Razorback Sucker and Humpback Chub in the Colorado River

1
Razorback Sucker and Humpback Chub in the
Colorado River
Abstract
The Colorado River has been called the lifeline
of the Southwest United States because it
provides water and electricity to over 25 million
people. In fact, a body of laws collectively
referred to as the Law of the River allowed the
development of the Southwest because it promoted
use of the Colorado River water for industry,
agriculture, and human needs. However, the
creators of the Law of the River didnt
consider what impact water development (e.g.,
building of dams, channels, etc.) would have on
the native fish in the river. Dams built on the
Colorado River changed a number of habitat
conditions, including decreasing temperature,
interrupting natural flow regimes, and reducing
turbidity. These alterations were a problem for
native fish as they were better suited to live in
pre-dam conditions. Although habitat alteration
was a big problem for native fish, introductions
of non-native fish species to the Colorado River
were also problematic. Non-native fish are
efficient predators on the eggs and young of
native fish and have virtually eliminated younger
age classes from populations of native fish.
With little suitable habitat and predation of
non-native fish, species like the Razorback
Sucker and Humpback Chub, are in a dire
situation.
2
Description of Conservation Issue
Razorback Sucker and Humpback Chub are both
endangered species in the Colorado River Basin.
The main causes of these species decline are
habitat alterations and non-native species
introductions (U.S. Fish and Wildlife Service
2000). There are two inherent conflicts in this
situation (1) How do humans use more Colorado
River water for economic development and their
daily needs while still maintaining water levels
and flows for endangered fish species? (2) How do
state and federal wildlife agencies protect these
endangered species while simultaneously stocking
non-native fish to enhance sports fisheries in
the Colorado River Basin?
3
Historic Conditions
The Colorado River was an unobstructed system
that flowed freely for over 1,400 miles. Its
headwaters in the Rocky Mountains of Wyoming
provided for large flooding events and a
siltation of the river in the spring after
snowmelt. These large flooding events carved out
shallow sections of river that provided spawning
habitat for many of the thirty-six native species
of fish that historically lived in the Colorado
River system. The silt carried by the river
inspired the first Spanish explorers to call it
Rio-Colorado or Red River (Gelt, 1997). The
river was also much warmer than it is today
without the influence of the cooling effects of
hydroelectric dams.
Learn More
4
In the 1800s
Private citizens, state, and federal wildlife
agencies began stocking non-native fish species
into the Colorado River to enhance sports
fisheries. They stocked flathead catfish,
largemouth bass, bluegill, green sunfish, trout,
and many other fish species into the Colorado
River system. Currently, there are forty species
of non-native fish in the Colorado River. The
number of introduced fish species (40) outnumbers
the number of native fish species, those that
originally lived there. Native fish species
numbers declined dramatically after the
introductions of non-native fish species because
non-native fish were efficient predators of the
native species young and eggs (U.S. Fish and
Wildlife Service 2002).
5
In the 1900s
States in the Colorado River Basin had many
disputes over who had rights over the water in
the Colorado River. Each state wanted to
establish its own limits on use of Colorado River
water. A body of interstate compacts, federal
laws, water contracts, state laws, a treaty with
Mexico, Supreme Court decrees, and Federal and
State administrative actions were developed to
resolve these differences. These laws are
collectively referred to as the Law of the
River and have been very instrumental in the
development of the Southwest United States. The
Hydroelectric Dams provide water and electricity
to industry, agriculture, and over 25 million
people living in the Colorado River Basin states
(Gelt, 1997). Although these laws were successful
in developing the Southwest, they were also
detrimental to native fish species living in the
river. Habitat conditions changed rapidly with
the closing of the gates of the Glen Canyon Dam
in 1963. Almost immediately, water temperatures
dropped, flow was interrupted, and silt began
being trapped by the dam. As the habitat in the
river changed from a system to which native fish
were well adapted to a system to which they were
not well suited, native fish populations started
to decline.
6
Present Conditions
The Colorado River today is a reflection of what
the Law of the River and the humans who created
that body of legislation wanted it to be. It is a
series of connected reservoirs blocked by
hydroelectric dams for the use of humans. These
dams have been beneficial for the development of
the Southwest, but have changed the habitat
conditions in the river. Now the river is clear
and cool there are few flooding events in the
spring (beneficial for spawning habitats) and
there is erratic flow the rest of the year. The
river also provides great opportunities for
sportsman to go fishing for many game fish
species, even though most of them are not native
to the system. Endangered Species in the system
still face the danger of going extinct without
action from State and Federal wildlife agencies
The Colorado River is vastly different than it
was before the influence of man, and this change
is a direct result of the history of human
interaction with the river.
7
Relevant Research
There is a lot of research that has been
conducted on the endangered species of the
Colorado River. What is striking about all this
research is that it is very consistent as to the
cause of the declines of Humpback Chub and
Razorback Sucker. It seems that every piece of
scientific evidence we have on the Humpback Chub
and Razorback Sucker point to the same challenges
of habitat destruction caused by water
development and predation by non-native fish
species. The next few slides provide a
study-by-study synopsis of the challenges these
species face as defined by research  
8
Life History and Ecology of the Humpback Chub in
the Little Colorado and Colorado Rivers of the
Grand Canyon By LYNN R. KAEDING AND MARIAN A.
ZIMMERMAN Synopsis This study shows that the
only viable population of Humpback Chub lives in
the Little Colorado, which is a shallow and warm
tributary of the Colorado River. This tributary
is protected from predators because it is too
shallow for them to live there. This study also
shows that the cold temperatures in the Colorado
River cause nearly complete mortality of
embryonic and larval Humpback Chubs. The
researchers of this study suggest that the Little
Colorado be protected from species introductions
as it is the only place that Humpback Chub can
reproduce and devastating effects could result
from these introductions.
9
Predation by Introduced Fishes on Endangered
Humpback Chub and Other Native Species in the
Little Colorado River, Arizona By PAUL C. MARSH
AND MICHAEL E. DOUGLAS Synopsis This study
showed that native fish species represent a
significant percentage of introduced species
diets. More specifically, this study sampled
rainbow trout, channel catfish, yellow bullhead,
black bullhead, and brown trout diets in the
Colorado River. Researchers found that native
fish species represented thirty percent of these
fishs diets. Three percent of these diets were
comprised of Humpback Chub. The researchers
calculated that each the predator fish they
sampled eat an average of 2.3 Humpback Chubs per
week. This means that 1,000 predators will
consume around 4,000 Chubs annually. This
predation represents a major negative effect on
the population. Researchers also pointed out the
fact that juveniles represented a large portion
of the Humpback Chubs consumed. This study shows
how non-native predation not only limits
recruitment, but also decreases the total adult
population and reproduction from such.
10
Ecology of Spawning Humpback Chub, Gila Cypha, in
the Colorado River near Grand Canyon, Arizona By
OWEN T. GORMAN AND DENNIS M. STONE Synopsis This
study describes the spawning activity of Humpback
Chub in the Colorado River. Researchers found
that Humpback Chub spawning activity was
correlated with peak flows in April and also with
higher temperatures found in tributaries, such as
the Little Colorado River. They stress that
temperatures in the Colorado River do not
typically get warm enough to induce spawning
activity of Humpback Chub. They also state that
spawning sites were correlated with the
structural complexity found in the tributaries of
the Colorado River. The researchers state that
since flooding events no longer occur in the
Colorado River, there are no forces to carve out
the shallow spawning pools on the banks of the
river that provide the structural complexity
Humpback Chubs use to spawn. This study also
provides evidence for spawning migrations of
adult Humpback Chub that live in the Colorado
River approximately 13 kilometers up the Little
Colorado River.
11
Effects of a Test Flood on Fishes of the Colorado
River in Grand Canyon, Arizona By RICHARD A.
VALDEZ, TIMOTHY L. HOFFNAGLE, CAROLE C. MCIVOR,
TED MCKINNEY, AND WILLIAM C. LEIBFRIED
Synopsis This study looked at the effects of
an experimental test flood on the Humpback Chubs
species in the Colorado River. Researchers found
that Humpback Chub and native fish species had
good spawning success in the slack water pools
created by the flood, but had little overall
impact on the survival of non-native fish
species. The flood displaced these species, but
they came back after eight months. The conclusion
of this study is that floods may serve to
temporarily reduce non-native species competition
with native fish species, but a flood of many
more orders of magnitude would be required to
reduce non-native fish substantially.
12
Population Status of the Razorback Sucker in the
Middle Green River (U.S.A.) By TIMOTHY MODDE,
KENNETH P. BURNHAM, AND EDMUND J.
WICK Synopsis The results of this study were
that the Razorback Sucker are able to reproduce
during high flow years, but these flows are
reduced greatly by the influence of dams. Floods
are essential to Razorback Sucker reproduction
because they use the shallow water habitat caused
by overbank flooding to reproduce. This study
shows that there is positive recruitment during
high flow years, which reinforces that flooded
bottomlands on the Colorado River are important
for reproduction. This study also emphasizes that
the increase in introduced fish species
populations is closely associated with the
decrease in Razorback Sucker populations.
13
Relative Sensitivity of Three Endangered Fishes
Colorado Squawfish, Bonytail, and Razorback
Sucker to Selected Metal Pollutants By KEVIN
J. BUHL Synopsis This study looked at metal
pollution concentrations and its effect on
Razorback Sucker populations. The researchers
found that most EPA regulations on metal
pollution were adequate or had no effect on the
Razorback Sucker. They also found that cadmium
was an important metal that has strong
implications on Razorback Sucker because it
greatly reduced their ability to reproduce.
14
Geomorphology and Endangered Fish Habitats of the
Upper Colorado River 1. Historic changes in
streamflow, sediment load, and channel
morphology By MARK M VAN STEETER AND JOHN
PITLICK Synopsis The results of this study
showed that peak discharges have decreased 19
38 and that annual sediment loads have decreased
40 65 in the Colorado River. It also states
that the main channel of the Colorado River has
narrowed an average of twenty meters, which means
that 25 of the area formed by side channels and
backwaters has been lost. All of these changes in
the habitat are related to reduced and restricted
water flow in the river. This reduced flow caused
by dams has effectively reduced the heterogeneity
of the habitat used for spawning by native fish
species in the Colorado River.
15
Habitat Use by Hatchery-Reared Adult Razorback
Suckers Released into the Lower Colorado River,
CaliforniaArizona By RICHARD H. BRADFORD AND
SCOTT D. GURTIN Synopsis This study looked at
the habitat use by hatchery-reared Razorback
Suckers. The results of this study were that
backwater habitats were used the most often among
hatchery-reared Razorback. The second-most
important habitat used by Razorbacks was side
channel habitats. Main channel habitats were
rarely used by this fish species. Researchers
emphasize the need to protect backwater and side
water habitats for Razorback Suckers. They also
make recommendations for stocking of Razorback
Sucker in areas that provide a suitable amount of
backwater and side channel habitats.
16
Conflicts And Debate
The stakeholders of the Colorado River are vast
as there are a number of private citizen
organizations in addition to state and federal
agencies involved. On the governmental side, you
have Colorado River Basin States fish and game
departments, Colorado River Basin States EPAs
and legislative bodies, the United States Fish
and Wildlife Service, the Army Corps of
Engineers, and the United States Environmental
Protection Agency. On the other side, you have
private citizens, private citizen organizations,
agricultural operations, industry, and mining
operations. Neither side totally agrees on what
needs to be done with the river to benefit such
native fish species as the Humpback Chub or
Razorback Sucker. The two basic conflicts between
many of these groups are (1) One side wants to
protect native fish species by restoring habitat
conditions that are beneficial to these fish
while another side would like to use more water
or develop land and degrade habitat further to
provide for some facet of human need and (2) One
side likes fishing for game species in the
Colorado River System, but the other realizes
that these species have eliminated reproduction
of native fish species and have caused their
decline and therefore, this agency or group is
for the removal of non-native fish or at least
the elimination of stocking non-native fish.
17
Relevant Legislation

• There are four relevant laws that apply to
  endangered species in the Colorado River Basin
• The Mining Law of 1872
• Water Law
• Clean Water Act
• Endangered Species Act

18
The Mining Law of 1872
The price for metals is increasing and many
multinational companies are looking to make
mining claims on Federal lands near the Colorado
River. Most companies want to stake a claim on
these Federal lands for the rich uranium deposits
that are found near the Colorado River. Even
though the Colorado River supplies drinking water
for over 25 million people, there is little
protection to stop mining because the Mining Law
of 1872 allows all citizens of the US to locate
hard rock or gravel and claim it for mining (EWG,
2008a). These minerals include, but are not
limited to, platinum, gold, silver, copper, lead,
zinc, tungsten, and uranium. The EPA has reported
that mining has contaminated the headwaters of
more than 40 percent of Western watersheds.
Furthermore, the Environmental Protection Agency
has identified metal mining as the nations
leading source of toxic pollution for nine
consecutive years (EWG, 2008b). With metal prices
on the rise, it is likely that these mines will
be opened and cause contamination of the Colorado
River. This contamination could have strong
negative impacts on fish health in the river.
19
Water Law Most water law is formed by disputes
between people who want to use the water for some
purpose. The Western United States uses prior
appropriation in which the first person to use
water for a beneficial use has rights over the
water to limit these disputes. In fact, the Law
of the River was formed because of disputes over
water usage among the states in the Colorado
River Basin. While each law of The Law of the
River individually has some effect on the
Humpback Chub and Razorback Sucker, for the
purpose of this discussion well focus on some of
the most important legislation and briefly
discuss what the other laws in the Law of the
River were meant to accomplish.
20
The Law of the River The foundation for the Law
of the River was the Colorado River Compact of
1922 (Gelt 1997). This Compact divided the
Colorado River Basin into Upper and Lower Basins
with the dividing line at Lees Ferry, Arizona.
The upper states were apportioned 7.5 million
acre feet of flow, and the lower basin was
apportioned the same amount of flow with the
option of using an additional 1 million acre feet
of flow. The problem is that legislatures
apportioned more water for use by the states than
what actually flows through the river. Basically,
all water is apportioned for use by the states
and no water is left for fish species habitat.
The Boulder Canyon Project Act of 1928 and the
Colorado River Storage Project Act of 1956
authorized the building of the Glen Canyon Dam,
the Hoover Dam, and several other dams for
hydroelectric power and flood control (Gelt
1997). These Acts also had provisions for how
water was going to be used for economic
development of the region and put to a
beneficial use for humans. The other laws that
form the Law of the River dealt specifically
with how water was going to be used between
states, the U.S. and Mexico, and people within
the states. These laws also focused on how to use
the water toward development and beneficial use
by humans.
21
Clean Water Act Section 101(a) of the Federal
Water Pollution Control Act (i.e., Clean Water
Act 33 U.S.C. 125113287) states that the
objective of this law is to restore and maintain
the chemical, physical, and biological integrity
of the Nations waters and provide the means to
assure the ...protection and propagation of
fish, shellfish, and wildlife... . This statute
contributes in a significant way to the
protection of the Razorback Sucker and Humpback
Chub and their food supply through provisions for
water quality standards protection from the
discharge of harmful pollutants, contaminants
Section 303(c), Section 304(a), and Section 402
and discharge of dredge or fill material into all
waters, including certain wetlands (Section 404)
(U.S. Fish and Wildlife Service 2002).
22
Endangered Species Act The primary regulatory
mechanism for protection of the Razorback Sucker
and Humpback Chub is through Section 7(a)(2) of
the Endangered Species Act (ESA), which states
that Each Federal agency shall, in consultation
with and with the assistance of the Secretary,
insure that any action authorized, funded, or
carried out by such agency... is not likely to
jeopardize the continued existence of any
endangered species or threatened species or
result in the destruction or adverse modification
of habitat of such species which is determined by
the Secretary, after consultation as appropriate
with affected States, to be critical... (U.S.
Fish and Wildlife Service 2002).
23
Endangered Species Act (Continued) The Upper
Colorado River Basin Recovery Program (UCRRP)
provides a mechanism for dealing with Section 7
consultations. There are currently no formal
recovery programs in the lower basin, and Section
7 consultations are addressed on a case-by-case
basis (U.S. Fish and Wildlife Service 2002) .
None of the recovery or conservation programs in
the Colorado River Basin are regulatory
mechanisms that provide permanent, long-term
protection for the species after delisting. In
addition to Federal protection under the ESA,
Razorback Suckers and Humpback Chub are protected
by all basin States under categories such as
endangered, threatened, or sensitive. This
protection prohibits intentional take-and-keeping
or harming in any way any fish captured
incidentally, and may need to remain in place
after the species is delisted (U.S. Fish and
Wildlife Service 2002).
24
Effectiveness of the Endangered Species Act
The Endangered Species Act has been a good thing
for the Razorback Sucker and Humpback Chub in the
Colorado River. Many of the studies mentioned as
contributing toward the management of these
endangered species were funded through ESA
provisions. These studies depended on ESA money
to fund their research, but the ESA depends on
them to make the appropriate decisions when
designating critical habitat under Section 7 of
the ESA. Critical habitat designations have
allowed for protection from habitat modifications
that threaten these fish species, but also from
the stocking of non-native fish species and, in
some instances, the removal of non-native fish
species from these areas. It also protects these
species from being taken from the river through
fishing or other means. Without the ESA, the
Razorback Sucker and Humpback Chub may very well
have gone extinct.
25
Problems with the ESA
While the ESA is important for the protection of
the Humpback Chub and Razorback Sucker, the
legislation itself can only go so far to protect
and enhance the Colorado River for these fish
species. ESA decisions are based on best
biological information, but as most fisheries
biologists know, much of fisheries conservation
is socioeconomic or political (Minckley, 2003).
As is the case on the Colorado River many
factors other than biology influence most plans
and projects for the conservation of these native
fish. These factors contribute to reducing the
benefit of the ESA to the species of concern.
26
Problems with the ESA (continued)
The US Fish and Wildlife service is supposed to
enforce ESA regulations and promote sport
fishing, but it has trouble balancing these
conflicting interests. There is an inherent
conflict between the management of non-native
sport fish and recovery of endangered fishes.
Where valued sport fisheries occur, there is an
ongoing dilemma between public demands for
maintenance and expansion of fisheries and
management actions to conserve and recover
endangered fish (Minckley, 2003). State agencies
have the same problem on the Colorado River,
trying to balance private citizen and companies
interest with the biological integrity of the
system. Unfortunately, much of the time private
citizen and companies who represent much of the
support for state and federal wildlife agencies
win out over the interest of the species of
concern.
27
Problems with the ESA (continued)
Companies typically have more money and political
clout than the agency trying to enforce the
regulations, and challenging these companies is
very difficult when trying to protect endangered
species. Much of the time these companies
interests will win out over the regulations set
forth by the ESA (Minckley, 2003). Legislative
relief and many exemptions have been given to
companies and other agencies who would like to
use the Colorado River for economic benefit.
Provisions for habitat management plans and
reasonable and prudent alternatives have
successfully pierced the ESAs armor to allow
non-Federal entities to develop and operate
projects with a take of listed taxa. This is
permitted so long as a species existence is not
jeopardized and the impacts of these projects are
offset in some form.
28
Conclusion
There is no technical solution for solving the
problems that State and Federal wildlife agencies
are facing to recover Humpback Chub and Razorback
Suckers. Human interests have long won out to the
detriment of our environment. With concrete
penalties and stronger language, the ESA can be
revised to fix some of the problems, but it is
not likely that fish and game agencies will have
the political clout to reform this legislation.
The ESA is not a failure because it has provided
numerous benefits to endangered fish populations
in the Colorado River. The main problem is that
private citizens and companies are not very
concerned with the recovery of these fish. The
support from resource users is not present at
this time to ensure that governmental agencies
can do more to protect these species.
29
THE END
30
Resources

• http//www.fws.gov/coloradoriverrecovery/ - Upper
  Colorado River Endangered Fish Recovery Program
• http//cpluhna.nau.edu/Biota/fishes.htm - Land
  Use History of the Colorado Plateau
• http//www.colorado.edu/conflict/full_text_search/
  AllCRCDocs/93-12.htm - The Upper Colorado River
  Basin Endangered Fish Recovery Initiative
• http//www.cowatercongress.org/images/tom20pitts
  20-20upper20colorado20river20endangered20fish
  20recovery20program.pdf USFWS Presentation

31
References
Bradford, R., S. Gurtin. 2000. Habitat Use by
Hatchery-Reared Adult Razorback Suckers Released
into the Lower Colorado River, California-Arizona.
North American Journal of Fisheries Management,
20 (1) 154-167. Buhl, K., J1997 Relative
Sensitivity of Three Endangered Fishes, Colorado
Squawfish, Bonylail, and Razborback Sucker, to
Selected Metal Pollutans. Ecotox and Env Safety
37 186-192. Environmental Working Group. 2008a.
Mining Surge Near Colorado River Threatens
Drinking Water For 25 Million. lt
http//www.ewg.org/node/2646gt 10/29/08. Environme
ntal Working Group. 2008b. Without a PaddleU.S.
Law Powerless to Protect Colorado River From
Mining. lthttp//www.ewg.org/sites/mining_google/Co
loradoRiver/index.php?nothanks1gt 10/29/08. Fish
and Wildlife Service. 2000. Species information
threatened and endangered animals and plants.
lthttp//endangered.fws.gov/wildlife.htmlgt
10/29/08. Fish and Wildlife Service. 2002.
Razorback Sucker (Xyrauchen texanus) Recovery
Goals. U.S. Department of the Interior, U.S. Fish
and Wildlife Service, Washington, D.C. Fish and
Wildife Service. 2006. Why some native fish in
the upper Colorado River basin are endangered.
http//www.fws.gov/ColoradoRiverrecovery/Crwhynnf.
htm 10/29/08 Gelt , J., 1997. Sharing Colorado
River Water History, Public Policy and the
Colorado River Compact, Arroyo, Volume 10, No. 1,
ltag.arizona.edu/ AZWATER/arroyo/101commgt
10/29/08. Gorman, O. T., and D. M. Stone. 1999.
Ecology of spawning humpback chub, Gila cypha, in
the Little Colorado River near Grand Canyon,
Arizona. Environmental Biology of Fishes
55115133. Keading, L. R., and M. A. Zimmerman.
1983. Life history and ecology of the humpback
chub in the Little Colorado and Colorado rivers
of the Grand Canyon. Transactions of the American
Fisheries Society 112577594. Marsh, P. C., and
M.E. Douglas (1997) Predation by Introduced
Fishes on Endangered Humpback Chub and Other
Native Species in the Little Colorado River,
Arizona. Transactions of the American Fisheries
Society Vol. 126, No. 2 pp. 343346 Minckley,
W. L., P. C. Marsh, J. E. Deacon, T. E. Dowling,
P. W. Hedrick, W. J. Matthews, and G. A. Mueller.
2003.A conservation plan for native fishes of the
lower Colorado River. BioScience
53219233. Modde, T., K.P. Burnham, and E.J.
Wick. 1996. Population status of the razorback
sucker in the middle Green River (U.S.A).
Conservation Biology 10(1)110-119. Pitlick, J.,
and M. M. Van Streeter, Geomorphology and
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River, 1, Historic changes in streamflow,
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11686700.
32
kim Use more complete def. For heterogeneity
Glossary Age Class Fish in the same age
range Embryonic In an early stage of
development Headwater The source of a
river Heterogeneity A state of consisting of
dissimilar elements Peak Discharge The highest
rate of discharge of a volume of water passing a
given location Predation The act of preying by
a predator who kills and eats the prey
Recruitment The number of new juvenile fish
reaching a size/age where they represent a viable
target for the commercial, subsistence or sport
fishery for a given species Sediment Load The
solid material that is transported by a
stream Tributary A stream or river that flows
into a larger one Turbidity Having sediment or
foreign particles stirred up or suspended
muddy Viable Capable of life or normal growth
and development Watershed The region draining
into a river, river system, or other body of
water
33
APPENDIX
2) Flow is restricted by dam
1) Silt gets trapped behind dam
As a result river carries less silt, has
restricted flow, and is much cooler
3) Intake in deeper cooler region of lake
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