[Federal Register Volume 81, Number 194 (Thursday, October 6, 2016)]
[Rules and Regulations]
[Pages 69417-69425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-24138]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2015-0142; 4500030113]
RIN 1018-BB09
Endangered and Threatened Wildlife and Plants; Threatened Species
Status for Suwannee Moccasinshell
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine
threatened species status under the Endangered Species Act of 1973
(Act), as amended, for the Suwannee moccasinshell (Medionidus walkeri),
a freshwater mussel species from the Suwannee River Basin in Florida
and Georgia. The effect of this regulation will be to add this species
to the List of Endangered and Threatened Wildlife.
DATES: This rule becomes effective November 7, 2016.
ADDRESSES: This final rule is available on the internet at http://www.regulations.gov at Docket No. FWS-R4-ES-2015-0142 and the Panama
City Ecological Services Field Office. Comments and materials we
received, as well as supporting documentation we used in preparing this
rule, are available for public inspection at http://www.regulations.gov. Comments, materials, and documentation that we
considered in this rulemaking will be available by appointment, during
normal business hours at: U.S. Fish and Wildlife Service, Panama City
Ecological Services Field Office, 1601 Balboa Avenue, Panama City, FL
32405; by telephone 850-769-0552; or by facsimile at 850-763-2177.
FOR FURTHER INFORMATION CONTACT: Catherine T. Phillips, Project Leader,
U.S. Fish and Wildlife Service, Panama City Ecological Services Field
Office, 1601 Balboa Avenue, Panama City, FL 32405; by telephone 850-
769-0552; or by facsimile at 850-763-2177. Persons who use a
telecommunications device for the deaf (TDD) may call the Federal
Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Endangered Species Act
(Act), a species may require protection through listing if it is
endangered or threatened throughout all or a significant portion of its
range. Listing a species as an endangered or threatened species can
only be completed by issuing a rule.
What this document does. This rule will finalize the listing of the
Suwannee moccasinshell (Medionidus walkeri) as a threatened species. In
the near future, we intend to publish a proposed rule in the Federal
Register to designate critical habitat for the Suwannee moccasinshell
under the Act.
The basis for our action. Under the Act, we may determine that a
species is an endangered or threatened species based on any of five
factors: (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. We have determined that the Suwannee moccasinshell
is threatened by the degradation of its habitat due to polluted runoff
from agricultural lands, pollutants discharged or accidentally released
from industrial and municipal wastewater sources and mining operations,
decreased flows due to groundwater extraction and drought, stream
channel instability, and excessive sedimentation (Factor A); State and
Federal water quality standards that are inadequate to protect
sensitive aquatic organisms like mussels (Factor D); the potential of
contaminant spills as a result of transportation accidents (Factor E);
increased drought frequency and degraded water quality as a result of
changing climatic conditions (Factor E); greater vulnerability to
certain threats because of small population size and range (Factor E);
and competition and disturbance from the introduced Asian clam (Factor
E).
Peer review and public comment. We sought comments from independent
specialists to ensure that our listing rule is based on scientifically
sound data, assumptions, and analyses. We invited three peer reviewers
with expertise in Suwannee moccasinshell biology and ecology, and
freshwater mussel biology and conservation, to comment on our listing
proposal. We also considered all other comments and information
received during the public comment period. All comments and information
received are available on the internet at http://www.regulations.gov in
Docket No. FWS-R4-ES-2015-0142.
Previous Federal Action
Please refer to the proposed listing rule for the Suwannee
moccasinshell
[[Page 69418]]
(80 FR 60335; October 6, 2015) for a detailed description of previous
Federal actions concerning this species.
Background
For a more detailed discussion of the biology, status, and threats
affecting the species, please refer to the proposed listing rule for
the Suwannee moccasinshell published in the Federal Register on October
6, 2015 (80 FR 60335). In the proposed rule, we evaluated the
biological status of the species and factors affecting its continued
existence. Our assessment was based upon the best available scientific
and commercial data available on the status of the species, including
past, present, and future threats to the species.
Summary of Comments and Recommendations
In the proposed rule published on October 6, 2015 (80 FR 60335), we
requested that all interested parties submit written comments on the
proposal by December 7, 2015. We also contacted appropriate Federal and
State agencies, scientific experts and organizations, and other
interested parties and invited them to comment on the proposal.
Newspaper notices inviting general public comment were published in The
Lake City Reporter, Columbia County, FL; The Gainesville Sun, Alachua
County, FL; and The Valdosta Daily Times, Lowndes County, GA. During
the public comment period, we received public comments from 11
individuals or organizations, including 3 submissions by the
individuals asked to serve as peer reviewers. We did not receive any
requests for a public hearing. All substantive information provided
during the comment period is summarized below in the Summary of Changes
From the Proposed Rule and has either been incorporated directly into
this final determination or addressed in the more specific response to
comments below.
Comments From Peer Reviewers
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinion from three knowledgeable
individuals with scientific expertise in the species' biology, habitat,
and threats and stream ecology. We received responses from all of the
peer reviewers.
We reviewed all comments from the peer reviewers for substantive
issues and new information regarding the listing of the Suwannee
moccasinshell. In general, the peer reviewers concurred with our
methods and conclusions. Where appropriate, we incorporated new
information into the final rule as a result of the peer reviewer
comments, and any substantive comments are discussed below.
(1) Comment: One peer reviewer expressed concern that there has
been no modern taxonomic study to assess whether the Suwannee
moccasinshell is a distinct species from the Gulf moccasinshell. The
peer reviewer mentioned that shell morphological traits are notoriously
problematic taxonomic features that have led to the misclassification
of many freshwater mussel taxa, and that only with molecular data can
you be reasonably sure that you are dealing with separate species. The
reviewer also added that there was no reason to suspect that the
Suwannee moccasinshell is not a valid species.
Our Response: We relied on the best information currently available
regarding the taxonomy of the species. The Suwannee moccasinshell is
considered a distinct taxonomic entity by the general scientific
community, and we are aware of no contradicting views on the taxonomy
of this entity. However, in the final rule we have refined our
discussion of the species' taxonomy and added a recent publication by
Johnson et al. (in press) to the list of authors who recognize the
entity as a separate species.
(2) Comment: One peer reviewer expressed concerned about the lack
of surveys in the Withlacoochee drainage, and stated that this stream
still supports large populations of freshwater mussels. The reviewer
stated that there has apparently been very little recent work in the
system, and that intensive surveys should be done in the Withlacoochee
Drainage to determine the status of the Suwannee moccasinshell in this
system.
Our Response: We agree and stated in the proposed rule that
additional survey work is needed in the Withlacoochee River subbasin
(80 FR 60335, October 6, 2015; p. 60338). Since publishing the proposed
rule, some additional surveys were conducted in the lower Withlacoochee
drainage. Those surveys are included in Table 2 below. Surveyors using
snorkel gear searched seven locations in the lower basin in September
2015. Several mussel species were detected, but not Suwannee
moccasinshell. Likely contributing factors for non-detection include
the conditions noted at survey locations within this species'
historical range, including an odor of treated sewage and considerable
amounts of filamentous algae (an indicator of excess nutrients).
Also, since the proposed rule was published, the Service's Panama
City Field Office received two reports of mussel surveys conducted in
2005 and 2007 around the State Road 31 Bridge in Georgia, where the
Suwannee moccasinshell was collected in 1969. Comprehensive surveys
were conducted over several days using SCUBA gear to search a 1.5-
kilometer reach (approximately) of the Withlacoochee River (Bowers
2006, entire; Bowers 2007, entire). The species was not detected during
these dive surveys. These additional data support our conclusion that
the Suwannee moccasinshell may no longer occur in the Withlacoochee
subbasin.
(3) Comment: One peer reviewer commented that spate flows (e.g.,
sudden fast flows with high sediment loads) in the upper Santa Fe River
should be listed as a threat.
Our Response: We agree and have added this threat to the Factor A
discussion under the heading of Stream Channel Instability.
(4) Comment: One peer reviewer commented that deadhead logging,
though probably past its heyday, is still a potential threat to the
Suwannee moccasinshell as it can cause destabilization of microhabitat
occupied by freshwater mussels. The peer reviewer also stated that the
impact of constant and, in many cases, large boat wakes frequently
striking shore is a problem, especially in the lower Santa Fe River,
which is a relatively narrow channel frequented by large numbers of
boats.
Our Response: We appreciate this information, and we have added a
discussion of both activities to the Factor A discussion under the
heading of Stream Channel Instability.
(5) Comment: One peer reviewer suggested deleting flathead catfish
as a potential threat. The reviewer pointed out that there is only one
record from the Suwannee River of flathead catfish, which was collected
near Branford in 1989, and the species is not currently considered to
be extant in the basin. The reviewer believed that flathead catfish may
represent a future threat if they ever become successfully established
in the basin.
Our Response: Based on this information, we agree that flathead
catfish are not a significant concern at this time and have deleted the
discussion from the final rule.
Comments From States
The proposed rule was reviewed by the three members of the Florida
Fish and Wildlife Conservation Commission's (FWC) freshwater mussel
conservation program, one of which was asked to serve as a peer
reviewer. The
[[Page 69419]]
comments were combined into one document and submitted as a single peer
review. The FWC reviewers provided additional information and
clarification on threats, and provided updated information on surveys
conducted by the agency. Their comments are addressed in Comments 3, 4,
and 5 above, and are incorporated into the final rule as appropriate.
The FWC generally concurred with our methods and conclusions, and
supports the listing.
We also received comments from the Florida Department of
Transportation (FDOT). They are addressed below.
(6) Comment: The FDOT expressed concern about our use of the term
``transportation accidents'' with regard to possible contamination
spills. The agency stated that transportation agencies have protocols
in place to address and track these spills.
Our Response: We continue to maintain that accidents involving
vehicles transporting large volumes of hazardous materials are a
potential threat to the Suwannee moccasinshell. Accidental spills of
hazardous materials or organic materials into streams as a result of
transportation accidents have occurred in the past. Incidents in or
near streams that illustrate the potential risk include two train
derailments: one on September 12, 2006, that spilled four tank cars of
soybeans into a tributary of Yellow Leaf Creek in Alabama resulting in
a drastic decline in dissolved oxygen, killing fishes, mussels, and
snails (USFWS 2009); and another on January 28, 2014, that spilled up
to 30,000 gallons of phosphoric acid into a small tributary to the
Escambia River in Florida (NorthEscambia.com), and was contained before
reaching critical habitat in the mainstem.
(7) Comment: The FDOT expressed concerns regarding our discussion
of water quality degradation and increased sedimentation. The agency
commented that State DOTs abide by rigorous environmental permit
processes (both Federal and State) that address these matters including
requirements of the ESA. Specifically, roadway projects have to obtain
a State Water Quality Certification in order for the U.S. Army Corps to
issue a permit under section 404 of the Clean Water Act.
Our Response: FDOT's standard Best Management Practices (BMPs) for
erosion and sediment control are a good baseline measure to protect
water quality. However, the success of these measures is highly
dependent on their contractors to meticulously implement, monitor, and
repair erosion control measures. In instances where endangered and
threatened species are present in combination with highly erodible
soils, a higher level of protection may be needed. While not frequent,
instances of erosion control failures that have impacted waterways
during road construction in Florida have been documented.
(8) Comment: The FDOT commented that the following activities
listed in the proposed rule (80 FR 60335, October 6, 2015; p. 60347) as
potentially harming the Suwannee moccasinshell and, therefore,
resulting in take, could impact State DOT projects: destruction or
alteration of the species' habitat by discharge of fill material;
dredging or modification of stream channels or banks; and discharge of
pollutants into a stream or into areas hydrologically connected to a
stream occupied by the species.
Our Response: The majority of the stream channels currently
occupied by the Suwannee moccasinshell, including the Suwannee River
mainstem and the lower Withlacoochee River, are also occupied by, or
designated as critical habitat for, the federally threatened Gulf
sturgeon. The lower Santa Fe River is the only area occupied by
Suwannee moccasinshell, but not by Gulf sturgeon. Therefore, because
activities that affect the Suwannee moccasinshell would also affect the
Gulf sturgeon or its habitat (for example, dredging, filling,
modification of stream channels or banks, and discharge of pollutants),
in the majority of the Suwannee moccasinshell's current range, the FDOT
already consults on such activities. When formal section 7 consultation
is required, we will work with the FDOT to find solutions that will
reduce impacts to all listed species and aquatic habitats, while
allowing the activity to proceed.
Public Comments
(9) Comment: One commenter expressed concern about our finding that
forestry is a contributing threat to the Suwannee moccasinshell. The
commenter provided information on the implementation rates and
effectiveness of forestry BMPs and cited various studies purported to
demonstrate that forestry BMPs minimize erosion and sediment transport
to streams below levels that degrade aquatic habitats and/or harm
aquatic species, including the Suwannee moccasinshell.
Response: We appreciate the commenters' support of forestry BMPs as
a means of protecting water quality and we concur that, when properly
implemented, forestry BMPs can reduce erosion and sedimentation levels,
especially as compared to past forestry practices. However, the best
available data indicate that, even when forestry BMPs are properly
implemented, erosion rates at harvested sites, skid trails, unpaved
haul roads, and stream crossings are significantly higher than from
undisturbed sites. We consider sediment from silvicultural activities
to be one of many potential sediment sources within the Suwannee River
watershed.
Summary of Changes From the Proposed Rule
After consideration of the comments we received during the public
comment period (refer to Summary of Comments and Recommendations
above), and new information published or obtained since the proposed
rule was published, we made changes to the final listing rule. Many
small, nonsubstantive changes and corrections, not affecting the
determination (e.g., updating the Background section in response to
comments, minor clarifications) were made throughout the document.
Below is a summary of substantive changes made to the final rule.
(1) The Taxonomy discussion was refined slightly. The
distinctiveness of Suwannee moccasinshell as a separate species was
further bolstered by a recent study (Johnson et al. in Press).
(2) Table 2 was added to provide a clear and updated summary of all
recent survey information.
(3) The flathead catfish (Pylodictis olivaris) was removed as a
threat to reflect information provided by the Florida FWC indicating
that flathead catfish have not become established in the Suwannee River
Basin.
(4) Stream Channel Instability was added as a threat under Factor
A. The Present or Threatened Destruction, Modification, or Curtailment
of Its Habitat or Range. The new discussion adds threats identified by
a peer reviewer that include scouring flows, boat wakes, and deadhead
logging.
Summary of Biological Status
Below we present a summary of the biological and distributional
information discussed in the proposed listing rule. We also present new
information published or obtained since the proposed rule was
published, including a study by Johnson et al. (in Press), additional
survey data, and information received during the comment period.
The Suwannee moccasinshell (Medionidus walkeri) is a small
freshwater mussel of the family Unionidae. The species was originally
described by B.H. Wright in 1897. It was briefly considered a synonym
of Medionidus penicillatus (Clench and
[[Page 69420]]
Turner 1956), but subsequently was recognized as a valid species by
Johnson (1977, pp. 176-177), who described walkeri as being ``quite
distinct'' from the other members of the genus. Its sharp posterior
ridge and generally dark, rayless shell distinguishes it from other
species of Medionidus in Gulf drainages (Johnson 1977, p. 177; Williams
and Butler 1994, p. 86). Its distinctiveness as a separate species is
recognized by recent authors (Williams and Butler 1994, pp. 85-86;
Williams et al. 2014, pp. 278-280; Johnson et al. in Press).
The Suwannee moccasinshell typically inhabits larger streams where
it is found in substrates composed of muddy sand or sand with some
gravel, and in areas with slow to moderate current (Williams and Butler
1994, p. 86; Williams 2015, p. 2). The species is also associated with
large woody material, and individuals are often found near embedded
logs. Like other freshwater mussels, the Suwannee moccasinshell
requires a fish host to complete its life cycle. Reproduction in
freshwater mussels is unique in that they require specific fish species
to serve as hosts for their larvae (called glochidia); the larval
mussel must attach to the gills or fins of a suitable host fish in
order to transform into a juvenile mussel. Parasitism serves as a means
of upstream dispersal for this relatively sedentary group of organisms
(Haag 2012, p. 145). A recent study examining the early life history of
the Suwannee moccasinshell has provided information about its
reproductive biology. Females were found gravid with mature glochidia
from October to May (Johnson et al. in Press). In laboratory trials,
Suwannee moccasinshell glochidia transformed only on darters--primarily
on the blackbanded darter (Percina nigrofasciata) and to a lesser
extent on the brown darter (Etheostoma edwini)--indicating that the
mussel is a host specialist and dependent on darters for reproduction
(Johnson et al. in Press). Darters are small, bottom-dwelling fish that
generally do not move considerable distances (Freeman 1995, pp. 363-
365; Holt 2013, p. 657). Thus, the exclusive use of darters as a host
may limit the Suwannee moccasinshell's ability to disperse and to
recolonize some areas from which it has become extirpated.
The Suwannee moccasinshell is endemic to the Suwannee River Basin
in Florida and Georgia. Its historical range includes the lower and
middle Suwannee River mainstem, and two large tributary rivers--the
Santa Fe River subbasin and the lower Withlacoochee River mainstem
(Williams 2015, p. 7). An evaluation of historical and recent
collection data show that its range has declined in recent decades, and
the species is presently known only from the middle Suwannee River and
lower Santa Fe River in Florida. In the Suwannee River mainstem, the
species occurs intermittently throughout a 75-mile (121-kilometer)
reach of the middle river, and sporadically in a 28-mile (45-kilometer)
segment of the lower Santa Fe River. The species was not detected in
recent surveys in the Withlacoochee River or in the upper Santa Fe
River subbasin. A summary of Suwannee moccasinshell occurrence and
distribution by waterbody are shown in Table 1 below.
In addition to a reduction of range, recent surveys targeting the
Suwannee moccasinshell show that its numbers are very low. Florida FWC
and Georgia Department of Natural Resources biologists surveyed 144
sites during 2013-2015, covering nearly all of its historical range
(FFWCC 2015 unpub. data; USFWS 2015 unpub. data). Suwannee
moccasinshell densities were found to be exceedingly low in comparison
to other mussel species, particularly in the lower Santa Fe River. A
summary of survey results are shown in Table 2 below.
Table 1--Summary of Suwannee Moccasinshell Populations by Waterbody
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Distribution and
Water body State and county Occurrence * abundance
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Suwannee River mainstem.................... FL: Madison Suwannee, Recent............ Occurs in a 75-mile
Lafayette, Gilchrist, reach of middle
Dixie, Levy. river; abundance low
but population
stable. May be
extirpated from the
lower river.
Lower Santa Fe River....................... FL: Suwannee, Recent............ Occurs in 28-mile
Gilchrist, Columbia, reach in lower river;
Alachua, Union, drastic decline and
Bradford. abundance very low.
Upper Santa Fe and New Rivers.............. FL: Union, Alachua, Historical........ May be extirpated;
Bradford. last collected in
system in 1996.
Withlacoochee River........................ GA: Brooks, Lowndes;... Historical........ May be extirpated;
FL: Madison, Hamilton.. last collected in
system in 1969.
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* Recent occurrence is based on collections made from 2000 to 2015; historical occurrence is based on
collections made prior to 2000.
Table 2--Summary of 2013-2015 Suwannee Moccasinshell Surveys by Waterbody
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Number of Live suwannee
Water body Survey year sites Total mussels moccasinshells
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Suwannee River mainstem......................... 2013-2015 103 15,195 73
Lower Santa Fe River............................ 2015 15 7,044 1
Upper Santa Fe and New Rivers................... 2015 19 1,969 0
Withlacoochee River............................. 2014-2015 17 4,377 0
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Historical mussel collection data are often limited, making it
difficult to compare trends in abundance over time. However, it does
seem clear from museum collections that Suwannee moccasinshell numbers
have declined over time, especially in the Santa Fe River subbasin
where it has declined dramatically in recent decades (see our
discussion on page 60339 of the proposed rule (80 FR 60335, October 6,
2015). Despite its low abundance, populations in the Suwannee River
mainstem presently appear to be stable. We attribute its persistence in
the mainstem to the stability of habitat and the attenuation of certain
threats by larger flow volumes (threats are summarized below).
Summary of Threats
Below we present a summary of the threats information discussed in
the proposed listing rule. We also present new information published or
obtained since the proposed rule was published
[[Page 69421]]
and information received during the comment period.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
The stream habitats of freshwater mussels are vulnerable to
degradation and modification from a number of threats associated with
modern civilization. Within the Suwannee River Basin, a rapidly growing
human population and changing land use represent significant threats to
the aquatic ecosystem, primarily through pollution and water withdrawal
(Katz and Raabe 2005, p. 14). The Suwannee moccasinshell's habitat is
subject to degradation as a result of pollutants discharged from
industries, mines, and sewage treatment facilities, polluted runoff
from agricultural lands, reduced flows as a result of groundwater
extraction and drought, and stream channels destabilized by scouring
floods and other perturbations.
Two pollutants of particular concern to the Suwannee moccasinshell
are ammonia and pesticides. Both are highly toxic to freshwater
mussels, particularly juveniles, and both are widely used on
agricultural lands within the basin. Ammonia is also a common pollutant
in wastewater discharged into streams of the basin by numerous
permitted wastewater treatment facilities. Another concern is that
nitrogen and phosphorus levels have increased within the range of the
Suwannee moccasinshell. In excess, these two plant nutrients may
indirectly affect the species by causing algal blooms that deplete
oxygen and cause dense mats of filamentous algae that entrain
juveniles.
Perhaps the most significant threat to Suwannee moccasinshell
populations is flow reduction due to the withdrawal of groundwater.
Groundwater pumping for agricultural purposes in neighboring basins,
along with periods of extreme drought conditions, has caused
unprecedented declines in groundwater levels, resulting in decreases in
the amount of groundwater entering streams of the basin. Flow declines
of approximately 30 percent have been observed in the lower Santa Fe
and lower Suwannee Rivers; the upper Santa Fe River, once a perennial
system, has gone dry multiple times since 2000 (Johnson et al. in
Press). Reduced flows may exacerbate drought conditions (elevating
temperature, pH, and pollutant concentrations (causing biotic die-off,
and reducing dissolved oxygen), which in turn may have lethal or other
harmful effects (prematurely aborting glochidia, reduced growth rates)
to the species, or may cause stranding mortality.
Stream Channel Instability
In the following paragraphs, we include a full discussion of stream
channel instability, a threat identified by a peer reviewer and not
discussed in the proposed rule.
The Suwannee moccasinshell requires geomorphically stable stream
channels to maintain its habitats. Channel instability occurs when the
natural erosion process is accelerated, leading to erosion
(degradation) and sediment deposition (aggradation). Channel
instability can cause profound changes to mussel habitats due to
scouring and sediment deposition (Hartfield 1993, p. 138). Channels can
become destabilized as a result of physical alterations to the stream
channel (such as dredging, straightening, impounding, and hardening),
and because of alterations to the flow regime. Changes to land use that
accelerate surface runoff (for example, croplands and development) can
increase the amount and rate in which stormwater runoff enters stream
channels, causing increases in flow volume and velocity. These more
forceful flows can scour the streambed and banks and eventually lead to
channel incision (lowering of the streambed) (Booth 1990, p. 407; Wood
and Armitage 1997, pp. 204-205; Doyle et al. 2000, pp. 156-157, 175).
Disturbance to riparian areas (particularly the removal of vegetation)
can also lead to bank erosion (Rosgen 1996, pp. 8-11). This accelerated
erosion process can also cause sedimentation in downstream areas