[Federal Register Volume 79, Number 6 (Thursday, January 9, 2014)]
[Proposed Rules]
[Pages 1615-1619]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-00164]



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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2012-0101; 4500030113]
RIN 1018-AY25


Endangered and Threatened Wildlife and Plants; 6-Month Extension 
of Final Determination for the Proposed Listing of the Zuni Bluehead 
Sucker as an Endangered Species

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule; reopening of comment period.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
6-month extension of the deadline for a final determination concerning 
the listing of the Zuni bluehead sucker (Catostomus discobolus yarrowi) 
as an endangered species. We also reopen the comment period on the 
proposed rule to list this species as an endangered species. We are 
taking this action because there is substantial disagreement regarding 
the sufficiency or accuracy of the available data relevant to our 
determination regarding the proposed listing rule, making it necessary 
to solicit additional information by reopening the comment period for 
30 days.

DATES: The comment period end date is February 10, 2014. If you comment 
using the Federal eRulemaking Portal (see ADDRESSES), you must submit 
your comment by 11:59 p.m. Eastern Time on the closing date.

ADDRESSES: You may submit written comments by one of the following 
methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the Search box, enter FWS-R2-ES-2012-0101, 
which is the docket number for the proposed rule to list the Zuni 
bluehead sucker as endangered. Then, in the Search panel on the left 
side of the screen, under the Document Type heading, check on the 
Proposed Rules link to located the proposed rule. You may submit a 
comment by clicking on ``Comment Now!''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R2-ES-2012-0101; Division of Policy and 
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax 
Drive, MS 2042-PDM; Arlington, VA 22203.
    We request that you send comments only by the methods described 
above. We will post all comments on http://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Public Comments section below for more information).

FOR FURTHER INFORMATION CONTACT: Wally ``J'' Murphy, Field Supervisor, 
U.S. Fish and Wildlife Service, New Mexico Ecological Services Field 
Office, 2105 Osuna NE., Albuquerque, NM 87113; by telephone 505-346-
2525; or by facsimile 505-346-2542. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

    The Zuni bluehead sucker is a small fish that is believed to be 
endemic to streams in east-central Arizona and west-central New Mexico. 
On January 25, 2013, we published in the Federal Register a proposed 
rule (78 FR 5369) to list the Zuni bluehead sucker (Catostomus 
discobolus yarrowi) as an endangered species under the Endangered 
Species Act of 1973, as amended (Act; 16 U.S.C. 1531 et seq.), because 
we found the subspecies in danger of extinction. On the same date, we 
also published in the Federal Register a proposed rule to designate 
critical habitat for the Zuni bluehead sucker (78 FR 5351; January 25, 
2013). Identified threats to the subspecies included water withdrawals, 
sedimentation, impoundments, housing development, and predation by 
nonnative green sunfish (Lepomis cyanellus). We believe the range of 
the subspecies has already been reduced by approximately 90 percent in 
New Mexico, but we do not know the extent of potential range reduction 
in Arizona. Low water levels from drought and water withdrawals in 
remaining occupied streams have reduced the available habitat for the 
subspecies. The proposed listing rule had a 60-day comment period, 
ending March 26, 2013. For a description of previous Federal actions 
concerning the Zuni bluehead sucker, please refer to the proposed 
listing rule (78 FR 5369; January 25, 2013). Since the publication of 
the proposed rules, we have found substantial scientific disagreement 
about the status of the Zuni bluehead sucker as explained below, and we 
are therefore reopening the comment period for the proposed listing 
rule and extending the schedule for the final determination for 6 
months in order to solicit and analyze information that will help to 
clarify these issues.
    Section 4(b)(6) of the Act and its implementing regulations at 50 
CFR 424.17(a) require that we take one of three actions within 1 year 
of a proposed listing: (1) Finalize the proposed listing; (2) withdraw 
the proposed listing; or (3) extend the final determination by not more 
than 6 months, if there is substantial disagreement regarding the 
sufficiency or accuracy of the available data relevant to the 
determination. Our review of the information described below suggests 
there is substantial disagreement regarding the taxonomic status of 
some populations that we considered Zuni bluehead sucker in the 
proposed rule. The following discussion describes these disagreements.
    In the proposed listing rule, we reported that the Zuni bluehead 
sucker has been documented in three discrete watersheds--the Zuni River 
watershed in New Mexico, the Little Colorado River watershed in 
Arizona, and the San Juan River watershed at the borders of New Mexico 
and Arizona. However, the taxonomy of the occurrences of the subspecies 
outside of the Zuni River watershed has been disputed and remains in 
question. In the Zuni River watershed of New Mexico, the subspecies is 
believed to be restricted to three isolated populations in the upper 
Rio Nutria drainage (Carman 2008, pp. 2-3). Streams in the upper Rio 
Nutria drainage of the Zuni River watershed include the Rio Nutria, 
Cebolla Creek, and Rio Pescado, in addition to Tampico Spring and Agua 
Remora Springs, which are headwater springs to Rio Nutria. In eastern 
Arizona, there is evidence that the subspecies occurs in low numbers in 
the Kinlichee Creek area of the Little Colorado River watershed and 
Canyon de Chelly area of the San Juan River watershed (Hobbes 2000, pp. 
9-16; Albert 2001, pp. 10-14; David 2006, p. 35). Both the Kinlichee 
Creek and Canyon de Chelly areas occur on the Navajo Nation. Streams in 
the Kinlichee Creek area include Red Clay Wash, Black Soil Springs, 
Scattered Willow Wash, and Kinlichee Creek itself. Streams in the 
Canyon de Chelly area include Tsaile Creek, Sonsela Creek, Crystal 
Creek, Coyote Wash, Whiskey Creek, and Wheatfields Creek. These streams 
originate along the western slope of the Chuska Mountains in New 
Mexico, flow through Arizona, and eventually flow into the San Juan 
River. It is the taxonomic status of these populations in the Kinlichee 
Creek area of the Little Colorado River watershed and the Canyon de 
Chelly areas in the San Juan River watershed that is in question. A map 
for geographical

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reference is available for review on the New Mexico Ecological Services 
Field Office Web site at http://www.fws.gov/southwest/es/NewMexico/.
    During the public comment period on the proposed listing rule, we 
received multiple comments regarding our interpretation of scientific 
literature related to the genetics of the Zuni bluehead sucker. 
Commenters were particularly concerned with whether or not populations 
on the Navajo Nation, which include the Kinlichee Creek area of the 
Little Colorado River watershed and the Canyon de Chelly area of the 
San Juan River watershed, that were recognized in the proposed rule as 
Zuni bluehead suckers are appropriately classified as such rather than 
a different subspecies of the bluehead sucker (see Taxonomy and 
Genetics section, below). In addition, since the closing of the comment 
period, we have received additional information and genetic analyses of 
the bluehead sucker populations found on lands of the Navajo Nation, 
including both the Kinlichee Creek area and the Canyon de Chelly area 
(Unmack et al. 2012, entire; Hopken et al. 2013, entire; Douglas et al. 
2013, entire). In particular, both the Hopken et al. (2013) and Douglas 
et al. (2013) reports find that the populations on the Navajo Nation 
should not be categorized as Zuni bluehead sucker, thereby 
contradicting the information we presented in the proposed rule. This 
new information and data, along with input we received during the 
comment period, have led to substantial scientific disagreement about 
the status of these populations as explained in more detail below.
    In conclusion, section 4(b)(6) of the Act allows the Service to 
extend the final determination by not more than 6 months, if there is 
substantial disagreement regarding the sufficiency or accuracy of the 
available data relevant to the determination. In light of the 
substantial disagreement regarding the taxonomic status of some 
populations that we considered Zuni bluehead sucker in the proposed 
listing rule, we are reopening the comment period for the proposed 
listing rule and extending the schedule for the final determination for 
6 months in order to solicit and analyze information that will help to 
clarify these issues. We will make a final determination no later than 
July 25, 2014.

Taxonomy and Genetics

    Although there is disagreement regarding where the Zuni bluehead 
sucker occurs, our review of the available information has concluded 
that the Zuni bluehead sucker is a valid subspecies. It is believed 
that the first specimen of the Zuni bluehead sucker was collected from 
the Zuni River near Zuni Pueblo in McKinley County, New Mexico, in 1873 
(Cope 1874, p. 138). The next collection was made in 1926, from the 
Zuni River, near Zuni Pueblo (Propst et al. 2001, p. 159). It was not 
subsequently collected in New Mexico until W.J. Koster (University of 
New Mexico, Museum of Southwestern Biology) collected the species in 
the Rio Pescado in 1948, and in the Rio Nutria in 1960 (Propst 1999, p. 
49; Propst et al. 2001, p. 159).
    The Zuni bluehead sucker subspecies is believed to have originated 
as a hybrid of the Rio Grande sucker (Catostomus plebeius) and the 
bluehead sucker (C. discobolus) from the Little Colorado River. 
Historically, the bluehead sucker occurred in streams and rivers in 
Idaho, Wyoming, Colorado, Arizona, and New Mexico. Gerald R. Smith 
(University of Michigan) was the first person to provide evidence for 
the hybrid origin of the Zuni bluehead sucker (Smith 1966, pp. 87-90). 
Smith (1966, pp. 87-90) and Smith et al. (1983, pp. 37-38) hypothesized 
that the subspecies resulted from a prehistoric geological event in 
which two species of sucker that were formerly geographically separated 
came into contact with one another in the late Pleistocene (which 
occurred more than 11,700 years ago) and exchanged genes through 
hybridization over some time. Since collections of Zuni bluehead 
suckers occurred as early as 1873, Smith (1966, p. 88) discounted that 
the origin of the subspecies could be a product of human translocation 
and, instead, proposed that a stream capture occurred causing the two 
suckers to come into contact. A stream capture is a geomorphological 
phenomenon occurring when a river drainage system or watershed is 
diverted from its own bed and flows instead down the bed of a 
neighboring stream. During this particular stream capture, part of the 
headwaters of San Jose Creek (a Rio Puerco--Rio Grande tributary where 
Rio Grande sucker occurred) were brought into the headwaters of the 
Zuni River (a Little Colorado River tributary where bluehead sucker 
occurred); this caused Rio Grande suckers from San Jose Creek to 
intermingle with resident bluehead suckers in the Zuni River (Smith et 
al. 1983, p. 45). Unmack et al. (2012, p. 29) estimated that the 
introgression (gene flow from one species into the gene pool of another 
species) between the Rio Grande sucker and bluehead sucker occurred 
about 1.1 million years ago based on aging fossils.
    In 1983, Smith et al. (entire) formally designated Zuni bluehead 
sucker as a subspecies. Based on a review of morphological (pertaining 
to the physical form and structure of the fish), meristic (quantitative 
features of fish, such as fins or scales), and biochemical genetic 
data, Smith et al. (1983, pp. 1, 45-47) determined that that the Zuni 
bluehead sucker subspecies is an intermediate between Rio Grande sucker 
and bluehead sucker, with the Rio Nutria population (Zuni River 
watershed) characters (characters are attributes or features that 
distinguish a subspecies, such as coloration) more like Rio Grande 
sucker and Kinlichee Creek (Little Colorado River watershed) characters 
more like bluehead sucker. Based on morphology, they assigned fish 
samples in Kinlichee Creek (Little Colorado River watershed) as Zuni 
bluehead suckers and Whiskey Creek fish samples (in the Canyon de 
Chelly area of the San Juan River watershed) as bluehead suckers. 
However, Smith et al. (1983, p. 46) could not genetically differentiate 
Kinlichee Creek samples from Whiskey Creek fish samples. In other 
words, based on genetics, fish from Kinlichee Creek (Little Colorado 
River watershed) and Whiskey Creek (in the Canyon de Chelly area of the 
San Juan River watershed) are the same.
    Further study by Crabtree and Buth (1987, p. 843) replicated and 
expanded upon the Smith et al. (1983, entire) genetic analysis and 
reevaluated their data and interpretation. This study provided 
supporting evidence confirming assignment of populations in the Zuni 
River headwater streams as the Zuni bluehead sucker subspecies based on 
the presence of unique alleles at several loci (loci are specific 
locations of a gene or DNA sequence on a chromosome). However, they 
recognized that Smith et al. (1983, pp. 42, 46) attributed a broader 
geographical range to the Zuni bluehead sucker. The genetic analysis by 
Crabtree and Buth (1987, p. 852) did not support the geographical range 
identified by Smith et al. (1983, pp. 42, 46). Crabtree and Buth (1987, 
pp. 851-852) suggested that the genetic interaction between the Rio 
Grande sucker and bluehead sucker is limited to the upper Rio Nutria 
populations in the Zuni River watershed. Thus, the findings of Crabtree 
and Buth (1987, entire) suggest that the Zuni bluehead sucker 
subspecies occurs only in the Zuni River watershed of New Mexico.
    Our analysis of morphological and genetic information supports the 
recognition of the Zuni bluehead sucker

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as being distinct from both the Rio Grande sucker and the bluehead 
sucker (Smith 1966, pp. 87-90; Smith et al. 1983, pp. 37-38; Crabtree 
and Buth 1987, p. 843; Propst 1999, p. 49). Based on our review of the 
best available scientific and commercial data, we concluded in the 
proposed listing rule that the Zuni bluehead sucker is a valid 
subspecies.
    Although the Zuni bluehead sucker is a valid taxon, there is 
substantial disagreement as to which populations of the fish should be 
assigned to the Zuni bluehead sucker subspecies based on various 
interpretations of the morphological and genetic analyses. In the 
discussion below, we review the results of three recent studies related 
to the evolutionary relationships of the populations we have considered 
to be Zuni bluehead sucker.
    In 2012, Thomas Dowling (a geneticist at Arizona State University) 
presented the Schwemm and Dowling (2008, entire) data that some 
bluehead sucker found in the Kinlichee Creek area of the Little 
Colorado River watershed and the Canyon de Chelly area of the San Juan 
River watershed also contain Rio Grande sucker alleles, suggesting that 
these fish may be the result of the introgression between Rio Grande 
sucker and bluehead sucker described above (Service 2012, entire). 
Schwemm and Dowling (2008, entire) investigated the extent of 
introgression of Rio Grande sucker within bluehead sucker within the 
Little Colorado River drainage (Kinlichee Creek area and Zuni River 
watershed area) and San Juan River drainage (Canyon de Chelly area) 
through analysis of both mitochondrial and nuclear DNA sequences. The 
mitochondrial DNA analysis identified three distinct lineages 
(ancestry) and one distinct sublineage: (1) Mainstem Colorado River/San 
Juan River bluehead sucker lineage; (2) Canyon de Chelly bluehead 
sucker sublineage (in San Juan River watershed); (3) Little Colorado 
River bluehead sucker lineage; and (4) Rio Grande sucker lineage. The 
Rio Grande sucker lineage was found in only one upper Little Colorado 
River population: the Rio Nutria of the Zuni River watershed in New 
Mexico. However, the nuclear DNA not only identified Rio Grande sucker 
alleles in the Rio Nutria in New Mexico (consistent with mitochondrial 
DNA analysis), but also identified Rio Grande sucker alleles in 
bluehead sucker populations in Black Soil Springs and in Kinlichee 
Creek as it flows through Bear Canyon (both populations are in the 
Kinlichee Creek area of the Little Colorado River watershed), and in 
Wheatfields Creek (in the Canyon de Chelly area of the San Juan River 
watershed). Therefore, the nuclear DNA analysis presented by Dowling in 
2012 suggests that, based on the presence of Rio Grande sucker alleles 
(via nuclear DNA), the Zuni bluehead sucker subspecies occurs in 
certain streams of all three watersheds: the Zuni River watershed, the 
Little Colorado River watershed, and the San Juan River watershed.
    Unmack et al. (2012, p. 20) assigned Zuni bluehead sucker to a 
complex (group of related species) of ancient Arizona and New Mexico 
lineages that share molecular, meristic, and osteological (osteology is 
the study of bone structure and function) characteristics of bluehead 
sucker and Rio Grande sucker. Their study included populations found in 
the headwaters of the San Juan and Little Colorado Rivers (including 
the Zuni River headwaters) in northeastern Arizona. This assignment was 
based on the information provided above (Smith 1966, entire; Smith et 
al. 1983, entire; Crabtree and Buth 1987, entire; Schwemm and Dowling 
2008, entire). Their assignment suggests that the Zuni bluehead sucker 
subspecies originated from three separate but adjacent drainages (San 
Juan River, Little Colorado River, and the Rio Grande) in the 
Pleistocene via multiple stream captures. Therefore, the Zuni bluehead 
sucker subspecies is not restricted to the headwaters of the Zuni River 
watershed, but includes others areas in the Little Colorado River 
(Kinlichee Creek area) and San Juan River drainages (Canyon de Chelly 
area).
    Hopken et al. (2013, entire) published a paper after the 
publication of the proposed listing rule that evaluates bluehead 
suckers rangewide using both mitochondrial and nuclear DNA to infer 
evolutionarily significant units and management units. These 
researchers looked at 39 sampling locations; however, only 2 (Canyon de 
Chelly in the San Juan River watershed and Agua Remora in the Zuni 
River watershed) were relevant to the Zuni bluehead sucker. The 
mitochondrial DNA only detected bluehead sucker haplotypes (combination 
of alleles at adjacent locations on a chromosome) in Canyon de Chelly 
(San Juan River watershed in Arizona) and Agua Remora (Zuni River 
watershed in New Mexico). Results are consistent with the Schwemm and 
Dowling (2008, pp. 7-10) mitochondrial DNA analysis of the fish in the 
Kinlichee Creek area of the Little Colorado River watershed and the 
Canyon de Chelly area of the San Juan River watershed, both of which 
are located within the Navajo Nation. Similar results were concluded 
for both Agua Remora and Tampico Springs in the Zuni River watershed of 
New Mexico (Turner and Wilson 2009, p. 8). Conversely, the nuclear DNA 
(via microsatellites) analyses by both Schwemm and Dowling (2008, 
entire) and Turner and Wilson (2009, p. 8) found alleles related to 
both bluehead and Rio Grande suckers, albeit in low frequency for Agua 
Remora and Tampico Springs in the Zuni River watershed of New Mexico. 
Note that these results were based on one specific microsatellite, 
whereas the Hopken et al. (2013, entire) nuclear DNA test analyzed 16 
different microsatellites to identify levels of introgression with 
other species of suckers known to hybridize with bluehead suckers 
(e.g., Rio Grande sucker) and tested distinctiveness of the bluehead 
sucker across several drainages. Hopken et al. (2013, p. 966) did not 
find fish in the Canyon de Chelly area of the San Juan River watershed 
or in Agua Remora of the Zuni River watershed to be introgressed and, 
therefore, concluded that fish from both sampling locations belonged to 
the bluehead sucker species of the Colorado River rather than the Zuni 
bluehead sucker subspecies. Canyon de Chelly in the Little Colorado 
River watershed and Agua Remora in the Zuni River watershed were both 
identified to have distinct gene pools from one another and other 
bluehead suckers (Hopken et al. 2013, p. 966). In other words, the 
Hopken et al. (2013, entire) paper indicates that the populations in 
the Little Colorado River watershed and Zuni River watershed are 
geographically isolated and reflect low gene flow. These results are in 
disagreement with the results of the nuclear DNA analysis provided by 
Dowling in his 2012 presentation of the Schwemm and Dowling (2008, 
entire) report.
    Despite their analysis of the Canyon de Chelly populations (San 
Juan River watershed) of bluehead suckers, Hopken et al. (2013, entire) 
did not analyze the Kinlichee Creek populations within the Little 
Colorado River watershed in Arizona. In cooperation with the Navajo 
Nation, the Service collected additional genetic tissue samples for 
analysis in 2013. Douglas et al. (2013, entire) used these additional 
genetic tissue samples to expand upon the Hopken et al. (2013, entire) 
paper results, applying the same methods. The results of the 
mitochondrial DNA analysis by Douglas et al. (2013, pp. 19-20) were 
very similar to Hopken et al. (2013) for samples within the Navajo 
Nation (Kinlichee Creek area of the Little

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Colorado River watershed and Canyon de Chelly area of the San Juan 
River watershed), except a third bluehead sucker haplotype was 
identified and the Rio Grande sucker haplotype was present in Rio 
Nutria in the Zuni River watershed in New Mexico. This is consistent 
with Schwemm and Dowling (2008, entire). As in Hopken et al. (2013, p. 
966), Douglas et al. (2013, pp. 15-16) evaluated levels of 
introgression with other species of suckers known to hybridize with 
bluehead sucker (e.g., Rio Grande suckers) and tested for 
distinctiveness between the Zuni River watershed populations and 
populations in the Little Colorado River watershed and the San Juan 
River watershed, and they compared the results with other drainages of 
the Colorado River Basin (Colorado River in the Grand Canyon and Upper 
Colorado River areas in Utah, Colorado, and Wyoming). No introgression 
was detected with any other suckers, except for samples from Rio 
Nutria, which exhibited genotypes of a mixed origin consistent with the 
subspecies assignment. These results suggest that the Zuni bluehead 
sucker is restricted to the Zuni River watershed. In addition to Hopken 
et al. (2013, entire), Douglas et al. (2013, p. 16) identified one more 
population of bluehead suckers that constitutes a unique gene pool 
(Kinlichee Creek in the Little Colorado River watershed). These 
combined results conclude that bluehead suckers from the headwaters of 
the Little Colorado River watershed (Zuni River area where the Zuni 
bluehead sucker recognized subspecies occurs and Kinlichee Creek area) 
and the San Juan River watershed (Canyon de Chelly area) are distinct 
from each other and any other bluehead suckers within the species' 
range.
    Since the publication of the proposed rule to list the Zuni 
bluehead sucker as an endangered species (78 FR 5369; January 25, 
2013), there has been substantial disagreement regarding whether the 
bluehead suckers found within the Kinlichee Creek area of the Little 
Colorado River watershed and the Canyon de Chelly area of the San Juan 
River watershed are appropriately characterized as Zuni bluehead 
suckers. This has led to substantial disagreement regarding the current 
range of the subspecies in Arizona and New Mexico.
    As illustrated by the above discussion, the best available 
scientific information is unclear as to which populations of fish 
should be attributed to the Zuni bluehead sucker subspecies. Some 
studies support that Zuni bluehead sucker subspecies occurs only in the 
Rio Nutria within the Zuni River watershed in New Mexico (Crabtree and 
Buth 1987,entire; Hopken et al. 2013, entire; Douglas et al. 2013, 
entire), whereas other studies support that Zuni bluehead sucker is 
also found in the Kinlichee Creek area of the Little Colorado River 
watershed and the Canyon de Chelly areas of the San Juan River 
watershed (Smith et al. 1983, entire; Schwemm and Dowling 2008, entire; 
Unmack et. al. 2012, p. 20). All of the literature discussed in this 
document and a map for geographical reference is available for review 
on the New Mexico Ecological Services Field Office Web site at http://www.fws.gov/southwest/es/NewMexico/.
    As discussed earlier, section 4(b)(6) of the Act and its 
implementing regulations at 50 CFR 424.17(a) require that we take one 
of three actions within 1 year of a proposed listing: (1) Finalize the 
proposed listing; (2) withdraw the proposed listing; or (3) extend the 
final determination by not more than 6 months, if there is substantial 
disagreement regarding the sufficiency or accuracy of the available 
data relevant to the determination. Therefore, in consideration of the 
substantial disagreements surrounding the Zuni bluehead sucker's 
taxonomic status in some locations, we are extending the final 
determination for 6 months in order to solicit and analyze additional 
information that will help to clarify these issues. Consequently, our 
final determination on the critical habitat designation for the Zuni 
bluehead sucker will be also delayed until we make a final listing 
determination for this subspecies. Therefore, we will make a final 
determination on the proposed listing rule no later than July 25, 2014.

Public Comments

    We will accept written comments and information during this 
reopened comment period on our proposed listing for the Zuni bluehead 
sucker that was published in the Federal Register on January 25, 2013 
(78 FR 5369). We will consider information and recommendations from all 
interested parties. We intend that any final action resulting from the 
proposals be as accurate as possible and based on the best available 
scientific and commercial data.
    In consideration of the disagreements surrounding the data used to 
support the proposed rulemaking, we are extending the final 
determination for 6 months in order to solicit information that will 
help to clarify these issues. In addition to the information requested 
in the proposed listing rule, we are particularly interested in new 
information and comments regarding:
    (1) The historical and current status and distribution of the Zuni 
bluehead sucker, its biology and ecology, specific threats (or lack 
thereof) and regulations that may be addressing those threats, and 
ongoing conservation measures for the subspecies and its habitat.
    (2) Whether or not the populations in the Kinlichee Creek area of 
the Little Colorado River watershed and the Canyon de Chelly area of 
the San Juan River watershed should be considered the Zuni bluehead 
sucker subspecies.
    (3) Additional information relevant to the genetic analysis of Zuni 
bluehead sucker populations.
    (4) Additional information relevant to the morphology of Zuni 
bluehead sucker populations.
    (5) Information regarding genetic disagreements related to other 
suckers or similar species of fish that could be used as a surrogate to 
better understand the genetics of Zuni bluehead sucker
    (6) An explanation for the apparent discrepancy between nuclear DNA 
analyses. We are seeking clarification to explain the presence of Rio 
Grande sucker alleles by using a singular microsatellite marker 
(Schweem and Dowling 2008) whereas 16 different microsatellites did not 
detect any Rio Grande sucker alleles (Douglas et al. 2013).
    (7) An explanation for the overlap in morphological characteristics 
in Smith et al. (1983, entire) where he assigned bluehead suckers in 
Kinlichee Creek (the Little Colorado River watershed) as Zuni bluehead 
sucker.
    If you previously submitted comments or information on the proposed 
listing rule, please do not resubmit them. We have incorporated them 
into the public record, and we will fully consider them in the 
preparation of our final determination. Our final determination 
concerning this proposed listing will take into consideration all 
written comments and any additional information we receive.
    You may submit your comments and materials concerning the proposed 
rule by one of the methods listed in ADDRESSES. We request that you 
send comments only by the methods described in ADDRESSES.
    If you submit a comment via http://www.regulations.gov, your entire 
comment--including any personal identifying information--will be posted 
on the Web site. We will post all hardcopy comments on http://www.regulations.gov as well. If you submit a hardcopy comment that 
includes personal identifying information, you may request at the top 
of your document that we withhold this information from public review.

[[Page 1619]]

However, we cannot guarantee that we will be able to do so.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing the proposed rule, will be available 
for public inspection on http://www.regulations.gov at Docket No. FWS-
R2-ES-2012-0101, or by appointment, during normal business hours, at 
the U.S. Fish and Wildlife Service, New Mexico Ecological Services 
Field Office (see FOR FURTHER INFORMATION CONTACT). You may obtain 
copies of the proposed rule on the Internet at http://www.regulations.gov at Docket No. FWS-R2-ES-2012-0101, or by mail from 
the New Mexico Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT).

References Cited

    A complete list of references cited and a geographical reference 
map in this rulemaking is available on the Internet at http://www.regulations.gov and http://www.fws.gov/southwest/es/NewMexico/ and 
upon request from the New Mexico Ecological Services Field Office (see 
FOR FURTHER INFORMATION CONTACT).

Authority

    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: December 30, 2013.
Stephen Guertin,
Acting Director, Fish and Wildlife Service.
[FR Doc. 2014-00164 Filed 1-8-14; 8:45 am]
BILLING CODE 4310-55-P