Daily Rules, Proposed Rules, and Notices of the Federal Government
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This document consists of: (1) A proposed rule to list the fluted kidneyshell (
We intend that any final action resulting from this proposed rule will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we request comments or
(1) Biological, commercial trade, or other relevant data concerning any threats (or lack thereof) to these species and regulations that may be addressing those threats.
(2) Additional information concerning the historical and current status, range, distribution, and population size of either of these species, including the locations of any additional populations.
(3) Any information on the biological or ecological requirements of these species, and ongoing conservation measures for the species and their habitat.
(4) Any information regarding water quality data that may be helpful in determining the water quality parameters necessary for the fluted kidneyshell and the slabside pearlymussel.
(5) Current or planned activities in the areas occupied by these species and possible impacts of these activities on these species.
(6) The factors that are the basis for making a listing determination for a species under section 4(a) of the Act (16 U.S.C. 1531
(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.
(7) The reasons why we should or should not designate habitat as “critical habitat” under section 4 of the Act including whether there are threats to these species from human activity, the degree of which can be expected to increase due to the designation, and whether that increase in threat outweighs the benefit of designation such that the designation of critical habitat may not be prudent.
(8) Specific information on:
(a) The amount and distribution of habitat for the fluted kidneyshell and slabside pearlymussel;
(b) What areas, that were occupied at the time of the proposed listing and that contain features essential to the conservation of these species, should be included in the designation and why;
(c) Special management considerations or protection that may be needed in critical habitat areas we are proposing, including managing for the potential effects of climate change; and
(d) What areas not occupied at the time of the proposed listing are essential for the conservation of these species and why.
(9) Land use designations and current or planned activities in the subject areas and their possible impacts on proposed critical habitat.
(10) Information on the projected and reasonably likely impacts of climate change on these species and proposed critical habitat.
(11) Any probable economic, national security, or other relevant impacts of designating any area that may be included in the final designation; in particular, we seek information on any impacts on small entities or families, and the benefits of including or excluding areas that exhibit these impacts.
(12) Whether any specific areas we are proposing for critical habitat designation should be considered for exclusion under section 4(b)(2) of the Act, and whether the benefits of potentially excluding any specific area outweigh the benefits of including that area under section 4(b)(2) of the Act.
(13) Any impact that critical habitat designation would have, positive or negative, on conservation efforts associated with designated nonessential experimental populations for other listed species in the lower Holston and French Broad river systems in Tennessee, or the North Fork Holston River in Virginia.
(14) Information on habitat suitability for these two mussels in the proposed units that are not occupied at the time of the proposed listing, including the Rockcastle River, Kentucky, and the Sequatchie River, Tennessee.
(15) Whether we could improve or modify our approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.
Please note that submissions merely stating support for or opposition to the action under consideration without providing supporting information, although noted, will not be considered in making a determination, as section 4(b)(1)(A) of the Act directs that determinations as to whether any species is a threatened or endangered species must be made “solely on the basis of the best scientific and commercial data available.”
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Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on
The fluted kidneyshell was first identified as a candidate for protection under the Act in the October 25, 1999,
On December 6, 2007 (72 FR 69034), we changed the LPN for the fluted kidneyshell from five to two. A listing priority of two reflects threats that are both imminent and high in magnitude, as well as the taxonomic classification of the fluted kidneyshell as a full species. In our 2008 (73 FR 75176), 2009 (74 FR 57804), 2010 (75 FR 69222), and 2011 (76 FR 66370) Candidate Notices of Review, we retained a listing priority number of two for this species.
The slabside pearlymussel was first identified as a candidate for protection under the Act in the May 22, 1984,
On October 25, 1999, we identified the slabside pearlymussel in the
On December 10, 2008 (73 FR 75176), we changed the listing priority number for the slabside pearlymussel from five to two. In our 2009 (74 FR 57804), 2010 (75 FR 69222), and 2011 (76 FR 66370) Candidate Notices of Review, we retained a listing priority number of two for this species.
It is our intent to discuss only those topics directly relevant to the listing and critical habitat designations for the fluted kidneyshell and slabside pearlymussel in this proposed rule. A summary of topics relevant to this proposed rule is provided below. Additional information on both species may be found in the most recent Candidate Notice of Review, which was published October 26, 2011 (76 FR 66370).
North American mussel fauna are more biologically diverse than anywhere else in the world, and historically numbered around 300 species (Williams
Most studies of the distribution and population status of the fluted kidneyshell and slabside pearlymussel presented below were conducted after the early 1960s. Gordon and Layzer (1989, entire), Winston and Neves (1997, entire), and Parmalee and Bogan (1998, pp. 204-205) give most of the references for regional stream surveys. In addition to these publications, we have obtained more current, unpublished distribution and status information from State heritage programs, agency biologists, and other knowledgeable individuals.
These two species are bivalve mussels and are endemic to the Cumberland and Tennessee River drainages. The Cumberland River drainage originates in southeastern Kentucky and flows southwest across Tennessee before turning north and reentering Kentucky to empty into the lower Ohio River. The Cumberland River drainage spans the Appalachian Plateaus and Interior Low Plateaus Physiographic Provinces. The Tennessee River originates in southwest Virginia and western North Carolina, eastern Tennessee, and northern Georgia and flows southwesterly into western Tennessee and Alabama, then turns north and flows into Kentucky, before emptying into the Ohio River. The larger Tennessee River drainage spans five physiographic provinces, including the Blue Ridge, Valley and Ridge, Appalachian Plateaus, Interior Low Plateaus, and Coastal Plain.
The fluted kidneyshell,
Mussels generally live embedded in the bottom of rivers and other bodies of water. They siphon water into their shells and across four gills that are specialized for respiration, food collection, and brooding larvae in females. Food items include detritus (disintegrated organic debris), algae, diatoms, and bacteria (Strayer
Mussels tend to grow relatively rapidly for the first few years; then growth slows appreciably after sexual maturity, when energy is being diverted from growth to reproductive activities. Mussel longevity varies tremendously among species (from 4 to 5 years to well over 100 years), but most species live 10 to 50 years (Haag and Rypel 2011, pp. 230-236). Relatively large, heavy-shelled riverine species tend to be slower growing and have longer life spans. By thin-sectioning the valves, various authors have aged fluted kidneyshell from the Clinch River at 26 and 55 years (Henley
The gametogenic cycle (annual cycle in the development of reproductive cells or gametes) of fluted kidneyshell, like most mussels, is probably regulated by annual temperature regimes (Davis and Layzer, p. 90). Most mussels, including the fluted kidneyshell, have separate sexes. Males expel sperm into the water column, which are drawn in by females through their incurrent apertures or siphons. It has been hypothesized that pheromones might trigger synchronous sperm release among males, because all fertilization observed by females from the Clinch River occurred in fewer than 5 days (Davis and Layzer 2012, p. 90). Fertilization takes place internally, and the resulting zygotes develop into specialized larvae, termed glochidia, inside the water tubes of the females' gills. The fluted kidneyshell, along with other members of its genus, is unique in that the marsupial portion of the outer gills (portion of a brooding female's gill which holds embryos and glochidia) are folded in a curtain-like fashion. The fluted kidneyshell is thought to have a late summer or early fall fertilization period with the glochidia overwintering. Davis and Layzer (2012, p. 90) observed embryo development within the marsupium (brood pouch) at 4 weeks after fertilization. The following spring or early summer, glochidia are released as conglutinates, which are similar to cold capsules or gelatinous containers with scores of glochidia within. Davis and Layzer (2012, p. 86) report an average of 208 conglutinates and an average fecundity (total reproductive output) of 247,000 glochidia per female. Davis and Layzer (2012, p. 92) report a skewed adult sex ratio of 1.9 females per 1 male in the Clinch River, in Tennessee, although the cause of the skewed ratio is unknown. Using the observed sex ratio and percent of females that were gravid, Davis and Layzer (2012, p. 92) hypothesized that some females go through reproductive “pausing” periods to acquire the energy reserves needed to produce gametes in subsequent years.
Glochidia must come into contact with a specific host fish(es) quickly in order for their survival to be ensured. Without the proper species of host fish, the glochidia will perish. Conglutinate masses often mimic food items of glochidial fish hosts in order to attract and infest potential host fishes. Fluted kidneyshell conglutinates are shaped like black fly (Simuliidae) pupae and have an adhesive end that sticks to silt-free stones on the stream bottom, with an orientation that is also similar to that of blackfly pupae (Barnhart and Roberts 1997, p. 17; Barnhart
After a few weeks parasitizing the host fish's gill, newly metamorphosed juveniles drop off to begin a free-living existence on the stream bottom. Unless they drop off in suitable habitat, they will perish. Thus, the complex life history of the fluted kidneyshell and other mussels has many critical steps that may prevent successful reproduction or recruitment of juveniles into existing populations or both.
The fluted kidneyshell occurs in medium-sized creeks to large rivers, inhabiting sand and gravel substrates in relatively shallow riffles and shoals with moderate to swift current (Williams
The fluted kidneyshell is a Cumberlandian Region mussel, meaning it is restricted to the Cumberland (in Kentucky and Tennessee) and Tennessee (in Alabama, Kentucky, Tennessee, and Virginia) River systems. Historically, this species occurred in the Cumberland River mainstem from below Cumberland Falls in southeastern Kentucky downstream through the Tennessee portion of the river to the vicinity of the Kentucky-Tennessee State line. In the Tennessee River mainstem it occurred from eastern to western Tennessee. Records are known from the following Cumberland River tributaries: Horse Lick Creek [KY], Middle Fork Rockcastle River [KY], Rockcastle River [KY], Buck Creek [KY], Rock Creek [KY], Kennedy Creek [KY], Little South Fork [KY], Big South Fork [KY, TN], Pitman Creek [KY], Otter Creek [KY], Wolf River [TN], Town Branch [TN], West Fork Obey River [TN], Obey River [TN], Caney Fork [TN], South Harpeth River [TN], and West Fork Red River [KY]. In addition, it is known from the following Tennessee River tributaries: South Fork Powell River [VA], Powell River [TN, VA], Indian Creek [VA], Little River [VA], Clinch River [TN, VA], Copper Creek [VA], North Fork Holston River [TN, VA], Big Moccasin Creek [VA], Middle Fork Holston River [VA], South Fork Holston River [TN, VA], Holston River [TN], Nolichucky River [TN], West Prong Little Pigeon River [TN], Tellico River [TN], French Broad River [TN], Little Tennessee River [TN], Hiwassee River [TN], Flint River [AL], Limestone Creek [AL], Elk River [AL, TN], Shoal Creek [AL], Buffalo River [TN], and Duck River [TN] (Gordon and Layzer 1989, entire; Winston and Neves 1997, entire; Parmalee and Bogan 1998, pp. 204-205; Layzer and Scott 2006, p. 481). The fluted kidneyshell's known historical and current occurrences, by water body and county, are shown in Table 1 below.
Prior to 1980, the fluted kidneyshell was fairly widespread and common in many Cumberlandian Region streams based on collections in museums and from the literature record. The extirpation of this species from numerous streams within its historical range indicates that substantial population losses and range reductions have occurred.
In this document, populations of the fluted kidneyshell are generally considered extant (current) if live individuals or fresh dead specimens have been collected since circa 1980. This criterion (circa 1980) was chosen because a large number of collections were conducted in the 1980s in the Cumberland and Tennessee River systems and due to the longevity of these species (40-55 years), they are still thought to occur in these areas.
Some of the historical occurences have not been surveyed since the 1980s. Based on this criterion, the species appears to be limited to Horse Lick Creek [KY], Middle Fork Rockcastle River [KY], Buck Creek [KY], Rock Creek [KY], Little South Fork Cumberland River [KY], Big South Fork Cumberland River [KY, TN], Wolf River [TN], Town Branch [TN], and West Fork Obey River [TN] in the Cumberland River system; and the Powell River [TN, VA], Indian Creek [VA], Little River
Other populations considered extant at the time this species was elevated to candidate status in 1999 (e.g., Rockcastle River, Kennedy Creek) are now considered to be extirpated. In addition, the population in the upper North Fork Holston River, although still large, has declined substantially since circa 2000. The North Fork Holston River population is predominately composed of large individuals, unlike the Clinch River population, which is skewed towards smaller size classes (Ostby
Resource managers have been making attempts to reintroduce the fluted kidneyshell into historical habitat over the past decade. In Tennessee, thousands of individuals of the species have been reintroduced into three sites in the upper Duck River, and into two sites in the Nolichucky River, by Tennessee Wildlife Resource Agency (TWRA) biologists translocating adult individuals from the Clinch River (Hubbs 2011, unpubl. data). In 2010, six individuals were collected during a quantitative survey at Lillard's Mill in the Duck River, confirming some level of survival and persistence of the reintroduced population (Hubbs 2011, unpubl. data). The individuals collected appeared in good condition and had grown noticeably since their release (as evidenced by external shell marks), but recruitment has yet to be documented (Hubbs 2011, unpubl. data). In 2008, the Kentucky Department of Fish and Wildlife Resources (KDFWR) translocated 144 individuals from the Clinch River into the Big South Fork of the Cumberland River, Kentucky (Hubbs 2011, unpubl. data). It is not known if the Nolichucky or Big South Fork reintroductions have been successful. Approximately 691 adult individuals of the species have been translocated from the Clinch River, Tennessee, into the Little Tennessee River bypass reach below Calderwood Dam, Tennessee (Moles 2012, pers. comm.). The Virginia Department of Game and Inland Fisheries (VDGIF) reintroduced 58 adults into Indian Creek, a tributary to the Clinch River, using Clinch River stock. They have also propagated and released 562 juveniles into the North Fork Holston River (Duncan 2012, pers. comm.).
The extant fluted kidneyshell populations (including the potentially reintroduced populations) in the Cumberlandian Region generally represent small, isolated occurrences. Only in the Clinch River is a population of the fluted kidneyshell known to be large, stable, and viable, but in a relatively short reach of river primarily in the vicinity of the Tennessee-Virginia State line. Jones (2012, unpub. data) estimates 500,000 to 1,000,000 individuals occur in the Clinch River from just a 32-river-kilometer (rkm) (20-river-mile (rmi)) reach (rkm 309 to 277 (rmi 172 to 192)). Live adults and juveniles have been observed over the past 10 years in shoal habitats in the upper Clinch River, Virginia, particularly at and above Cleveland Islands, and many more fresh dead shells have been collected in muskrat middens in this reach. Eckert and Pinder (2010, pp. 23-30) collected 18 individuals in quantitative samples and 11 individuals in semi-quantitative samples in the Clinch River at Cleveland Island in 2008, and 15 individuals in quantitative samples and 62 individuals in semi-quantitative samples in the Clinch River at Cleveland Island in 2002. Ostby and Angermeier (2011, entire) found two live individuals in the Little River (tributary to Clinch River). Henley
Live fluted kidneyshell have not been collected in the Middle Fork Rockcastle River since the mid-1980s (Layzer and Anderson 1992, p. 64). Haag and Warren (2004, p. 16) collected only fresh dead shell material in Horse Lick Creek, and reported that a small, extremely vulnerable population of the fluted kidneyshell may exist there, but at very low levels that they were not able to detect. Warren and Haag (2005, pp. 1384, 1388-1396) reported a vast reduction of the once sizable Little South Fork population since the late 1980s. Live fluted kidneyshell have not been collected in the Big South Fork since the mid-1980s (Ahlstedt
Extirpated from both the Cumberland and Tennessee River mainstems, the fluted kidneyshell has been eliminated from approximately 50 percent of the total number of streams from which it was historically known. Population size data gathered during the past decade or two indicate that the fluted kidneyshell is rare in nearly all extant populations, the Clinch River being a notable exception. The fluted kidneyshell is particularly imperiled in Kentucky. Haag and Warren (2004, p. 16) reported that a small, extremely vulnerable population of the fluted kidneyshell may exist in Horse Lick Creek, but at
In summary, the fluted kidneyshell has been eliminated from approximately 50 percent of the total number of streams from which it was historically known. Populations in Buck Creek, Little South Fork, Horse Lick Creek, Powell River, and North Fork Holston River have clearly declined over the past two decades. Based on recent information, the overall population status of the fluted kidneyshell rangewide is declining. A few populations are considered to be viable (e.g., Wolf, Clinch, Little, North Fork Holston Rivers). However, all other populations are of questionable viability, with some on the verge of extirpation (e.g., Horse Lick and Rock Creeks). Newly reintroduced populations will hopefully begin to reverse the overall downward trend of this species.
The fluted kidneyshell was considered a species of special concern by Williams
The taxonomic status of the slabside pearlymussel (family Unionidae) as a distinct species is undisputed within the scientific community. The species is recognized as
The following description, biology, and life history of the slabside pearlymussel is taken from data summarized in Parmalee and Bogan (1998, pp. 150-152). The slabside pearlymussel is a moderately sized mussel that reaches about 9 cm (3.5 in) in length. The shape of the shell is subtriangular, and the very solid, heavy valves are moderately inflated. Shell texture is smooth and somewhat shiny in young specimens, becoming duller with age. Shell color is greenish yellow, becoming brownish with age, with a few broken green rays or blotches, particularly in young individuals. Internally, the pseudocardinal teeth are triangular or blade-like in shape. The lateral teeth are slightly curved, with two in the left valve and one in the right valve. The color of the nacre is white, or rarely, straw-colored.
General life history information for the slabside pearlymussel is similar to that given for the fluted kidneyshell above. Samples from approximately 150 shells of the slabside pearlymussel from the North Fork Holston River were thin-sectioned for age determination. The maximum age exceeded 40 years (Grobler
The slabside pearlymussel utilizes all four gills as a marsupium for its glochidia. It is thought to have a spring or early summer fertilization period with the glochidia being released during the late summer in the form of conglutinates. Slabside pearlymussel conglutinates have not been described. The slabside pearlymussel's host fishes include 11 species of minnows (popeye shiner,
The slabside pearlymussel is primarily a large creek to large river species, inhabiting sand, fine gravel, and cobble substrates in relatively shallow riffles and shoals with moderate current (Parmalee and Bogan 1998, p. 152; Williams
Historically, the slabside pearlymussel occurred in the lower Cumberland River mainstem from the vicinity of the Kentucky State line downstream to the the Caney Fork River, Tennessee, and in the Tennessee River mainstem from eastern Tennessee to western Tennessee. Records are known from two Cumberland River tributaries, the Caney Fork [TN] and Red Rivers [KY, TN]. In addition, it is known from 30 Tennessee River system tributaries, including the South Fork Powell River [VA], Powell River [TN, VA], Puckell Creek [VA], Clinch River [TN, VA], North Fork Holston River [TN, VA], Big Moccasin Creek [VA], Middle Fork Holston River [VA], South Fork Holston River [TN], Holston River [TN], Nolichucky River [TN], West Prong Little Pigeon River [TN], French Broad River [TN], Tellico River [TN], Little Tennessee River [TN], Hiwassee River [TN], Sequatchie River [TN],