what we learned is, is
in fact the majority of that sediment was moved in about the first two or
three days. So we learned that you don't need to have these for a very
long period of time. You can only, you can have them for just 48 to say 96
hours, something like that. And that's more than enough to, to move that
sediment. Um
So, so the uh so what happened is that um as that understanding was
becoming better known than there was eventually a protocol developed for
releasing water from Glen Canyon Dam. That was both a fall HFV and a
spring HFV for the possibility of releasing water depending on when
sediment was available. Now, it just so happens that the major sources of
sediment to Grand Canyon now, because all the sediment from the upper
basin is trapped in Lake Powell. The major sources of sediment are of
course the Perla River which is 15 miles downstream from the dam and the
little Colorado River which is about 76 miles downstream from the dam. The
Perla River is principally a fall monsoonal storm driven system. So that,
that sediment is usually driven in the late uh is usually transported in
the late summer time in about July August. During the monsoonal storms,
the LCR, the little Colorado River further downstream is a spring flood
system so that sediment is available at a different time of year.
Initially, the high flow experiments were being done in the springtime
with the idea that it was more simulating the natural hydra that you know
, those were spring floods. Eventually, it became better understood that
the majority of sediment in fact would be available from the PA because it
was right there just downstream from the dam and you could release it in a
timely way that you could take advantage of that large amount of sediment.
Besides the majority, many of those large recirculating complexes that
entrained that sediment are located upstream of the Little Colorado River.
So it's that area around from Vys Paradise on down all the way down
pretty much to the LCR. That's, that's where a lot of the benefit would
come. Although there are other areas downstream as well now. Um So HFES
then high flow experiments became initially were spring high flow
experiments and then became fall high flow experiments. Now, most recently
and, and here's, here's adaptive management coming into play, right? Where
most recently the people that are looking at uh production of insects in
the Grand Canyon and production of algae and everything else are saying,
we're seeing a real decline in our food base in the Grand Canyon and we
think part of the reason is it's tied to these fall high flow experiments
where uh where in the fall when you have a high flow experiment, you have
got 40,000 or so cubic feet per second coming out of the dam, you've got a
real scouring effect, especially on that uh where most of that primary
production takes place. And that's in that 15 mile reach of Lee's ferry.
So if you scour that production at that time of year, you are now at the
point in the, in the year to where you've got a low sun angle and you
don't have as much potential photosynthetic production taking place as you
might otherwise. And then you've got the entire winter period where that
community does not have a chance to recover and have, you know, and be
back and productive again as you might otherwise think. So that's one of
the things we're learning the fall hfes may be beneficial for storage of
sediment because it maximizes that sediment availability. But it also
might be ne negative or detrimental to, to production in the system which
drives the whole the whole food basin system. We've been hearing about low
bug flows lately. Can you explain that? Yeah. Um
The combination of cold water releases through the Grand Canyon
in a uniform manner without seasonal warming because the water is always
coming out or, you know, at one about one temperature before, before Lake
Paul went down, it was always at about 8 to 10 °C. Now it's between 1012,
maybe 13, but it's not warming up to say what the river used to be
historically, which was 25 °C. So you don't see that seasonal warming that
combined with the fluctuating flows that we see has precluded
the establishment of certain species of invertebrates, especially may
flies, stone flies, catus flies, species that fish food, exactly, fish
food, the the basis of production in the system. Um,
species of insects that are what we refer to as multi volte species or
species that require both a warm period and a very cold period to complete
their life cycle. So those species are not in the system. They are Univ
species which can, which can survive and exist in places like we have in
the Grand Canyon now. And so the idea came up, uh, gentleman named Ted
Kennedy, who's with GCMRC, came up with the idea of what are known as the
bug flows. So that on weekends, especially when there's not that much
power demand and we have more flexibility in, in dam operations, then then
perhaps instead of fluctuating, then you run the flow at a certain level
and then you allow these bugs to crawl up on the rocks and deposit their
eggs and keep the eggs wet, so they don't dry out and die. And then you
have hatching of those and you've got at least some reinstatement of some
of that historical bug community so to speak is that working it, it
appears to be working. The experiments are limited, of course, at this
time because they're being done on a limited time basis. But they do
appear to be working, they do appear to be, there are more of certain
species of insects in the system that are potentially food for the fish.
And so that in and of itself is working. However, the issue of Fall hfes
and their scouring effect on production is still one that's being
considered and talked about. And in fact, there is consideration of now
switching perhaps back to spring HBs or switching back and forth perhaps
and not having these continuously during the fall. So, um as I understand
it, they won't even do an HFE if they haven't determined that a certain
amount of sediment has come down one of those two tributaries and is
available to push down the Colorado. So some years they won't do, they do
one every fall or do some falls. They don't do an HFE at all if there
isn't enough sediment. Yeah. There, there's two factors that determine the
, the um uh an HFE taking place. One of course is the availability of
water availability of enough volume to be able to release that volume that
may not otherwise be part of normal operations. And then the second is the
availability of the sediment, the amount of sediment in the system. And of
course, that's monitored on an ongoing basis to make sure that there's
enough sediment there that if you do an HFV, you're going to have some
benefit from it. So, yes, there are some times when an HFE is not
authorized, authorized or suitable because of the lack of sediment.
How about if we take a short break now and then come back in about five
minutes? Ok. Pausing, recording,
resuming, recording.
Um One of the topics we touched on in the first half of the interview was
the topic of mechanical removal of predatory fish that, uh, impact the
chubb population, brown trout in particular, but also rainbow. Um, can you
talk a little bit about how mechanical remo, what role mechanical removal
has played in fish management and what happened when it was adopted for
the Glen Canyon, um Adaptive Management program? Yeah. Uh, the, the, the
threat of predation especially and to a certain degree competition on
especially the Humpback chub was a common theme across the Colorado River
basin in all populations. One of the biggest concerns was the numbers of
young fish, especially that would be lost to, uh, things like smallmouth
bass or largemouth bass or channel catfish or other species, literally
eating those young, removing them from the population. So, um, the idea,
there were, there were many ideas that were, that were discussed in terms
of how to manage these non native species and one of the, of course most
outstanding and most direct was the concept of mechanical removal. That is
you simply just put people out there in electro fishing boats or nets or
whatever gears you can use and catch as many of those non native fish as
you can and remove them from the system with presumably the desired
outcome that you would have fewer of them. And therefore you would have
less predation and fewer of the native fish, more than more of the native
fish surviving and, and helping to sustain the population. So, um, in the
Grand Canyon,
going back to pretty much pretty much after the 90 1995 biological opinion
and the 1996 record of decision on the final environmental impact
statement. A a at that time, one of the biggest threats to the Humpback
job was seen as, uh, as predation and because we recognized it was a cold
water system, we acknowledge the possibility of, of competition and
predation from warm water fish. Um, but we, we knew that there weren't
that many. We knew that the cold water was pretty much limiting the
populations in the Grand Canyon, but we began to recognize that, uh,
perhaps the biggest threat was predation and competition, especially
predation from rainbow trout and brown trout. And like I mentioned earlier
, uh, Mike Yard did I think a very good, uh, piece of work there when he
looked at those proportions of fish that were being taken by the two
species and found out that the big predator was, was brown trout. However
, um, rainbow trout were still far, far more abundant than brown trout in
the Grand Canyon
Carl Walters brought up the idea that if you look genetically and
historically, at the rainbow trout, it really is the, uh, progeny of an
anatomist species, right? A species that moves or migrates. So we should
not discount the possibility that fish. And at that time, the rainbow
trout were in fact being actively introduced every year by Arizona Game
and Fish department to sustain the fishery because the water was literally
too cold for rainbow trout to reproduce in the Grand Canyon. And the
fluctuations were so great that it stranded and isolated their eggs. So
the population of trout in the Grand Canyon was not self sustainable until
we went to modified low fluctuating flows. Those high fluctuating flows
were simply not allowing trout to sustain themselves in the Grand Canyon.
So once, once that population became more self sustainable in the Lee
ferry reach, then we started to see some of those younger trough moving
downstream. And we were concerned that that movement downstream. All they
have to do is go from the, from Lee's ferry down to the LCR is 61 miles.
So they don't have to go very far to be in Humpback chub heaven, let's say
Humpback chub territory. Um And so we, uh, came up with the idea that one
of the things we could do was set up a uh uh lease ferry to, to Badger the
Badger Creek removal as, as being intensive removal in that area. At key
times of the year, when we thought that those rainbow trout would be
moving downstream to so to speak, to intercept them before they would
reach the little Colorado River. So it actually was, it was called the
Pera the Badger uh proposal per he had a badger mechanical removal
proposal. And there were some experiments that were done. There was some
removal. There was a, a complete uh in fact, there was a high uh an E A an
environmental assessment done on that coordinate by Mike Runge to look at
that prospect of doing that and then linking that to the 1995 EIS
as a way to authorize that removal. Now, research on that and the proposal
for that was before the 1995 I was being developed at the time, it was
being developed and immediately after and it was after correct. Right. And
then starting in the early two thousands, then the idea was floated that
it could also be just targeting and removing fish trout that is from
around the little Colorado river because the trying to intercept them in
that pie. A badger reach was perhaps more chance than something more
certain. And and instead go to the source itself, go to the end point and
remove them there. So that became uh a program that was designed as a
multiyear experiment to where there were, there were multiple trips. I
think there was something like six or eight removal trips through that
area uh, of the little Colorado River, both upstream and below. Uh the
little Colorado River where electro fishing boats were removing trout in
mass and just taking them from the system.
Now, that became complicated to a certain degree because you had two
issues. One is what do you do with them? Once you pull them from the
system, you have a mass of, uh, you know, several, yeah, several £100 of
fish protein. What do you do with it? The park service would not let us
grind them up and put them back into the system. We thought of burying
them in some riverside pits or something. But that didn't go over very
well either. So someone came up with the idea of something called the
Basam Attic, which was basically a huge grinder and you just put them
through a grinder and then put all that, pour all that soup into. Um, I
think there were like 30 gallon barrels that were put on boats and then
floated out all the way to Diamond Creek and then taken out and made
available for fertilizer and they were used by the Wallabies. And I think
others too as fertilizer. Eventually it became, we had a, we eventually
had a surplus of fish soup that no one had any further use for those. So
we didn't quite know what to what to do. Meantime, the Native American
tribes and, and rightfully so um had concerns about taking life in the
Grand Canyon, what was referred to the sanctity of life which we of course
wanted to make sure was respected. So, um so those removal that those
removal experiments went on for, I think about three years and the
information was written up and what we found is that they were effective
as long as that removal was ongoing. But as soon as it was relieved for
about a year or so, you started to see the influx of additional fish to
repopulate that area. And I'm talking specifically rainbow trout. And so
it became questionable whether that was in fact a sustainable management
action, whether you could keep doing that or whether, you know, maybe
something else would be better or maybe so. So then we started thinking,
ok, so what would the Humpback chub population need to reach? How many,
how many adults, 5000, 10,000, 15,000 or more in order to be able to
sustain a certain amount of predation by rainbow trout? And so that became
, then we developed triggers around that. We said, ok, we won't implement
non native fish removal until it's necessary to do so. And the trigger
will be not just the abundance of rainbow trout in that area, not how many
fish are there, but also how low that Humpback chub population is and how
much, how susceptible it might be to effective predation. So those two
factors came into effect and that was all, eventually, that was all part
of the consideration of the, of the 2016 LT MP. But by the time we got
there, people like Mike Yard had done these studies on the relative effect
of predation by brown trout versus, versus rainbow trout. And it was
determined that in fact, probably brown trout were perhaps a bigger threat
than rainbow trout. So instead of implementing the pet a badger strategy
or removal around the LCR, it was decided instead to go to Bright Angel
Creek and try to go to the source of brown trout that were primarily
spawning, uh, in Bright Angel Creek. And you see these £10 brown trout and
we've caught them off the mouth of Bright Angel Creek that go into Bright
Angel Creek to spawn. So they're using the, the main river a lot like
humpback job. They're living and being sustained in the main Colorado
river. And every year in the fall, they fall spawners, they migrate and go
into Bright Angel Creek to spawn. And then that's where their younger hats
and that's where they come out and that's where you intercept them. And so
in about 2000 and I probably have the year wrong here, but about 2000 and
12 or so, uh, there was a, the park service together with, uh, other
biologists put a, um, of a fish wear at the mouth of Bright Angel Creek
that was literally catching all of the, all the fish going into Bright
Angel Creek and they removed, uh, excuse me, large numbers of rainbow
trout and brown trout at that. We so rainbow trout we're spotting also in
bright rainbow trout. We're also using that and going into it. And then
most recently in about the last now five years, the park service has
implemented a program to where they go into Bright Angel Creek and
literally just remove the trout directly from Bright Angel Creek, both
both brown trout and rainbow trout. I just reviewed a manuscript submitted
to one of the Canadian journals that reports that the effect of that or
result of that and the no, the, the non native fish have declined by like
75 or 80%. I mean, it's, it's really had an effect.
Excuse me. Mhm. Maybe, let's pause,
recording resumes. So the, um, the decision was made then to, uh, move the
mechanical removal to Bright Angel Creek and the park service, uh, was the
lead in this, in this effort. Um, there was a, uh, a fish weir that was
set up in about 2010, 2012 that was intercepting these large spawning
adults that were coming out in from the main stem, both rainbow trout and
, and, and uh, brown trout. I remember we were handling £10 brown trout in
the main channel just off of Bright Angel Creek. So these fish were coming
into Bright Angel Creek and spawning there. Um That was not without
controversy either because there were fishermen, a select group of
fishermen that had recognized this for some years and would make annual
annual treks to hiking down the trail to Phantom Ranch to fish. Those big
rainbow, those big brown trout, especially in the fall. The weather was
nice, it was cool, it wasn't so hot, hiking up and down that trail. And so
the B A trail and so that became a bit of a controversy that those fish
were being removed from that system. I recently received the manuscript uh
from one of the Canadian uh journals, uh where uh Brian Healy from the
National Park Service and Charles Yule from GCMRC have put together a
paper evaluating the results of those, those removals in there. And it,
and it was, it's absolutely amazing how well that has worked. Um They've
removed something about 75 to 80% of the, of the trout in that system,
mostly rainbow trout, but browns as well. And the, the native fish
population, the flannel mouse sucker, flannel mouse suckers, blue head
suckers. There are no humpback chub in Bright Angel, but those other
native species have just increased, something like 400% of their, of their
former abundance. So, so it has worked pretty well, but once again, once
you remove that effort, the question becomes, how long will it be before
that system becomes re invaded? So, again, there are costs associated with
management actions that have to be considered whenever one implements
those actions and looks at the prospect of having to do that, you know,
for whatever long it takes or perhaps to do them periodically to just
maintain some balance of what's going on. So, so the the issue of non
native fish and especially mechanical removal has been a major issue in
the Grand Canyon and it has been at the center of uh of some of the
proposed management policies, but also it, it has been controversial um in
a number of different areas where that's going to go. Now, um I think
there are some different prospects or possibilities of what may happen
next. The system because of the way that GCMRC and the Arizona Game and
Fish Department are currently sampling through the Grand Canyon, the
system is currently essentially being monitored so that any uh sudden
explosion, you might say, or expansion of a given species, whether it's
small mouth bass or something else should be detectable before perhaps it
gets, it gets too far. And, and I think the strategy now is to try to get
at something like that if it were to happen to try to get into those areas
and mechanically remove before that expansion takes place. So I, I think
that that system is being monitored right now. But I would suspect small
mouth bass may be the next problematic species in the Grand Canyon. So, as
far as you know, right now, 2019 2020 there isn't an active mechanical
removal program, but it's still a possibility and may become necessary for
smallmouth bass in the future. The the mechanical removal program in
Bright Angel Creek is is ongoing, it is ongoing. So that's still going on.
There's also some removal uh in Havasu Creek, which is one of the places
that Humpback chub have been translocated to hump back job were
translocated into uh Shino Creek and then Havasu Creek to try to establish
additional populations. But as far as I know at this point in time, those
are the only two places where there is mechanical removal. And, and I
think the approach is, you know, given the native American concerns, the
approach is to try to improve the Humpback chub population sufficiently so
that it is able to sustain a certain level of predation and, and you don't
have to go in and mechanically remove. But so, so now what's going on in
the Grand Canyon as a result of this uh Brown trop management team that we
convene in 4017,
there are just being put in place uh incentivized removal programs at
least ferry. So, for example, the, um the program will pay uh eee
essentially a bounty on Brown trout that, that are brought in by, by
fishermen, by anglers. So that if you bring in x number of brown trout,
you, you, you can make some money fishing basically, if you're, if you're
good at it and can catch those fish and have fresh fish for dinner and
have fresh fish for dinner. Exactly. You, you basically just take them to
a person who's, who's, uh, examining those fish and verifies that, that's
what they are. And you, yeah, you keep them and take them home. Now,
that's just being implemented right now. The, the interesting thing about
it is that you can actually, and this is part of what the Brown Trout
Management team did is from an economic perspective, you can actually look
at the cost of mechanical removal that is putting crews out there with
electro fishing boats repeatedly removing these fish from the system and
compare that to the cost of an, an incentivized program. And it's actually
potentially cheaper to implement an incentivized program. Even though you
may be paying people, you may pay them, uh, you know, 5 $10 a fish,
whatever it might be. And then periodically you might offer, uh, for AAA
tagged fish. Let's say that that that's $100 fish or maybe even $1000 fish.
So, you incentivize people to continue to try to remove those fish, to
try to catch them. So those are some, you know, new ideas that we're
coming up with as a way to deal with this mechanical removal or this non
native fish issue? Are you aware of any objections by the Havasupai tribe
of mechanical removal of trout in Havasu Creek? That, that is a sensitive
issue at this time, I haven't been directly involved with that program. I
know that there are some concerns about that. I really couldn't answer
that at this time. I haven't had recent involvement with that.
Well, thank you for going back over that topic with us again. Um Can you
uh tell us who you think the most important researchers and the most
important participants in the adaptive management program have been over
time should be called out for their long term high quality work. Well,
from my perspective, of course, I, I look more at the scientists in the
program, perhaps more so than the managers or administrators, not that
they not that there aren't people there that have done excellent work in
terms of facilitating the science and some of the research that's been
taking place. But, but II, I think that um certainly when I first got
involved in the program in 1989 Dave Wagner was a an instrumental person
in terms of being able to bring together scientists under the Glen Canyon
environmental studies, the G CE S at that time. Um After that, uh the
program transitioned as a result of the um of the Grand Canyon uh
Protection Protection Act. Thank you. Uh transitioned into the GCMRC, the
, the uh Grand Canyon Monitoring and Research Center. Um
That program then was what Facilli facilitated people like Carl Walters to
come into the program. And Carl Carl really, I think shook up the
scientific community in Grand Canyon because we thought we were pretty
darn good at what we were doing. Carl made us realize that we could do
more, much more, especially introducing this concept of adaptive
management and how that really works into uh being able to work in the
system. So, so Carl fundamentally came in and said, OK, what are your
hypothesis about how you think the system works? You think it's
temperature that affects Humpback chub? All right, then, then look at it,
investigate it, look at different options, look at opportunistic uh
warming periods. We had 2005, for example, that uh where the, where the
release of the dam in 2005 was very similar to a two unit T CD. So we had
in some ways natural experiments that were taking place right in front of
our eyes, but we weren't seeing it that way. So he made us better
understand the opportunities that were available in the system at the time
and, and, and how to implement those experiments and then how to evaluate
them over time under the concept of condition dependency. So that if, if
we wanted to, to implement an an experiment, we had to realize that the
condition in the Grand Canyon, whether it's water availability or
temperature or whatever else, climate change was not going to be the same
every year. So, so it was basically conducting a huge outdoor experiment
over which you have little control over environmental variables. And so in
order to deal with that, he, you know, proffered the idea of of condition
dependent experiments whereby you, you conduct experiments when the
conditions are suitable for doing that. And in years when you can't do
that, you don't. So your condition, your your sampling design may be a
rather expanded matrix that has probability of occurrence associated with
a certain volume of water or a certain temperature that you may be trying
to test, but you're not going to be able to do it every year. So Carl was
significant in terms of introducing some very novel, very, very, I think,
very good ideas in terms of understanding the science. Better. Carl also
uh brought with him and enabled us to also have access to people like Bill
Pine. Uh Carl of course, with was with, with the University of British
Columbia in Vancouver. Bill Pine was with the University of Florida at
Gainesville. So Bill brought forward concepts that we of how we better
understand young Humpback chub survival. He initiated some what are known
as the near shore ecology studies in the Grand Canyon. They were looking
at the Humpback chub coming out of the little Colorado River and what they
were doing to survive in the main stem, how they were using those tailless
slopes for protection for food availability and so on. And so Bill was
instrumental in that as well as other things. He, he introduced technology
like uh like laser ablation technology that is taking a uh an otolith, the
inner ear bone of a fish of a humpback chub, the inner ear, of course, is
one of the first calcified parts of a fish when they're born, they have
inner ears, they have odorless when they're born. So it's a complete
record of the uh of the life of the fish. And those Odalis establish um
daily growth rings that you can track and you can look at like the growth
rings on a tree and they also have broader, wider annual growth rings. And
so you have a, a record that you can go back and look at. Now if you take
a laser and take uh samples of the different parts in the life of that
ring where you know how old the fish is when it experienced certain things
, you can then trace back what um what environments it occupied by looking
at isotope ratios, for example. So you can tell when the fish left the
little Colorado River, you can tell what habitats they were using in the
main stem, whether they were using warm near shore habitats backwaters or
the main channel or other experiences or whether they were going into the
main stem turning around and going back up into the little Colorado River
as part of a, a uh an archive of the life history of the species in the
system. So it was, it was these things that we had not thought of before
and that you need external scientists like this to, to introduce these
ideas and these concepts. Um One of Carl Walters, uh A and Bill Pine's
students was a, was a man named Lou Coggins who got his phd under Bill
Pine and, and Carl and Lou now introduced new analytical techniques for us.
Now, you had two fundamentally, two scientists, Carl Walters and Bill
Pine with very strong uh marine fish backgrounds
and marine fisheries is so much further ahead in terms of analytical
techniques than freshwater fisheries because they deal with large fish
populations, they deal with unknowns, they deal with uncertainties, they
deal with fish that are being reported from large fishing boats, not with
a lot of Mark recapture opportunities. They're not dealing with small
streams and lakes, they're dealing with something the size of the Pacific
Ocean. So they have to have much better developed uh analytical skills.
And so with their help, we had Lou Coggins come in and redo our Mark
recapture program of how we were estimating the numbers of Humpback chub
that were in the Grand Canyon. And he developed a wonderful Mark recapture
model with the help of both, you know, especially Carl Walters but Bill
Pine as well. Um, another student of, uh, of Carl's was, um, was, um, uh,
in addition to Lou Coggins was, uh, uh, I, I'll have to think of his name
here in a little bit, but he also brought in, um, a, a wealth of knowledge
with respect to understanding, uh, the trout population. His experience
was mostly up in Canada and Alaska with rainbow trout and, and other
species of trout. So, uh, a and his name was Josh Corman. I apologize for
not remembering that earlier, Josh Corman was also instrumental and, and
Josh is still working in the canyon now. He works a lot with Mike Yard and
they've done a absolutely marvelous job of, of better understanding the
population of rainbow trout, especially rainbow trout, but brown trout as
well in the Grand Canyon, how those populations function, how they spawn
the survival of the young, what habitats they use, how they are affected
by operation of Glen Canyon Dam. One of the things that they found out is
that, for example, uh, when, uh, the, the, the rainbow trout in the Grand
Canyon is a, is actually a late winter spawner, they spawn in about
January, February. And when they, and, and their eggs will incubate for 60
to maybe, maybe as much as well for 40 or maybe 60 days, something like
that. When they hatch, when they emerge, they will go to the near
shoreline areas a as fry. So when they're very, very young, they're
looking for shallow sheltered areas. So they will go into the shorelines
in that lease ferry area and go to about the shallow area. If you are
running a fluctuating flow scenario, you're going to strand those
individuals, right? Because they're in very, very low, very shallow water.
Now, as they get older, they go from these low angle shorelines to the
more high angle shorelines to more rocky steeper shorelines. So
understanding that of course, enables you to better understand not just
how the population survived but perhaps potential um management flows for
regulating those populations. So as a result of that, the concept of
trough management flows came about that you can regulate the population to
a certain degree if you want to by basically raising flows to a certain
level, say 15,000 cubic feet per second in that January. Well, in about,
in about that March, April period and have those young fish go up on those
shallow areas in le ferry, then drop the water on them quite suddenly and
you strand them, you regulate the population that way by not having to do
any mechanical removal by not having to intercept the fish in the pet a
badger reach by maybe not having to worry about the fish moving downstream
to the LCR because there, there is a certain degree of density dependence
that takes place with these populations. Whereas if you have too many
trout in the least ferry reach just by common sense, the surplus of those
fish are going to want to leave that area and would move downstream. So
that's been another option as an alternative to mechanical removal is
better understanding the population than managing those populations to
where they don't exceed their carrying capacity for the system. Has anyone
tried that option yet? Uh Yes. Um Drought management flows have been
implemented on an experimental basis. They have worked to a certain degree.
But again, there are these little twists of fate, so to speak, where um,
the, the a, a big part of the uh trout population in Grand Canyon least
ferry reach was in fact, not necessarily spawning in those shallow areas.
They're spawning to more toward the middle of the channel. You still have
some of those young fish coming up that combined with the with warmer
releases of out of the dam have also expanded the, the window of spawning.
So we have those young of different ages now being more occurring more
over longer periods of time. So those have been effective at some times
and perhaps not so much at others because of these nuances having to do
with spawning. What we think is happening now that Brown Trout Management
team, what we concluded from that is that one of the possibilities is that
, um,
that, that there's competition for uh spawning areas between rainbow trout
and brown trout to where you could have 11 species spawning on top of the
other because brown trout are fall spawners. And so there's almost an
overlap in the spawning now between brown trout that spawned in October,
November, December, even in January and rainbow trout that are spawning in
maybe even late December, January, February. So you have a little bit of
that competition, maybe taking place as well. So these are again, the
things that are still being looked at to, to better know how to manage
that system. But I think the the important message here is that um if you
understand the life history of the species, it may not be a direct
sledgehammer. That's the solution. You may be able to find out nuances
about the life history. And that's what people like Carl Walters and Bill
Pine enable us to understand. Now, um There have been of course, other
scientists that have been very instrumental, Jack Schmidt I think is one
whose name is associated. In fact, almost with a Grand Canyon. Jack was at
the front of better understanding this concept of sediment distribution to
the system, the concept of beach habitat building flows and high flow
experiments. He was right in the middle. I remember I was down there in
1996 during the that control flood and I was uh doing fisheries work down
uh just downstream of the little Colorado River. He came by and he was
doing some of the research he was doing, of course, on sediment. They were
tracing the dye as it was, they, they had introduced dye into the water
and they wanted to understand the kinematic waves through the system. So
Jack of course, has been instrumental and he's many, had many graduate
students down there. Paul Grahams is one of those. Paul is now a member of
the staff of the Grand Canyon Monitoring Research Center. So he carries
forth that so called flag of, of sediment, you know, geom morphologies
that are in the Grand Canyon. Um
and most recently and probably most significantly, uh a gentleman named
Charles Yuli, who is a graduate of Columbia University. And Oxford Charles
joined the Grand Canyon Monitoring Research Center in 2000, about 2010,
2011. They hadn't been there very long, but he his back, he has a very,
very strong background in quantitative ecology and he has a an uh an
incredible background in uh ecosystem uh models and ecosystem design and
has the ability to be able to bring together complex interactions among
different species of organisms and has focused some of his focus has been
on Humpback Chub where he has helped us to really understand that
relationship between the mains stem Colorado River and the Little Colorado
River. And how Humpback Chub are using that system. Charles was
instrumental in doing the evaluation of the alternatives of the 2016 EIS
he coordinate uh across the different disciplines, all the data that was
available from hydrology to sediment to humpback job, to trout, to repair
and habitat, to recreation, everything. He's the one that coordinate all
that work. He has been a significant, uh I think scientist in the Grand
Canyon, especially most recently. Um Larry Stevens. Of course, what can
you say about Larry Stevens? Larry Stevens is just the person who has just
been there all the time. His, his uh knowledge, his areas of expertise. In
fact, um, go across virtually every discipline you can think of in the
Grand Canyon. Larry is always out there. Larry doesn't do trips down the
river to study one thing, Larry when he's down there is looking at fish,
he's looking at lizards, he's looking at insects, he's looking at
virtually everything around him. One of the most incredible ecologists I
think that, that I can think of anyway. His knowledge is almost
insurmountable in terms of understanding the, the Grand Canyon. I think
another one who goes back, in fact, predates me certainly and predates
many, many biologists in the Grand Canyon. He was one of the first to
conduct fish surveys through the Grand Canyon and that's Steve Carruthers
, Steve Carruthers, um, uh, was the manager of the museum in Northern
Arizona, which is right there in Flagstaff and he, uh, started the company
SWC A back in the, in the seventies and I, I happened to, to run, well, I
, my relationship with Steve was that we were both bidding on that
humpback job. Life, history, ecology work. The reclamation issued back in
the, in the late 19 eighties and, and I won the contract and he did not.
And so he finally came up to me one day and he said, you know, I'm tired
of you and I competing against each other. We should join forces. And
that's been a wonderful relationship that I've had with Steve since he's a
, if you want to know about birds in the Grand Canyon or reptiles in the
Grand Canyon, Steve Carruthers is one of the more knowledgeable. Certainly
, I'm sure I'm, I'm leaving certain scientists out, but those are the ones
that come to me at this time. How about key reports or studies that you
want to highlight is particularly important that have retained their value
over time? Yeah. Um Well, certainly, um
the uh the final environmental impact statement of 1996 is, is pivotal. Um
because of that was the first, there, there was never ne a compliance done
on Glen Canyon Dam because it was built way before NE A and so that was
the first effort to try to consolidate all that information. Um
The uh the 2016, the most recent LT MP I SI think is also a good archival
document for many of the things that have taken place. There are four
reviews from the National Academy of Sciences that I think people, people
sometimes overlook in terms of going back and looking at the history of
the Grand Canyon. And I think those are significant because it really
shows this, this transition uh and evolution of thinking by scientists in
the Grand Canyon, as I mentioned earlier, uh the first review because it
was right after the 8384 high flows, the natural high flows through. There
was of course historic snowfall in the upper Colorado River Basin. Uh I
remember doing cataract at about 75 80,000 CFS. And it was a, it was a
nightmare and of course, flows through the Grand Canyon reached a peak of
almost 90,000 CFS when everything was being allowed to go downstream of
the dam. And as a result of that, when the National Academy of Sciences
met, they said don't do any kind of high flows in the Grand Canyon, right
? Because that'll flush all the sediment downstream into lake mead. Well,
of course, subsequent reviews from the National Academy of Sciences said,
no, that's not really true. And again, Jack Schmidt, I think was
instrumental in bringing that back to some common sense management policy
that could be put in place. And so now we have it's not policy. It's
experiments. Now we have the high flow experiments that are in fact
showing that that is one way to conserve sediment in the Grand Canyon. Um
There are of course a collection of reports and published manuscripts
having to do with the Grand Canyon, wonderful pieces of work by many, many
scientists. Um The one that the one that, that I, that I was associated
with that I'm most proud of is uh 1999 publication in bioscience. Uh that
I did with uh Jack Schmidt was the lead author. Uh Bob Webb was involved
in it, Dick Marzo, Larry Stevens and myself. It was, it was the result of
a brainchild that took place in San Francisco. We were, we were at the uh
Geophysical Union meeting in San Francisco sitting uh in the, in the
lounge in between sessions. And Jack had asked the five of us to get
together. And he said, uh gentlemen, we should, we should document what
we're learning in the Grand Canyon. This is before the concept of adaptive
management. This is before any of that had ever come together. This is
before Carl Walters or anybody. And he said, what do we know and what we,
what have we learned? And we went through uh I, I wish I had recorded it
because it was a wonderful conversation with um who I considered the top
scientists probably that were involved, you know, Dick Marzo was at that
time with the uh US Geological Survey out of Reston, Virginia. He was one
of the main science coordinators for us, GS Bob Webb was out of us GS out
of Tucson, one of the noted authorities on Whitewater Rapids and had done
a lot of work in the Grand Canyon on lava falls on lava rapid and so on.
And of course, Larry Stevens was involved in that as well and we sat
around and talked about what it is that was happening in the Grand Canyon
and what was possible in terms of science. And so it was called Science
and Values in the Grand Canyon. That was the, the title we came up with
the conclusions I thought were remarkable for that time, given our
fundamentally feeble understanding of the way the system worked, but we
made observations over what we saw. And one of the things that we
concluded was was this concept of what we referred to as the intractable
dilemma where um we realized and recognized that there was no single
management action that could,
that could simultaneously benefit all resources. You couldn't have one
Glen Canyon Dam operations that would be best for sand and best for
Humpback chub and best for repairing habitat and recreation and everything
else. It didn't work that way. You of course, had different conditions
that were available at different times of the year. And so you basically,
you managed according to that. And, and so what that did is it
fundamentally opened the door beautifully for adaptive management whereby
you recognize that you realize that and you say, OK, what we have to do
then is implement a series of, of experiments over hypotheses. And then
you evaluate those over time, they work sometimes they don't work. Other
times you benefit some resources, sometimes not other times. So that, that
uh val science and values in the Grand Canyon and Bioscience 1999 was I
think a, a landmark paper.
Um Thanks again to Jack, I think largely to Jack Schmidt on that one. Um
There were a number of other papers of course, that were published by Lou
Coggins, Carl Walters on Humpback chub populations. It was the first
opportunity we had to really bring together the, the life history and
ecology. The work that I had done was mostly in a large report. They, I
think, uh you know, very well brought that information together and
published it. Um did an excellent job of that. Um Then, and there and
those papers are in various journals uh that you can find. And then most
recently Charles Yuli published a paper about now uh about six or seven
years ago and, and it is uh it, it's entitled Something Like Growth and
Survival of Humpback Chub in the Grand Canyon. And he, and he has a, this
is this is, this is how scientists think wonderfully. He has a lot of
little uh icons of fish as part of his models in that manuscript showing
how Humpback Chub come from the main stem into the LCR spawn and then
their little babies come drifting out or move into the main stem and then
grow up and then turn around and some of them come back and some of them
don't. And then there's a concept of skipped spawning where they don't
spawn every year, they may skip a year. And so he very nicely
characterized that in the paper and, and it's by Charles Yuli. I think
it's a wonderful piece of work. How do you spell Ky Ac Kul, IC Charles
Yuli. And that was co-authored by, uh, Mike Yard, Randy Van Habe. And, um
oh my goodness. I uh I can't remember who the other author is. We'll look
it up. Yeah, but that was, that's a, that's a very good paper, more, more
recent type of paper. Um Jack, of course, Schmidt did some uh landmark
pieces of work that I think can be found under his name relative to Grand
Canyon. Um
Those are the ones that come, I think to mind at, at this time, Graham.
Great, thanks. Well, how about a couple of big picture questions? What do
you think is the value of adaptive management in trying to manage complex
resources in an environment that we can't predict or control?
Yeah. And, and that's uh that's probably the, the, you know, $50 million
question, I think for, for many systems, um The, the Grand Canyon system
is somewhat similar to other river basin programs across the Western
United States in that there are most river basin programs have dams or
water diversions or whatever that have fundamentally altered the basic
structure. And function of the ecosystem ecosystems that in the case of
the Colorado River were probably in place although dynamic, maybe over a
period of 3 to 4 million years. And yes, in the Grand Canyon probably
about a million years ago or so, there were uh it, it was a very
seismically active area at the time that the plateau was rising. There is
very strong evidence that there were lava flows that dammed the Colorado
River in the Grand Canyon and those dams probably lasted quite some time.
Although the releases were not Hypolite coal releases, like we see today
, they probably were overflow or topping over the top of those lava dams
until they eventually eroded over a period of time. Some of those
presumably could have lasted about 1000 years, perhaps, perhaps a little
less. Um so, but, but fundamentally, I you can, despite the dynamics that
you see over say a million years or a 3 to 4 million year period, you
still recognize that there was a dynamic system that was there before
there were any uh any um
any of man's influences such as dams such as water diversions, such as
depletion of sediment and so on
when one considers those kinds of effects.
The first, the first thing to understand is that it is unlikely that that
so-called historical system, whatever that used to look like. Pre Preman
say, it's unlikely that that would ever be restored to what it was. And so
you have to, you have to work with an altered system. It is also unlikely
that one can restore the the function, the structure and function of the
components of that system. The way the river used to work, the big floods
in the spring time, the high temperatures, et cetera, the absence of of
alien fish. And so um so the the problems are so, so the problem becomes
first understanding the way the system works in its current state, the
dynamics of that contemporary river system.
And part of that, of course is trying to better explain how some
components of that system might work that are in scientific terms,
expressed as hypotheses. And so it is, it is in fact the almost the ideal
setting for adaptive management whereby you try to explain a particular
problem or a particular issue having to do with the Grand Canyon or
operation of Grand Canyon Dam, you establish a hypothesis and then you
test that hypothesis in different ways. You realize that when you do test
it like high flow experiments, for example, you don't quite get it right.
The first time the first high flow experiment was 1996 we went for 10 or
12 days. I can't remember how long it was and most of the sediment moved
in about the first two or three days. So we learn from that, we learn that
those don't need to be as long. So that was part of the cycle of adaptive
management. Uh It's true of virtually every resource in the Grand Canyon
that you have to understand that. So adaptive management in, in, in, in
and of itself as a concept is probably well suited to something like like
Grand Canyon to, to be implemented in that, in that system. Now, what Carl
Walters also taught us though was what we talked about earlier. Those
unexpected surprises that nature may throw on you. The condition
dependency where you have times when you cannot implement an experiment
because there's not enough water available to do it or the experiment goes
awry because the temperatures weren't what you expected from the river.
Again, you're basically doing experimentation in a large open laboratory
with no control whatsoever except for perhaps a large spigot call Glen
Canyon Dam. And so um the the to me, the most informative part of it
though is to be able to implement adaptive management and then perhaps
even remove yourself from the program as, as I have and not that I've
removed myself, but I, I'm not as involved as I was. And then look at it
from the outside in, in a really objective way and look at what it has
worked and what hasn't worked. And I think by and large um aspects of what
has have been put in place, have worked and aspects of it have not worked
in some cases. Um Well, for example, the, the, the concept of um when we
first started looking at mechanical non fish control, we thought, OK, we
can, we can go in there and put electro fishing boats in the river and
take out a lot of trout and that'll solve the problem. Well, not quite
because you had this invasion, this re invasion of those areas. Uh Another
example is perhaps uh high flow experiments where you're trying to
preserve sand and sediment. You take advantage of when that sediment is
most available in the fall. But now perhaps you're scouring the food base.
And so you have to understand that every one of those actions that you're
implementing as, as an experiment has some kind of reaction perhaps to
other resources. So again, that's something that Carl Walters cautioned us
about that management, that experimentation, you have to go through
experimentation first before you implement policy. Before you put that as
part of your normal operation, you have to evaluate it first. What many of
us did not understand and certainly many managers and administrators and
even today don't understand is how long that takes to do that. I mean,
we've had a science program in the Grand Canyon since about 1985 with G Ce
s with Dave Wagner. That's a long time that you know, that's 30 some odd
years of experimentation in the Grand Canyon. And of course, managers
always say, how long is this gonna take you? When are you going to give us
the answer. Well, there is no particular answer. It really, it really
speaks to the need for ongoing involvement, an ongoing understanding of
what's happening in the system and the ongoing dynamics. So that to me is
the most valuable part is this retrospective opportunity to look back on
it and see what worked, what didn't work and what surprises we had. And
it's that last one that's often the largest effect of any of those.
Well, that's a,
an articulate defense of the value of the program over time. Um Yeah, it's
been 30 I think, 38 years since the launching of G ce S one that came up,
started in 1982 almost four decades and 25 years since um the launching of
the Glen Canyon Dam Adaptive Management Program proper.
It's pretty expensive program. We have learned a lot. Do you anticipate
that there will be some point in the future in which the program is, we've
learned enough that we don't really need the program anymore? Or is the
constant evolution and accretion of knowledge so valuable that it should
be continued, at least for the foreseeable future in your opinion. Well,
unfortunately, the continuance of that program is not under our control,
of course, but I would certainly hope that that program continue. And the
reason is because, um it's not for science, it's not for the sake of
science alone. It is for the sake of better understanding how to manage
one of the most valuable resources we have in North America and society
has made that decision that it's important to maintain the Grand Canyon as
well as we can and maintain all the resources within the Grand Canyon when
it is a societal decision and it is a s a societal value. I think it does
rise to the level of justifying an ongoing funding of the program in its
current state. It is a um it is a federal advisory committee so it's under
the direct authority of the Secretary of the Interior. I hope it stays
that way because it, it certainly, I think has um eliminated a lot of the
complexity, especially for funding the program. Now, whether that can be
part back, some, I think only managers can make that decision. Uh Again,
the the the role of science in the process is gathering information in an
in an objective manner in order to give that information for managers to
make informed decisions and for administrators to facilitate those
decisions and provide the logistics for those being done. I think that's
important. I think those roles are necessary in a system like the Grand
Canyon. And again, not for the sake of science, but really for the sake of
the resources in the Grand Canyon, not just in the Grand Canyon, but
downstream as well. Because that water that's delivered through the system
is also important to the downstream states, Nevada, California, and
Arizona as well. As it, as it goes downstream. So I, I see. And I'm hoping
that the program continues in some form because I think it's necessary um
to do so if one were to um speculate a little bit on what might happen, if
the program would go away. For one thing we've learned from programs like
the Grand Canyon program, like the upper Colorado River recovery program,
like the San Juan River recovery implementation program, like the lower
Colorado river MS CP. We've learned that those programs have certainly
brought together all of the interest in the system. Many millions of
people rely on these rivers for delivery of water for recreation, for many
other values. Those are those programs are important to maintain because I
, I do remember before, for example, the Upper Colorado River Basin
program, I do remember uh what were then almost termed water wars where
there was some uncertainty about how to best manage the water, who owned
the water, how it was to be transferred and passed through the system. Um
People like Tom Pitts who was a water coordinator in the upper Colorado
River basin came up with many concepts as to how to do this. And one of
the ideas he came up with was to establish a recovery implementation
program which was to enable water users to get together and talk about how
to best manage
water resources in concert with natural resources. And so I am hoping that
this program does continue
last question. What advice would you have for people coming newly into the
program? Some young post doc who gets his, his or her first research grant
or somebody a stakeholder that gets uh placed on the adaptive management
work group or technical work group. What advice would you have for them
about how to be uh successful in advancing the program,
patience and humility, not necessarily in that order.
Um
The uh the there are the recognition that there have been many people
before them working to the best of their ability to try to put a program
in place. The best man, the best balances, water management and protection
of resources. That's important, the understanding of roles, especially
those with scientific backgrounds to understand that that the role of a
scientist is in fact to provide information by which others can make
informed decisions. And that was one of the big things that we talked
about in that bioscience paper. I mentioned earlier the role of science.
That that's an important concept I think because we make decisions on the
basis of societal needs and societal demands, not on the basis of what
scientists think. However, the better informed those decisions are the
better off we're going to be. So I think that that's important. The other
part of it is humility and I certainly learned that one the hard way
because all of us uh as young phd s think we pretty much know about all
there is to know and just turn us loose on the planet and we'll solve all
the problems. Um You know, that that is where people like Carl Walters and
Bill Pine were so um so enigmatic about being able to tell us how to
better manage a system while being patient with us and while being, you
know, tutorial, more or less helping us understand better how to, how to
see things, how to view things. So I I think, I think patients and
humility are probably the best guidance I could give to someone coming
into the system. Uh be patient with other stakeholders, especially those
that have been in the program for some time. They may be knowing things
that may be a surprise. And yet at the same time as a scientist, 1 may
observe a new scientist may observe that gosh, you guys recommended such
and such back when and it didn't work, did it? Well, again, that's part of
patience. That's part of adaptive management. No, it may have not worked.
But let's look at it further, let's let's do it better, let's figure out
a way to do it better. Um And I see a lot of new scientists coming into
the program that I think are aware of some of those fundamentals. I I
certainly see people like Charles J Kulick who has been very, very helpful
and and understands that having worked around the world, I think he's
encountered these situations before. But um the, the uh the GC Damp does a
wonderful job of coordinating the science. The twig technical work group
of the GC Damp has done a wonderful science of uh a wonderful job of
helping to coordinate and, and assimilate that information in a meaningful
way. And they've been very good, I think at issuing reports and reporting
and, and giving scientists the opportunity. Uh a good thing was to bring
the US or the GCMRC under the US Geological Survey because now if you go
to the website, you will find all of the reports. They're up to date.
Everything is being archived in a very good fashion. You don't have any
trouble finding what people are doing. You can see it right there. That's
not true of all river basin programs. This one is, is a wonderful example
, is everything perfect. Of course not. No, there are many things that
need improvement within the, the GC damp, but those are the kinds of
things that you learn as you go and you try to improve as, as best as
possible. So, um yeah, like I said, patience and humility.
Well, thanks rich for um your meeting with us today, for your wisdom and
your openness and, and your lifetime of research trying to advance these
really important goals of balancing, as you said, balancing societal needs
with um with the health and resilience of the ecosystems we depend on.
Well, thank you. I appreciated uh you asking me to do this interview and
thoroughly enjoyed it. Thank you. Ok.