Vol. 76 Thursday, No. 194 October 6, 2011

Part II

Department of the Interior

Fish and Wildlife Service 50 CFR Part 17 Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List Fatmucket, Golden Orb, Smooth Pimpleback, Texas Pimpleback, and Texas Fawnsfoot as Threatened or Endangered; Proposed Rule

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00001 Fmt 4717 Sfmt 4717 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62166 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

DEPARTMENT OF THE INTERIOR FOR FURTHER INFORMATION CONTACT: Gary additional mussels from eastern Texas, Mowad, Texas State Administrator, U.S. the Texas heelsplitter ( Fish and Wildlife Service Fish and Wildlife Service (see amphichaenus) and Salina mucket (P. ADDRESSES); by telephone at 512–927– metnecktayi), were also included in this 50 CFR Part 17 3557; or by facsimile at 512–927–3592. petition. The petition incorporated all If you use a telecommunications device analyses, references, and documentation [FWS–R2–ES–2011–0079; MO 92210–0–0008 for the deaf (TDD), please call the provided by NatureServe in its online B2] Federal Information Relay Service database at http://www.natureserve.org/ Endangered and Threatened Wildlife (FIRS) at 800–877–8339. into the petition. Included in and Plants; 12-Month Finding on a SUPPLEMENTARY INFORMATION: NatureServe was supporting information regarding the ’ Petition To List Texas Fatmucket, Background Golden Orb, Smooth Pimpleback, and ecology, historical and Texas Pimpleback, and Texas Section 4(b)(3)(B) of the Act (16 current distribution, present status, and Fawnsfoot as Threatened or U.S.C. 1531 et seq.) requires that, for actual and potential causes of decline. Endangered any petition to revise the Federal Lists We sent a letter dated July 11, 2007, to of Endangered and Threatened Wildlife Forest Guardians acknowledging receipt AGENCY: Fish and Wildlife Service, and Plants that contains substantial of the petition and stating that the Interior. scientific or commercial information petition was under review by staff in ACTION: Notice of 12-month petition that listing the species may be our Southwest Regional Office. finding. warranted, we make a finding within 12 On October 15, 2008, we received a months of the date of receipt of the petition dated October 9, 2008, from SUMMARY: We, the U.S. Fish and petition. In this finding, we will WildEarth Guardians, requesting that Wildlife Service (Service), announce a determine that the petitioned action is: the Service list as threatened or 12-month finding on a petition to list (1) Not warranted, (2) warranted, or (3) endangered and designate critical five mussel species in Texas as warranted, but the immediate proposal for six species of freshwater threatened or endangered and to of a regulation implementing the mussels, including the smooth designate critical habitat under the petitioned action is precluded by other pimpleback, Texas pimpleback, and Act of 1973, as pending proposals to determine whether Texas fawnsfoot. Two additional amended (Act). The five species are species are threatened or endangered, mussels from the basin, the Texas fatmucket ( bracteata), and expeditious progress is being made false spike (Quincuncina mitchelli) and golden orb (Quadrula aurea), smooth to add or remove qualified species from Mexican fawnsfoot (Truncilla congata), pimpleback (Q. houstonensis), Texas the Federal Lists of Endangered and were also included in this petition. In Threatened Wildlife and Plants. Section pimpleback (Q. petrina), and Texas addition to other information, the 4(b)(3)(C) of the Act requires that we fawnsfoot (Truncilla macrodon). After petition incorporated all analyses, treat a petition for which the requested review of all available scientific and references, and documentation provided action is found to be warranted but commercial information, we find that by NatureServe in its online database at precluded as though resubmitted on the listing these five mussel species is http://www.natureserve.org/. In a date of such finding, that is, requiring a warranted. Currently, however, listing November 26, 2008, letter to the subsequent finding to be made within of these species is precluded by higher petitioner, we acknowledged receipt of 12 months. We must publish these 12- priority actions to amend the Federal the second petition and stated that the month findings in the Federal Register. Lists of Endangered and Threatened petition for the six mussel species was Wildlife and Plants. Upon publication Previous Federal Actions under review by staff in our Southwest of this 12-month petition finding, we This 12-month petition finding covers (Region 2) and Southeast (Region 4) will add these five species to our Regional Offices. The southern candidate species list. We will develop five species of mussels that are grouped together because of their overlapping or hickorynut (Obovaria jacksoniana) was a proposed rule to list these species as proximate ranges within the river basins also included in this 2008 petition, and our priorities allow. We will make any of central Texas. The petitions for listing on March 23, 2010 (75 FR 13717), we determination on critical habitat during these five species were parts of two found that the petition did not present development of the proposed listing multi-species petitions, dated June 18, substantial information supporting that rule. In any interim period, we will 2007, and October 9, 2008. The other that species may be endanagered or address the status of the candidate taxa species from those petitions, including threatened. through our annual Candidate Notice of other Texas mussels, will be considered On December 15, 2009, we published Review. in separate petition findings. our 90-day finding that the petitions DATES: The finding announced in this On June 25, 2007, we received a presented substantial scientific document was made on October 6, 2011. formal petition dated June 18, 2007, information indicating that listing nine ADDRESSES: This finding is available on from Forest Guardians (now WildEarth Texas mussels may be warranted (74 FR the Internet at http:// Guardians), requesting that we: (1) 66260). As a result of the finding, we www.regulations.gov at Docket Number Consider all full species in our initiated a status review for all nine FWS–R2–ES–2011–0079. Supporting Southwest Region ranked as G1 or G1G2 species. This notice constitutes the 12- documentation we used in preparing by the organization NatureServe, except month finding on the June 18, 2007, this finding is available for public those that are currently listed, proposed petition to list the Texas fatmucket and inspection, by appointment, during for listing, or candidates for listing; and golden orb and the October 9, 2008, normal business hours at the U.S. Fish (2) List each species as either threatened petition to list the smooth pimpleback, and Wildlife Service, 1505 Ferguson or endangered with critical habitat. The Texas pimpleback, and Texas fawnsfoot Lane, Austin, TX 78754. Please submit petitioned group of species included as threatened or endangered. Our any new information, materials, four Texas mussels, two of which are petition findings for the remaining comments, or questions concerning this included in this finding: the Texas Texas mussel species will be published finding to the above address. fatmucket and golden orb. Two at a later time.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00002 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62167

Summary of Procedures for Determining with a discussion of the priority and juvenile mussels weeks or months after the Listing Status of Species progress of our listing actions. attachment (Arey 1932, pp. 214–215). Review of Status Based on Five Factors General Mussel Biology Mussels experience their primary opportunity for dispersal and movement Section 4 of the Act (16 U.S.C. 1533) All five species are freshwater within the stream as glochidia attached and implementing regulations (50 CFR mussels in the family and to a host fish (Smith 1985, p. 105). Upon occur only in Texas, in portions of the part 424) set forth procedures for adding release from the host, newly species to, removing species from, or Colorado, Guadalupe, Nueces-Frio, and transformed juveniles drop to the reclassifying species on the Federal Brazos River systems (Howells et al. substrate on the bottom of the stream. Lists of Endangered and Threatened 1996, p. 1). Adult freshwater mussels Those juveniles that drop in unsuitable Wildlife and Plants. Under section are suspension feeders, drawing in food 4(a)(1) of the Act, a species may be and oxygen through their incurrent substrates die because their immobility determined to be endangered or siphon (tube that draws water into the prevents them from relocating to more threatened based on any of the shell). They may also feed on organic favorable habitat. Juvenile freshwater following five factors: particles in sediment using the large, mussels burrow into interstitial (A) The present or threatened muscular foot (an organ used to anchor substrates and grow to a larger size that destruction, modification, or the mussel in the substrate or for is less susceptible to predation and curtailment of its habitat or range; locomotion) (Raikow and Hamilton displacement from high flow events (B) Overutilization for commercial, 2001, p. 520). Adults feed on algae, (Yeager et al. 1994, p. 220). Throughout recreational, scientific, or educational bacteria, detritus (dead organic the rest of their life cycle, mussels purposes; material), microscopic , and generally remain within the same small (C) Disease or predation; dissolved organic matter (Fuller 1974, area where they released from the host (D) The inadequacy of existing pp. 221–222; Silverman et al. 1997, p. fish. regulatory mechanisms; or 1862; Nichols and Garling 2000, pp. (E) Other natural or manmade factors 874–876; Christian et al. 2004, p. 109). Species Information for Texas affecting its continued existence. For their first several months, as they Fatmucket In making these findings, we discuss inhabit interstitial spaces (small spaces Species Description below information pertaining to each between sediment particles) within the species in relation to the five factors substrate, juvenile mussels feed using The Texas fatmucket is a large, provided in section 4(a)(1) of the Act. In cilia (fine hairs) on the foot to capture elongated mussel that reaches a considering what factors might suspended as well as depositional maximum length of 100 millimeters constitute threats to a species, we must material, such as algae and detritus (mm) (3.94 inches (in)) (Howells 2010c, look beyond the exposure of the species (Yeager et al. 1994, pp. 253–259). p. 2). The shell is oval to elliptical or to a particular factor to evaluate whether Mussels tend to grow relatively rapidly somewhat rhomboidal and tan to the species may respond to the factor in for the first few years, and then slow greenish-yellow with numerous a way that causes actual impacts to the appreciably at sexual maturity, when species. If there is exposure to a factor energy presumably is being diverted irregular, wavy, and broad and narrow and the species responds negatively, the from growth to reproductive activities dark brown rays, with broad rays factor may be a threat, and during the (Baird 2000, pp. 66–67). widening noticeably as they approach status review, we attempt to determine As a group, mussels are extremely the ventral (underside) margin. The how significant a threat it is. The threat long lived, living from two to several nacre (inside of the shell) is white with is significant if it drives or contributes decades (Rogers et al. 2001, p. 592), and occasional yellow or salmon coloration to the risk of extinction of the species possibly up to 200 years in extreme and iridescent posteriorly (Howells such that the species warrants listing as instances (Bauer 1992, p. 427). Most 2010c, p. 2). Females have mantle flaps endangered or threatened as those terms mussel species, including the five in (extensions of the tissue that covers the are defined by the Act. However, the this finding, have distinct forms of visceral mass) that often resemble identification of factors that could males and females. During minnows, including eye spots, lateral impact a species negatively may not be reproduction, males release clouds of line, and fins (Howells 2010c, p. 2). sufficient to compel a finding that the sperm into the water column, which species warrants listing. The females draw in through their siphons. Taxonomy information must include evidence Fertilization takes place internally, and The Texas fatmucket was first sufficient to suggest that the potential the resulting eggs develop into described in 1855 by Gould as Unio specialized larvae (called glochidia) threat has the capacity (i.e., it should be bracteatus and later moved to the genus within the female gills. The females of sufficient magnitude and extent) to Lampsilis by Simpson (1900, p. 543). release matured glochidia individually, affect the species’ status such that it Some forms found in headwater streams meets the definition of endangered or in small groups, or embedded in larger were historically split into a different threatened under the Act. mucus structures called conglutinates. The glochidia of freshwater mussels species, L. elongatus, but they have Evaluation of the Status of Each of the are obligate parasites (cannot live since been determined to be Five Mussel Species independently of their hosts) on the ecophenotypes (individuals whose In this finding, we first provide a gills or fins of fishes (Vaughn and shape is determined by their description of general mussel biology. Taylor 1999, p. 913). Glochidia die if environment) of L. bracteata (Howells Then, for each of the five species, we they fail to find a host fish, attach to a 2010c, p. 5). The Texas fatmucket is describe the species, its life history, and fish that has developed immunity from recognized by the Committee on habitat; evaluate listing factors for that prior infestations, or attach to the wrong Scientific and Vernacular Names of species; and present our finding that the location on a host fish (Neves 1991, p. Mollusks of the Council of Systematic petitioned action is warranted or not for 254; Bogan 1993, p. 299). Glochidia Malacologists, American Malacological that species. We follow these encyst (enclose in a cyst-like structure) Union (Turgeon et al. 1998, p. 34), and descriptions, evaluations, and findings on the host’s tissue and develop into we recognize it as a valid species.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00003 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62168 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

Biology and Life History In the Guadalupe-San Antonio River River, Spring Creek, Llano River basin, the Texas fatmucket occupied (including Threadgill Creek), Pedernales Although there is no specific approximately 240 km (150 mi) of the River (including Live Oak Creek), Onion information on age and size of maturity Guadalupe River, from Gonzales County Creek, Jim Ned Creek, Elm Creek, and of the Texas fatmucket, it is likely upstream to Kerr County, including the the San Saba River. similar to a related species, the North Guadalupe River, Johnson Creek, Evidence of persisting Texas Louisiana fatmucket (L. hydiana), which and the Blanco River. In the San fatmucket populations has been found reaches sexual maturity around 36 mm Antonio River, it ranged from its in Spring Creek, a tributary to the (1.4 in) (Howells 2000b, pp. 35–48; confluence with the Medina River in Middle Concho River, which flows into Howells 2010c, p. 3). Texas fatmucket Bexar County upstream to the City of the Concho River, a large tributary of the females have been found gravid (with San Antonio, as well as in the Medina . Historically, Spring glochidia in the gill pouch) from July River and Cibolo Creek (Howells et al. Creek harbored Texas fatmucket in Irion through October, although brooding 1996, p. 61; Howells 2010c, p. 6). and Tom Green Counties (Randklev et may continue throughout much of the Strecker (1931, pp. 66–68) reported al. 2010c, p. 1). In 1993, discovery of year (Howells 2010c, p. 3). Texas Texas fatmucket from a lake in Victoria shell material prompted additional fatmucket females display a mantle lure County in the lower Guadalupe River surveys, and in 1997, one live to attract host fish, releasing glochidia drainage (Howells 2010c, p. 6), but this individual was found in Irion County when the lure is bitten or struck by the is probably a misidentified Louisiana (Howells 1998, p. 13). Farther fish. Bluegill (Lepomis macrochirus) fatmucket, which occurs in lakes or downstream, in Tom Green County, two and green sunfish (L. cyanellus) have impoundments. A Salado Creek record live individuals were recorded in 1997, been successful hosts in laboratory from Bell County (Strecker 1931, pp. upstream of Twin Buttes Reservoir studies (Howells 1997b, p. 257). Hosts 62–63) is also probably a misidentified (Howells 1998, pp. 13–14), but no such as these sunfishes are common, Louisiana fatmucket, since the Texas evidence of this population was found widely distributed species in Texas that fatmucket is not known to occur in the in 2008 (Burlakova and Karatayev occur in an array of habitat types (Hubbs Brazos River basin or its western 2010a, p. 12). Spring Creek was reported et al. 2008, p. 45) and would not tributaries (Howells et al. 1996, p. 61; to have dried in 1999 and 2000, which generally be expected to be a limiting Howells 2010c, p. 6). may have eliminated the population factor in Texas fatmucket reproduction there (Howells et al. 2003, p. 5). and distribution (Howells 2010c, p. 3). Current Distribution In the Llano River, there are three Based on historical and current data, areas that are currently known to Habitat the Texas fatmucket has declined contain Texas fatmucket populations. The Texas fatmucket occurs in significantly rangewide and is now The species occurred throughout the moderately sized rivers in mud, sand, or known from only nine streams in the length of the river historically (Ohio gravel, or mixtures of these substrates Colorado and Guadalupe River systems State University Museum (OSUM) (Howells 2010c, p. 4) and sometimes in in very limited numbers. All existing 2011a, p. 1). A single shell was collected narrow crevices between bedrock slabs populations are represented by only one in Llano County in 1992 (Howells 1994, (Howells 1995, p. 21). Live individuals or two individuals and are likely not p. 6), and eight live individuals were have been found in relatively shallow stable or recruiting (juvenile mussels found in 2011 (Burlakova and Karatayev water, rarely more than 1.5 meters (m) joining the adult population). In the 2011, p. 1). Individuals were small in (4.9 feet (ft)) deep, and usually less. streams where the species is extant size, indicating a potentially Remaining populations typically occur (surviving), populations are highly reproducing population. The species at sites where one or both banks are fragmented and restricted to short also persists in Mason County, where relatively low, allowing floodwaters to reaches with few exceptions. The Texas two shell fragments of recently dead spread out over land and thereby fatmucket has been considered a species Texas fatmucket were found in 1995 reducing damage from scouring of special concern by some (Howells 1996, p. 22), and two live (Howells 2010c, p. 4). The species does malacologists for several decades individuals were collected at the same not occur in ponds, lakes, or reservoirs, (Athearn 1970, p. 28). site in 2009 (Burlakova and Karatayev 2010a, pp. 12–13). The species also suggesting that it is intolerant of deep, Colorado River System low-velocity water created by artificial appears to persist in Kimble County, impoundments. The Texas fatmucket was historically where one live Texas fatmucket was known to occur throughout the recorded in 2009 (Burlakova and Distribution and Abundance Colorado River and numerous Karatayev 2010a, pp. 12–13). Historical Distribution tributaries (Randklev et al. 2010c, p. 4). In 2004, four live Texas fatmucket However, in the mainstem Colorado were recorded from Threadgill Creek, a The Texas fatmucket historically had River, the Texas fatmucket has not been tributary to the Llano River in Gillespie populations in at least 18 rivers in the found, live or dead, in several decades and Mason Counties (Howells 2005, pp. upper Colorado, Guadalupe, and San despite numerous surveys (Howells 6–7). This population is on private land, Antonio River systems in the Texas Hill 1994, p. 4; 1995, pp. 20–21, 25, 29; which limits survey access, but Howells Country and east-central Edwards 1996, pp. 20, 23; 1997a, pp. 27, 31, 34– (2009, p. 5) indicates it likely persists Plateau region of central Texas. In the 35; 1998, p. 10; 1999, p. 18; 2000a, pp. due to favorable land management. Colorado River, it ranged from Travis 25–27; 2002a, pp. 6–7; 2004, pp. 7, 10– Live Oak Creek, a tributary to the County upstream approximately 320 11; 2005, p. 6; Johnson 2009, p. 1; Pedernales River in Gillespie County, kilometers (km) (200 miles (mi)) to Burlakova and Karatayev 2010a, p. 12), also contains a sparse Texas fatmucket Runnels County in the Colorado River. and thus is considered extirpated population. In 2002, 11 shells were It was also found in many tributaries, (eliminated from) from the Colorado discovered, and in 2003, one live including the Pedernales, Llano, San River mainstem. Within this system, the individual was recorded, confirming the Saba, and Concho Rivers, and Jim Ned, species is only known from sparse species persisted in low numbers Elm, and Onion Creeks (Howells et al. populations in Colorado River (Howells 2003, p. 10; Howells 2004, pp. 1996, p. 61). tributaries, including the South Concho 8–9). Since that time, surveys have been

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00004 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62169

conducted in Live Oak Creek on a fairly Texas fatmucket have not been found downstream in Louise Hayes Park regular basis. The stream was visited in alive in the Pedernales River since 1978 during a drawdown (Howells 1999, pp. two different occasions in 2004, with (Howells 1999, p. 16). In 1992, a 18–19), and 6 live individuals were only shell material found (Howells thorough search of the habitat yielded found at the same location in 2005 2005, pp. 7–8), and again in 2005, when no live Texas fatmuckets, with only very (Howells 2006, pp. 71–72). Surveys in two live individuals were recorded old dead shell material collected in the 2007 and 2008 yielded no live or (Burlakova and Karatayev 2010a, p. 12). banks above the normal high water line recently dead individuals (Burlakova The stream was surveyed in 2007 and (Howells 1994, p. 4). Because the and Karatayev 2010a, p. 12). It is likely 2008, but no evidence of the species was species was documented from Blanco that the species persists in the vicinity. found (Howells 2009, p. 5). This County by museum records (OSUM There has been no other evidence of population is presumed to be small but 2011a, p. 1), additional sections of the Texas fatmucket in the mainstem persisting. river were also surveyed in 1992, with Guadalupe River in recent years. Original records of speckled no evidence of Texas fatmucket found, In 1999, two recently dead Texas pocketbook (Lampsilis streckeri) from although in 1993, very old Texas fatmucket were found in North Fork Onion Creek in Travis County in 1931 fatmucket shell fragments were Guadalupe River (Howells 2000a, p. 27). are now believed to have been discovered in Pedernales Falls State This river was surveyed again in 2000 misidentified; instead they represent Park (Howells 1995, p. 28). Mussel and 2003 at several sites, and no Texas records of Texas fatmucket (Howells habitat in this area is poor, and it is fatmucket were found (Howells 2001, p. 2010c, p. 6; Randklev et al. 2010c, p. 4). unlikely the species persists there. 31; Howells 2004, pp. 13–14). The stream was surveyed in 1993, and Subsequent searches of the river in 1998 Johnson Creek was a historical no live freshwater mussels were found yielded only dead shell material location for Texas fatmucket, but no live (Howells 1995, p. 28). However, in (Howells 1999, p. 16). freshwater mussels of any species have 2010, several live Texas fatmucket were The Texas fatmucket is considered been found in this stream for decades found during a survey near Highway 71 extirpated from the South Concho River (Howells 1996, p. 25; Howells 1998, p. 18; Howells 2002a, p. 8). Additionally, (Groce 2011, pers. comm.), indicating and Jim Ned Creek. In the South Concho the Blanco River has been surveyed the species persists there. River, old Texas fatmucket shell fragments were found in gravel bars in extensively since 1992, and no evidence Elm Creek, a tributary to the Colorado Tom Green County in 1997, but there of Texas fatmucket has been collected, River, has been known to harbor a Texas has been no additional evidence of the nor is suitable habitat present (Howells fatmucket population since 1993, when species (Howells 1998, p. 12). 1994, p. 9; Howells 1995, pp. 32–33; 10 live individuals were recorded Additionally, three live individuals Howells 1996, p. 28; Johnson 2011, p. (Howells 1995, p. 21). Since that time, were recorded from Jim Ned Creek in 1). The last collection of Texas the population has declined, with two Brown County in 1979 (Randklev et al. fatmucket from the Blanco River individuals found in 1995 (Howells 2010c, p. 3), but the species has not occurred in the 1970s or 1980s (Howells 1996, pp. 19–20), and no live been found in this stream since then 2005, p. 10). individuals found in 2001 or 2005 (Howells 1997a, pp. 29–30). Texas fatmucket have also been (Howells 2002a, p. 5; 2006, p. 63). In extirpated from the entire San Antonio 2008, additional sites downstream of the Guadalupe River System River system. The mainstem San known population were surveyed and While the Texas fatmucket was never Antonio River was surveyed in 1993 one live individual was recorded after widely distributed in the Guadalupe and 1996, and no live or dead Texas 15 person-hours of searching (Burlakova River system, the only remaining fatmucket were found (Howells 1995, p. and Karatayev 2010a, p. 12), indicating populations are in the mainstem 35; 1997a, pp. 41–42). It was known that the species continues to persist in Guadalupe River and possibly the North from the Medina River, a tributary to the Elm Creek, although in very low Fork Guadalupe River. It is presumed San Antonio River, historically numbers. extirpated from the entire San Antonio (Randklev et al. 2010c, p. 3), but no Texas fatmucket also persist in the River system, as well as the Blanco mussels of any species have been found San Saba River, where the species has River and Johnson Creek. in this river in recent years (May 2011, been known to occur historically In the mainstem Guadalupe River, pers. comm.). Additionally, although (Randklev et al. 2010c, p. 2; OSUM Texas fatmucket historically occurred in Texas fatmucket were collected from 2011a, p. 1). The river was surveyed in Kerr County (OSUM 2011a, p. 1). In Cibolo Creek historically (OSUM 2011a, 1997, and three live individuals were 1992 and 1995, surveys yielded no p. 1) and shell material, likely from found (Howells 1998, p. 16). In 2000 evidence of the species (Howells 1994, Texas fatmucket, was found in 1993 and 2004, no Texas fatmucket were pp. 7–8; Howells 1996, p. 25), although (Howells 1995, p. 36), no live freshwater found in this stretch of river (Howells shell fragments collected in 1993 in mussels have been found in Cibolo 2001, p. 29; Howells 2005, pp. 8–9). One Guadalupe County may have been Texas Creek since (Howells 1997a, pp. 40–41). live individual was found in 2005 fatmucket but were too weathered for an (Howells 2006, p. 64), and, in 2008, only accurate determination (Howells 1995, Summary one shell of a recently dead individual p. 31). In 1996, two live individuals Based on historical and current data, was found (Burlakova and Karatayev were recorded in Kerr County directly the Texas fatmucket has declined 2010a, p. 12). In 2005, the number of below a dam (Howells 1997a, p. 36), and significantly rangewide and has been mussels of all species collected was in 1997, three shells were found at the extirpated from most of the Guadalupe about 40 percent of the 1997 numbers same site following a flood (Howells River system and hundreds of miles of (Howells 2006, p. 64), indicating an 1998, p. 18). No Texas fatmucket or the Colorado River, as well as from overall decline in the freshwater mussel other freshwater mussels have been numerous tributaries. Extant fauna. Aquatic macrophyte (aquatic found at that site since, and it is populations are represented by only a plants larger than algae) abundance has unlikely that Texas fatmucket persist few individuals, and they are highly increased in this river, confounding there (Howells 2006, p. 71). However, disjunct and restricted to short reaches. survey efforts and degrading mussel 20 recently dead individuals were Two of the populations considered habitat (Howells 2006, p, 64). discovered approximately 1 km (0.6 mi) extant in recent years may now be

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00005 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62170 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

extirpated, and the remaining seven action may simulate flowing water Guadalupe River System populations are extremely small and conditions (Howells 2010a, p. 3). This In the Guadalupe River system, the likely not stable. No evidence of recent species is found in substrates of firm golden orb historically ranged recruitment has been found in any of mud, sand, and gravel, and it does not throughout the length of the Guadalupe, the populations, with the possible appear to tolerate more unstable San Antonio, and San Marcos Rivers. exception of the Llano River. substrates such as loose sand or silt Currently in this basin, the species only Species Information for Golden Orb (Howells 2002b, p. 6). persists in the uppermost Guadalupe Distribution and Abundance River and lower San Marcos, San Species Description Antonio, and Guadalupe Rivers. The The golden orb is small, usually less Historical Distribution lower portion of this basin (within than 82 mm (3.2 in), with an oval to The golden orb is endemic (native) to approximately 120 km (75 mi) of the nearly round, smooth, and unsculptured nearly the entire lengths of the ) harbors all four of the shell, except for concentric growth rings Guadalupe, San Antonio, and Nueces- large, presumably reproducing (Howells 2002b, p. 6). External shell Frio River basins in central Texas populations of golden orb. coloration varies from yellow-brown, (Howells 2010a, p. 5), including the Historically known from the gold, or orangish-brown to dark brown Guadalupe, Medina, San Antonio, Frio, mainstem Guadalupe River (Howells or black, and some individuals may and Nueces Rivers and Cibolo Creek. It 2002a, p. 8), the golden orb was not seen show faint greenish rays. Internally, the was originally reported from four sites in the upper Guadalupe River in Kerr nacre is white to bluish-white (Howells County again, despite repeated surveys 2002b, p. 6). in the Brazos River system (Strecker 1931, p. 63), but these are almost (Howells 1994, pp. 7–8; 1996, p. 30; Taxonomy certainly misidentified smooth 1997a, p. 36), until 1997, when three pimpleback (Howells 2002b, p. 5) based shells were discovered (Howells 1998, The golden orb was originally p. 18). No live freshwater mussels of any described as Unio aureas by Lea in 1859 on numerous mussel surveys throughout the Brazos River system species have been found in this area, and later moved to the genus Quadrula just downstream of a dam, since 1997 in 1900 (Simpson 1900, p. 783). Graf since the 1970s that failed to find any golden orb. The species has not been (Howells 1999, p. 18; Howells 2006, p. and Cummings (2007, p. 18) have 71), and it is unlikely golden orb proposed moving it to the genus found in studies of archaeological specimens from the Brazos River persists there. However, upstream of Amphinaias, but other freshwater this area, above the dam and mussel taxonomists recommend waiting (Howells 2010a, p. 5), further indicating golden orb did not historically occur in impounded reach, a single recently dead for additional work to be completed on individual was found in 1998 during an members of Quadrula before splitting the Brazos River system. extended drawdown of the river to the genus (Bogan 2011, pers. comm.). The golden orb has also been reported construct a footbridge in a local park Because the golden orb can exhibit an from the upper Colorado River drainage (Howells 1999, pp. 18–19). In 2005, two elongated shell structure in headwater (Howells et al. 1996, pp. 108–109; live individuals were also found at this riffles, old records of Unio bolli in the Randklev et al. 2010c, p. 4), but these site (Howells 2006, pp. 71–72), showing Colorado River (Dall 1882, p. 956) are appear to have been misidentified Texas that the species had survived the very likely elongated forms of golden pimpleback (Howells 2010a, p. 5). Since drawdown and persists at the site. orb (Howells 2010a, p. 5). The golden no other golden orb have been reported Golden orb also occurs farther orb is recognized by the Committee on from the Colorado River system, we do downstream in the mainstem Guadalupe Scientific and Vernacular Names of not believe it occurred in that basin. River, near Lake Gonzales in Gonzales Mollusks of the Council of Systematic County. Upstream of the reservoir, Malacologists, American Malacological Current Distribution subfossil shells (very old shells that are Union (Turgeon et al. 1998, p 36), and Based on historical and current data, brittle, crumbling, and with extensive we recognize it as a valid species. the golden orb has declined erosion) were found in 1993 (Howells Biology and Life History significantly rangewide and is now 1995, p. 31), but the species has not There is no specific information on known from only four streams in been found there since. However, below age, size of maturity, or host fish use for disjunct locations. Despite mussel the reservoir, one recently dead golden orb. Other species in the genus surveys across the historical range, since individual was collected in 1995 Quadrula successfully parasitize catfish, 1995 golden orb has only been found in (Howells 1996, pp. 26–27), and in 1996, and it is likely golden orb do as well Lake Corpus Christi and the Guadalupe, 25 live golden orb were recorded at two (Howells 2010a, p. 3). Gravid females lower San Marcos, and lower San sites in this area (Howells 1997a, pp. have been found from May through Antonio Rivers. The species has been 37–38). Later, in 2006, three live golden August (Howells 2000b, p. 38). Mussels extirpated from the entire Nueces-Frio orb were also found in this area in the genus Quadrula are short-term River basin, except at the extreme (Howells 2006, pp. 85–86). A small brooders, which are species that hold downstream end of the , population apparently continues to fertilized eggs and glochidia for a short where a population persists in Lake persist below Lake Gonzales. period, usually 3 to 6 weeks, before Corpus Christi. Aside from the upper A large golden orb population occurs releasing glochidia (Gorden and Layzer Guadalupe River, all existing farther downstream in the mainstem 1989, p. 6; Garner et al. 1999, p. 277). populations occur in the lower portion Guadalupe River, below Lake Wood, of occupied basins in a small also in Gonzales County. Although none Habitat geographical area; only about 130 km were found during a survey in 1995 The golden orb has been found almost (80 mi) separate the farthest two (Howells 1996, p. 27), 36 live golden orb exclusively in flowing waters in populations. Only four populations were found at two sites below Lake moderately sized rivers (Howells 2010a, appear to be relatively stable and Wood in 1996 (Howells 1997a, pp. 38– p. 3). It has been found in only one recruiting, while the remaining five 40). Density estimates were calculated reservoir in the lower Nueces River populations are represented by only a based on the quantitative information (Lake Corpus Christi), where wave few individuals. collected from these surveys, but they

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00006 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62171

were not considered statistically valid remains present (Karatayev and flowing water conditions and has (Howells 1997a, p. 40) and so are not Burlakova 2008, p. 40). supported a golden orb population since reported here. Only one live golden orb The lower portion of the San Antonio at least the 1970s (OSUM 2011b, p. 1). was found at this site in 2002 (Howells River supports the largest known golden A few live individuals of golden orb 2003, p. 11), but a relatively large orb population. In 2007, 37 live golden have been found within the reservoir population continues to persist; a total orb were recorded near Goliad in Goliad consistently since 1994 (Howells 1995, of around 100 live golden orb were County, both within and downstream of p. 39; 1996, pp. 30–31; Burlakova and found at three sites within 2 km (1.2 mi) Goliad State Park (Howells 2009, p. 11). Karatayev 2010c, p. 1). Numbers of of the Lake Wood Dam in 2006 (Howells The following year, 285 live golden orb golden orb collected increased in 1996, 1996, pp. 87–91). Also, in 2008, 33 were found within the park and when 86 live golden orb were found at golden orb were recorded alive downstream surrounded by private three different locations within the downstream of Lake Wood (Burlakova lands (Burlakova and Karatayev 2010a, reservoir (Howells 1996, pp. 30–31). and Karatayev 2010a, p. 14). This p. 15). This site represents the largest However, a drawdown of the lake in portion of the Guadalupe River supports known population of golden orb. 1996 resulted in large numbers of a relatively large population of golden In 2009, a single live golden orb was golden orb stranded and killed (Howells orb, and it also contains one of the most discovered in the lower San Antonio 2010a, p. 9), and in 1998 no live abundant freshwater mussel River south-southwest of Victoria in individuals were found (Howells 1999, communities in Texas (Burlakova and Victoria County (Johnson 2009, p. 1); p. 19). Again in 2005, no live Karatayev 2010a, p. 14). this site has not been surveyed since. individuals were found during surveys, In 2009, a large population of golden We presume golden orb may persist in but in 2006, a total of nine were orb was discovered farther downstream this stretch of river. collected at three different sites within in the mainstem Guadalupe River in The golden orb appears to have been the reservoir (Howells 2006, pp. 73–76, Victoria County, when over 100 extirpated from the Medina River. The 91–93). A small golden orb population individuals were found (Johnson 2009, species historically occurred in Medina likely persists in the reservoir. p. 1). Multiple size classes were and Bexar Counties (Randklev et al. 2010b, p. 4; OSUM 2011b, p. 1), but no Very little information is available on observed, including juveniles, the distribution of golden orb in the Frio indicating this population is live or dead mussels of any species have been found in this river in recent years River. Shells were last seen in reproducing and recruiting new McMullen County in 1994 (Burlakova individuals into the population. A large (May 2011, pers. comm.). Cibolo Creek, a tributary to the San and Karatayev 2010c, p. 1), but no number of shells was collected Antonio River, was extensively evidence of the species has been found upstream of this site in 1994 (Burlakova surveyed in the 1990s, with only old in this river since (Howells 1995, pp. and Karatayev 2010c, p.1), but no golden orb shells collected in Wilson 37–38; 1996, p. 29; 2002a, pp. 9–10; golden orb were seen alive until 2009. County (Howells 1995, pp. 35–37; 2004, pp. 19–20). The San Marcos River, a tributary to 1997a, pp. 40–41). In 2006 and 2007, Summary the Guadalupe River, also supports a Burlakova and Karatayev (2010b, p. 1) large golden orb population near its surveyed this same general area and Based on historical and current data, confluence with the tailwaters (outflow) found only shell material. It is unlikely the golden orb has declined rangewide of Lake Wood Dam. Although much of golden orb remain in Cibolo Creek. and is now known from only nine the San Marcos River has been populations in four rivers and has been Nueces-Frio River System extensively surveyed, with very few eliminated from nearly the entire freshwater mussels present of any Information is limited on the Nueces-Frio River system. Four of these species (Howells 1995, pp. 33–34; occurrence of golden orb in the Nueces populations appear to be stable and 1997a, p. 40; 2004, pp. 15–16, 18; 2005, River. Other than a population that reproducing; the remaining five p. 10), one old golden orb shell was occurs in a reservoir on the lower populations are small and isolated and found near the town of Staples (Howells Nueces River (Lake Corpus Christi), the show no evidence of recruitment. Only 1998, p. 19), and a single live individual species appears to be extirpated from the populations in the middle was found near the town of Luling the remainder of the basin. Guadalupe River and lower San Marcos (Howells 1999, p. 28). Downstream from Historically, the golden orb occurred River are likely connected; the these locations, a large population in the Nueces River in Live Oak County remaining extant populations are highly persists in the vicinity of Palmetto State (OSUM 2011b, p. 1). It was last seen fragmented and restricted to short Park in Gonzales County. In 1995, a alive in the Nueces River in 1993, when reaches. recently dead individual was discovered unreported numbers were found in the downstream of the park, indicating the same area (Burlakova and Karatayev Species Information for Smooth recent presence of the species (Howells 2010c, p. 1). A shell was collected in the Pimpleback 1996, p. 28), and, based on surveys from same general area in 1995 (Burlakova Species Description 2000–2006, a relatively large population and Karatayev 2010c, p. 1), but was confirmed to be in the area additional surveys in 1996 and 1997 The smooth pimpleback is a nearly (Howells 2001, pp. 32–33; 2006, pp. 72– found no evidence of the species round, thick-shelled freshwater mussel 73; 2006, p. 91; Burlakova and (Howells 1997a, pp. 43–44; 1998, p. 20). that generally reaches at least 60 mm Karatayev 2010a, pp. 14–15). We presume the species no longer (2.6 in) in length (Howells 2010b, p. 4). Historically, golden orb were occurs in the upper portions of the It is moderately thick, solid, and numerous in the San Antonio River in Nueces River. inflated. Externally, the smooth Karnes County (OSUM 2011b, p. 1), but An anomalous (odd) population of pimpleback, like its name suggests, is only a single subfossil shell was found golden orb has persisted in Lake Corpus relatively smooth with minute at each of two sites in Karnes County in Christi Reservoir in the lower Nueces sculpturing; it may or may not have a 1996 (Howells 1997a, pp. 41–42). No River. While the species does not few small pustules (raised bumps) live animals have been found there typically inhabit lentic (ponded) water, (Howells 2010b, p. 2). The external since, although abundant shell material wave action is presumed to simulate coloration of the shell ranges from tan

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00007 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62172 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

to light brown, dark brown, and black where it occurred; from the 1960s having been surveyed in 1995 and none with no rays (Howells 2010b, p. 4). through the 1990s, experts failed to find found (Howells 1996, p. 23). large populations persisting throughout Taxonomy Inks Lake is a small mainstem its range (Howells 2009, p. 12). reservoir on the Colorado River in The smooth pimpleback was In the Colorado River, historical Burnet County. Several live smooth originally described by Lea in 1859 as reports indicate that the smooth pimpleback were found in 1992 Unio houstonensis. It was later placed pimpleback occurred from San Saba (Howells 1994, p. 4); however, since in the genus Margaron and ultimately County downstream to Wharton County, that time only shell material has been moved to Quadrula by Simpson (1900, as well as in the Llano River and Onion p. 782). Graf and Cummings (2007, p. found during four separate surveys and Skull Creeks. Within the Brazos between 1996 and 2005 (Howells 1997a, 18) have proposed moving it to the River basin, the species historically genus Amphinaias, but other freshwater pp. 32–33; 1999, p. 16; 2005, p. 8; 2006, occurred throughout the length of the p. 67). Frequent drawdowns in this lake mussel taxonomists recommend waiting mainstem of the Brazos River (Howells for additional work to be completed on appear to have affected all species of 2009, p. 12), as well as in the Clear Fork freshwater mussels, as there has been a members of Quadrula before splitting Brazos, Leon, Navasota, Little Brazos, the genus (Bogan 2011, pers. comm.). sharp decline in the overall mussel San Gabriel, Lampasas, and Little Rivers community (Howells 1999, p. 16). The smooth pimpleback is recognized and Yegua Creek (Howells 2010b, pp. 4– One live smooth pimpleback was by the Committee on Scientific and 6; Randklev et al. 2010b, p. 20). Vernacular Names of Mollusks of the found in Lake Lyndon B. Johnson, a Council of Systematic Malacologists, Current Distribution large mainstem reservoir on the American Malacological Union Colorado River, in 2001, but no live The smooth pimpleback has been (Turgeon et al. 1998, p 37), and we individuals have been found since nearly extirpated from the Colorado recognize it as a valid species. (Howells 2002a, pp. 6–7; 2006, pp. 68– River basin, and a few small 69). Farther downstream, in Lake Biology and Life History populations persist in the Brazos River Marble Falls, 13 live smooth basin. Recent surveys suggest a greater There is no specific information on pimpleback were found in 1995 during abundance and distribution of the age, size of maturity, or host fish use for a drawdown of lake levels (Howells smooth pimpleback in the central smooth pimpleback. Numerous 1996, p. 22), but subsequent surveys in Brazos River drainage than was individuals were examined for gravidity 1996 failed to find any additional living indicated by collections from the past between June and November, with no animals (Howells 1997a, p. 33). The 40 years, with five populations evidence of eggs or glochidia (Howells small recent survey effort is not represented by more than a few 2000b, p. 38). Other species in the genus sufficient to conclude that the smooth individuals. Quadrula successfully parasitize catfish, pimpleback no longer occur in these and it is likely smooth pimpleback does Colorado River System lakes, and small populations may still as well (Howells 2010b, p. 2); persist there. additionally, mussels in the genus The smooth pimpleback historically Quadrula are typically short-term occurred throughout the mainstem Smooth pimpleback were recently brooders (Gorden and Layzer 1989, p. 6; Colorado River as well as several found in the San Saba River in San Saba Garner et al. 1999, p. 277), and we tributaries, but it is currently restricted County, when 29 individuals were expect the same of the smooth to one mainstem reservoir, two sites on found at two locations (Burlakova and pimpleback. the mainstem Colorado River, and the Karatayev 2011, p. 5). Various size and San Saba River. Populations in all of the age classes were represented, indicating Habitat other historically occupied tributaries a reproducing, recruiting population The smooth pimpleback has been and two reservoirs appear to have been (Burlakova and Karatayev 2011, p. 5). found in mud, sand, and fine gravel in extirpated. Even more recently, 206 smooth medium-to-large rivers and some In the mainstem Colorado River, pimpleback, including adults and reservoirs (Howells 2010b, p. 3). Unlike smooth pimpleback were historically juveniles, were recorded in this same most other Quadrula species in central known from much of the length of the area in riffle and pool habitat (Randklev Texas, smooth pimpleback do occur in river (Howells 1996, p. 21; 1997a, pp. 2011b, p. 1). some reservoirs (Howells 2002b, p. 8; 34–35; Randklev et al. 2010c, p. 4; No smooth pimpleback populations 2010b, p. 3). OSUM 2011c, p. 1). Numerous surveys remain in any of the Colorado River Distribution and Abundance in many locations on the Colorado River tributaries in which the species was occurred between 1993 and 2009, and historically known to occur, including Historical Distribution no evidence of smooth pimpleback was the full length of the Llano River The smooth pimpleback is native to found (Howells 1995, p. 29; 1996, p. 23; (Howells 1996, pp. 21–22; 1998, p. 17; the central and lower Brazos and 1997a, pp. 27, 31; 2002a, p. 6; 2004, p. 2000a, p. 25; 2005, p. 8; Randklev et al. Colorado Rivers and their tributaries in 7, 11; 2005, p. 6; Burlakova and 2010c, p. 4; OSUM 2011c, p. 1). A single central Texas (Howells 2010b, p. 4). The Karatayev 2010a, pp. 15–16), except for subfossil shell, likely a smooth smooth pimpleback has also been in Colorado County in 1999, when three pimpleback, was found in the Llano reported from the Trinity River and live smooth pimpleback were found River in Kimble County in 1995 other drainages in Texas, as well as from (Howells 2000a, p. 27). During two (Howells 1996, pp. 21–22), but no other areas outside of Texas, including surveys in 2009, live smooth evidence of the species has been found southern Arkansas and the Verdigris pimpleback were found in the same in the Llano River in recent years. River in Kansas. These reports are likely general area as in 1999 (Burlakova and Additionally, although Onion and Skull misidentifications of other pimpleback Karatayev 2010a, p. 16; Johnson 2009, p. Creeks were historically occupied by species that can sometimes closely 1). Farther downstream, in Wharton smooth pimpleback (Randklev et al. resemble smooth pimpleback (Howells County, live smooth pimpleback were 2010c, p. 4), the species has not been 2010b, pp. 4–5). The smooth found at two sites in 2009 (Burlakova found recently in either stream (Howells pimpleback was historically uncommon and Karatayev 2010a, p. 16), despite 1995, pp. 28–29).

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00008 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62173

Brazos River System historically contained smooth in this stream since (Howells 1999, p. The smooth pimpleback historically pimpleback throughout its length in 19). occurred in the Brazos River system Hamilton, Coryell, and Bell Counties In the Navasota River, smooth from Palo Pinto County downstream to (Howells 1994, p. 19, 1997a, p. 20; pimpleback historically occurred in Austin and Waller Counties, as well as Randklev et al. 2010c, p. 4; OSUM Leon, Brazos, Grimes, and Washington in numerous tributaries. The species has 2011c, p. 1). Currently, a smooth Counties (Randklev et al. 2010c, p. 4; been extirpated from the upstream half pimpleback population persists in OSUM 2011c, p. 1). Currently, the of the mainstem Brazos River and from Hamilton County, where numerous live species persists in each of those at least three tributaries. Substantial individuals were found in 2006 and counties, with a large population populations persist in the Leon River, 2011 (Howells 2006, pp. 82–83; occurring in the lower river. In Leon Navasota River, and Yegua Creek, and Randklev 2011a, p. 1), as well as several County three recently dead smooth small populations remain in the lower locations in Coryell County, where pimpleback shells were found in 2000 Brazos and Little Brazos Rivers. numerous individuals were also (Howells 2001, p. 23), indicating that a In the mainstem Brazos River, surveys recently found (Randklev 2011a, p. 1). few individuals may persist in the area. in Palo Pinto, Somervell, and Bosque Only subfossil smooth pimpleback However, one of the largest known Counties between 1996 and 2000 shells have been found in the Lampasas populations occurs farther downstream indicate that the smooth pimpleback has River in Bell County in 1996 (Howells near the confluence of the Navasota and been extirpated from the upstream 1997a, pp. 20, 23). Subsequent surveys Brazos Rivers. Nine live individuals portion of the river (Howells 1997a, pp. of the river in both Bell and Lampasas were found in this area in 2006 16, 18–19; 1999, pp. 11–12; 2001, p. 19). Counties yielded no evidence of smooth (Karatayev and Burlakova 2008, pp. 6– Despite surveys in 1996 and 1998 in pimpleback (Howells 1999, p.14; 2001, 10), and in 2008 a total of 117 live which no individuals were found p. 20), and the species has likely been smooth pimpleback were recorded at 3 (Howells 1997a, p. 21; 1999, p. 12), a extirpated from the Lampasas River. different locations within Washington single live smooth pimpleback was The Little River in Milam County is and Grimes Counties (Randklev et al. found in McLennan County in the also a historical location for the smooth 2009, pp. 6, 18). A large population middle Brazos River in 2005 (Howells pimpleback (Randklev et al. 2010c, p. continues to persist in the Navasota 2010b, p. 5), and two live individuals 4). Old shells were found at this site in River, with a total of 314 smooth were recorded in Falls County in 2006 1996 (Howells 1997a, p. 22), and a pimpleback recorded at two sites in (Karatayev and Burlakova 2008, pp. 6– single live individual was found here in 2011 (Randklev 2011a, p. 1). 10). 2006 (Karatayev and Burlakova 2008, p. In Yegua Creek, no smooth Although not extirpated from the 6). Farther downstream, at the pimpleback were found during several middle Brazos River, the smooth confluence with the Brazos River, none surveys between 1996 and 2003 pimpleback occurs only in low have been found (Howells 1996, p. 17). (Howells 1997a, pp. 24–26; 2001, p. 22; numbers. In Milam and Robertson A single old smooth pimpleback shell 2004, p. 6), although subfossil shells Counties, no smooth pimpleback were has been found in the San Gabriel River were found in Washington County in found in 1998 (Howells 1999, p. 13), but in Milam County (Howells 1997a, p. 23), 1996. However, in 2006, a live eight live individuals were found in and it is likely the species has been individual was discovered (Karatayev 2006 (Burlakova and Karatayev 2010b, extirpated from this Brazos River and Burlakova 2008, pp. 6–10), which p. 1). More recently, in 2008, 13 live tributary as well. prompted further surveys in 2008. smooth pimpleback were found at the In the Little Brazos River, the smooth Numerous smooth pimpleback were same site (Randklev et al. 2009, p. 18). pimpleback appears to persist in low found during subsequent surveys at four Additionally, downstream in Burleson numbers. Although none were found in different locations within Washington and Brazos Counties, which were Robertson County in 1993 and there had and Burleson Counties (Randklev et al. historically occupied by the smooth appeared to be a die off of numerous 2009, pp. 16–18; Randklev 2011a, p. 1), pimpleback (OSUM 2011c, p. 1), a small freshwater mussel species (Howells indicating the presence of a potentially population persists. In 1995, one live 1995, p. 18), one live smooth large population in this stream. and one recently dead individual were pimpleback was found during a 2006 Summary collected within Brazos County survey (Karatayev and Burlakova 2008, (Howells 1996, pp. 17–18). Although p. 6). Farther downstream in Brazos Based on historical and current data, none were found here in 1999 (Howells County, recently dead individuals were the smooth pimpleback has declined 2000a, pp. 21–22), in 2006 a single live discovered in 2001 (Howells 2002a, pp. rangewide and is now known from only smooth pimpleback was collected at this 4–5). The species occurred in this area nine locations. The species has been site (Karatayev and Burlakova 2008, pp. historically (Randklev et al. 2010c, p. 4), eliminated from nearly the entire 6–10). Additionally, further downstream and reports of mussels in the Little Colorado River and all but one of its in Grimes and Waller Counties, a single Brazos River from the 1950s described tributaries, as well as from the upper live individual was found in 2006 the freshwater mussel community as Brazos River and several tributaries. The (Burlakova and Karatayev 2010b, p. 1) numerous, including smooth San Saba River, lower Brazos River, and again in 2008 (Randklev et al. 2009, pimpleback (Gentner and Hopkins 1966, Navasota River, Leon River, and Yegua p. 18). Smooth pimpleback are more pp. 458–459), but no live individuals Creek populations appear to be stable numerous in the lower mainstem Brazos have been collected in this area in and reproducing, but the remaining River, in Austin and Waller Counties, recent years (Howells 1996, p. 18; 1999, populations are small, isolated, and where 38 live individuals were found in p. 14). represented by only a few individuals. 2006 (Karatayev and Burlakova 2008, The smooth pimpleback has been Species Information for Texas pp. 6–10). extirpated from the Clear Fork Brazos Pimpleback Tributaries to the Brazos River also River. Although this species was contain smooth pimpleback originally documented from this river in Species Description populations. The Leon River, in the Shackelford County in 1893 (Randklev The Texas pimpleback is a large Little River drainage of the Brazos, et al. 2010c, p. 4), none have been found pimpleback species with a moderately

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00009 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62174 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

inflated shell that generally reaches 60– species is intolerant of deep, low- Saba Counties (Howells 1995, pp. 20, 90 mm (2.4–3.5 in) (Howells 2002b, pp. velocity waters created by artificial 29; 1997a, pp. 27, 31, 35; 2000a, p. 27; 3–4). With the exception of growth impoundments (Howells 2002b, p. 4). In 2002a, p. 7). In Runnels County, Texas lines, the shell of the Texas pimpleback fact, Texas pimpleback appear to pimpleback shells were found in 1993 is generally smooth and moderately tolerate faster water more than many (Howells 1995, p. 20), but several thick (Howells 2002b, p. 4). Externally, other mussel species (Horne and subsequent surveys between 1996 and coloration ranges from yellowish-tan to McIntosh 1979, p. 123). 2008 detected no further evidence of the dark brown with some individuals species (Howells 1997a, p. 27; 1998, p. mottled or with dark green rays. Distribution and Abundance 10; 2002a, p. 7; 2004, p. 7; Burlakova Internally, the nacre is white and Historical Distribution and Karatayev 2010a, p. 10). In San Saba iridescent posteriorly (Howells 2002b, County, a single shell was collected in The Texas pimpleback is endemic to p. 4). 1989 (Howells 2002b, p. 6), and three the Colorado and Guadalupe-San recently dead individuals were found in Taxonomy Antonio River basins of central Texas 1999 (Howells 2000a, pp. 25–26). An (Howells 2002b, p. 3). In the Colorado The Texas pimpleback was originally additional shell was collected in 2001 described as Unio petrinus by Gould in River basin, Texas pimpleback occurred (Howells 2002a, p. 6). No live 1855. It was placed in the genus throughout nearly the entire mainstem, individuals have been collected from Margaron by Lea in 1870 and ultimately as well as numerous tributaries, this reach of the Colorado River. moved to Quadrula by Simpson in 1900 including the Concho, North Concho, In Runnels County, Elm Creek once (Simpson 1900, p. 783). Graf and San Saba, Llano, and Pedernales Rivers, supported a Texas pimpleback Cummings (2007, p. 18) have proposed and Elm and Onion Creeks (Howells population. Small numbers of Texas moving it to the genus Amphinaias, but 2010e, p. 5; Randklev et al. 2010c, p. 4; pimpleback were found in 1993 and other freshwater mussel taxonomists OSUM 2011d, p. 1). Within the 1995 (Howells 1995, p. 21; 1996, p. 20), recommend waiting for additional work Guadalupe-San Antonio River basin, it but none were found in 1997, 2001, or to be completed on members of occurred throughout most of the length 2003 (Howells 1998, p. 11; 2002a, p. 5; Quadrula before splitting the genus of the Guadalupe River, as well as in the 2004, p. 7). In 2005 and 2008, only dead (Bogan 2011, pers. comm.). The Texas San Antonio, San Marcos, Blanco, and individuals were collected (Howells pimpleback is recognized by the Medina Rivers (Horne and McIntosh 2006, pp. 63–64; Burlakova and Committee on Scientific and Vernacular 1979, p. 122; Howells 2010e, p. 5; Karatayev 2010a, p. 10). No live Names of Mollusks of the Council of OSUM 2011d, p. 1). individuals have been found in over a Systematic Malacologists, American Current Distribution decade despite repeated sampling Malacological Union (Turgeon et al. efforts, and it is likely the Texas 1998, p. 37), and we recognize it as a The Texas pimpleback has declined pimpleback has been extirpated from valid species. significantly rangewide, and only four this stream. streams—the San Saba River, Concho The Concho River in Concho County Biology and Life History River, Guadalupe River, and San Marcos supports the largest Texas pimpleback There is very little specific River—are known to harbor persisting population. Thirteen and 28 individuals information on age, size of maturity, or Texas pimpleback populations. These were collected in 1993 and 1994, host fish use for Texas pimpleback. populations are disjunct, small, and respectively (Howells 1995, pp. 24–25; Gravid females have been found from isolated. The species has been 2006, p. 61). However, low water and June through August, and the smallest extirpated from the remainder of its high temperatures in 1997 killed large documented gravid female was 45 mm historical range. numbers of many freshwater mussel (1.8 in) long (Howells 2000b, p. 38). Colorado River System species in the area up and downstream Glochidia are hookless and elliptical in of Paint Rock, and 63 recently dead shape (Howells et al. 1996, p. 120). To In the Colorado River system, Texas Texas pimpleback were found (Howells date, no host fish have been confirmed pimpleback once occurred throughout 1998, pp. 14–15). A severe drought in for the Texas pimpleback; however, the mainstem and in many major 1999 resulted in this area of the Concho glochidia have been reported attached to tributaries. Currently, the species has River being reduced to a series of small and encysted on flathead catfish been extirpated from the Pedernales, pools. Few live Texas pimpleback were (Pylodictis olivaris), yellow bullhead North Concho, and Llano Rivers, as well collected during this drought, in (Ameiurus natalis), and bluegill in as Onion Creek. It has also likely been addition to many recently dead laboratory settings, although none extirpated from the mainstem Colorado individuals (Howells 2000a, p. 23). No transformed to the juvenile stage River and Elm Creek. The Concho River evidence of the species was found in (Howells 2010e, p. 3). This is consistent contains the most abundant population 2004 (Howells 2005, p. 9), but eight live with other species in the genus of Texas pimpleback and one of only individuals were found in 2005 Quadrula, which also parasitize catfish two populations of the species likely to (Howells 2006, p. 60), evidence that the species. be remaining in the Colorado River species had survived the extreme system, but most individuals are old dewatering of the river. In 2008, 61 live Habitat and there has been very little evidence Texas pimpleback were collected in this The Texas pimpleback typically of recruitment. same area, and the population was occurs in moderately sized rivers, In the mainstem Colorado River, estimated to contain approximately usually in mud, sand, gravel, and Texas pimpleback historically occurred 4,000 individuals (Burlakova and cobble, and occasionally in gravel-filled from Runnels County downstream to Karatayev 2010a, p. 10; 2010b, p. 1). cracks in bedrock slab bottoms (Horne Colorado County (Howells 2010e, p. 5; However, the average length of and McIntosh 1979, p. 122; Howells Randklev et al. 2010c, pp. 3–4; OSUM individuals collected at this site was 2002b, p. 4). The species has not been 2011d, p. 1). However, surveys in over 90 mm (3.5 in), indicating that found in water depths over 2 m (6.6 ft). numerous locations along the river reproduction is limited in this Texas pimpleback have not been found yielded no evidence of the species population. Further, although no mussel in reservoirs, which indicates that this anywhere except in Runnels and San surveys occurred in 2009 and 2010, the

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00010 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62175

river was reported to be extremely low San Marcos Rivers, represented by one Species Information for Texas during this time (Howells 2010e, p. 6); or two individuals in each. Fawnsfoot the result of this additional dewatering In the mainstem Guadalupe River, the Species Description on the population is unknown. Texas pimpleback was historically The San Saba River historically known throughout the length of the The Texas fawnsfoot is a small, contained Texas pimpleback (Randklev river, from as long ago as 1905 relatively thin-shelled freshwater et al. 2010c, p. 2), but no live (Randklev et al. 2010c, p. 1; OSUM mussel that can reach 60 mm (2.4 in) in individuals had been collected in over 2011d, p. 1). Numerous surveys between length but is usually much smaller a decade until recently when shells 1992 and 2005 have not yielded any (Howells 2010d, p. 2). The shell is long were collected in 1992 and 1995 evidence of the species anywhere but in and oval, generally free of external (Howells 1994, p. 7; 1996, p. 21), and Victoria County (Howells 1994, pp. 7– sculpturing, with external coloration five live individuals were collected in 9; 1995, pp. 30–32; 1996, pp. 25–27; that varies from yellowish- or orangish- 1997 (Howells 1998, p. 16). However, 1997a, pp. 37–40; 1999, pp. 18–19; tan, brown, reddish-brown, to smoky- subsequent surveys were conducted in 2002a, p. 8; 2003, pp. 15, 17; 2006, pp. green with a pattern of broken rays or 2000, 2004, and 2005, with only shell 71–72; Johnson 2009, p. 1), where two irregular blotches (Howells 2010d, p. 2). material being found in 2000 (Howells live individuals were collected in 2009. The nacre is bluish-white or white and 2001, pp. 28–29), and no evidence of A small population may remain in the iridescent posteriorly (Howells 2010d, Texas pimpleback was found in 2004 lower Guadalupe River. p. 2). In the San Marcos River near the and 2005 (Howells 2005, pp. 8–9; 2006, Taxonomy pp. 64–65). A single shell was collected confluence with the Blanco River in The Texas fawnsfoot was first in 2008 (Burlakova and Karatayev Hays County, repeated surveys between 1992 and 2000 yielded no evidence of described as Unio macrodon by Lea in 2010b, p. 1). However, in 2011, 39 live Texas pimpleback (Howells 1994, pp. 9– 1859 and was subsequently placed in individuals were found at two sites in 10; 1995, pp. 33–34; 1996, p. 27; 1997a, the genus Margaron by Lea in 1870 and San Saba County (Burlakova and p. 40; 2000a, p. 28; 2001, pp. 32–33). then moved to Plagiola by Simpson Karatayev 2011, p. 3). The individuals However, in 2003 two shells were (1900, p. 605). Ultimately the species found were of various sizes and ages, collected (Howells 2004, p. 16), and in was placed in the genus Truncilla by indicating a reproducing population 2004, a single live individual was found Strecker (1931, pp. 63, 65). The Texas (Burlakova and Karatayev 2011, p. 4). (Howells 2005, p. 10). The Texas fawnsfoot is recognized by the Further surveys at this site confirm a pimpleback likely persists in this river Committee on Scientific and Vernacular large population in the area, with 140 in very low numbers. Names of Mollusks of the Council of individuals, including many juveniles, The Texas pimpleback appears to be Systematic Malacologists, American found here (Randklev 2011b, p. 1). extirpated from the San Antonio River, Malacological Union (Turgeon et al. The Texas pimpleback also with only shell fragments found near 1998, p. 37), and we recognize it as a historically occurred in the North the City of San Antonio in Bexar County valid species. Concho, Pedernales, and Llano Rivers, in 1993 (Howells 1995, p. 35). No as well as Onion Creek (Howells 2010e, evidence of the species was found Biology and Life History p.5; Randklev et al. 2010c, p. 4; OSUM downstream in Karnes County in 1996 There is no specific information on 2011d, p. 1); all are tributaries within (Howells 1997a, pp. 41–42). age, size of maturity, or host fish use for the Colorado River system. In the North The Texas pimpleback was once Texas fawnsfoot. However, other species Concho River, all freshwater mussels are described as abundant in the Blanco in the genus Truncilla parasitize presumed extirpated from historically River just upstream of its confluence freshwater drum (Aplodinotus occupied areas (Howells 1995, pp. 22– with the San Marcos River in Hays grunniens) (OSUM 2011f, p. 1), and it is 23). The Pedernales River historically County (Horne and Mcintosh 1979, p. likely the Texas fawnsfoot does as well. harbored a Texas pimpleback 126), but repeated surveys of this area Freshwater drum are ubiquitous population (OSUM 2011d, p. 1), but between 1992 and 1995 yielded no throughout the range of Texas fawnsfoot only old shells have been collected in recent evidence of the species (Howells (Hubbs et al. 2008, p. 53). this river in recent years (Howells 1994, 1994, p. 9; 1995, pp. 32–33; 1996, p. 27), Habitat p. 5). Since 1993, no evidence of Texas with only a subfossil shell collected in pimpleback has been found (Howells 1993 (Howells 1995, p. 33). No shell Since Texas fawnsfoot were not found 1995, pp. 27–28; 1999, p. 16), and the material or live individuals were found alive for many years, very little species is presumed to be extirpated. in additional surveys in 2011 (Johnson information is available about its habitat Additionally, repeated surveys in the 2011, p. 1). preferences. In the past only Texas Llano River in Kimble and Mason fawnsfoot shells and recently dead Counties consistently failed to collect Summary individuals were occasionally found live Texas pimpleback, with shells The Texas pimpleback has been along rivers following drought-related found only in Llano County in 1997 eliminated from long reaches of former dewatering or bank deposition after high (Howells 1996, pp. 21–22; 1998, p. 17; habitat in hundreds of miles of the floods. These shells and recently dead 2005, p. 8). The Texas pimpleback is Colorado and Guadalupe River systems. individuals indicated that the Texas likely extirpated from all of these Only two populations appear large fawnsfoot occurs in flowing water, as it streams. enough to be stable, but evidence of was never found in ponds, lakes, or recruitment in the Concho River reservoirs, suggesting that it is intolerant Guadalupe River System population is limited. The San Saba of deep, low-velocity waters created by In the Guadalupe River system, the River population may be the only artificial impoundments (Howells Texas pimpleback has been extirpated remaining recruiting population of 2010d, p. 3). The recently discovered from nearly the entire reach of the Texas pimpleback. Two additional live population in the Brazos River mainstem Guadalupe, San Antonio, and populations are represented by one or indicates that the species occurs in Blanco Rivers. Very small populations two individuals; all populations are rivers with soft, sandy sediment with remain only in the lower Guadalupe and highly disjunct. moderate water flow (Randklev and

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00011 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62176 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

Lundeen 2010, p. 1; Randklev et al. Texas fawnsfoot in the Colorado River Palo Pinto County downstream to Fort 2010a, p. 298; Johnson 2011, p. 1). basin is in the San Saba River, where a Bend County (Randklev et al. 2010c, pp. population persists. 2–4; Burlakova and Karatayev 2010b, p. Distribution and Abundance In the mainstem Colorado River, the 1; OSUM 2011e, p. 1). While the species Historical Distribution Texas fawnsfoot historically occurred appears to have retained its range from Wharton County upstream into the The Texas fawnsfoot is endemic to the through the length of the Brazos River, headwaters (Randklev et al. 2010c, p. 4; Brazos and Colorado Rivers of central occurrences are represented by very few OSUM 2011e, p. 1). Surveys throughout Texas (Howells et al. 1996, p. 143; live or recently dead individuals. In the the upper Colorado River between 1993 upper Brazos River in Palo Pinto and Randklev et al. 2010a, p. 297). From the and 2009 yielded no evidence of Texas 1960s to the 1990s, malacologists Parker Counties, two live individuals fawnsfoot (Howells 1994, pp. 20–21, 29; were found at each of two sites in 1996, working in central Texas found few 1996, pp. 20–21, 23; 1997a, pp. 27, 31, individuals and few new population as well as numerous shells (Howells 34–35; 1998, p. 10; 2000a, p. 27; 2002a, 1997a, pp. 16, 17). A survey in 2000 locations (Howells 2010d, p. 6). p. 6; 2004, p. 7; Burlakova and Historical records suggest the Texas yielded no evidence of Texas fawnsfoot Karatayev 2010a, p. 16), except for one in this area (Howells 2001, p. 19). fawnsfoot inhabited much of the recently dead individual found in 1999 Colorado River, from Wharton County Nearby, in Somervell County, four in San Saba County when the entire recently dead individuals were found in upstream as far as the North Fork river was dewatered and all mussels Concho River in Sterling County, as the mainstem Brazos River in 1996 were eliminated from the area (Howells (Howells 1997a, pp. 18–19. In 2007, well as throughout the Concho, San 2000a, pp. 25–26; 2009, p. 17). The lack Saba, and Llano Rivers and Onion Creek only one old shell was found in the of evidence of the species since that same area (Burlakova and Karatayev within the Colorado River basin time indicates that the population may (Howells 2010d, p. 4; Randklev et al. 2010b, p. 1). have been lost. In the lower Colorado Surveys in Milam and Falls Counties 2010b, p. 24). In the Brazos River, the River in Colorado County, several old species occurred from Fort Bend County have not yielded any evidence of Texas shells of Texas fawnsfoot were found at fawnsfoot, indicating the species has upstream to the lower reaches of the several sites in 1996 (Howells 1997a, p. Clear Fork Brazos River in Shackelford been extirpated from this section of the 35), and, subsequently in 2009, two live Brazos River (Howells 1995, p. 17; 1999, County, as well as in the Leon River, individuals were discovered (Johnson Little River, San Gabriel River, Deer pp. 12–13). 2011, p. 1). The population was later In the middle Brazos River, Texas Creek, and Yegua Creek (Howells 2010d, estimated to be approximately 2,800 fawnsfoot persists in low numbers in pp. 4–5; Randklev et al. 2010b, p. 24). individuals, with individuals ranging in the vicinity of Brazos County. One live Species reports from the Trinity River size from 21 to 38 mm (0.8–1.5 in) individual was found in 1994 (Howells and other east Texas locations are of (Burlakova and Karatayev 2010a, p. 17), 1996, pp. 17–18), representing the first misidentified fawnsfoot (Truncilla indicating that reproduction and live collection of the species anywhere donaciformis) (Howells 2010d, p. 4). recruitment is occurring. since the 1970s. In 1999, numerous Texas fawnsfoot were not known to Current Distribution recently dead Texas fawnsfoot of mixed occur in the San Saba River until a sizes and ages were found at several Relatively few Texas fawnsfoot have single live individual was collected in sites in Burleson and Brazos Counties been documented since this species was 2011 (Burlakova and Karatayev 2011, p. (Howells 2000a, pp. 21–22), indicating a first described in 1859, and very few 6). Additional surveys yielded 16 Texas recruiting population existed in the live individuals have been found in fawnsfoot of various ages collected at area. The species has been documented recent decades (Randklev et al. 2010a, the site (Randklev 2011b, p. 1), here in repeated surveys in 2000, 2003, p. 297). All of these animals were flood indicating a persistent, recruiting and 2006 (Howells 2001, p. 22; deposited on gravel bars and near death population. just prior to collection (Randklev et al. Texas fawnsfoot is presumed Karatayev and Burlakova 2008, p. 7; 2010a, p. 297), preventing information extirpated from the remainder of the Howells 2009, p. 17), indicating that the from being gathered about population Colorado River basin. Although species continues to persist in the area. size, preferred habitat, and other historical records exist in the North The first account of a living parameters. A live population of Texas Concho, Concho, and Llano Rivers and population of Texas fawnsfoot (animals fawnsfoot was not discovered until 2008 in Onion Creek (Randklev et al. 2010c, living in situ rather than deposited on in the Brazos River near its confluence p. 4), numerous surveys of these streams or near the banks by floods) occurred in with the Navasota River (Randklev et al. indicate the extirpation of the species 2008 in the lower Brazos River near its 2010a, p. 297). A second live population (Howells 1994, pp. 5–6; 1995, pp. 22– confluence with the Navasota River was found in 2009 in the Colorado River 25, 28–29; 1996, pp. 21–22; 1998, pp. (Randklev et al. 2010a, p. 297). Ten live (Johnson 2009, p. 1). These two 14–17; 1999, pp. 15–16; 2000a, pp. 23, individuals were collected, and all were locations contain the only confirmed 25; 2001, p. 27; 2005, p. 9; Burlakova small, indicating successful populations of the species to date. and Karatayev 2011, p. 6). reproduction and recent recruitment. Evidence of other remnant populations An additional Texas fawnsfoot was has also been found in the Clear Fork Brazos River System found in this area in 2011 (Randklev Brazos River, San Saba River, and Deer In the Brazos River system, the Texas 2011a, p. 1). Creek. fawnsfoot persists in the mainstem The farthest downstream collection of Brazos River, Clear Fork Brazos River, Texas fawnsfoot in the Brazos River in Colorado River System Navasota River, and possibly in Deer recent years was in Austin and Waller The Texas fawnsfoot has been Creek. The species has been extirpated Counties, when one live individual was eliminated from almost all of the from the Leon River, Little River, San found in 2006 (Karatayev and Burlakova Colorado River system. Live individuals Gabriel River, and Yegua Creek. 2008, p. 39). It is likely the species were found in the lower mainstem In the mainstem Brazos River, the occurs sporadically through the section Colorado River in 2009, and the only Texas fawnsfoot historically occurred of the Brazos River between Brazos and other evidence of current occurrence of throughout the length of the river, from Austin Counties.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00012 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62177

Texas fawnsfoot was first discovered impoundments is a common threat to all regime, scouring and erosion of stream in the Navasota River in 2011, when five species, so a full description of the channels, reduced dissolved oxygen three individuals were found in threat was provided for the Texas levels and water temperatures, and Washington and Grimes Counties fatmucket, and for the remaining species changes in resident fish assemblages (Randklev 2011a, p. 1). Previous surveys the initial description was referenced (Williams et al. 1992, p. 7; Layzer et al. had not yielded evidence of the species with species-specific information 1993, p. 69; Neves et al. 1997, pp. 63– in this river (Howells 2001, p. 23). provided, as available. 64; Pringle et al. 2000, pp. 810–815; In Deer Creek, a tributary to the Watters 2000, pp. 265–266). Numerous Five-Factor Evaluation for Texas Brazos River in Falls County, a recently dams have been constructed throughout Fatmucket dead Texas fawnsfoot was collected in the Colorado, Guadalupe, Brazos, and 2006 (Burlakova and Karatayev 2010b, Information pertaining to the Texas Nueces-Frio River systems within the p.1), despite previous surveys that fatmucket in relation to the five factors range of all five mussels addressed in yielded no evidence of the species provided in section 4(a)(1) of the Act is this finding (Stanley et al. 1990, p. 61). (Howells 1999, p. 12). discussed below. Population losses due to the effects of Additionally, a Texas fawnsfoot Factor A. The Present or Threatened dams and impoundments have likely population persists in the Clear Fork Destruction, Modification, or contributed more to the loss of diversity Brazos River. Recently dead Texas Curtailment of Its Habitat or Range. and abundance of freshwater mussels fawnsfoot have been collected in several The decline of mussels in Texas and across Texas, including the Texas locations along the length of the river, across the United States is primarily the fatmucket, than any other factor. Stream in Shackelford, Stephens, and Young result of habitat loss and degradation habitat throughout nearly all of the Counties (Randklev et al. 2010c, p. 4; (Neves 1991, pp. 252, 265; Howells et al. range of Texas fatmucket has been Randklev 2011, pers. comm.). Several 1996, pp. 21–22). Chief among the affected by numerous impoundments, other tributaries to the Brazos River that causes of mussel decline in Texas are leaving generally short, isolated patches historically contained Texas fawnsfoot the effects of impoundments, of remnant habitat between dams. appear to no longer support the species sedimentation, dewatering, sand and Impoundments have resulted in after numerous surveys reveal no living gravel mining, and chemical profound changes to the nature of the or dead individuals, including the Leon contaminants (Neck 1982a, pp. 33–35; rivers, primarily replacing free-flowing River (Howells 1994, pp. 18–20; 1997a, Howells et al. 1996, pp. 21–22; river systems with a series of large pp. 19–20), the Little River (Howells Winemiller et al. pp. 17–18). These reservoirs. 1997a, pp. 22–23), the San Gabriel River threats are discussed below. There are no natural lakes within the (Howells 1997a, p. 23), and Yegua Creek Impoundments range of the Texas fatmucket, nor has it (Howells 1997a, pp. 24, 25–26; 1999, p. ever been found in reservoirs. Surveys 14; 2001, p. 22; 2004, p. 6). A major factor in the decline of of the reservoirs on the Guadalupe and freshwater mussels across the United Colorado Rivers have been ongoing Summary States has been the large-scale since at least 1992, and no evidence of The Texas fawnsfoot has declined impoundment of rivers (Vaughn and live or dead Texas fatmucket has been rangewide and is now known from only Taylor 1999, p. 913). Dams are the found in any reservoir (Howells 1994, five populations. The species has been source of numerous threats to pp. 1–20; 1995, pp. 1–50; 1996, pp. 1– extirpated from nearly all of the freshwater mussels: They block 45; 1997a, pp. 1–58; 1998, pp. 1–30; Colorado River basin and from much of upstream and downstream movement of 1999, pp. 1–34; 2000a, pp. 1–56; 2001, the Brazos River basin. Of the species by blocking host fish movement; pp. 1–50; 2002a, pp. 1–28; 2003, pp. 1– populations that remain, only the they eliminate or reduce river flow 42; 2004, pp. 1–48; 2005, pp. 1–23; Colorado, San Saba, and Brazos River within impounded areas, thereby 2006, pp. 1–106; Karatayev and populations are likely to be stable and trapping silts and causing sediment Burlakova 2008, pp. 1–47; Burlakova recruiting; the remaining populations deposition; and dams change and Karatayev 2010a, pp. 1–30; 2011, are disjunct and restricted to short downstream water flow timing and pp. 1–8), further indicating this species stream reaches. temperature, decrease habitat is not tolerant of impoundments. heterogeneity, and affect normal flood Impoundments occur throughout the Five-Factor Evaluation and Findings patterns (Layzer et al. 1993, pp. 68–69; range of the Texas fatmucket. The Texas fatmucket, golden orb, smooth Neves et al. 1997, pp. 63–64; Watters majority of the Nueces-Frio, Guadalupe, pimpleback, Texas pimpleback, and 2000, pp. 261–264; Watters 1996, p. 80). San Antonio, Colorado, and Brazos Texas fawnsfoot all occur in central Within reservoirs (the impounded Rivers, as well as many tributaries, are Texas across four major river basins waters behind dams), the decline of now impounded. There are 31 major (Brazos, Colorado, Guadalupe, and freshwater mussels has been attributed reservoirs within the Colorado River Nueces-Frio River basins). These species to sedimentation, decreased dissolved basin, with another reservoir depend on similar physical and oxygen, and alteration of resident fish (Goldthwaite Reservoir) being biological features and on the successful populations (Neves et al. 1997, pp. 63– considered on the Colorado River in functioning of riverine ecosystems to 64; Pringle et al. 2000, pp. 810–815; Mills and San Saba Counties; this survive. Many of the species face the Watters 2000, pp. 261–264). Dams reservoir was the number one same or very similar threats. For each significantly alter downstream water recommendation in the water plan for species, we identified and evaluated all quality and stream (Allan and the region (Texas Water Development the factors that may be threatening the Flecker 1993, p. 36; Collier et al. 1996, Board (TWDB) 2011, p. 4–85). There are species. However, to avoid redundancy pp. 1, 7) resulting in negative effects to 29 reservoirs throughout the Guadalupe of information when the analysis of the tailwater (the area downstream of a River basin and 34 reservoirs threats is the same between species, we dam) mussel populations (Layzer et al. throughout the San Antonio River basin, referenced the reader to the initial 1993, p. 69; Neves et al. 1997, p. 63; each with a storage capacity of 3000 description of the common threats. For Watters 2000, pp. 265–266). Below acre-feet or more, and many smaller example, the degradation of habitat and dams, mussel declines are associated reservoirs (Exelon 2010, p. 2.3–4). The habitat loss due to dams and with changes and fluctuation in flow majority of the large dams were

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00013 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62178 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

constructed for power generation, flood from one with many different species to reproduce less frequently, if at all control, and water supply, primarily by a community dominated by one to (Layzer et al. 1993, p. 69). Low water the Lower Colorado River and several very common species (Neck temperatures can also significantly Guadalupe-Blanco River Authorities, 1982b, p. 174). Texas fatmucket does delay or prevent metamorphosis beginning in the early twentieth century not occur in reservoirs, indicating it is (Watters and O’Dee 1999, pp. 454–455) (Guadalupe-Blanco River Authority not tolerant of lentic conditions, and it and glochidial release, which is often 2011, p. 1; Lower Colorado River is now extirpated from impounded areas triggered by water temperature (Watters Authority (LCRA) 2011a, p. 1). These, where it occurred prior to inundation. and O’Dee 2000, p. 136). and numerous smaller dams, occur The inundation of stream habitat by Similar changes in water temperatures throughout the Colorado and Guadalupe impoundments is a likely cause of the downstream of dams may be responsible River basins and have resulted in reduction in the distribution of the for the loss of some Texas fatmucket ongoing destruction and modification of Texas fatmucket. The presence of the populations. For example, Canyon Texas fatmucket habitat and the impoundments has caused the Reservoir on the Guadalupe River in curtailment of its range. permanent loss of Texas fatmucket Comal County is a deep impoundment Dams threaten freshwater mussels in habitat throughout its range. built in 1964 that has hypolimnetic several ways. First, they can prevent the The loss of seven freshwater mussel water releases. Temperature monitoring movement of freshwater mussel host species native to Texas, including Texas stations throughout the Guadalupe River fish. The overall distribution of mussels fatmucket and golden orb, due to basin show that maximum temperatures is a function of the dispersal of their impoundment construction was above Canyon Reservoir averaged 29.6 hosts (Watters 1996, p. 83). For documented on the Medina River (Neck degrees Celsius (°C) (85.3 degrees example, Watters (1996, p. 80) found 1989, p. 323). The Medina River was Fahrenheit (°F)); the maximum stream that the distributions of the fragile impounded in 1913 by construction of temperatures below the reservoir papershell ( fragilis) and pink Medina Dam, and now only three averaged only 19.7 °C (67.5 °F) heelsplitter (Potamilus alatus) in five different species of mussels, all of (Edwards 1978, p. 72). After midwestern rivers were determined by which are tolerant of lentic habitats, impoundment, dissolved oxygen and the presence of low-head dams. These occur in the impounded area. The water temperature dropped, with an dams were non-navigable (without bottom of Medina Lake now consists of accompanying drop in mussel numbers locks), lacked fish ladders, and varied in moderate and steep limestone slopes and species diversity (Young et al. 1976, height from 1 to 17.7 m (3 ft to 58 ft), and excessive silt deposits, whereas p. 216). According to historical museum and the host fish could not disperse before it was most likely made up of a records analyzed by Randklev et al. through them. Although the distribution combination of silt, sand, and gravel (2010b, pp. 1–32), the Texas fatmucket of mussels may depend on many substrates. Most mussels native to the once occurred in this area of the ecological factors, the evidence Medina River were unable to adapt to Guadalupe River prior to the presented in Watters (1996, pp. 79–85) the change in flowing water and construction of Canyon Reservoir. The illustrates that dams as small as 1 m (3 substrate conditions (Neck 1989, p. Guadalupe River and in ft) high can limit the distribution of 323), including the Texas fatmucket, Comal and Kendall Counties were mussels. There are many dams that which is no longer found in the river. surveyed in 2009, and no live or occur throughout the range of the Texas Mussels downstream of recently dead Texas fatmucket were fatmucket that lack fish ladders and may impoundments are often affected found (Burlakova and Karatayev 2010a, be a barrier to the movement of fish through changes in fish host pp. 12–13). We reasonably conclude hosts and, therefore, the distribution of availability, water quality (particularly that the loss of the Texas fatmucket from mussels. Because the Texas fatmucket lower water temperatures), habitat this area was caused by the changes to populations are all separated by dams of structure, and stream channel scouring the aquatic habitat of the Guadalupe various sizes that are not passable by (Vaughn and Taylor 1999, p. 916). The River from the effects of Canyon fish, the mussel is unable to disperse release of cold water from the Reservoir. Many of the dams throughout from its current occupied range through hypolimnion (deeper and colder layer of the range of Texas fatmucket have host fish migration. water in reservoirs) can decrease the hypolimnetic water releases, including Dams also alter aquatic habitat within occurrence of fish species adapted to Canyon Reservoir on the Guadalupe the resulting impoundments. It is well warm water and increase the occurrence River (Magnelia 2001, p. 1), and Inks documented that many mussel species of fish species adapted to colder water Lake, Lake LBJ (Schnoor and Fruh 1979, that are adapted to flowing water stream (Edwards 1978, pp. 73–75). This p. 506), and Lake Travis (Texas Natural environments do poorly in the altered changes the species composition of Resource Conservation Commission aquatic conditions found within suitable host fish and may prevent 2001, p. 4) on the Colorado River, impoundments (Williams et al. 1992, p. mussels from completing an essential among others. We anticipate that 7; Vaughn and Taylor 1999, p. 913). part of their reproductive cycle. This changes in water temperatures from Once a dam is constructed, the original has been demonstrated by the water released by these and other river channel upstream remains intact extirpation of mussel species from reservoirs also alter mussel habitats in but under much deeper water with several rivers on the eastern seaboard of streams, causing the elimination of much lower velocities. As water the United States, which has been mussel populations downstream. velocity decreases, water loses its ability linked to the disappearance of In addition to the temperature of to carry sediment; sediment falls to the appropriate host fish; the reintroduction water released from dams, highly substrate, eventually smothering of the host fish to rivers has enabled fluctuating, turbulent tailwaters devoid mussels that cannot adapt to soft mussel species to recolonize areas (Kat of sediment will scour the riverbed substrates (Watters 2000, p. 263). Over and Davis 1984, p. 174). In addition, downstream of dams, rendering the area time, the original mussel species because mussel reproduction is without mussel habitat (Layzer et al. composition of the stream channel may temperature dependent (Watters and 1993, p. 69). Depending on the use of be eliminated or changed in favor of silt- O’Dee 1999, pp. 455–456), it is likely the dam, water levels may fluctuate on tolerant species (Watters 2000, p. 264). that individual mussels living in cold a regular interval (for hydroelectric The mussel community may be altered waters downstream of dam releases may purposes) or at random (for flood

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00014 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62179

control) (Watters 2000, p. 265). On the Dam construction also fragments the degrading (scouring) channels; and Colorado River, Inks Lake, Lake Marble range of Texas fatmucket, leaving changes in channel position that may Falls, , Lake Austin, Lake remaining habitats and populations leave mussels stranded (Brim Box and Travis, and Lady Bird Lake are each isolated by the structures as well as by Mossa 1999, pp. 109–112). used for one or both of these purposes. extensive areas of deep uninhabitable, Increased sedimentation and siltation Mortality of another rare mussel species impounded waters. These isolated may explain, in part, why Texas in Texas, the Texas heelsplitter populations are unable to naturally fatmucket appear to be experiencing (Potamilus amphichaenus) was recolonize suitable habitat that may be recruitment failure in some streams. attributed to scheduled dewatering of impacted by temporary but devastating Interstitial spaces (small openings the Neches River below B.A. Steinhagen events, such as severe drought, floods, between rocks and gravels) in the Reservoir in east Texas (Neck and or pollution. Dams impound river substrate provide essential habitat for Howells 1994, p. 15). habitats throughout almost the entire juvenile mussels. When clogged with Fluctuating water levels below dams range of the species, and these sand or silt, interstitial flow rates and also result in dramatic changes in water impoundments have left short and spaces may become reduced (Brim Box velocity. Downstream of Lake isolated patches of remnant habitat, and Mossa 1999, p. 100), thus reducing Livingston on the Trinity River in east typically between impounded reaches. juvenile habitat availability. Juvenile Texas, for example, high-volume water In summary, the widespread freshwater mussels, including Texas discharges and abrupt stoppages of flow construction of dams has affected the fatmucket juveniles, burrow into resulted in a river bed composed of Texas fatmucket throughout its range by interstitial substrates, making it large rocks and shifting sand (Neck and significantly altering stream habitat both particularly susceptible to degradation Howells 1994, p. 14); these kinds of upstream and downstream of the dams of this habitat. habitat changes would be inhospitable by changing fish assemblages, water Even in 1959, both the Colorado and to Texas fatmucket below the dams depths and velocities, water Guadalupe Rivers were noted as having within its range. In some rivers this temperature, dissolved oxygen, high sedimentation rates from agricultural activities (Soil Conservation unstable zone may be extensive. For substrate, and stream channels. The Service 1959, pp. 56, 59). example, on the Brazos River effects of dams are ongoing and Approximately 40 percent of U.S. river downstream of Possum Kingdom continue to negatively impact the Texas miles do not meet Clean Water Act Reservoir in Texas exhibited unstable fatmucket rangewide. Because of this standards due to excessive sediment substrate for 150 km (240 mi) below the loss of habitat and its effects on the loads (Environmental Protection Agency dam (Yeager 1993, p. 68). populations, we find that the effects of impoundments are a threat to the Texas (EPA) 2000, p. 1), with agricultural In one study of the downstream fatmucket. activities being the primary source of effects of dams, Vaughn and Taylor sediment in streams (Waters 1995, p. (1999, p. 915) found a strong, gradual, Sedimentation 170). In general, sedimentation, linear increase in mussel species Siltation and general sediment runoff resulting from unrestricted access by richness and abundance at sites on the is a pervasive problem in streams and livestock, has been shown to be a Little River in Oklahoma downstream has been implicated in the decline of significant threat to many streams and from Pine Creek Reservoir. Their stream mussel populations (Ellis 1936, their mussel populations (Fraley and research revealed that mussel species pp. 39–40; Vannote and Minshall 1982, Ahlstedt 2000, p. 193). A primary land richness and total abundance did not p. 4105; Dennis 1984, p. ii; Brim Box use throughout the range of the Texas begin to rebound until 20 km (12 mi) and Mossa 1999, p. 99; Fraley and fatmucket is grazing by cattle, sheep, downstream of the impoundment and Ahlstedt 2000, pp. 193–194). Specific and goats (Hersh 2007, p. 11). Soil did not peak until 53 km (33 mi) biological effects on mussels from compaction, which reduces vegetative downstream. They noted the most excessive sediment include reduced growth, from intensive grazing may obvious difference since reservoir feeding and respiratory efficiency from reduce infiltration rates and increase construction has been the alteration of clogged gills (Ellis 1936, p. 40), runoff and erosion, and trampling of the flow and temperature regimes, disrupted metabolic processes, reduced riparian vegetation increases the which gradually return to pre- growth rates, increased substrate probability of erosion (Armour et al. impoundment levels with downstream instability, limited burrowing activity 1994, p.10; Brim Box and Mossa 1999, distance from the dam. These alterations (Marking and Bills 1979, pp. 208–209; p. 103). appear to have produced an extinction Vannote and Minshall 1982, p. 4106), Another cause of increased sediments gradient of mussels that is most severe physical smothering, and disrupted host in streams is widespread brush removal, near the dam (Vaughn and Taylor 1999, fish attractant mechanisms (Hartfield such as that of the native plant, p. 915). We expect similar effects on the and Hartfield 1996, p. 373). The primary Juniperus ashei (Ashe juniper), Texas fatmucket and other Texas effects of excess sediment on mussels throughout central Texas. Juniperus mussels downstream of dams. are sublethal, with detrimental effects ashei removal can cause a marked In one area on the Guadalupe River in not immediately apparent (Brim Box increase in sediment runoff into streams Kerr County, a Texas fatmucket and Mossa 1999, p. 101). (Greer 2005, p. 76). The Texas State Soil population once existed directly below The physical effects of sediment on and Water Conservation Board has a a small dam (Howells 1997a, p. 36), mussel habitats are multifold and funding program specifically for indicating the effects of the dam include changes in suspended material Juniperus ashei removal in Blanco, construction and closure were not load; changes in streambed sediment Gillespie, Kerr, Kendall, and Travis immediately lethal. However, the composition from increased sediment Counties (Gillespie County Soil and population has been presumed production and runoff in the watershed; Water Conservation District 2011, p. 1), extirpated since 1998 (Howells 2006, p. changes in the form, position, and which includes the watersheds of three 71), and it is likely that fluctuating stability of stream channels; changes in known Texas fatmucket populations in downstream flows from the dam water depth or the width-to-depth ratio, Live Oak Creek, Threadgill Creek, and contributed to the loss of this which affects light penetration and flow the upper Guadalupe River. In one population. regime; actively aggrading (filling) or example, Howells (2010f, p. 6) noted

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00015 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62180 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

increased sediment deposition after habitat if construction or maintenance within the Colorado River basin were widespread Juniperus ashei removal of the transmission line requires extremely low during this time due to upstream of the Texas fatmucket removal of vegetation within the the drought (Clean Water Action 2011, population in Live Oak Creek. riparian zone and that removal results p. 1), as were river levels. Minimal to no Sedimentation may become an in an increase in sediment runoff into flow was recorded at numerous sites increasing threat to the Texas fatmucket Live Oak Creek and the Guadalupe and within the basin (U.S. Geological Survey in the Colorado and Guadalupe River San Saba Rivers (Clary 2010, pp. 7, 9, (USGS) 2011a, p. 1). Four of the five basins as the Austin and San Antonio 15). Similar infrastructure development current sites of the Texas fatmucket may metro areas continue to expand. activities to accommodate Texas have had very low flows during the Activities associated with urbanization, population growth are expected to be 2009 drought, including populations in such as road construction and increased undertaken across the species’ range the San Saba, Llano, Pedernales, and impervious surfaces (surfaces that do and will likely lead to additional Guadalupe Rivers (Howells 2010c, pp. not allow infiltration of rain water), can sources of sediment in the streams 9–10). As low flows persist, mussels be detrimental to stream habitats (Couch inhabited by the Texas fatmucket. face oxygen deprivation, increased and Hamilton 2002, p. 1). Runoff from Streams occupied by Texas fatmucket water temperature, and, ultimately, increased impervious surfaces increases are subject to increasing levels of stranding (Golladay et al. 2004, p. 501). sediment loads in streams and sedimentation from agricultural Only the Llano River has been surveyed destabilizes stream channels (Pappas et activities, instream sand and gravel since 2009, and the species persists in al. 2008, p. 151). Impervious surfaces mining, vegetation removal, and that river (Burlakova and Karatayev also result in channel instability by urbanization. All of these activities are 2011, p. 1). Central Texas is currently accelerating stormwater runoff, which ongoing throughout the range of the experiencing another extreme drought, increases bank erosion and bed Texas fatmucket and are unlikely to with rainfall between October 2010 and scouring, thereby further increasing decrease, resulting in significant threats July 2011 being the lowest on record downstream sedimentation (Brim Box to the Texas fatmucket. during those months (LCRA 2011c, p. and Mossa 1999, p. 103). While erosion Dewatering 1), and the effects of this drought are and sedimentation associated with road being observed but are not yet fully construction may be temporary, the River dewatering can occur in several known. As of the date of publication of existence of road crossings is shown to ways: Anthropogenic activities such as this finding, the Llano River has nearly have ongoing impacts to mussel habitat. surface water diversions and stopped flowing (Mashhood 2011, p. 1); For example, in the Guadalupe River, groundwater pumping, and natural this has undoubtedly affected Texas road crossings were found to cause a events, such as drought. Surface water fatmucket populations in this river. long-term increase in sedimentation diversions and groundwater pumping We do not know the extent of the both upstream and downstream, as can lower water tables, reducing river impacts of stream dewatering on the channel constriction reduced flow flows and reservoir levels. When water Texas fatmucket; however, because this upstream, causing sediment deposition, levels in streams and reservoirs are species’ populations are so small and and runoff from the road increased lowered dramatically, it can result in isolated, the loss of numerous sedimentation downstream (Keen- mussels being stranded and dying in individuals at a site can have dramatic Zebert and Curran 2009, p. 301). Urban previously wetted areas. This is a consequences to the population. development activities may also affect particular concern within and below Hydropower facilities, construction, streams and their mussel fauna where reservoirs where water levels are surface water diversions, groundwater adequate streamside buffers are not managed for purposes that result in pumping, and drought are occurring maintained and erosion from adjacent water levels in the reservoir or throughout the range of the Texas land is allowed to enter streams downstream to rise or fall in very short fatmucket; therefore, the effects of (Brainwood et al. 2006, p. 511). periods of time, such as when dewatering are ongoing and unlikely to Large projects that reduce vegetative hydropower facilities release water decrease in the future, resulting in cover within the watersheds supporting during peak energy demand periods. significant threats to the Texas Texas fatmucket populations can also Rivers can also be dewatered to expedite fatmucket. increase sedimentation flowing into construction activities, which happened streams. For example, the Lower in the upper Guadalupe River in Kerr Sand and Gravel Mining Colorado River Authority Transmission County in 1998 for bridge construction; Sand and gravel mining (removing Services Corporation (LCRA TSC) is numerous Texas fatmuckets were bed materials from streams) has been proposing to construct two new 345- exposed and desiccated (dried out and implicated in the destruction of mussel kilovolt (kV) electric transmission line died) (Howells 1999, pp. 18–19). populations across the United States facilities between Tom Green (in the Drought can also severely affect Texas (Hartfield 1993, pp. 136–138). Sand and Colorado River basin near San Angelo) fatmucket populations. For example, gravel mining causes stream instability and Kendall Counties (in the Guadalupe near-record dry conditions in 2008, by increasing erosion and turbidity (a River basin north of San Antonio) to followed by a pattern of below-normal measure of water clarity) and causing provide electrical power to rainfall during the winter and spring of subsequent sediment deposition accommodate increased human 2009, led to one of the worst droughts downstream (Meador and Layher 1998, populations (Clary 2010, p. 1). All of the in recorded history for most of central pp. 8–9). These changes to the stream proposed project routes occur within Texas, including the range of the Texas can result in large-scale changes to the range of the Texas fatmucket. Two fatmucket (Nielsen-Gammon and aquatic fauna, by altering habitat and proposed segments would cross through McRoberts 2009, p. 2). This drought’s affecting spawning of fish, mussels, and Live Oak Creek, one through the San severity was exacerbated by abnormally other aquatic species (Kanehl and Lyons Saba River, and one through the upper high air temperatures, a likely effect of 1992, pp. 4–11). Guadalupe River; all of these streams climate change, which has increased Sedimentation and increased contain populations of the Texas average air temperatures in Texas by at turbidity can accrue from instream fatmucket. The proposed project could least 1 °C (1.8 °F) (Nielsen-Gammon and mining activities. In the Brazos River, a negatively affect Texas fatmucket McRoberts 2009, p. 22). The reservoirs gravel dredging operation was

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00016 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62181

documented as depositing sediment as activities occur over a long period of p. 205). Complete recovery of benthic far as 1.6 km (1 mi) downstream time, destabilizing habitat and altering communities may be a matter of years, (Forshage and Carter 1973, p. 697). substrates and banks both upstream and with communities in the meantime Accelerated streambank erosion and downstream. Altered habitat will cause consisting solely of pollutant-tolerant downcutting of streambeds are common a decrease in the likelihood of organisms (Bhattacharyya et al. 2002, p. effects of instream sand and gravel recolonization by mussels after the 205). Oil spills can occur from on-site mining, as is the mobilization of fine activity has been completed. Therefore, accidents (tank, pipeline spills) or from sediments during sand and gravel the effects of sand and gravel mining are tanker truck accidents within extraction (Roell 1999, p. 7). an ongoing threat to the Texas watersheds occupied by Texas Mining activities may threaten some fatmucket. fatmucket. For example, 450 gallons of local Texas fatmucket populations. oil were spilled into Lake Bastrop, a Chemical Contaminants Currently, one mining operation is reservoir on a tributary to the Colorado permitted near the population in Onion Chemical contaminants are River, in February 2011 (Cihock 2011, Creek (TPWD 2008c, p. 1), and another ubiquitous throughout the environment p. 1). in the Llano River watershed in Kimble and are a major reason for the decline Exposure of mussels to persistent low County (TPWD 2008a, p. 1). The permits of freshwater mussel species nationwide concentrations of contaminants likely to allow for repeated removal of sand and (Richter et. al. 1997, p. 1081; Strayer et be found in aquatic environments can gravel at various instream locations. al. 2004, p. 436; Wang et al. 2007a, p. also adversely affect mussels and their Two additional mining operations occur 2029). Chemicals enter the environment populations. Such concentrations may in historical habitat for the species—the through both point and nonpoint not be immediately lethal, but over time mainstem Colorado River (U.S. Army discharges, including spills, industrial can result in mortality, reduced Corps of Engineers (USACE) 2010, p. 2) sources, municipal effluents, and filtration efficiency, reduced growth, and Johnson Creek (TPWD 2007a, p. 1). agriculture runoff. These sources decreased reproduction, changes in In areas where repeated mining contribute organic compounds, heavy enzyme activity, and behavioral changes occurs, an upstream progression of metals, pesticides, herbicides, and a to all mussel life stages (Naimo 1995, channel degradation and erosion (called wide variety of newly emerging pp. 351–352; Baun et al. 2008, p. 392). headcutting) can occur (Meador and contaminants to the aquatic Frequently, procedures that evaluate the Layher 1998, p. 8). Headcutting may environment. As a result, water quality ‘‘safe’’ concentration of an move miles upstream in a zipper-like can be degraded to the extent that environmental contaminant (for fashion as the upper boundary of the mussel populations are adversely example, national water quality criteria) modified area collapses. Headcutting affected. do not have data for freshwater mussel can be found within the majority of Chemical and oil spills can be species or do not consider data that are rivers and streams in Texas, including especially devastating to mussels available for freshwater mussels (March within the Texas fatmucket’s current because they may result in exposure of et al. 2007, pp. 2066–2067, 2073). and historical range (Kennon et al. 1967, a relatively immobile species to elevated One chemical that is particularly toxic p. 22). Headcuts induced by sand and concentrations that far exceed toxic to early life stages of mussels is gravel mining can cause dramatic levels. Acute and chronic exposure to ammonia. Sources of ammonia include changes in streambank and channel oil spills in freshwater systems is largely agricultural activities ( feedlots shape that may affect instream flow, understudied; therefore, little and nitrogenous fertilizers), municipal water chemistry and temperature, bank information is available on effects of oil wastewater treatment plants, and stability, and siltation (Meador and spills on freshwater ecosystems (Harrel industrial waste (Augspurger et al. 2007, Layher 1998, p. 8), all of which are 1985, p. 223; Bhattacharyya et al. 2002, p. 2026), as well as precipitation and harmful to freshwater mussels. Mussels p. 205). Oil is retained much longer in natural processes (decomposition of are particularly vulnerable to channel marshes and other low-energy organic nitrogen) (Goudreau et al. 1993, degradation and sedimentation environments, such as slow-moving p. 212; Hickey and Martin 1999, p. 44; processes associated with headcutting streams and rivers, than on wave-swept Augspurger et al. 2003, p. 2569; Newton due to their immobility (Pringle 1997, coasts (Bhattacharyya et al. 2002, p. 2003, p. 2543). Therefore, ammonia is p. 429). 205). Oils have been found in sediments considered a limiting factor for survival In addition to headcutting, mines that at low energy sites as much as 5 years and recovery of some mussel species are located near stream channels are after the occurrence of spills, and they due to its ubiquity in aquatic subject to the gravel pit being captured may be released into the water column environments, high level of toxicity, and by the stream during flood events or due long after the initial spill. Oil may have because the highest concentrations to gradual channel migration (Simmang various chronic effects on water-column typically occur in mussel microhabitats and Curran 2006, p. 1). For example, and benthic (bottom-dwelling) species. (Augspurger et al. 2003, p. 2574). In two gravel mines along the Colorado These effects include sensory addition, studies have shown that River downstream of Austin were disruption, behavioral and ammonia concentrations increase with inundated; one by stream channel developmental abnormalities, and increasing temperature and low-flow migration in 1984, one by stream reduced fertility (Bhattacharyya et al. conditions (Cherry et al. 2005, p. 378; capture in 1991 (Simmang and Curran 2002, p. 205). Oil spilled on the water Cooper et al. 2005, p. 381), which may 2006, p. 1). Once captured by the surface may also limit oxygen exchange, be exacerbated during low-flow events mainstem river, gravel mines contribute coat the gills of aquatic organisms, and in streams. Within the range of Texas large amounts of suspended sediment to cause pathological lesions on fatmucket, high ammonia levels are the river, causing additional turbidity respiratory surfaces, thereby affecting common, either chronically, such as in and sedimentation and further respiration in aquatic organisms. Effects Elm Creek, which is listed as impaired degrading mussel habitat. of oil on freshwater mussels may result due to high ammonia concentrations Two Texas fatmucket populations in from oil settling on the sediment (Texas Commission on Environmental the mainstem Colorado River and surfaces and accumulating in the Quality (TCEQ) 2010a, p. 294), or due to Johnson Creek may be currently affected sediment. This can prevent invertebrate spills. A wastewater leak in August by sand and gravel mining. These colonization (Bhattacharyya et al. 2002, 2010 spilled approximately 380,000

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00017 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62182 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

liters (L) (100,000 gallons (gal)) of Valenti et al. 2005, p. 1244). Metals timing of agricultural pesticide sewage into Elm Creek (Bramlette and occur in industrial and wastewater applications in the spring often Cosel 2010, p. 1); ammonia is present in effluents and are often a result of coincides with the reproductive and high concentrations in sewage, among atmospheric deposition from industrial early life stages of mussels, which may other pollutants. Additionally, a sewage processes and incinerators. Studies have increase the vulnerability of mussels to spill in 2008 in Onion Creek discharged shown that copper can have toxic effects pesticides (Bringolf et al. 2007a, p. nearly 380,000 L (100,000 gal), and on glochidia and juvenile freshwater 2094). Little is known regarding the another sewage spill occurred in April mussels (Wang et al. 2007a, pp. 2036– effect of currently used pesticides to 2011 in Quinlan Creek, a tributary to the 2047; Wang et al. 2007b, pp. 2048– freshwater mussels even though some Guadalupe River near the Kerr County 2056). In the range of Texas fatmucket, pesticides, such as glyphosate (active population (MacCormack 2011, p. 1). high copper concentrations have been ingredient in Roundup®), are used High ammonia levels from chronic recorded in fish in the lower Guadalupe globally. Recent studies tested the sources as well as from spills may be River and San Antonio River (Lee and toxicity of glyphosate, its formulations, affecting Texas fatmucket populations. Schultz 1994, p. 8). While these high and a surfactant (MON 0810) used in In addition to ammonia, agricultural levels of copper in fish are not directly several glyphosate formulations, to early sources of chemical contaminants informative of the level of copper within life stages of the fatmucket (Lampsilis include two broad categories that have the habitat of the Texas fatmucket, these siliquoidea) (Bringolf et al. 2007a, p. the potential to adversely affect mussel observations demonstrate that copper 2094), a freshwater mussel closely species: Nutrients and pesticides. High levels are likely high in the lower related to the Texas fatmucket. Studies amounts of nutrients, such as nitrogen Guadalupe and San Antonio Rivers. conducted with fatmucket juveniles and and phosphorus, in streams can Because we know that copper glochidia determined that the surfactant stimulate excessive plant growth (algae contamination in water can lead to was the most toxic of the compounds and periphyton, among others), which death of mussels, we conclude that the tested and that fatmucket glochidia were in turn can reduce dissolved oxygen copper may be adversely affecting Texas the most sensitive organisms tested to levels when dead plant material fatmucket. date (Bringolf et al. 2007a, p. 2094). decomposes. Nutrient over-enrichment Mercury is another heavy metal that Roundup®, technical grade glyphosate in streams is primarily a result of runoff has the potential to negatively affect isopropylamine salt, and of fertlizer and animal manure from mussel populations, and it is widely isopropylamine were also acutely toxic livestock farms, feedlots, and heavily distributed in the environment. Mercury to juveniles and glochidia (Bringolf et fertilized row crops (Peterjohn and has been detected throughout aquatic al. 2007a, p. 2097). These commonly Correll 1984, p. 1471). Over-enriched environments as a product of municipal applied pesticides may be adversely conditions are exacerbated by low-flow and industrial waste and atmospheric affecting Texas fatmucket populations. stream conditions, such as those deposition from coal burning plants. The effects of other widely used experienced during typical summer Rainbow mussel ( iris) glochidia pesticides, including atrazine, season flows. Bauer (1988, p. 244) found have been demonstrated to be more chlorpyrifos, and permethrin, on that excessive nitrogen concentrations sensitive to mercury than juvenile glochidia and juvenile life stages have can be detrimental to the adult mussels, with the median lethal also recently been studied (Bringolf et freshwater pearl mussel (Margaritifera concentration value of 14 parts per al. 2007b, p. 2101). Environmentally margaritifera), as was evident by the billion (ppb) for glochidia, compared to relevant concentrations (concentrations positive linear relationship between 114 ppb for the juvenile life stages that may be found in streams) of mortality and nitrate concentrations. (Valenti 2005, p. 1242). The chronic permethrin and chlorpyrifos were found Also, a study of mussel life span and toxicity tests conducted determined that to be toxic to glochidia and juvenile size (Bauer 1992, p. 425) showed a juveniles exposed to mercury greater fatmucket (Bringolf et al. 2007b, pp. negative correlation between growth than or equal to 8 ppb exhibited 2104–2106). Commonly applied rate and high nutrient concentrations, reduced growth. Acute mercury toxicity pesticides are a threat to mussels as a and longevity was reduced as the was determined to be the cause of result of their widespread use. All of concentration of nitrates increased. extirpation of a diverse mussel these pesticides are commonly used on Juvenile mussels in interstitial habitats community for a 112 km (70 mi) portion agricultural lands throughout the range are particularly affected by depleted of the North Fork Holston River in of the Texas fatmucket, which may be dissolved oxygen levels resulting from Virginia (Brown et al. 2005, pp. 1455– adversely affecting the species. nutrient over-enrichment (Sparks and 1457). Mercury has been documented A potential, but undocumented, threat Strayer 1998, p. 133). The Texas throughout the Guadalupe and San to freshwater mussels, including Texas fatmucket occurs within the Concho Antonio Rivers, with particularly high fatmucket, are compounds referred to as River watershed, which has been concentrations in fish in the upper ‘‘emerging contaminants’’ that are being documented as having particularly high reaches of both rivers (Lee and Schultz detected in aquatic ecosystems at an nitrates for nearly 20 years, likely due 1994, p. 8). As with copper, we do not increasing rate. These include to intensive agriculture in the area have information on the concentration pharmaceuticals, hormones, and other (Texas Clean Rivers Program 2008, p. 2), of mercury that Texas fatmucket is being organic contaminants that have been which may be affecting the Texas exposed to in these streams, but the detected downstream from urban areas fatmucket population. higher than expected levels in fish and livestock production (Kolpin et al. Mussels are also affected by metals indicate high mercury levels in the area, 2002, p. 1202) and have been shown to (Keller and Zam 1991, p. 543) such as which may be adversely affecting Texas affect fish behavior (TCEQ 2010b, p. 3). cadmium, chromium, copper, mercury, fatmucket. In samples of the Trinity River, for and zinc, which can negatively affect Pesticides are another source of example, compounds such as biological processes such as growth, contaminants in streams. Elevated antidepressants, antihistamines, blood filtration efficiency, enzyme activity, concentrations of pesticides frequently pressure lowering medication, anti- valve closure, and behavior (Keller and occur in streams due to pesticide runoff, seizure medication, and antimicrobial Zam 1991, p. 543; Naimo 1995, pp. 351– overspray application to row crops, and compounds were all detected during a 355; Jacobson et al. 1997, p. 2390; lack of adequate riparian buffers. The 2006 study (TCEQ 2010b, pp. 27–28). A

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00018 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62183

large potential source of these emerging Impoundments occur throughout the purposes does not pose a significant contaminants is wastewater being range of the species and have far- threat to the Texas fatmucket. discharged through both permitted reaching effects both up- and Factor C. Disease and Predation. (National Pollutant Discharge downstream. Both the Colorado and Disease Elimination System (NPDES)) and non- Guadalupe River systems have permitted sites within the Colorado and experienced a large amount of Little is known about disease in Guadalupe River systems. Although sedimentation from agriculture, mining, freshwater mussels. However, disease is streams within the range of Texas urban development, and widespread believed to be a contributing factor in fatmucket have not been tested for these Juniperus ashei removal. Sand and documented mussel die-offs in other emerging contaminants, permitted gravel mining affects Texas fatmucket parts of the United States (Neves 1987, discharge sites are ubiquitous in habitat by increasing sedimentation and pp. 11–12). Diseases have not been watersheds with Texas fatmucket channel instability downstream and documented or observed during any populations, providing many causing headcutting upstream. Finally, studies of Texas fatmucket. opportunities for contaminants to chemical contaminants have been Predation impact the species. documented throughout the range of the A study in the Blanco River found species and are significant concern to Raccoons have preyed on individual that mussels may be adversely affected Texas fatmucket. Based upon our review Texas fatmuckets stranded by low by sewage effluent (Horne and McIntosh of the best commercial and scientific waters or deposited in shallow water or 1979, p. 132). Ammonia levels below data available, we conclude that the on bars following flooding or low water the outfall were three times higher than present or threatened destruction, periods (Howells 2010c, p. 12). the levels above the outfall and were modification, or curtailment of its Predation of Texas fatmucket by higher than recently determined toxicity habitat or range is an immediate threat raccoons may be occurring occasionally values of ammonia for mussels of high magnitude to the Texas but there is no indication it is a (Augsperger et al. 2003, p. 2572). The fatmucket. significant threat to the status of the river was nutrient-enriched for miles Factor B. Overutilization for species. downstream, and mussels were less Commercial, Recreational, Scientific, or Some species of fish feed on mussels, abundant below the outfall than above Educational Purposes. such as common carp (Cyprinus carpio), (Horne and McIntosh 1979, pp. 124– The Texas fatmucket is not a freshwater drum, and redear sunfish 125, 132). Texas fatmucket have not commercially valuable species and has (Lepomis microlophus), all of which are been found alive in the Blanco River never been harvested in Texas as a common throughout the range of Texas since 1978. commercial mussel species (Howells fatmucket (Hubbs et al. 2008, pp. 19, 45, Texas Commission on Environmental 2010c, p. 11), although in the Llano 53). Common species of flatworms are Quality (TCEQ) data for 2010 indicated River shells were found that were voracious predators of newly that 26 of the 98 assessed water bodies apparently collected by anglers for use metamorphosed juvenile mussels of within the Texas fatmucket’s historical as bait (Howells 1996, p. 22; 2010c, p. many species (Zimmerman et al. 2003, and current range did not meet surface 11). Additionally, the Elm Creek p. 30), including other species in the water quality standards and were population is suspected to have genus Lampsilis (Delp 2002, pp. 12–13). classified as impaired water bodies declined in part due to the publication Predation is a normal aspect of the under the Clean Water Act (Texas Clean of detailed location information, which population dynamics of a healthy Rivers Program 2010a, p. 5; 2010b, p. may have inspired collectors to visit the mussel population; however, predation 13), including Elm Creek, due to high site (Howells 2009, pp. 5–6). Scientific may amplify declines in small ammonia. These water bodies were collecting is not likely to be a significant populations. impaired with dissolved solids, nitrates, threat to the status of the species, bacteria, low dissolved oxygen, although disturbing gravid females can Summary of Factor C aluminum, sulfates, selenium, chloride, result in glochidial loss and subsequent Disease in freshwater mussels is and low pH associated with agricultural, reproductive failure. Additionally, poorly known, and we do not have any urban, municipal, and industrial runoff. handling has been shown to reduce information indicating it is a threat to Of these, nitrates and low dissolved shell growth in other mussel species, the Texas fatmucket. Additionally, oxygen pose the greatest threat to Texas including several other species of while predation is likely occurring fatmucket, as discussed above. Chemical Lampsilis (Haag and Commens-Carson within Texas fatmucket populations, it contaminants, such as oil, ammonia, 2008, pp. 505–506). Repeated handling is a natural ecological interaction and copper, mercury, nutrients, pesticides, by researchers may adversely affect we have no information indicating the and other compounds, are currently a Texas fatmucket individuals, but these extent of such predation is large enough threat to the Texas fatmucket. The activities are occurring rarely and are to be a threat to populations of Texas species is vulnerable to acute not likely to be a threat to populations. fatmucket. Based upon the best contamination from spills, which have Handling for scientific purposes scientific and commercial information been documented in four of the seven contributes to the long-term available, we conclude that disease or remaining populations, as well as conservation of the species. predation is not a threat to the Texas chronic contaminant exposure, which is We do not have any evidence of risks fatmucket. occurring rangewide. to the Texas fatmucket from Factor D. The Inadequacy of Existing overutilization for commercial, Regulatory Mechanisms. Summary of Factor A recreational, scientific, or educational The Act requires us to examine the The reduction in numbers and range purposes, and we have no reason to adequacy of existing regulatory of the Texas fatmucket is primarily the believe this factor will become a threat mechanisms with respect to threats that result of the long-lasting effects of to the species in the future. Based upon may place the Texas fatmucket in habitat alterations such as the effects of the best scientific and commercial danger of extinction or increase its impoundments, sedimentation, information available, we conclude that likelihood of becoming so in the future. dewatering, sand and gravel mining, overutilization for commercial, Existing regulatory mechanisms that and chemical contaminants. recreational, scientific, or educational could affect threats to the Texas

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00019 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62184 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

fatmucket include State and Federal affect mussels or their habitats. extremely low levels of contaminants laws such as the Texas Threatened and Therefore, these designations provide (see ‘‘Chemical Contaminants’’ under Endangered Species regulations, Texas no regulatory mechanisms to protect Factor A in the Five-Factor Evaluation freshwater mussel sanctuaries, State and Texas fatmucket from habitat alteration. for Texas Fatmucket section). The EPA’s Federal sand and gravel mining established water quality criteria may State Sand and Gravel Mining regulations, and regulation of point and not be protective of mussels. Current Regulations non-point source pollution. water quality standards applied by EPA TPWD has been responsible for were established to be protective of Texas Threatened and Endangered regulating the ‘‘disturbance of taking’’ aquatic life; however, freshwater Species Regulations streambed materials since 1911 (Meador mussels were not used to develop these On January 8, 2010, the Texas Parks and Layher 1998, p. 11) and has issued standards (EPA 2005, p. 5), and current and Wildlife Commission placed 15 several permits for ongoing activities research reveals mussels to be more species of freshwater mussels, including within the Texas fatmucket range (for sensitive to many aquatic pollutants the Texas fatmucket, on the State more information on the effects of sand than the tested organisms (Augsperger et threatened list (Texas Register 2010, pp. and gravel mining on Texas fatmucket, al. 2007, p. 2025). For example, 6–10). Section 68.002 of the Texas Parks please refer to ‘‘Sand and Gravel Augspurger et al. (2003, p. 2572) and and Wildlife (TPW) Code and Section Mining’’ under Factor A in Five-Factor Sharpe (2005, p. 28) suggested that the 65.171 of the Texas Administrative Evaluation for Texas Fatmucket). In criteria for ammonia may not be Code (TAC) prohibit the direct take of addition to authorized activities, there sufficient to prevent impacts to mussels a threatened species, except under are ongoing unauthorized sand and under current and future climate issuance of a scientific collecting gravel mining activities within the range conditions. In addition, chronic copper permit. ‘‘Take’’ is defined in Section of Texas fatmucket. For example, the concentrations lethal to juvenile 1.101(5) of the TPW Code as collect, LCRA, which monitors water quality freshwater mussels have been shown to hook, hunt, net, shoot, or snare, by any permit applications submitted through be less than the EPA’s 1996 chronic means or device, and includes an other agencies (LCRA 2011b, p. 1), water quality criterion for copper (Wang attempt to take or to pursue in order to found unpermitted sand removal from et al. 2007b, pp. 2052–2055), and, as take. While this law protects individuals the Llano River in Llano County during stated above (see ‘‘Chemical from take, it is difficult to enforce and a site visit in 2010 (Lehman 2010, p. 1). Contaminants’’ under Factor A in Five- does not provide any protection for This site is located upstream from a Factor Evaluation for Texas Fatmucket), Texas fatmucket habitat. Moreover, our known population of the Texas high copper concentrations have been assessment finds that the species is not fatmucket and other rare mussels documented in the lower Guadalupe threatened by take (see Factor B above). (Howells 1994, p. 6), and the sand and San Antonio Rivers (Lee and There are no State provisions under the removal may have increased turbidity Schultz 1994, p. 8). Based on this Texas Threatened and Endangered and sedimentation downstream within information, the existing EPA water Species Regulations for reducing or Texas fatmucket habitat. Sand and quality criteria may not be sufficient to eliminating the threats (see Factor A gravel mining may be one of the least prevent negative effects to the Texas above) that may adversely affect Texas regulated of all mining activities fatmucket. fatmucket or its habitat. In addition, (Meador and Layher 1998, p. 10). Nonpoint source pollution such as these State regulations do not call for Clean Water Act sedimentation and chemical development of a recovery plan that will contaminantation is considered a restore and protect existing habitat for The U.S. Army Corps of Engineers significant threat to Texas fatmucket the species. For these reasons, we find (USACE) retains oversight authority and habitat; however, the Clean Water Act that existing Texas regulatory requires a permit for gravel and sand does not adequately protect Texas mechanisms for State-listed threatened mining activities that deposit fill into fatmucket habitat from nonpoint source species are currently inadequate to streams under section 404 of the Clean pollution, because most activities that protect Texas fatmucket and its habitat Water Act (33 U.S.C. 1251 et seq.). cause nonpoint source pollution are not or to prevent further decline of the Additionally, a permit is required under regulated under the Clean Water Act. species. section 10 of the Rivers and Harbors Act (33 U.S.C. 401 et seq.) for navigable Summary of Factor D Freshwater Mussel Sanctuaries waterways. However, many mining Despite some State and Federal laws The TPWD has designated specific operations do not fall under these two protecting the species and water quality, areas of streams and reservoirs as no- categories. For example, nationwide the Texas fatmucket continues to harvest mussel sanctuaries (31 TAC, permits are issued by the USACE for decline due to the effects of habitat part 2, chapter 57, subpart B, Rule types of projects that are presumed to destruction, poor water quality, 57.157). The locations of the designated have minimal environmental impacts. contaminants, and other factors. The mussel sanctuaries were selected However, projects permitted by regulatory measures described above are because they support populations of nationwide permits, such as small not sufficient to significantly reduce or rare and endemic mussel species or are mining operations, may have remove the threats to the Texas important for maintaining, repopulating, cumulative effects on aquatic species fatmucket. Based upon our review of the or allowing recovery of mussels in like the Texas fatmucket through best commercial and scientific data watersheds where they have been increased sedimentation and channel available, we conclude that the lack of depleted. As a result of the designation instability. existing regulatory mechanisms is an of mussel sanctuaries, four of the Texas Point source discharges of potential immediate threat of moderate fatmucket populations are protected contaminants within the range of the magnitude to the Texas fatmucket. from harvesting disturbance of other Texas fatmucket have been reduced Factor E. Other Natural or Manmade species (Howells 2010f, p. 12). since the inception of the Clean Water Factors Affecting Its Continued Unfortunately, mussel sanctuaries only Act, but this reduction may not provide Existence. restrict the harvest of mussels and do adequate protection for filter-feeding Other natural and manmade factors not address other activities that may organisms that can be affected by that threaten the Texas fatmucket

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00020 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62185

include climate change, population temperatures, and unsustainable water 258) or dewatering. Inbreeding fragmentation and isolation, and use practices. depression can result in death, nonnative species. One preliminary study forecasting the decreased fertility, smaller body size, possible hydrological impacts of climate loss of vigor, reduced fitness, and Climate Change change on the annual runoff and its various chromosomal abnormalities It is widely accepted that changes in seasonality in the upper Colorado River (Smith 1974, pp. 350). Despite any climate are occurring worldwide watershed was conducted by CH2M evolutionary adaptations for rarity, (International Panel on Climate Change HILL (2008). In this initial evaluation, habitat loss and degradation increase a (IPCC) 2007, p. 30). Understanding the four modeling scenarios (chosen to species’ vulnerability to extinction effects of climate change on the Texas represent a range of possible future (Noss and Cooperrider 1994, pp. 58–62). fatmucket is important because the climatic conditions) were each run Numerous authors (including Noss and disjunct nature of the remaining Texas under a 2050 and 2080 time scenario, Cooperrider 1994, pp. 58–62; Thomas fatmucket populations, coupled with producing annual surface water runoff 1994, p. 373) have indicated that the the limited ability of mussels to migrate, estimates at multiple sites with stream probability of extinction increases with makes it unlikely that the Texas gages in the Colorado River basin. For decreasing habitat availability. Although fatmucket can adjust its range in the 2050 scenarios, the results from all changes in the environment may cause response to changes in climate (Strayer four climate change scenarios predicted populations to fluctuate naturally, small 2008, p. 30). For example, changes in significant decreases in annual runoff and low-density populations are more temperature and precipitation can totals compared to historic averages likely to fluctuate below a minimum increase the likelihood of flooding or (CH2M HILL 2008, pp. 7–30—7–32). For viable population (the minimum or increase drought duration and intensity, the 2080 scenarios, one model predicted threshold number of individuals needed resulting in direct effects to freshwater increases in annual runoff; the other in a population to persist in a viable mussels like the Texas fatmucket (Hastie three 2080 scenarios predicted state for a given interval) (Gilpin and et al. 2003, pp. 40–43; Golloday et al. decreases in annual runoff (CH2M HILL Soule 1986, pp. 25–33; Shaffer 1981, p. 2004, p. 503). Because the range of the 2008, pp. 7–30—7–33). The modeling 131; Shaffer and Samson 1985, pp. 148– Texas fatmucket has been reduced to efforts from this study focus on annual 150). isolated locations with low population averages and cannot necessarily account The Texas fatmucket was widespread numbers in small rivers and streams, the for the seasonal variations in flooding throughout much of the Colorado and Texas fatmucket is vulnerable to events or long periods of drought. Guadalupe River systems when few climatic changes that could decrease the However, the study demonstrates the natural barriers existed to prevent availability of water or produce more potential effects of climate change on migration (via host species) among frequent scouring flood events. Indirect surface water availability, which is suitable habitats. Construction of dams, effects of climate change may include forecasted to result in an overall decline however, likely destroyed many Texas in stream flows in the region where the fatmucket populations through drastic declines in host fish populations, Texas fatmucket occurs. habitat changes and isolated the habitat reduction, and changes in In summary, climate change could remnant populations from each other. human activity in response to climate affect the Texas fatmucket through the For fertilization, Texas fatmucket change (Hastie et al. 2003, pp. 43–44). combined effects of global and regional females need an upstream male to For the next two decades, a warming climate change, along with the ° ° release sperm; populations with few of about 0.2 C (0.4 F) per decade is increased probability of long-term individuals reduce the likelihood that projected across the United States (IPCC drought. Climate change exacerbates females will be exposed to sperm while 2007, p. 12), and hot extremes, heat threats such as habitat degradation from siphoning. Therefore, recruitment waves, and heavy precipitation and prolonged periods of drought, increased failure is a potential problem for many flooding are expected to increase in water temperature, and the increased small populations rangewide, a frequency (IPCC 2007, p. 18). As with allocation of water for municipal, potential condition exacerbated by its many areas of North America, central agricultural, and industrial use. As reduced range and increasingly isolated Texas is projected to experience an such, climate change, in and of itself, populations. If downward population overall warming trend in the range of may affect the Texas fatmucket, but the trends continue, further significant ° ° 2.5 to 3.3 C (4.5 to 6 F) over the next magnitude and imminence (when the declines in total Texas fatmucket 50 to 200 years (Mace and Wade 2008, effects occur) of the effects remain population size and consequent p. 656). Even under lower greenhouse uncertain. Based upon our review of the reduction in long-term survivability gas emission scenarios, recent best commercial and scientific data may soon become apparent. projections forecast a 2.8 °C (5 °F) available, we conclude that the effects of The small, isolated nature of the increase in temperature and a 10 climate change in the future will likely Texas fatmucket’s remaining percent decline in precipitation in exacerbate the current and ongoing populations also increases the species’ central Texas by 2080–2099 (Karl et al. threats of habitat loss and degradation vulnerability to stochastic (random) 2009, pp. 123–124). Based on our caused by other factors, as discussed natural events. When species are limited current understanding of climate above. to small, isolated habitats, as the Texas change, air temperatures are expected to fatmucket is, they are more likely to rise and precipitation patterns are Population Fragmentation and Isolation become extinct due to a local event that expected to change in areas occupied by All of the remaining populations of negatively effects the population the Texas fatmucket. Karl et al. (2009, p. the Texas fatmucket are small and (McKinney 1997, p. 497; Minckley and 12) also suggests that climate change geographically isolated and thus are Unmack 2000, pp. 52–53; Shepard 1993, impacts on water resources in the susceptible to genetic drift (change of pp. 354–357). While the populations’ southern Great Plains (including central gene frequencies in a population over small, isolated nature does not represent Texas) are expected as rising time), inbreeding depression, and an independent threat to the species, it temperatures and decreasing random or chance changes to the does substantially increase the risk of precipitation exacerbate an area already environment, such as toxic chemical extirpation from the effects of all other plagued by low rainfall, high spills (Watters and Dunn 1995, pp. 257– threats, including those addressed in

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00021 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62186 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

this analysis, and those that could occur locomotion (both laterally and example, in 1994 30 black carp escaped in the future from unknown sources. vertically), interferes with normal valve from an aquaculture facility in Missouri Based upon our review of the best movements, deforms valve margins, and during a flood. Other escapes into the commercial and scientific data essentially suffocates and starves the wild by non-sterile carp are likely to available, we conclude that native mussels by depleting the occur. Because of the high risk to fragmentation and isolation of small surrounding water of oxygen and food freshwater mussels and other native remaining populations of the Texas (Strayer 1999, pp. 77–80). Heavy mollusks, the Service recently listed fatmucket exacerbate ongoing threats to infestations of zebra mussels on native black carp as an injurious species under the species throughout all of its range mussels may overly stress the animals the Lacey Act (72 FR 59019, October 18, and are expected to continue. by reducing their energy reserves. Zebra 2007), which prevents importations and Nonnative Species mussels may also filter the sperm and interstate transfer of this harmful possibly glochidia of native mussels species, but does not prevent its release Various nonnative species of aquatic from the water column, thus reducing into the wild once it is in the State. If organisms are firmly established within reproductive potential. Habitat for the black carp were to escape within the the range of the Texas fatmucket and native mussels may also be degraded by range of the Texas fatmucket, it would pose a threat to the species. Golden large deposits of zebra mussel likely negatively affect native mussels, algae (Prymnesium parvum) is a pseudofeces (undigested waste material including the Texas fatmucket. microscopic algae considered to be one passed out of the incurrent siphon) Based upon our review of the best of the most harmful algal species to fish (Vaughan 1997, p. 11). commercial and scientific data and other gill-breathing organisms Zebra mussels are not currently found available, we conclude that golden algae (Lutz-Carrillo et al. 2010, p. 24). Golden within the range of the Texas fatmucket. is an ongoing threat to the Texas algae was first discovered in Texas in However, a live adult zebra mussel was fatmucket, and other nonnative species, 1985 and is presumed to have been first documented in Lake Texoma on the such as zebra mussels and black carp, introduced from western Europe (Lutz- Red River (on the north Texas border are a potential future threat to the Texas Carrillo et al. 2010, p. 30). Since its with Oklahoma) in 2009 (TPWD 2009a, fatmucket that is likely to increase as introduction, golden algae has been p. 1). Since that time, additional zebra these exotic species expand their found in Texas rivers and lakes, mussels have been reported from Lake occupancy within the range of the Texas including two lakes in central Texas Texoma, where they are now believed to fatmucket. (Baylor University 2009, p. 1). Under be well established (TPWD 2009c, p. 1). Summary of Factor E certain environmental conditions, this Zebra mussels are likely to spread to algae can produce toxins that can cause many other Texas reservoirs through The effects of climate change, while massive fish and mussel kills (Barkoh accidental human transport (Schneider difficult to quantify at this time, are and Fries 2010, p. 1; Lutz-Carrillo et al. et al. 1998, p. 789). Although zebra likely to exacerbate the current and 2010, p. 24). Evidence shows that mussels tend to proliferate in reservoirs ongoing threat of habitat loss caused by golden algae probably caused fish kills or large pools, released zebra mussel other factors, and the small sizes and in Texas as early as the 1960s, but the larvae, called veligers, float downstream fragmented nature of the remaining first documented fish kill due to golden and attach to any hard surface available, populations render them more algae in inland waters of Texas occurred rendering downstream Texas fatmucket vulnerable to extirpation. In addition, in 1985 on the Pecos River in the Rio populations extremely vulnerable to nonnative species, such as golden algae, Grande basin (TPWD 2002, p. 1). The attachment and fouling. Because zebra currently threaten the Texas fatmucket, range of golden algae has increased to mussels are so easily introduced to new and the potential introduction of zebra include portions of the Brazos and locations, the potential for zebra mussels and black carp are potential Colorado River basins, among others, mussels to continue to expand in Texas future threats. Based upon our review of and it has been responsible for killing and invade the range of the Texas the best commercial and scientific data more than 8 million fish in the Brazos fatmucket is high. If this occurs, the available, we conclude that other River since 1981 and more than 2 Texas fatmucket is vulnerable to zebra natural or manmade factors are million fish in the Colorado River since mussel attachment and subsequent immediate threats of moderate 1989 (TPWD 2010a, p. 1). Although deprivation of oxygen, food, and magnitude to the Texas fatmucket. actual mussel kills in Texas due to mobility. golden algae have not been recorded in A molluscivore (mollusk eater), the Finding for Texas Fatmucket the past, the toxin can kill mussels. black carp (Mylopharyngodon piceus) is As required by the Act, we considered Therefore, the elimination of host fish a potential threat to the Texas the five factors in assessing whether and the poisonous nature of the toxin to fatmucket. The species has been Texas fatmucket is threatened or mussels make future golden algae commonly used by aquaculturists to endangered throughout all of its range. blooms a threat to the Texas fatmucket. control snails or for research in fish We examined the best scientific and An additional nonnative species, the production in several States, including commercial information available zebra mussel (Dreissena polymorpha), Texas (72 FR 59019, October 18, 2007). regarding the past, present, and future poses a potential threat to the Texas Black carp can reach more than 1.3 m threats faced by the Texas fatmucket. fatmucket. This invasive species has (4 ft) in length and 150 pounds (68 We reviewed the petition, information been responsible for the extirpation of kilograms (kg)) (Nico and Williams available in our files, and other freshwater mussels in other regions of 1996, p. 6). Foraging rates for a 4-year- available published and unpublished the United States, including the Higgin’s old fish average 3 to 4 pounds (1.4 to1.8 information, and we consulted with eye (Lampsilis higginsii) in Wisconsin kg) a day, indicating that a single recognized Texas fatmucket experts and and Iowa (Service 2006, pp. 9–10). individual could consume 10 tons other Federal and State agencies. Zebra mussels attach in large numbers (9,072 kg) of native mollusks over its This status review identified threats to the shells of live native mussels and lifetime (Mississippi Interstate to the Texas fatmucket attributable to are implicated in the loss of entire Cooperative Resource Association Factors A, D, and E. The primary threat native mussel beds (Ricciardi et al. (MICRA) 2005, p. 1). Black carp can to the species is from 1998, p. 615). This fouling impedes escape from aquaculture facilities. For and modification (Factor A) from

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00022 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62187

impoundments, which scour riverbeds, establish a rational system for utilizing for Texas Fatmucket section to be thereby removing mussel habitat, available resources for the highest imminent because these threats have decrease water quality, modify stream priority species when adding species to affected the species in the past, are flows, and prevent fish host migration the Lists of Endangered and Threatened ongoing, and will continue in the and distribution of freshwater mussels, Wildlife and Plants or reclassifying foreseeable future. Habitat loss and as well as sedimentation, dewatering, species listed as threatened to destruction have already occurred and sand and gravel mining, and chemical endangered status. These guidelines, will continue as the human population contaminants. Additionally, most of titled ‘‘Endangered and Threatened continues to grow in central Texas. these threats may be exacerbated by the Species Listing and Recovery Priority Texas fatmucket populations may current and projected effects of climate Guidelines,’’ address the immediacy already be below the minimum viable change (discussed in Factor E). Threats and magnitude of threats, and the level population requirement, which would to the Texas fatmucket and its habitat of taxonomic distinctiveness by cause a reduction in the number of are not being adequately addressed assigning priority in descending order to populations and an increase in the through existing regulatory mechanisms monotypic genera (genus with one species’ vulnerability to extinction. (Factor D). Because of the limited species), full species, and subspecies (or These threats are exacerbated by climate distribution of this endemic species and equivalently, distinct population change, which will increase the its lack of mobility, these threats are segments of vertebrates). frequency and magnitude of droughts. likely to result in the extinction of the As a result of our analysis of the best Therefore, we consider these threats to Texas fatmucket in the foreseeable available scientific and commercial be imminent. future. information, we have assigned the Texas The third criterion in our Listing On the basis of the best scientific and fatmucket a Listing Priority Number Priority Number guidance is intended to commercial information available, we (LPN) of 2, based on our finding that the devote resources to those species find that the petitioned action to list the species faces threats that are of high representing highly distinctive or Texas fatmucket under the Act is magnitude and are imminent. These isolated gene pools as reflected by warranted. We will make a threats include habitat loss and taxonomy. The Texas fatmucket is a determination on the status of the degradation from impoundments, valid taxon at the species level and, species as threatened or endangered sedimentation, sand and gravel mining, therefore, receives a higher priority than when we complete a proposed listing and chemical contaminants; other subspecies, but a lower priority than determination. When we complete a natural or manmade factors such as species in a monotypic genus. proposed listing determination, we will climate change, small, isolated Therefore, we assigned Texas fatmucket examine whether the species may be populations, and nonnative species; and an LPN of 2. endangered or threatened throughout all the fact that the threats to the species We will continue to monitor the of its range or whether the species may are not being adequately addressed by threats to the Texas fatmucket and the be endangered or threatened in a existing regulatory mechanisms. Our species’ status on an annual basis, and significant portion of its range. rationale for assigning the Texas should the magnitude or imminence of However, as explained in more detail fatmucket an LPN of 2 is outlined the threats change, we will revisit our below, an immediate proposal of a below. assessment of the LPN. regulation implementing this action is Under the Service’s guidelines, the While we conclude that listing the precluded by higher priority listing magnitude of threat is the first criterion Texas fatmucket is warranted, an actions, and progress is being made to we look at when establishing a listing immediate proposal to list this species add or remove other qualified species priority. The guidance indicates that is precluded by other higher priority from the Lists of Endangered and species with the highest magnitude of listings, which we address in the Threatened Wildlife and Plants. threat are those species facing the Preclusion and Expeditious Progress We reviewed the available greatest threats to their continued section below. Because we have information to determine if the existing existence. These species receive the assigned the Texas fatmucket an LPN of and foreseeable threats render the Texas highest listing priority. We consider the 2, work on a proposed listing fatmucket at risk of extinction now such threats that the Texas fatmucket faces to determination for the species is that issuing an emergency regulation be high in magnitude. Habitat loss and precluded by work on higher priority temporarily listing the species under degradation from impoundments, listing actions with absolute statutory, section 4(b)(7) of the Act is warranted. sedimentation, sand and gravel mining, court-ordered, or court-approved We determined that issuing an and chemical contaminants are deadlines and final listing emergency regulation temporarily widespread throughout the range of the determinations for those species that listing the species is not warranted for Texas fatmucket and profoundly affect were proposed for listing with funds the Texas fatmucket at this time, its survival and recruitment. Remaining from Fiscal Year (FY) 2011. This work because we have not identified a threat populations are small, isolated, and includes all the actions listed in the or activity that poses a significant risk, highly vulnerable to stochastic events. tables below under Preclusion and such that losses to the species during Under our LPN guidelines, the second Expeditious Progress. the normal listing process would criterion we consider in assigning a endanger the continued existence of the listing priority is the immediacy of Five-Factor Evaluation for Golden Orb entire species. However, if at any time threats. This criterion is intended to Information pertaining to the golden we determine that issuing an emergency ensure that the species facing actual, orb in relation to the five factors regulation temporarily listing Texas identifiable threats are given priority provided in section 4(a)(1) of the Act is fatmucket is warranted, we will initiate over those for which threats are only discussed below. this action at that time. potential or that are intrinsically Factor A. The Present or Threatened vulnerable but are not known to be Destruction, Modification, or Listing Priority Number for Texas presently facing such threats. We Curtailment of Its Habitat or Range. Fatmucket consider the threats to the Texas As discussed above, the decline of The Service adopted guidelines on fatmucket as described under Factors A, mussels in Texas and across the United September 21, 1983 (48 FR 43098), to D, and E in the Five-Factor Evaluation States is primarily the result of habitat

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00023 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62188 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

loss and degradation. Chief among the channels may never reproduce, or large amount of suspended sediment causes of decline of the golden orb in reproduce less frequently (Watters 2000, where a small golden orb population Texas are the effects of impoundments, p. 264). Any golden orb that survived was recently found. Sedimentation can dewatering, sedimentation, sand and the initial inundation may have been occur from agricultural activities, sand gravel mining, chemical contaminants, unable to reproduce, eventually and gravel mining, urban runoff, and and off-road vehicle use. These threats eliminating the species from large areas construction activities, among other are discussed below. of the reservoir. The same would be true sources. for mussels living in cold-water One example of a proposed project Impoundments discharges downstream of large that could lead to localized increases in For general information on the effects impoundments (Watters 2000, p. 264). sedimentation within the range of the of impoundments on freshwater Dam construction also fragments the golden orb is the LCRA TSC. This mussels, please refer to range of golden orb, leaving remaining project proposes to construct two new, ‘‘Impoundments’’ under Factor A in habitats and populations isolated by the 345-kV electric transmission line Five-Factor Evaluation for Texas structures, as well as by extensive areas facilities between Tom Green (in the Fatmucket. Golden orb occur in one of deep, uninhabitable, impounded Colorado River basin near San Angelo) impoundment, Lake Corpus Christi, waters. These isolated populations are and Kendall Counties (in the Guadalupe indicating that inundation may not be as unable to naturally recolonize suitable River basin north of San Antonio) to detrimental to this species as it is to habitat that may be impacted by provide electrical power to other, more flow-dependent mussel temporary but devastating events, such accommodate increased human species. However, dams continue to as severe drought, chemical spills, or populations (Clary 2010, p. 1). One of fragment golden orb populations. There unauthorized discharges. Dams the proposed transmission lines would are 29 reservoirs, each with a storage impound river habitats throughout cross the upper Guadalupe River in Kerr capacity of 3,000 acre-feet or more, almost the entire range of the species. County, which contains a small within the Guadalupe River basin and These impoundments have left short population of golden orb. The proposed 34 within the San Antonio River basin, and isolated patches of remnant habitat, project could negatively affect golden in addition to many other smaller typically in between impounded orb habitat by clearing land within the reservoirs in these basins (Exelon 2010, reaches, such as the golden orb riparian zone and may increase p. 2.3–4). Three large reservoirs exist population on the Guadalupe River sediment runoff into the Guadalupe within the Nueces River basin. within about one mile (1.6 km) River (Clary 2010, p. 7). Similar Historical records showed that the downstream of Lake Wood. This activities to accommodate Texas golden orb once occurred in the population is subject to dramatic flow population growth are expected to be Guadalupe River in Comal County fluctuations from the hydroelectric undertaken across the species’ range before the Canyon Reservoir was facility associated with the dam and will likely lead to additional constructed in 1964 (Randklev et al. (Howells 2010a, p. 4), which can leave sources of sediment in the streams 2010c, p. 4). No live or recently dead individuals stranded when water levels inhabited by the golden orb. golden orb have been found in this are quickly lowered or wash individuals Streams occupied by golden orb are reach since the reservoir was completed downstream when flow is increased. subject to increasing levels of (Burlakova and Karatayev 2010a, pp. The widespread construction of dams sedimentation from agriculture, 14–15), and we presume the species is throughout the range of golden orb has urbanization, and sand and gravel extirpated from this reach because of the significantly altered stream habitat both mining. Agriculture is a common land effects of the reservoir. Surveys of the upstream and downstream of the dams use in the Guadalupe and San Antonio reservoirs in the Guadalupe River by changing fish assemblages, River basins. Sedimentation may system have been ongoing since at least temperature, dissolved oxygen, and become an increasing threat to the 1992, and no evidence of live or dead substrate. The effects of dams on the golden orb in the Guadalupe River basin golden orb has been found in any of the golden orb are expected to be ongoing as the San Antonio metro area continues reservoirs (Howells 1994, pp. 1–20; decades after construction and are to expand. Activities associated with 1995, pp. 1–50; 1996, pp. 1–45; 1997a, presumed to be continuing today. urbanization, such as road construction, pp. 1–58; 1998, pp. 1–30; 1999, pp. 1– Because of this loss of habitat and its increased impervious surfaces, and road 34; 2000a, pp. 1–56; 2001, pp. 1–50; widespread effects on the populations, construction can be detrimental to 2002a, pp. 1–28; 2003, pp. 1–42; 2004, we conclude that the effects of dams are stream habitats (Couch and Hamilton pp. 1–48; 2005, pp. 1–23; 2006, pp. 1– a threat to the golden orb. 2002, p. 1), and the City of San Antonio, 106; Karatayev and Burlakova 2008, pp. the second largest city in Texas, 1–47; Burlakova and Karatayev 2010a, Sedimentation continues to grow (City of San Antonio pp. 1–30; 2011, pp. 1–8). For general information on the effects 2010, p. 5). Sedimentation from For species such as golden orb that of sedimentation on freshwater mussels agriculture, urbanization, and sand and may be able to survive the initial like the golden orb, please refer to gravel mining is widespread in the inundation of reservoirs, conditions ‘‘Sedimentation’’ under Factor A in range of the golden orb will continue to within the reservoir are likely to become Five-Factor Evaluation for Texas threaten the species. uninhabitable. The deep water in Fatmucket. reservoirs is very cold and often devoid As with other freshwater mussel Dewatering of oxygen and necessary nutrients species, the golden orb is affected by River dewatering can occur in several (Watters 2000, p. 264). Cold water (less excessive sedimentation in streams. ways: anthropogenic activities such as than 11 °C (52 °F)) has been shown to Even in 1959, the Guadalupe River was surface water diversions and stunt mussel growth (Hanson et al. noted as having high sedimentation groundwater pumping, and natural 1988, p. 352). Because mussel rates from agricultural activities (Soil events, such as drought, which can reproduction is temperature dependent Conservation Service 1959, p. 59). result in mussels stranded in previously (Watters and O’Dee 1999, p. 455), it is Turbidity has also been recorded as high wetted areas. This is a particular likely that individuals living in the in the Guadalupe River near Victoria concern within and below reservoirs, constantly cold hypolimnion in these (Exelon 2010, p. 2.3–186), indicating a whose water levels are managed for

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00024 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62189

various purposes that can cause water Gravel Mining’’ under Factor A in Five- high ammonia concentrations, including levels in the reservoir or downstream to Factor Evaluation for Texas Fatmucket. Elm Creek in the Guadalupe River basin rise or fall in very short periods of time, In 1995, the reach of the Guadalupe (TCEQ 2010a, p. 294). High copper such as when hydropower facilities River near Victoria, which contains a concentrations have been recorded in release water during peak energy golden orb population, was described as the lower Guadalupe and San Antonio demand periods. For example, Lake having numerous current and Rivers (Lee and Schultz 1994, p. 8), and Corpus Christi reservoir has abandoned sand and gravel mining mercury has been documented experienced several drawdowns of lake areas (USACE 1995, p. 7). Currently, throughout the Guadalupe and San levels to reduce salinity levels in the TPWD has permitted one sand mining Antonio Rivers, with particularly high reservoir, such as in 1996 and 2006. activity within the existing range of concentrations found in fish tissues Golden orb have been stranded above golden orb, in the Guadalupe River from the upper reaches of both rivers the water line during both drawdowns, basin in Comal County (TPWD 2009b, p. (Lee and Schultz 1994, p. 8). Row crop killing the exposed mussels (Howells 1); golden orb populations occur agriculture and wastewater discharges 2006, pp. 75–76). Rivers can also be upstream and downstream of this area are prominant within the range of the dewatered to facilitate construction in the Guadalupe River. The permit golden orb. These activities result in activities, such as in the upper allows for the repeated removal of sand chronic contamination from agricultural Guadalupe River in Kerr County, which and gravel at various locations within pesticides and emerging contaminants was dewatered in 1998 for bridge the stream. of rivers inhabited by the species and construction, which exposed and killed Headcuts from sand and gravel are a threat to golden orb. golden orb (Howells 1999, pp. 18–19). mining operations have been Numerous spills of potential Drought can also severely impact documented in the San Antonio River contaminant materials have occurred golden orb populations. Central Texas, basin in Karnes County from as early as within the range of the golden orb. including the Guadalupe River basin, 1967, with downstream channels having These can occur from on site accidents experienced a major drought in the late steep, eroded banks (Kennon et al. 1967, (tank, pipeline spills) or from tanker 1970s (Lewis and Oliveria 1979, p. 243). p. 22). The golden orb has not been truck accidents within watersheds Near record dry conditions in 2008 documented from this area since 1996, occupied by golden orb. For example, followed by a pattern of below-normal and only an old, eroded shell was 100,000 gallons of sewage spilled into rainfall during the winter and spring of collected at that time (Howells 1997a, the San Antonio River near the City of 2009 led to one of the worst droughts in pp. 41–42). San Antonio when a pipeline collapsed recorded history for most of central The golden orb populations in the in October 2010 (San Antonio Water Texas, including the range of the golden Guadalupe River may be currently System 2010, p. 1). The largest known orb (Nielsen-Gammon and McRoberts threatened by sand and gravel mining. golden orb population occurs 2009, p. 2). This drought’s severity was These activities occur over a long period downstream of this location. Raw exacerbated by abnormally high air of time, destabilizing habitat both sewage contains very high ammonia temperatures, a likely effect of climate upstream and downstream, which levels, which is toxic to freshwater change, which has already increased decreases the likelihood of mussels, as well as other pollutants. average air temperatures in Texas by at recolonization after the activity has been Additionally, 300 gallons of diesel fuel least 1 °C (1.8 °F) (Nielsen-Gammon and completed. Therefore, the effects of sand spilled into the San Antonio River near McRoberts 2009, p. 22). The Guadalupe and gravel mining are an ongoing threat the same location in May 2011 (Serna River in Kerr County experienced to the golden orb. 2011, p. 1). Another sewage spill minimal to no flow during periods of Chemical Contaminants occurred in April 2011 in Quinlan the 2009 drought (USGS 2011b, p. 2), Creek, a tributary to the Guadalupe which may have negatively affected this For general information on the effects River near the Kerr County population golden orb population. Central Texas is of chemical contaminants on freshwater of golden orb (MacCormack 2011, p. 1). currently experiencing another extreme mussels, please refer to ‘‘Chemical The actual effects on the golden orb of drought, with rainfall between October Contaminants’’ under Factor A in Five- spills such as these recent examples are 2010 and July 2011 being the lowest on Factor Evaluation for Texas Fatmucket. unknown, but there are likely to be record during those months (LCRA As with other freshwater mussel negative consequences. 2011c, p. 1); the effects of this drought species, the golden orb is also Because of the risk of spills as well as are being observed but are not yet fully threatened by chemical contaminants. chronic contamination, chemical known. TCEQ water quality standards for 2010 contaminants, such as oil, ammonia, We do not know the extent of the indicated the majority of the assessed copper, mercury, nutrients, pesticides, impacts of stream dewatering on the water bodies within the golden orb’s and other compounds are currently a golden orb; however, because several historical and current range did not threat to the golden orb. The species is populations are small and isolated, the meet surface water quality standards vulnerable to acute contamination from loss of numerous individuals at a site and were classified as impaired water spills as well as chronic contaminant can have dramatic consequences to the bodies (Nueces River Authority 2010, exposure, which is occurring rangewide. population. Hydropower facilities, pp. 1–37; Texas Clean Rivers Program Summary of Factor A construction, and drought are occurring 2010b, p. 13). These water bodies were throughout the range of the golden orb; impaired with dissolved solids, nitrates, The reduction in numbers and range therefore, the effects of dewatering are bacteria, low dissolved oxygen, sulfates, of the golden orb is primarily the result ongoing and unlikely to decrease, phosphates, chloride, chlorophyll-a, and of the long-lasting effects of habitat resulting in significant threats to the low pH associated with agricultural, alterations such as the effects of golden orb. urban, municipal, and industrial runoff. impoundments, sedimentation, Of these, nitrates and low dissolved dewatering, sand and gravel mining, Sand and Gravel Mining oxygen pose the greatest threat to the and chemical contaminants. For general information on the effects golden orb. Additionally, several Impoundments occur throughout the of sand and gravel mining on freshwater streams within the range of the golden range of the species and have far- mussels, please refer to ‘‘Sand and orb have been listed as impaired due to reaching effects both up- and

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00025 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62190 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

downstream. Both the Colorado and Disease the golden orb continues to decline due Guadalupe River systems experience a Little is known about disease in to the effects of habitat destruction, poor large amount of sedimentation from freshwater mussels. However, disease is water quality, contaminants, and other agriculture, instream mining, and urban believed to be a contributing factor in factors. The regulatory measures development. Sand and gravel mining documented mussel die-offs in other described above have been insufficient affects golden orb habitat by causing parts of the United States (Neves 1987, to significantly reduce or remove the headcutting upstream, increasing pp. 11–12). Diseases have not been threats to the golden orb. Based upon sedimentation concentrations in the documented or observed during any our review of the best commercial and water downstream, and causing channel studies of golden orb. scientific data available, we conclude instability downstream. Chemical that the lack of existing regulatory contaminants have been documented Predation mechanisms is an immediate threat of throughout the range of the species and Raccoons will prey on freshwater moderate magnitude to the golden orb. may represent a significant threat to the mussels stranded by low waters or Factor E. Other Natural or Manmade golden orb. However, the large deposited in shallow water or on bars Factors Affecting Its Continued populations in the middle and lower following flooding or low water periods Existence. Guadalupe River, lower San Antonio (Howells 2010c, p. 12). Predation of Natural and manmade factors that River, and San Marcos River indicate golden orb by raccoons may be threaten the golden orb include climate that some golden orb populations are occurring occasionally but there is no change, population fragmentation and not currently as vulnerable to habitat indication it is a significant threat to the isolation, and nonnative species. loss as others. Based upon our review of status of the species. Climate Change the best commercial and scientific data Some species of fish feed on mussels, For more general information on the available, we conclude that the present such as common carp, freshwater drum, effects of climate change on freshwater or threatened destruction, modification, and redear sunfish, all of which are mussels in central Texas, please refer to or curtailment of its habitat or range is common throughout the range of golden ‘‘Climate Change’’ under Factor E in an immediate threat of moderate orb (Hubbs et al. 2008, pp. 19, 45, 53). Five-Factor Evaluation for Texas magnitude to golden orb populations Common species of flatworms are Fatmucket. Because the range of the rangewide. voracious predators of newly metamorphosed juvenile mussels of golden orb has been reduced to isolated Factor B. Overutilization for many species (Zimmerman et al. 2003, locations, many with low population Commercial, Recreational, Scientific, or p. 30). Predation is a normal factor numbers in small rivers and streams, the Educational Purposes. influencing population dynamics of a golden orb is vulnerable to climatic The golden orb is not a commercially healthy mussel population; however, changes that could decrease the valuable species and has never been predation may amplify declines in small availability of water. harvested in Texas as a commercial populations primarily caused by other The disjunct nature of the remaining mussel species (Howells 2010a, p. 12). factors. golden orb populations, coupled with Some scientific collecting occurs but is the limited ability of mussels to migrate, not likely to be a significant threat to the Summary of Factor C makes it unlikely that golden orb can species because it occurs only rarely. Disease in freshwater mussels is adjust their range in response to changes However, handing mussels can disturb poorly known, and we do not have any in climate (Strayer 2008, p. 30). Climate gravid females and result in glochidial information indicating it is a threat to change could affect the golden orb loss and subsequent reproductive failure the golden orb. Additionally, predation through the combined effects of global (Waller et. al 1995, p. 205). is a natural ecological interaction and and regional climate change, along with Additionally, handling has also been we have no information indicating the the increased probability of long-term shown to reduce shell growth across extent of any predation is a threat to drought. Climate change exacerbates mussel species, including several populations of golden orb. Based upon threats such as habitat degradation from species of Lampsilis (Haag and the best scientific and commercial prolonged periods of drought, increased Commens-Carson 2008, pp. 505–506). information available, we conclude that water temperature, and the increased Repeated handling by researchers may disease or predation is not a threat to allocation of water for municipal, adversely affect golden orb individuals, the golden orb. agricultural, and industrial uses. but these activities are occurring rarely Factor D. The Inadequacy of Existing Climate change may be a significant and are not likely to threaten Regulatory Mechanisms. stressor that exacerbates existing threats populations. Handling for scientific Existing regulatory mechanisms that by increasing the likelihood of purposes contributes to the long-term could have an effect on threats to the prolonged drought. As such, climate conservation of the species. golden orb include State and Federal change, in and of itself, may affect the laws such as Texas Threatened and golden orb, but the magnitude and We do not have any evidence of risks Endangered Species regulations and imminence of the effects remain to the golden orb from overutilization freshwater mussel sanctuaries, State and uncertain. Based upon our review of the for commercial, recreational, scientific, Federal sand and gravel mining best commercial and scientific data or educational purposes, and we have regulations, and regulation of point and available, we conclude that the effects of no reason to believe this factor will non-point source pollution. For more climate change in the future will likely become a threat to the species in the information on the effects of these exacerbate the current and ongoing future. Based upon the best scientific regulations on the threats to freshwater threats of habitat loss and degradation and commercial information available, mussels in central Texas, please refer to caused by other factors, as discussed we conclude that overutilization of the Factor D under Five-Factor Evaluation above. golden orb for commercial, recreational, for Texas Fatmucket. scientific, or educational purposes does Population Fragmentation and Isolation not pose a significant threat to the Summary of Factor D For general information on the effects species rangewide. Despite State and Federal laws of population fragmentation and Factor C. Disease and Predation. protecting the species and water quality, isolation on freshwater mussels in

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00026 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62191

central Texas, please refer to and black carp. Zebra mussels and black nonnative species (discussed under ‘‘Population Fragmentation and carp are not currently found within the Factor E). Threats to the golden orb are Isolation’’ under Factor E in Five-Factor range of golden orb, but they are likely not being adequately addressed through Evaluation for Texas Fatmucket. As to be introduced within its range in the existing regulatory mechanisms (Factor with many freshwater mussels, several future. D). Because of the limited distribution of the remaining populations of the Based upon our review of the best of this endemic species and its lack of golden orb are small and geographically commercial and scientific data mobility, these threats are likely to lead isolated and thus are more susceptible available, we conclude that golden algae to the extinction of the golden orb in the to genetic drift, inbreeding depression, is an ongoing threat to the golden orb, foreseeable future. and random or chance changes to the and other nonnative species, such as On the basis of the best scientific and environment, such as toxic chemical zebra mussels and black carp, are a commercial information available, we spills (Watters and Dunn 1995, pp. 257– potential threat to the golden orb that is find that the petitioned action to list the 258) or dewatering. Historically, the likely to increase as these exotic species golden orb under the Act is warranted. golden orb was widespread throughout expand their occupancy to include the We will make a determination on the much of the Guadalupe River system range of the golden orb. status of the species as threatened or endangered when we complete a and in portions of the Nueces-Frio River Summary of Factor E system when few natural barriers proposed listing determination. When existed to prevent migration (via host The effects of climate change, while we complete a proposed listing species) among suitable habitats. The difficult to quantify at this time, are determination, we will examine extensive impoundment of the Nueces, likely to exacerbate the current and whether the species may be endangered Guadalupe, and San Antonio River ongoing threat of habitat loss caused by or threatened throughout all of its range basins by the construction of dams has other factors, and the small sizes and or whether the species may be fragmented the few remaining golden fragmented nature of the remaining endangered or threatened in a orb populations throughout these river populations render them more significant portion of its range. systems. vulnerable to extirpation. In addition, However, as explained in more detail Small golden orb populations, nonnative species, such as golden algae, below, an immediate proposal of a including those in Lake Corpus Christi currently threaten the golden orb, and regulation implementing this action is Reservoir, the upper Guadalupe River in the potential introduction of zebra precluded by higher priority listing Kerr County, and the San Antonio River mussels and black carp are potential actions, and progress is being made to in Victoria County, may now be below future threats. Based upon our review of add or remove qualified species from the minimum population size required the best commercial and scientific data the Lists of Endangered and Threatened to maintain population viability into the available, we conclude that other Wildlife and Plants. future, since they are less likely to be natural or manmade factors are We reviewed the available able to recover through recruitment immediate threats of moderate information to determine if the existing from events that reduce but do not magnitude to the golden orb. and foreseeable threats render the golden orb at risk of extinction now extirpate populations. Additionally, Finding for Golden Orb these small populations are more such that issuing an emergency vulnerable to extirpation from stochastic As required by the Act, we considered regulation temporarily listing the events, as the lack of connectivity the five factors in assessing whether the species under section 4(b)(7) of the Act among populations does not permit golden orb is threatened or endangered is warranted. We determined that nearby populations to recolonize areas throughout all of its range. We issuing an emergency regulation affected by intense droughts, toxic examined the best scientific and temporarily listing the species is not spills, or other isolated events that commercial information available warranted for the golden orb at this result in significant mussel dieoffs. regarding the past, present, and future time, because we have not identified a While the small, isolated populations do threats faced by the golden orb. We threat or activity that poses a significant not represent an independent threat to reviewed the petition, information risk, such that losses to the species the species, the situation does available in our files, and other during the normal listing process would substantially increase the risk of available published and unpublished endanger the continued existence of the extirpation from the effects of all other information, and we consulted with entire species. However, if at any time threats, including those addressed in recognized golden orb experts and other we determine that issuing an emergency this analysis, and those that could occur Federal and State agencies. regulation temporarily listing the golden in the future from unknown sources. This status review identifies threats to orb is warranted, we will initiate this Based upon our review of the best the golden orb attributable to Factors A, action at that time. commercial and scientific data D, and E. The primary threat to the Listing Priority Number for Golden Orb available, we conclude that species is from habitat destruction and fragmentation and isolation of small modification (Factor A) from The Service adopted guidelines on remaining populations of the golden orb impoundments, which scour riverbeds, September 21, 1983 (48 FR 43098), to are occurring and are ongoing threats to thereby removing mussel habitat, establish a rational system for utilizing the species throughout all of its range. decrease water quality, modify stream available resources for the highest flows, and restrict fish host migration priority species when adding species to Nonnative Species and distribution of freshwater mussels. the Lists of Endangered and Threatened For general information on the effects Additional threats under Factor A Wildlife and Plants or reclassifying of nonnative species on freshwater include sedimentation, dewatering, species listed as threatened to mussels of central Texas, please refer to sand and gravel mining, and chemical endangered status. These guidelines, ‘‘Nonnative Species’’ under Factor E in contaminants. Also, most of these titled ‘‘Endangered and Threatened Five-Factor Evaluation for Texas threats may be exacerbated by the Species Listing and Recovery Priority Fatmucket. Various nonnative aquatic current and projected effects of climate Guidelines’’ address the immediacy and species pose a threat to the golden orb, change, population fragmentation and magnitude of threats, and the level of including golden algae, zebra mussels, isolation, and the anticipated threat of taxonomic distinctiveness by assigning

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00027 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62192 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

priority in descending order to change, which will increase the impoundment conditions. Smooth monotypic genera (genus with one frequency and magnitude of droughts. pimpleback have been known to occur species), full species, and subspecies (or Therefore, we consider these threats to in three mainstem reservoirs on the equivalently, distinct population be imminent. Colorado River, although all but one segments of vertebrates). The third criterion in our Listing population is likely extirpated (Howells As a result of our analysis of the best Priority Number guidance is intended to 1997a, pp. 32–33; 1999, p. 16; 2005, p. available scientific and commercial devote resources to those species 8; 2006, p. 67). Dams continue to information, we have assigned the representing highly distinctive or fragment smooth pimpleback golden orb a Listing Priority Number isolated gene pools as reflected by populations, and the downstream effects (LPN) of 8, based on our finding that the taxonomy. The golden orb is a valid of dams are detrimental to smooth species faces threats that are of taxon at the species level and, therefore, pimpleback habitat. There are 74 major moderate magnitude and are imminent. receives a higher priority than reservoirs and numerous smaller These threats include habitat loss and subspecies, but a lower priority than impoundments within the historical and degradation from impoundments, species in a monotypic genus. current range of the smooth pimpleback. sedimentation, sand and gravel mining, Therefore, we assigned golden orb an Thirty-one of the 74 major reservoirs are and chemical contaminants; other LPN of 8. located within the Colorado River basin natural or manmade factors such as We will continue to monitor the and the remaining 43 reservoirs are climate change, small, isolated threats to the golden orb and the located within the Brazos River basin. populations, and nonnative species; and species’ status on an annual basis, and There are also eleven new reservoirs the fact that the threats to the species should the magnitude or imminence of that have been recommended for are not being adequately addressed by the threats change, we will revisit our development as feasible alternatives to existing regulatory mechanisms. Our assessment of the LPN. meet future water needs within the rationale for assigning the golden orb an While we conclude that listing the Brazos River basin (Brazos G Regional LPN of 8 is outlined below. golden orb is warranted, an immediate Water Planning Group 2010, p. 4B.12– Under the Service’s guidelines, the proposal to list this species is precluded 1). In addition, six new off-channel magnitude of threat is the first criterion by other higher priority listings, which reservoirs are also being considered for we look at when establishing a listing we address in the Preclusion and future development (Brazos G Regional priority. The guidance indicates that Expeditious Progress section below. Water Planning Group 2010, p. 4B.13– species with the highest magnitude of Because we have assigned the golden 2). At least one of the proposed reservoir threat are those species facing the orb an LPN of 8, work on a proposed sites on the Little River in Milam greatest threats to their continued listing determination for the species is County is in the vicinity of where a existence. These species receive the precluded by work on higher priority single live smooth pimpleback was highest listing priority. We consider the listing actions with absolute statutory, found in 2006 (Karatayev and Burlakova threats that the golden orb faces to be court-ordered, or court-approved 2008, p. 6). moderate in magnitude. Habitat loss and deadlines and final listing Dam construction fragments the range degradation from impoundments, determinations for those species that of smooth pimpleback, leaving sedimentation, sand and gravel mining, were proposed for listing with funds remaining habitats and populations and chemical contaminants are from Fiscal Year (FY) 2011. This work isolated by the structures as well as by widespread throughout the range of the includes all the actions listed in the extensive areas of deep, uninhabitable, golden orb, but several large tables below under Preclusion and impounded waters. These isolated populations remain, including one that Expeditious Progress. populations are unable to naturally was recently discovered, suggesting that recolonize suitable habitat that may be the threats are not high in magnitude. Five-Factor Evaluation for Smooth impacted by temporary but devastating Under our LPN guidelines, the second Pimpleback events, such as severe drought, chemical criterion we consider in assigning a Information pertaining to the smooth spills, or unauthorized discharges. Dams listing priority is the immediacy of pimpleback in relation to the five factors impound river habitats throughout threats. This criterion is intended to provided in section 4(a)(1) of the Act is almost the entire range of the species. ensure that the species facing actual, discussed below. These impoundments have left short identifiable threats are given priority Factor A. The Present or Threatened and isolated patches of remnant habitat, over those for which threats are only Destruction, Modification, or typically in between impounded potential or that are intrinsically Curtailment of Its Habitat or Range. reaches. Habitat downstream of dams vulnerable but are not known to be As discussed above, the decline of may be impaired for many miles; in the presently facing such threats. We mussels in Texas and across the United Brazos River downstream of Possum consider the threats to the golden orb as States is primarily the result of habitat Kingdom Reservoir, substrate was described in Factors A, D, and E under loss and degradation. Chief among the unstable for 150 km (240 mi) below the the Five-Factor Evaluation for Golden causes of decline of the smooth dam (Yeager 1993, p. 68). Orb to be imminent because these pimpleback in Texas are the effects of For species such as smooth threats are ongoing and will continue in impoundments, sedimentation, pimpleback that may be able to survive the foreseeable future. Habitat loss and dewatering, sand and gravel mining, the initial inundation of reservoirs, destruction has already occurred and and chemical contaminants. conditions within the reservoir are will continue as the human population likely to become uninhabitable. The continues to grow in central Texas. Impoundments deep water in reservoirs is very cold and Several golden orb populations may For general information on the effects often devoid of oxygen and necessary already be below the minimum viable of impoundments on freshwater nutrients (Watters 2000, p. 264). Cold population requirement, which would mussels, please refer to water (less than 11 °C (52 °F)) has been cause a reduction in the number of ‘‘Impoundments’’ under Factor A in shown to stunt mussel growth (Hanson populations and an increase in the Five-Factor Evaluation for Texas et al. 1988, p. 352). Because mussel species’ vulnerability to extinction. Fatmucket. As with golden orb, smooth reproduction is temperature dependent These threats are exacerbated by climate pimpleback are able to tolerate some (Watters and O’Dee 1999, p. 455), it is

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00028 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62193

likely that individuals living in the Sedimentation may become an p. 458). Later, central Texas, including constantly cold hypolimnion in these increasing threat to the smooth the Colorado and Brazos River basins, channels may never reproduce, or pimpleback in the Colorado and Brazos experienced a major drought in the late reproduce less frequently (Watters 2000, River basins as the Austin metropolitan 1970s (Lewis and Oliveria 1979, p. 243). p. 264). Any smooth pimpleback that area continues to expand. Activities Near record dry conditions in 2008 survived the initial inundation may associated with urbanization, such as followed by a pattern of below-normal have been unable to reproduce, road construction, increased impervious rainfall during the winter and spring of eventually eliminating the species from surfaces, and road construction can be 2009 led to one of the worst droughts in large areas of the reservoir. The same detrimental to stream habitats (Couch recorded history for most of central would be true for mussels living in cold- and Hamilton 2002, p. 1). The City of Texas, including the range of the water discharges downstream of large Austin, population approximately smooth pimpleback (Nielsen-Gammon impoundments (Watters 2000, p. 264). 800,000 people (Austin City Connection and McRoberts 2009, p. 2). This The widespread construction of dams 2011, p. 1) lies within the Colorado drought’s severity was exacerbated by throughout the range of smooth River basin, and 3.9 million people live abnormally high air temperatures, a pimpleback has significantly altered within the Brazos River basin (Brazos likely effect of climate change, which stream habitat both upstream and River Authority 2007, p. 1). Both of has already increased average air ° downstream of the dams by changing these basins have undergone substantial temperatures in Texas by at least 1 C ° fish assemblages, temperature, dissolved urbanization providing sources of (1.8 F) (Nielsen-Gammon and oxygen, and substrate. The effects of increased sediment runoff into habitats McRoberts 2009, p. 22). Instream flows dams are ongoing, decades after of the smooth pimpleback. throughout the Brazos River basin construction. In addition, the The range of the smooth pimpleback during this drought were significantly construction of new reservoirs is also receives sediment from increasing levels reduced (USGS 2011c, p. 1) and smooth being considered within the species’ of sedimentation from agriculture, pimpleback populations in areas with range that could result in additional urbanization, and sand and gravel reduced water levels, such as in the habitat loss. Because of this loss of mining; sedimentation is likely to middle Brazos River, may have been habitat and its effects on the continue to threaten the smooth negatively affected. Central Texas is populations, we conclude that the pimpleback. currently experiencing another extreme effects of impoundments are a threat to Dewatering drought, with rainfall between October the smooth pimpleback. 2010 and July 2011 being the lowest on River dewatering can occur in several record during those months (LCRA Sedimentation ways: Anthropogenic activities such as 2011c, p. 1); the effects of this drought surface water diversions and are being observed but are not yet fully For general information on the effects groundwater pumping, and natural of sedimentation on freshwater mussels, known. Droughts result in a decrease in events, such as drought, which can water depth and flow velocity in please refer to ‘‘Sedimentation’’ under result in mussels stranded in previously Factor A in Five-Factor Evaluation for streams inhabited by smooth wetted areas. This is a particular pimpleback, which reduces the Texas Fatmucket. concern for smooth pimpleback within availability of food and dissolved As with other freshwater mussel and below reservoirs, where water oxygen and reduces survivability. As species, the smooth pimpleback is also levels are managed for various purposes droughts persist, mussels face hypoxia, threatened by sedimentation. The that can cause water levels in the elevated water temperature and, dominant land use in the Colorado reservoir or downstream to rise or fall in ultimately, death due to stranding River basin is grazing (Hersh 2007, p. very short periods of time, such as when (Golladay et al. 2004, p. 501). 11). Soil compaction from intensive hydropower facilities release water grazing may reduce infiltration rates and during peak energy demand periods. Sand and Gravel Mining increase runoff, and trampling of The three impoundments on the For general information on the effects riparian vegetation increases the Colorado River with records of smooth of sand and gravel mining on freshwater probability of erosion (Armour et al. pimpleback all experience periodic mussels, please refer to ‘‘Sand and 1994, p. 10; Brim Box and Mossa 1999, water level drawdowns, which may Gravel Mining’’ under Factor A in Five- p. 103). Additionally, much of the have contributed to the species’ Factor Evaluation for Texas Fatmucket. Brazos River basin is grazed or farmed apparent extirpation from Inks Lake and The Brazos River has a long history of for row crops, which often contributes Lake Marble Falls. In fact, smooth sand mining, particularly in the lower large amounts of sediment to the basin pimpleback have been found stranded river, and channel morphology changes (Brazos River Authority 2007, p. 4). (which leads to death) after drawdowns have been attributed to destabilization Reservoir construction in the upper in both of these reservoirs (Howells due to instream sand mining in the area portion of the basin has been attributed 1996, p. 22; 1999, p. 16). (USGS 2001, p. 27). The removal of sand with the erosion and subsequent Drought can also severely impact from within the river creates sediment sedimentation of the lower river (USGS smooth pimpleback populations. For traps during periods of high flow, which 2001, p. 30), as sediment-poor tailwaters example, the Little Brazos River, which causes scouring and erosion scour the riverbanks below the dam and once contained a diverse and numerous downstream (USGS 2001, p. 27). One deposit sediment farther downstream. In freshwater mussel community that gravel dredging operation in the Brazos 2004, sedimentation was high enough in included smooth pimpleback (Gentner River was documented depositing the Brazos River below Possum and Hopkins 1966, p. 458), experienced sediment as far as 1.6 km (1 mile) Kingdom Reservoir to cause residents to a severe drought from about 1950 to downstream (Forshage and Carter 1973, raise concerns to the Brazos River 1956 that reduced the river to a series p. 697). Accelerated stream bank erosion Authority (Brazos River Authority 2006, of small, stagnant pools. The results of and downcutting of streambeds are p. 2), and elevated suspended sediment this habitat degradation from the low common effects of instream sand and levels have been reported throughout water nearly eliminated the mussel gravel mining, as is the mobilization of the basin (Brazos River Authority 2006, community and killed many smooth fine sediments during sand and gravel p. 8). pimpleback (Gentner and Hopkins 1966, extraction (Roell 1999, p. 7).

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00029 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62194 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

Within the range of the smooth segment of the Little Brazos River range of the species and have far- pimpleback, TPWD has issued permits upstream from a smooth pimpleback reaching effects to riverine habitat both for four current sand mining activities population. This site once supported an upstream and downstream of the dams. within the Brazos River (Austin, abundant and diverse number of mussel Both the Colorado and Brazos River Bosque, and Fort Bend Counties) species, including the smooth systems have experienced a large (TPWD 2004, p. 1; 2007b, p. 1, 2008b, pimpleback, but when it was revisited amount of sedimentation from p. 1; 2010b, p. 1). The permits allow for in 1993, a massive die-off of freshwater agriculture, instream mining, and urban the repeated removal of sand and gravel mussels had occurred (Howells 2010b, development. Sand and gravel mining at various locations within the Brazos p. 11). In another instance in 2010, affects smooth pimpleback habitat by River. The lower Brazos River, where crude oil overflowed from a failed increasing sedimentation and channel these mining activities occur, contains storage tank into Keechi Creek in Leon instability downstream and by causing one of the more numerous populations County, a tributary to the Navasota headcutting upstream. Chemical of smooth pimpleback. River (National Response Center 2010, contaminants exceeding the standards The smooth pimpleback population in p. 2). This location is near a small developed to support aquatic life have the lower Brazos River may be currently population of smooth pimpleback and been documented throughout the range affected by sand and gravel mining. upstream of one of the largest known of the species and may represent a These activities occur over a long period populations of the species. significant threat to the smooth of time, destabilizing mussel habitat Numerous other spills have occurred pimpleback. However, the large both upstream and downstream, which within the range of the smooth populations in the San Saba River, decreases the likelihood of pimpleback. These occurred from on- lower Brazos River, Navasota River, recolonization after the activity has been site accidents (storage tank or pipeline Leon River, and Yegua Creek indicate completed. Therefore, the effects of sand spills) or from tanker truck accidents that some smooth pimpleback and gravel mining are an ongoing threat within watersheds occupied by smooth populations are not currently as to the smooth pimpleback and are pimpleback. For example, oil has vulnerable to habitat loss as others. expected to continue to occur spilled into the Brazos River a number Therefore, based upon our review of the throughout the range of the species. of times. As much as 320,000 L (84,000 best commercial and scientific data gal) of crude oil was spilled in the Chemical Contaminants available, we conclude that the present Brazos River in Knox County in 1991 or threatened destruction, modification, For general information on the effects (Associated Press 1991, p. 1). In June or curtailment of its habitat or range is of chemical contaminants on freshwater 2010, flooding of holding ponds an immediate threat of moderate mussels, please refer to ‘‘Chemical adjacent to oil drilling operations leaked magnitude to the smooth pimpleback. Contaminants’’ under Factor A in Five- oil into Thompson Creek and Factor B. Overutilization for Factor Evaluation for Texas Fatmucket. subsequently into the Brazos River Commercial, Recreational, Scientific, or As with other freshwater mussels, the (Lewis 2010, p. 1). Also, in July 2010, Educational Purposes. smooth pimpleback is also threatened oil pipelines burst and released by chemical contaminants. TCEQ data approximately 165 barrels of crude oil The smooth pimpleback is not a for 2010 indicated that 26 of the 98 into the upper Double Mountain Fork of commercially valuable species and has assessed water bodies within Colorado the Brazos River in Garza County (Joiner never been harvested in Texas as a River basin and 81 of approximately 124 2010, p. 1). Although no analyses were commercial mussel species (Howells assessed water bodies within Brazos conducted of the specific effects of these 2010b, p.12). Some scientific collecting River basin did not meet surface water spills on smooth pimpleback, we expect occurs but is not likely to be a quality standards and were classified as that if the mussels are exposed to even significant threat to the species because impaired water bodies (Texas Clean moderate levels of toxic chemical it occurs only rarely. However, handling Rivers Program 2010a, p. 5; TCEQ contaminants, such as crude oil, adverse mussels can disturb gravid females and 2010c, pp. 1–106). These water bodies effects (both direct mortality and result in glochidial loss and subsequent were impaired with dissolved solids, indirect effects to food source reproductive failure. Additionally, nitrites, nitrates, bacteria, low dissolved availabity) are likely to occur. handling has also been shown to reduce oxygen, aluminum, sulfates, selenium, Releases of chemical contaminants, shell growth across mussel species, chloride, orthophosphorus, phosphorus, such as oil, ammonia, copper, mercury, including several species of Lampsilis Chlorophyll a, and low pH associated nutrients, pesticides, and other (Haag and Commens-Carson 2008, pp. with agricultural, urban, municipal, and compounds into the habitat of the 505–506). Repeated handling by industrial runoff. Of these, nitrites and smooth pimpleback are an ongoing researchers may adversely affect smooth low dissolved oxygen are known to be threat to the smooth pimpleback. The pimpleback individuals, but these harmful to freshwater mussels. species is vulnerable to acute activities are occurring rarely and are Agricultural pesticides and emerging contamination from spills, as well as not likely to be a threat to populations. contaminants are likely also present in chronic contaminant exposure, which Handling for scientific purposes streams inhabited by smooth has occurred and is expected to contributes to the long-term pimpleback. There are 53 wastewater continue to occur throughout the range conservation of the species. treatment plants permitted to discharge of the smooth pimpleback. We do not have any evidence of risks more than one million gallons per day to the smooth pimpleback from into the Brazos River basin (Valenti and Summary of Factor A overutilization for commercial, Brooks 2008, p. 12); the outfalls of these The reduction in numbers and range recreational, scientific, or educational treatment plants have not been tested to of the smooth pimpleback is primarily purposes, and we have no reason to determine if they contain contaminants the result of the long-lasting effects of believe this factor will become a threat of note. habitat alterations such as the effects of to the species in the future. Based upon Examples of the exposure of smooth impoundments, sedimentation, the best scientific and commercial pimpleback to chemical contaminants dewatering, sand and gravel mining, information available, we conclude that include an event in 1993 when an and chemical contaminants. overutilization for commercial, unknown substance was dumped into a Impoundments occur throughout the recreational, scientific, or educational

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00030 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62195

purposes does not pose a threat to the Factor D under Five-Factor Evaluation Population Fragmentation and Isolation smooth pimpleback rangewide. for Texas Fatmucket. Factor C. Disease and Predation. For general information on the effects Summary of Factor D of population fragmentation and Disease isolation on freshwater mussels of Despite State and Federal laws central Texas, please refer to Little is known about disease in protecting the species and water quality, ‘‘Population Fragmentation and freshwater mussels. However, disease is the smooth pimpleback continues to Isolation’’ under Factor E in Five-Factor believed to be a contributing factor in decline due to the effects of habitat Evaluation for Texas Fatmucket. As documented mussel die-offs in other destruction, poor water quality, with many freshwater mussels, several parts of the United States (Neves 1987, contaminants, and other factors. The of the remaining populations of the pp. 11–12). Diseases have not been regulatory measures described under smooth pimpleback are small and documented or observed during any Factor D in the Five-Factor Evaluation geographically isolated and thus are studies of smooth pimpleback. for Texas Fatmucket have been susceptible to genetic drift, inbreeding insufficient to significantly reduce or Predation depression, and random or chance remove the threats to the smooth changes to the environment, such as Raccoons will prey on freshwater pimpleback. Based upon our review of toxic chemical spills (Watters and Dunn mussels stranded by low waters or the best commercial and scientific data 1995, pp. 257–258), or dewatering. deposited in shallow water or on bars available, we conclude that the lack of Historically, the smooth pimpleback following flooding or low water periods existing regulatory mechanisms is an was widespread throughout much of the (Howells 2010c, p. 12). Predation of immediate and ongoing threat of Colorado and Brazos River systems smooth pimpleback by raccoons may be moderate magnitude to the smooth when few natural barriers existed to occurring occasionally, but there is no pimpleback. prevent migration (via host species) indication it is a significant threat to the Factor E. Other Natural or Manmade status of the species. among suitable habitats. The extensive Factors Affecting Its Continued impoundment of the Brazos and Some species of fish feed on mussels, Existence. such as common carp, freshwater drum, Colorado River basins has fragmented and redear sunfish, all of which are Natural and manmade factors that smooth pimpleback populations common throughout the range of threaten the smooth pimpleback include throughout these river systems. smooth pimpleback (Hubbs et al. 2008, climate change, population Small smooth pimpleback pp. 19, 45, 53). Common species of fragmentation and isolation, and populations, including those in Lake flatworms are voracious predators of nonnative species. LBJ Reservoir and the middle Brazos, newly metamorphosed juvenile mussels Climate Change Little, and Little Brazos Rivers, may be of many species (Zimmerman et al. below the minimum population size 2003, p. 30). Predation is a normal factor For general information on the effects required to maintain population influencing the population dynamics of of climate change on freshwater mussels viability into the future, therefore a healthy mussel population; however, of central Texas, please refer to ‘‘Climate making these populations more predation may amplify declines in small Change’’ under Factor E in Five-Factor vulnerable to extirpation since they are populations primarily caused by other Evaluation for Texas Fatmucket. less likely to be able to recover through factors. Because the range of the smooth recruitment from events that reduce but pimpleback has been reduced to do not extirpate populations. Summary of Factor C isolated locations, many with low Additionally, these small populations Disease in freshwater mussels is population numbers, in small rivers and are more vulnerable to extirpation from poorly known, and we do not have any streams, the smooth pimpleback is stochastic events, as the lack of information indicating it is a threat to vulnerable to climatic changes that connectivity among populations does the smooth pimpleback. Additionally, could decrease the availability of water. not permit nearby populations to predation is a natural ecological The disjunct nature of the remaining recolonize areas affected by intense interaction and we have no information smooth pimpleback populations, droughts, toxic spills, or other isolated indicating the extent of any predation is coupled with the limited ability of events that result in significant mussel a threat to populations of smooth mussels to migrate, makes it unlikely die-offs. While the small, isolated pimpleback. Based upon the best that smooth pimpleback can adjust their populations do not represent an scientific and commercial information range in response to changes in climate independent threat to the species, the available, we conclude that disease or (Strayer 2008, p. 30). Climate change situation does substantially increase the predation is not a threat to the smooth exacerbates threats to the smooth risk of extirpation from the effects of all pimpleback. pimpleback, such as habitat degradation other threats, including those addressed Factor D. The Inadequacy of Existing from prolonged periods of drought; in this analysis, and those that could Regulatory Mechanisms. increased water temperature; and the occur in the future from unknown Existing regulatory mechanisms that increased allocation of water for sources. could have an effect on threats to the municipal, agricultural, and industrial Based upon our review of the best smooth pimpleback include State and uses The magnitude and imminence of commercial and scientific data Federal laws such as Texas Threatened these effects, however, remain available, we conclude that and Endangered Species regulations and uncertain. Based upon our review of the fragmentation and isolation of small freshwater mussel sanctuaries, State and best commercial and scientific data remaining populations of the smooth Federal sand and gravel mining available, we conclude that the effects of pimpleback are occurring and are regulations, and regulation of point and climate change in the future will likely ongoing threats to the species non-point source pollution. For more exacerbate the current and ongoing throughout all of its range. Further, information on the effects of State and threats of habitat loss and degradation stochastic events may play a magnified Federal laws on the threats to freshwater caused by other factors, as discussed in role in extirpation of small, isolated mussels in central Texas, please refer to Factor A. populations.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00031 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62196 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

Nonnative Species Finding for Smooth Pimpleback regulation temporarily listing the For general information on the effects As required by the Act, we considered species under section 4(b)(7) of the Act of nonnative species on freshwater the five factors in assessing whether the is warranted. We determined that mussels of central Texas, please refer to smooth pimpleback is threatened or issuing an emergency regulation ‘‘Nonnative Species’’ in Factor E under endangered throughout all of its range. temporarily listing the species is not Five-Factor Evaluation for Texas We examined the best scientific and warranted for the smooth pimpleback at Fatmucket. As with other freshwater commercial information available this time, because we have not mussels, the smooth pimpleback is regarding the past, present, and future identified a threat or activity that poses a significant risk, such that losses to the threatened by nonnative species. threats faced by the smooth pimpleback. species during the normal listing Various nonnative aquatic species pose We reviewed the petition, information process would endanger the continued a threat to the smooth pimpleback, available in our files, and other existence of the entire species. However, including golden algae, zebra mussels, available published and unpublished if at any time we determine that issuing and black carp. Of these, golden algae information, and we consulted with an emergency regulation temporarily has been responsible for killing more recognized smooth pimpleback experts listing the smooth pimpleback is than eight million fish in the Brazos and other Federal and State agencies. warranted, we will initiate this action at River since 1981 and more than two This status review identifies threats to that time. million fish in the Colorado River since the smooth pimpleback attributable to 1989 (TPWD 2010a, p. 1). Although Factors A, D, and E. The primary threat Listing Priority Number for Smooth mussel kills due to golden algae have to the species is from habitat destruction Pimpleback not been recorded, we expect golden and modification (Factor A) from The Service adopted guidelines on algae to negatively affect mussel impoundments, which scour riverbeds, September 21, 1983 (48 FR 43098), to populations through loss of host fish thereby removing mussel habitat, establish a rational system for utilizing and direct toxicity. Zebra mussels and decreases water quality, modifies stream available resources for the highest black carp do not currently occur within flows, and restricts fish host migration priority species when adding species to the range of the smooth pimpleback, and distribution of freshwater mussels. the Lists of Endangered and Threatened although both are found in Texas and Additional threats under Factor A Wildlife and Plants or reclassifying could be introduced to the Brazos and include sedimentation, dewatering, species listed as threatened to Colorado Rivers in the forseeable future. sand and gravel mining, and chemical endangered status. These guidelines, Based on population responses of other contaminants. Also, most of these titled ‘‘Endangered and Threatened mussel species that overlap with zebra threats may be exacerbated by the Species Listing and Recovery Priority mussels and black carp in similar river current and projected effects of climate Guidelines’’ address the immediacy and conditions, we conclude that the change (discussed under Factor E). magnitude of threats, and the level of introduction of zebra mussels or black Threats to the smooth pimpleback are taxonomic distinctiveness by assigning carp into the range of smooth not being adequately addressed through priority in descending order to pimpleback would be devastating to the existing regulatory mechanisms (Factor monotypic genera (genus with one species. D). Because of the limited distribution species), full species, and subspecies (or Based upon our review of the best of this endemic species and its lack of equivalently, distinct population commercial and scientific data mobility, these threats are likely to lead segments of vertebrates). available, we conclude that golden algae to the extinction of the smooth As a result of our analysis of the best is an ongoing threat to the smooth pimpleback in the foreseeable future. available scientific and commercial pimpleback, and other nonnative On the basis of the best scientific and information, we have assigned the species, such as zebra mussels and black commercial information available, we smooth pimpleback an LPN of 8, based carp, are a potential threat to the smooth find that the petitioned action to list the on our finding that the species faces pimpleback that is likely to increase as smooth pimpleback under the Act is threats that are of moderate magnitude these exotic species expand their warranted. We will make a and are imminent. These threats include occupancy to include the range of the determination on the status of the habitat loss and degradation from smooth pimpleback. species as threatened or endangered impoundments, sedimentation, sand when we complete a proposed listing and gravel mining, and chemical Summary of Factor E determination. When we complete a contaminants; other natural or The effects of climate change, while proposed listing determination, we will manmade factors such as climate difficult to quantify at this time, are examine whether the species may be change, small, isolated populations, and likely to exacerbate the current and endangered or threatened throughout all nonnative species; and the fact that the ongoing threat of habitat loss caused by of its range; or whether the species may threats to the species are not being other factors, and the small sizes and be endangered or threatened in a adequately addressed by existing fragmented nature of the remaining significant portion of its range. regulatory mechanisms. Our rationale populations render them more However, as explained in more detail for assigning the smooth pimpleback an vulnerable to extirpation. In addition, below, an immediate proposal of a LPN of 8 is outlined below. nonnative species, such as golden algae, regulation implementing this action is We consider the threats that the currently threaten the Texas fatmucket, precluded by higher priority listing smooth pimpleback faces to be moderate and the potential introduction of zebra actions, and progress is being made to in magnitude. Habitat loss and mussels and black carp are potential add or remove qualified species from degradation from impoundments, future threats. Based upon our review of the Lists of Endangered and Threatened sedimentation, sand and gravel mining, the best commercial and scientific data Wildlife and Plants. and chemical contaminants are available, we conclude that other We reviewed the available widespread throughout the range of the natural or manmade factors are information to determine if the existing smooth pimpleback, but several large immediate and ongoing threats of and foreseeable threats render the populations remain, including one that moderate magnitude to the smooth smooth pimpleback at risk of extinction was recently discovered, indicating the pimpleback. now such that issuing an emergency threats are not high in magnitude.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00032 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62197

Under our LPN guidelines, the second provided in section 4(a)(1) of the Act is have been ongoing since at least 1992, criterion we consider in assigning a discussed below. and no evidence of live or dead Texas listing priority is the immediacy of Factor A. The Present or Threatened pimpleback has been found in any threats. We consider the threats to the Destruction, Modification, or reservoir (Howells 1994, pp. 1–20; 1995, smooth pimpleback as described under Curtailment of Its Habitat or Range. pp. 1–50; 1996, pp. 1–45; 1997a, pp. 1– ‘‘Factor A. The Present or Threatened As discussed above, the decline of 58; 1998, pp. 1–30; 1999, pp. 1–34; Destruction, Modification, or mussels in Texas and across the United 2000a, pp. 1–56; 2001, pp. 1–50; 2002a, Curtailment of Its Habitat or Range,’’ States is primarily the result of habitat pp. 1–28; 2003, pp. 1–42; 2004, pp. 1– ‘‘Factor D. The Inadequacy of Existing loss and degradation. Chief among the 48; 2005, pp. 1–23; 2006, pp. 1–106; Regulatory Mechanisms,’’ and ‘‘Factor causes of decline of the Texas Karatayev and Burlakova 2008, pp. 1– E. Other Natural Or Manmade Factors pimpleback are the effects of 47; Burlakova and Karatayev 2010a, pp. Affecting Its Continued Existence’’ impoundments, sedimentation, 1–30; 2011, pp. 1–8), further indicating under the Five-Factor Evaluation for dewatering, sand and gravel mining, that this species is not tolerant of Smooth Pimpleback to be imminent and chemical contaminants. These impoundments. because these threats are ongoing and threats are discussed below. Texas pimpleback populations will continue in the foreseeable future. Impoundments downstream of dams are affected as Habitat loss and destruction has already well. Cold water (less than 11 °C (52 °F)) occurred and will continue as the For general information on the effects has been shown to stunt mussel growth human population continues to grow in of impoundments on freshwater (Hanson et al. 1988, p. 352) and reduce central Texas. Several smooth mussels, please refer to or inhibit reproduction, because mussel pimpleback populations may already be ‘‘Impoundments’’ in Factor A under reproduction is temperature dependent below the minimum viable population Five-Factor Evaluation for Texas (Watters and O’Dee 1999, pp. 455). requirement, which would cause a Fatmucket. Texas pimpleback living in cold-water reduction in the number of populations As with other freshwater mussel discharges downstream of large and an increase in the species’ species, the Texas pimpleback is also impoundments are unlikely to vulnerability to extinction. These threatened by impoundments. There are reproduce (Watters 2000, p. 264). threats are exacerbated by climate 37 major reservoirs and numerous Dam construction also fragments the change, which will increase the smaller impoundments within the range of Texas pimpleback, leaving frequency and magnitude of droughts. historical and current range of the Texas remaining habitats and populations Therefore, we consider these threats to pimpleback. There are 31 major isolated by the structures as well as by be imminent. reservoirs within the Colorado River extensive areas of deep, uninhabitable, Thirdly, the smooth pimpleback is a basin, with another reservoir impounded waters. These isolated valid taxon at the species level and, (Goldthwaite Reservoir) proposed for populations are unable to naturally therefore, receives a higher priority than the Colorado River in San Saba County recolonize suitable habitat that may be subspecies, but a lower priority than near a Texas pimpleback population; impacted by temporary but devastating species in a monotypic genus. this reservoir was the number one events, such as severe drought, chemical Therefore, we assigned smooth recommendation in the water plan for spills, or unauthorized discharges. Dams pimpleback an LPN of 8. We will the region (TWDB 2011, pp. 4–85). impound river habitats throughout continue to monitor the threats to the There are 29 reservoirs within the almost the entire range of the species. smooth pimpleback and the species’ Guadalupe River basin and 34 within These impoundments have left short status on an annual basis, and should the San Antonio River basin, each with and isolated patches of suitable habitat, the magnitude or imminence of the a storage capacity of 3,000 acre-feet or typically in between impounded threats change, we will revisit our more, and many other smaller reservoirs reaches. assessment of the LPN. (Exelon 2010, p. 2.3–4). The majority of The widespread construction of dams While we conclude that listing the the large dams were constructed for throughout the range of Texas smooth pimpleback is warranted, an power generation, flood control, and pimpleback has significantly altered immediate proposal to list this species water supply by the Lower Colorado stream habitat both upstream and is precluded by other higher priority River and Guadalupe-Blanco River downstream of the dams by changing listings, which we address in the Authorities beginning as early as 1935 fish assemblages, temperature, dissolved Preclusion and Expeditious Progress (Guadalupe-Blanco River Authority oxygen, and substrate. The effects of section below. Because we have 2011, p. 1; LCRA 2011a, p. 1). These and dams are ongoing decades after assigned the smooth pimpleback an LPN numerous smaller dams occur construction. Because of this loss of of 8, work on a proposed listing throughout the Colorado and Guadalupe habitat and its effects on the determination for the species is River basins, fragmenting habitat and populations, we conclude that the precluded by work on higher priority populations of Texas pimpleback. effects of dams are a threat to the Texas listing actions with absolute statutory, There are no natural lakes within the pimpleback. court-ordered, or court-approved range of the Texas pimpleback, nor has deadlines and final listing it ever been found in reservoirs. Sedimentation determinations for those species that Historically, the Texas pimpleback For general information on the effects were proposed for listing with funds could be found in areas of the of sedimentation on freshwater mussels, from Fiscal Year (FY) 2011. This work Guadalupe River in Comal County please refer to ‘‘Sedimentation’’ in includes all the actions listed in the (Randklev et al. 2010c, p. 4), but it has Factor A under Five-Factor Evaluation tables below under Preclusion and not been found in the area since the for Texas Fatmucket. Expeditious Progress. construction of Canyon Reservoir As with other freshwater mussel (Burlakova and Karatayev 2009, p. 6). species, the Texas pimpleback is Five-Factor Evaluation for Texas We presume the species is extirpated affected by sedimentation. The Pimpleback from this reach because of the effects of dominant land use in the Colorado Information pertaining to the Texas the reservoir. Surveys of other reservoirs River basin is grazing (Hersh 2007, p. pimpleback in relation to the five factors on the Guadalupe and Colorado Rivers 11); soil compaction from intensive

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00033 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62198 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

grazing may reduce infiltration rates and and Texas pimpleback populations in of time, destabilizing habitat both increase runoff, and trampling of areas with reduced water levels may upstream and downstream, which riparian vegetation increases the have been negatively affected. Central decreases the likelihood of probability of erosion (Armour et al. Texas is currently experiencing another recolonization after the activity has been 1994, p. 10; Brim Box and Mossa 1999, extreme drought, with rainfall between completed. Therefore, the effects of sand p. 103). Even in 1959, the Guadalupe October 2010 and July 2011 being the and gravel mining are an ongoing threat River was noted as having high lowest on record during those months to the Texas pimpleback. sedimentation rates from agricultural (LCRA 2011c, p. 1); the effects of this Chemical Contaminants activities (Soil Conservation Service drought are being observed but are not 1959, p. 59). Turbidity has also been yet fully known. Droughts result in a For general information on the effects recorded as high in the Guadalupe River decrease in water depth and flow of chemical contaminants on freshwater near Victoria (Exelon 2010, p. 2.3–186), velocity, which reduces food and mussels, please refer to ‘‘Chemical indicating a large amount of suspended oxygen delivery. As droughts persist, Contaminants’’ in Factor A under Five- sediment where a small Texas mussels face hypoxia, elevated water Factor Evaluation for Texas Fatmucket. pimpleback population was recently temperature and, ultimately, stranding As with other freshwater mussels, the found. (Golladay et al. 2004, p. 501). Texas pimpleback is affected by Streams occupied by Texas We do not know the extent of the chemical contaminants. TCEQ data for pimpleback are subject to increasing impacts of stream dewatering on the 2010 indicated that 26 of the 98 levels of sedimentation from agriculture, Texas pimpleback; however, because assessed water bodies within the urbanization, and sand and gravel several populations are small and historical and current range of the Texas mining. Agriculture is a common land isolated, the loss of numerous pimpleback did not meet surface water use in the Guadalupe and San Antonio individuals at a site can have dramatic quality standards and were classified as River basins, and the city of San consequences to the population. impaired water bodies under the Clean Antonio, the second largest city in Hydropower facilities, diversions Water Act (Texas Clean Rivers Program Texas, continues to grow (City of San associated with construction, and 2010a, p. 5). These water bodies were Antonio 2010, p. 5). Sedimentation from drought are occurring throughout the impaired with dissolved solids, nitrates, agriculture, urbanization, and sand and range of the Texas pimpleback; bacteria, low dissolved oxygen, gravel mining will continue to threaten therefore, the effects of dewatering are aluminum, sulfates, selenium, chloride, the Texas pimpleback in the foreseeable ongoing and unlikely to decrease, and low pH associated with agricultural, future. resulting in significant threats to the urban, municipal, and industrial runoff. Texas pimpleback. Additionally, the Concho River near Dewatering Paint Rock has been repeatedly River dewatering can occur in several Sand and Gravel Mining documented as having high nitrates ways: Anthropogenic activities such as For general information on the effects (Texas Clean Rivers Program 2008, p. 2); surface water diversions and of sand and gravel mining on freshwater a significant Texas pimpleback groundwater pumping, and natural mussels, please refer to ‘‘Sand and population occurs just upstream of this events, such as drought, which can Gravel Mining’’ in Factor A under Five- site. Nitrates and low dissolved oxygen result in mussels stranded in previously Factor Evaluation for Texas Fatmucket. pose the greatest threat to Texas wetted areas. This is a particular In 1995, the reach of the Guadalupe pimpleback. concern below reservoirs, whose water River near Victoria, which contains a Within the range of Texas levels are managed for various purposes Texas pimpleback population, was pimpleback, several streams have been that can cause water levels in the described as having numerous current listed as impaired due to high ammonia reservoir or downstream to rise or fall in and abandoned sand and gravel mining concentrations, including Elm Creek in very short periods of time, such as when areas (USACE 1995, p. 7). Currently, the Guadalupe River basin (TCEQ hydropower facilities release water TPWD has permitted one sand mining 2010a, p. 294). Additionally, high during peak energy demand periods. activity within the current range of copper concentrations have been Drought can also severely impact Texas pimpleback, in the Guadalupe recorded in the lower Guadalupe and Texas pimpleback populations. Central River basin in Comal County (TPWD San Antonio Rivers (Lee and Schultz Texas, including the Colorado and 2009b, p. 1); a small Texas pimpleback 1994, p. 8), and mercury has been Guadalupe River basins, experienced a population occurs downstream of this documented throughout the Guadalupe major drought in the late 1970s (Lewis area in the Guadalupe River. The permit and San Antonio Rivers, with and Oliveria 1979, p. 243). Near record allows for the repeated removal of sand particularly high concentrations in fish dry conditions in 2008 followed by a and gravel at various locations within in the upper reaches of both rivers (Lee pattern of below-normal rainfall during the stream. and Schultz 1994, p. 8). Agricultural the winter and spring of 2009 led to one Headcuts from sand and gravel pesticides and emerging contaminants of the worst droughts in recorded mining operations have been are likely also present in streams history for most of central Texas, documented in the San Antonio River inhabited by Texas pimpleback. including the range of the Texas basin in Karnes County from as early as Chemical contaminants, such as pimpleback (Nielsen-Gammon and 1967, with downstream channels having ammonia, copper, mercury, nutrients, McRoberts 2009, p. 2). This drought’s steep, eroded banks (Kennon et al. 1967, pesticides, and other compounds are severity was exacerbated by abnormally p. 22). There has been no evidence of currently a threat to the Texas high air temperatures, a likely effect of Texas pimpleback in Karnes County in pimpleback. The species is vulnerable climate change, which has already recent years (Howells 1997a, pp. 41–42), to acute contamination from spills as increased average air temperatures in and the effects of sand mining may have well as chronic contaminant exposure, Texas by at least 1 °C (1.8 °F) (Nielsen- been a factor in the species’ extirpation. which is occurring rangewide. Gammon and McRoberts 2009, p. 22). The Texas pimpleback population in Instream flows throughout the Colorado the Guadalupe River may be currently Summary of Factor A River basin during this drought were threatened by sand and gravel mining. The reduction in numbers and range significantly reduced (USGS 2011c, p. 1) These activities occur over a long period of the Texas pimpleback is primarily the

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00034 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62199

result of the long-lasting effects of information available, we conclude that information on the effects of State and habitat alterations such as the effects of overutilization for commercial, Federal laws on the threats to freshwater impoundments, sedimentation, sand recreational, scientific, or educational mussels in central Texas, please refer to and gravel mining, and chemical purposes does not pose a significant Factor D under Five-Factor Evaluation contaminants. Impoundments occur threat to the Texas pimpleback for Texas throughout the range of the species and rangewide. have far-reaching effects both up and Factor C. Disease and Predation. Fatmucket downstream. Both the Colorado and Disease Summary of Factor D Guadalupe River systems have Despite State and Federal laws experienced a large amount of Little is known about disease in protecting the species and water quality, sedimentation from agriculture, freshwater mussels. However, disease is the Texas pimpleback continues to instream mining, and urban believed to be a contributing factor in decline due to the effects of habitat development. Sand and gravel mining documented mussel die-offs in other destruction, poor water quality, affects Texas pimpleback habitat by parts of the United States (Neves 1987, contaminants, and other factors. The increasing sedimentation and channel pp. 11–12). Diseases have not been regulatory measures described above instability downstream and causing documented or observed during any have been insufficient to significantly headcutting upstream. Chemical studies of Texas pimpleback. reduce or remove the threats to the contaminants have been documented Predation throughout the range of the species and Texas pimpleback. Based upon our may represent a significant threat to the Raccoons will prey on freshwater review of the best commercial and Texas pimpleback. Based upon our mussels stranded by low waters or scientific data available, we conclude review of the best commercial and deposited in shallow water or on bars that the lack of existing regulatory scientific data available, we conclude following flooding or low water periods mechanisms is an immediate threat of that the present or threatened (Howells 2010c, p. 12). Predation of moderate magnitude to the Texas destruction, modification, or Texas pimpleback by raccoons may be pimpleback. curtailment of its habitat or range is an occurring occasionally but there is no Factor E. Other Natural or Manmade immediate threat of high magnitude to indication it is a significant threat to the Factors Affecting Its Continued the Texas pimpleback. status of the species. Existence. Factor B. Overutilization for Some species of fish feed on mussels, Natural and manmade factors that Commercial, Recreational, Scientific, or such as common carp, freshwater drum, threaten the Texas pimpleback include Educational Purposes. and redear sunfish, all of which are climate change, population The Texas pimpleback was common throughout the range of Texas fragmentation and isolation, and historically harvested occasionally but pimpleback (Hubbs et al. 2008, pp. 19, nonnative species. never experienced high levels of 45, 53). Common species of flatworms Climate Change collecting pressure (Howells 2010e, are voracious predators of newly p.10). Although levels were light metamorphosed juvenile mussels of For general information on the effects enough that commercial harvest was many species (Zimmerman et al. 2003, of climate change on freshwater mussels likely not a threat to populations, all p. 30). Predation is a normal factor of central Texas, please refer to‘‘Climate commercial collecting became illegal influencing the population dynamics of Change’’ in Factor E under Five-Factor when Texas pimpleback was listed as a healthy mussel population; however, Evaluation for Texas Fatmucket. threatened by TPWD; therefore, predation may amplify declines in small Because the range of the Texas commercial harvest is not a current populations primarily caused by other pimpleback has been reduced to threat to Texas pimpleback. Some factors. isolated locations with low population scientific collecting occurs but is not numbers in small rivers and streams, the likely to be a significant threat to the Summary of Factor C Texas pimpleback is vulnerable to species because it occurs only rarely. Disease in freshwater mussels is climatic changes that could decrease the However, handling mussels can disturb poorly known, and we do not have any availability of water. gravid females and result in glochidial information indicating it is a threat to The disjunct nature of the remaining loss and subsequent reproductive the Texas pimpleback. Additionally, Texas pimpleback populations, coupled failure. Additionally, handling has been predation is a natural ecological with the limited ability of mussels to shown to reduce shell growth across interaction and we have no information migrate, makes it unlikely that Texas mussel species, including several indicating the extent of any predation is pimpleback can adjust their range in species of Lampsilis (Haag and a threat to populations of Texas response to changes in climate (Strayer Commens-Carson 2008, pp. 505–506). pimpleback. Based upon the best 2008, p. 30). Climate change could affect Repeated handling by researchers may scientific and commercial information the Texas pimpleback through the adversely affect Texas pimpleback available, we conclude that disease or combined effects of global and regional individuals, but these activities are predation is not a threat to the Texas climate change, along with the occurring rarely and are not likely to be pimpleback. increased probability of long-term a threat to populations. Handling for Factor D. The Inadequacy of Existing drought. Climate change exacerbates scientific purposes contributes to the Regulatory Mechanisms. threats such as habitat degradation from long-term conservation of the species. Existing regulatory mechanisms that prolonged periods of drought, increased We do not have any evidence of risks could have an effect on threats to the water temperature, and the increased to the Texas pimpleback from Texas pimpleback include State and allocation of water for municipal, overutilization for commercial, Federal laws such as Texas Threatened agricultural, and industrial use. Climate recreational, scientific, or educational and Endangered Species regulations and change may be a significant stressor that purposes, and we have no reason to freshwater mussel sanctuaries, State and exacerbates existing threats by believe this factor will become a threat Federal sand and gravel mining increasing the likelihood of prolonged to the species in the future. Based upon regulations, and regulation of point and drought. As such, climate change, in the best scientific and commercial non-point source pollution. For more and of itself, may affect the Texas

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00035 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62200 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

pimpleback, but the magnitude and available, we conclude that immediate threats of moderate imminence of the effects remain fragmentation and isolation of small magnitude to the Texas pimpleback. uncertain. Based upon our review of the remaining populations of the Texas Finding for Texas Pimpleback best commercial and scientific data pimpleback are occurring and are available, we conclude that the effects of ongoing threats to the species As required by the Act, we considered climate change in the future will likely throughout all of its range. Further, the five factors in assessing whether the exacerbate the current and ongoing stochastic events may play a magnified Texas pimpleback is threatened or threats of habitat loss and degradation role in extirpation of small, isolated endangered throughout all of its range. caused by other factors, as discussed populations. We examined the best scientific and above. commercial information available Nonnative Species regarding the past, present, and future Population Fragmentation and Isolation For general information on the effects threats faced by the Texas pimpleback. For more information on the effects of of nonnative species on freshwater We reviewed the petition, information population fragmentation and isolation mussels of central Texas, please refer to available in our files, and other on freshwater mussels of central Texas, ‘‘Nonnative Species’’ in Factor E under available published and unpublished please refer to ‘‘Population Five-Factor Evaluation for Texas information, and we consulted with Fragmentation and Isolation’’ in Factor Fatmucket. As with other freshwater recognized Texas pimpleback experts E under Five-Factor Evaluation for mussels, the Texas pimpleback is and other Federal and State agencies. This status review identifies threats to Texas Fatmucket. As with many threatened by nonnative species. the Texas pimpleback attributable to freshwater mussels, most of the Various nonnative aquatic species pose Factors A, D, and E. The primary threat remaining populations of the Texas a threat to the Texas pimpleback, to the species is from habitat destruction pimpleback are small and including golden algae, zebra mussels, and modification (Factor A) from geographically isolated and thus are and black carp. Of these, golden algae impoundments, which scour riverbeds, susceptible to genetic drift, inbreeding has been responsible for killing more thereby removing mussel habitat, depression, and random or chance than two million fish in the Colorado changes to the environment, such as decrease water quality, modify stream River since 1989 (TPWD 2010a, p. 1). toxic chemical spills (Watters and Dunn flows, and restrict fish host migration Although mussel kills due to golden 1995, pp. 257–258) or dewatering. and distribution of freshwater mussels. algae have not been recorded, we expect Historically, the Texas pimpleback was Additional threats under Factor A golden algae to negatively affect mussel once widespread throughout much of include sedimentation, dewatering, populations through loss of host fish the Colorado and Guadalupe River sand and gravel mining, and chemical and direct toxicity. Zebra mussels and systems when few natural barriers contaminants. Also, most of these black carp do not currently occur within existed to prevent migration (via host threats may be exacerbated by the the range of the Texas pimpleback, species) among suitable habitats. The current and projected effects of climate although both are found in Texas and extensive impoundment of the Colorado change (discussed under Factor E). and Guadalupe River basins has could be introduced to the Colorado and Threats to the Texas pimpleback are not fragmented Texas pimpleback Guadalupe Rivers in the forseeable being adequately addressed through populations throughout these river future. Their introduction into the range existing regulatory mechanisms (Factor systems. of Texas pimpleback would be D). Because of the limited distribution Small Texas pimpleback populations, devastating. of this endemic species and its lack of including those in the lower Guadalupe Based upon our review of the best mobility, these threats are likely to lead River, mainstem Colorado River, and commercial and scientific data to the extinction of the Texas San Marcos River, may be below the available, we conclude that golden algae pimpleback in the foreseeable future. minimum population size required to is an ongoing threat to the Texas On the basis of the best scientific and maintain population viability into the pimpleback and other nonnative commercial information available, we future. These populations are more species, such as zebra mussels and black find that the petitioned action to list the vulnerable to extirpation since they are carp, are a potential threat to the Texas Texas pimpleback under the Act is less likely to be able to recover through pimpleback that is likely to increase as warranted. We will make a recruitment from events that reduce but these exotic species expand their determination on the status of the do not extirpate populations. occupancy within the range of the Texas species as threatened or endangered Additionally, these small populations pimpleback. when we complete a proposed listing are more vulnerable to extirpation from Summary of Factor E determination. When we complete a stochastic events, as the lack of proposed listing determination, we will connectivity among populations does The effects of climate change, while examine whether the species may be not permit nearby populations to difficult to quantify at this time, are endangered or threatened throughout all recolonize areas affected by intense likely to exacerbate the current and of its range or whether the species may droughts, toxic spills, or other isolated ongoing threat of habitat loss caused by be endangered or threatened in a events that result in significant mussel other factors, and the small sizes and significant portion of its range. die-offs. While the small, isolated fragmented nature of the remaining However, as explained in more detail populations do not represent an populations render them more below, an immediate proposal of a independent threat to the species, the vulnerable to extirpation. In addition, regulation implementing this action is situation does substantially increase the nonnative species, such as golden algae, precluded by higher priority listing risk of extirpation from the effects of all currently threaten the Texas fatmucket, actions, and progress is being made to other threats, including those addressed and the potential introduction of zebra add or remove qualified species from in this analysis, and those that could mussels and black carp are potential the Lists of Endangered and Threatened occur in the future from unknown future threats. Based upon our review of Wildlife and Plants. sources. the best commercial and scientific data We reviewed the available Based upon our review of the best available, we conclude that other information to determine if the existing commercial and scientific data natural or manmade factors are and foreseeable threats render the Texas

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00036 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62201

pimpleback at risk of extinction now small, isolated, and highly vulnerable to As discussed above, the decline of such that issuing an emergency stochastic events. mussels in Texas and across the United regulation temporarily listing the Under our LPN guidelines, the second States is primarily the result of habitat species under section 4(b)(7) of the Act criterion we consider in assigning a loss and degradation. Chief among the is warranted. We determined that listing priority is the immediacy of causes of decline of the Texas fawnsfoot issuing an emergency regulation threats. We consider the threats to the in Texas are the effects of temporarily listing the species is not Texas pimpleback as described under impoundments, sedimentation, warranted for the Texas pimpleback at Factors A, D, and E in the Five-Factor dewatering, sand and gravel mining, this time, because we have not Evaluation for Texas Pimpleback and chemical contaminants. These identified a threat or activity that poses section to be imminent because these threats are discussed below. a significant risk, such that losses to the threats are ongoing and will continue in Impoundments species during the normal listing the foreseeable future. Habitat loss and process would endanger the continued destruction has already occurred and For general information on the effects existence of the entire species. However, will continue as the human population of impoundments on freshwater if at any time we determine that issuing continues to grow in central Texas. The mussels, please refer to an emergency regulation temporarily Texas pimpleback populations may ‘‘Impoundments’’ in Factor A under listing the Texas pimpleback is already be below the minimum viable Five-Factor Evaluation for Texas warranted, we will initiate this action at population requirement, which would Fatmucket. Impoundments and that time. cause a reduction in the number of numerous smaller dams occur populations and an increase in the throughout the Colorado and Guadalupe Listing Priority Number for Texas species’ vulnerability to extinction. River basins, fragmenting habitat and Pimpleback These threats are exacerbated by climate populations of Texas fawnsfoot. There The Service adopted guidelines on change, which will increase the are 74 major reservoirs and numerous September 21, 1983 (48 FR 43098), to frequency and magnitude of droughts. smaller impoundments within the establish a rational system for utilizing Therefore, we consider these threats to historical and current range of the available resources for the highest be imminent. smooth pimpleback. Thirty-one of the priority species when adding species to Thirdly, the Texas pimpleback is a 74 major reservoirs are located within the Lists of Endangered and Threatened valid taxon at the species level and, the Colorado River basin and the Wildlife and Plants or reclassifying therefore, receives a higher priority than remaining 43 reservoirs are located species listed as threatened to subspecies, but a lower priority than within the Brazos River basin. There are endangered status. These guidelines, species in a monotypic genus. also eleven new reservoirs that have titled ‘‘Endangered and Threatened Therefore, we assigned Texas been recommended for development as Species Listing and Recovery Priority pimpleback an LPN of 2. We will feasible alternatives to meet future water Guidelines’’ address the immediacy and continue to monitor the threats to the needs within the Brazos River basin magnitude of threats, and the level of Texas pimpleback and the species’ (Brazos G Regional Water Planning taxonomic distinctiveness by assigning status on an annual basis, and should Group 2010, p. 4B.12–1). In addition, priority in descending order to the magnitude or imminence of the six new off-channel reservoirs are also monotypic genera (genus with one threats change, we will revisit our being considered for future species), full species, and subspecies (or assessment of the LPN. development (Brazos G Regional Water equivalently, distinct population While we conclude that listing the Planning Group 2010, p. 4B.13–2). segments of vertebrates). Texas pimpleback is warranted, an There are no natural lakes within the As a result of our analysis of the best immediate proposal to list this species range of the Texas fawnsfoot, nor has it available scientific and commercial is precluded by other higher priority ever been found in reservoirs. Surveys information, we have assigned the Texas listings, which we address in the of the reservoirs on the Brazos and pimpleback an LPN of 2, based on our Preclusion and Expeditious Progress Colorado Rivers have been ongoing finding that the species faces threats section below. Because we have since at least 1992, and no evidence of that are of high magnitude and are assigned the Texas pimpleback an LPN live or dead Texas pimpleback has been imminent. These threats include habitat of 2, work on a proposed listing found in any reservoir (Howells 1994, loss and degradation from determination for the species is pp. 1–20; 1995, pp. 1–50; 1996, pp. 1– impoundments, sedimentation, sand precluded by work on higher priority 45; 1997a, pp. 1–58; 1998, pp. 1–30; and gravel mining, and chemical listing actions with absolute statutory, 1999, pp. 1–34; 2000a, pp. 1–56; 2001, contaminants; other natural or court-ordered, or court-approved pp. 1–50; 2002a, pp. 1–28; 2003, pp. 1– manmade factors such as climate deadlines and final listing 42; 2004, pp. 1–48; 2005, pp. 1–23; change, small, isolated populations, and determinations for those species that 2006, pp. 1–106; Karatayev and nonnative species; and the fact that the were proposed for listing with funds Burlakova 2008, pp. 1–47; Burlakova threats to the species are not being from Fiscal Year (FY) 2010. This work and Karatayev 2010a, pp. 1–30; 2011, adequately addressed by existing includes all the actions listed in the pp. 1–8), further indicating that this regulatory mechanisms. Our rationale tables below under Preclusion and species is not tolerant of for assigning the Texas pimpleback an Expeditious Progress. impoundments. LPN of 2 is outlined below. Texas fawnsfoot populations We consider the threats that the Texas Five-Factor Evaluation for Texas downstream of dams are affected as pimpleback faces to be high in Fawnsfoot well. Cold water (less than 11 °C (52 °F)) magnitude. Habitat loss and degradation Information pertaining to the Texas has been shown to stunt mussel growth from impoundments, sedimentation, fawnsfoot in relation to the five factors (Hanson et al. 1988, p. 352) and reduce sand and gravel mining, and chemical provided in section 4(a)(1) of the Act is or inhibit reproduction, because mussel contaminants are widespread discussed below. reproduction is temperature dependent throughout the range of the Texas Factor A. The Present or Threatened (Watters and O’Dee 1999, pp. 455). pimpleback and profoundly affect its Destruction, Modification, or Texas fawnsfoot living in cold-water habitat, and remaining populations are Curtailment of Its Habitat or Range. discharges downstream of large

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00037 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62202 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

impoundments are unlikely to raise concerns to the Brazos River McRoberts 2009, p. 2). This drought’s reproduce (Watters 2000, p. 264). Authority (Brazos River Authority 2006, severity was exacerbated by abnormally Dam construction also fragments the p. 2). Elevated suspended sediment high air temperatures, a likely effect of range of Texas fawnsfoot, leaving levels have been reported throughout climate change, which has already remaining habitats and populations the basin (Brazos River Authority 2006, increased average air temperatures in isolated by the structures as well as by p. 8). Texas by at least 1 °C (1.8 °F) (Nielsen- extensive areas of deep, uninhabitable, The LCRA TSC is proposing to Gammon and McRoberts 2009, p. 22). impounded waters. These isolated construct two new 345-kV electric Instream flows throughout the Colorado populations are unable to naturally transmission line facilities between Tom River basin during this drought were recolonize suitable habitat that may be Green (in the Colorado River basin near significantly reduced (USGS 2011c, p. impacted by temporary but devastating San Angelo) and Kendall Counties (in 1), and Texas fawnsfoot populations in events, such as severe drought, chemical the Guadalupe River basin north of San areas with reduced water levels may spills, or unauthorized discharges. Dams Antonio) to provide electrical power to have been negatively affected. Central impound river habitats throughout accommodate increased demand (Clary Texas is currently experiencing another almost the entire range of the species. 2010, p. 1). One of the proposed project extreme drought, with rainfall between These impoundments have left short lines would cross the San Saba River, October 2010 and July 2011 being the and isolated patches of remnant habitat, which contains one of the more lowest on record during those months typically in between impounded numerous Texas fawnsfoot populations. (LCRA 2011c, p. 1); the effects of this reaches. Habitat downstream of dams The proposed project could negatively drought are being observed but are not may be impaired for many miles; in the affect Texas fawnsfoot habitat by yet fully known. Droughts result in a Brazos River downstream of Possum clearing land within the riparian zone decrease in water depth and flow Kingdom Reservoir, substrate was and may increase sediment runoff into velocity, which reduces food and unstable for 150 km (240 mi) below the the San Saba River (Clary 2010, p. 9). oxygen delivery. As droughts persist, dam (Yeager 1993, p. 68). Similar activities to accommodate Texas mussels face hypoxia, elevated water The widespread construction of dams population growth and demands are temperature and, ultimately, stranding throughout the range of Texas fawnsfoot expected to be undertaken across the (Golladay et al. 2004, p. 501). has significantly altered stream habitat species’ range and will likely lead to We do not know the extent of the both upstream and downstream of the additional sources of sediment in the impacts of stream dewatering on the dams by changing fish assemblages, streams inhabited by the Texas Texas fawnsfoot; however, because temperature, dissolved oxygen, and fawnsfoot. several populations are small and substrate. The effects of dams are The City of Austin lies within the isolated, the loss of numerous ongoing decades after construction. Colorado River basin, and 3.9 million individuals at a site can have dramatic Because of this loss of habitat and its people live within the Brazos River effects on the populations, we conclude basin (Brazos River Authority 2007, p. consequences to the population. that the effects of dams are a threat to 1). The range of the Texas fawnsfoot Hydropower facilities, construction, and the Texas fawnsfoot. receives sediment from agriculture, drought are occurring throughout the urbanization, and sand and gravel range of the Texas fawnsfoot; therefore, Sedimentation mining. Sedimentation will continue to the effects of dewatering are ongoing For general information on the effects threaten the Texas fawnsfoot in the and unlikely to decrease, resulting in of sedimentation on freshwater mussels, foreseeable future. significant threats to the Texas please refer to ‘‘Sedimentation’’ in fawnsfoot. Dewatering Factor A under Five-Factor Evaluation Sand and Gravel Mining for Texas Fatmucket. River dewatering can occur in several As with other freshwater mussel ways: anthropogenic activities such as For general information on the effects species, the Texas fawnsfoot is also surface water diversions and of sand and gravel mining on freshwater threatened by sedimentation. The groundwater pumping, and natural mussels, please refer to ‘‘Sand and dominant land use in the Colorado events, such as drought, which can Gravel Mining’’ in Factor A under Five- River basin is grazing (Hersh 2007, p. result in mussels stranded in previously Factor Evaluation for Texas Fatmucket. 11); soil compaction from intensive wetted areas. This is a particular The Brazos River has a long history of grazing may reduce infiltration rates and concern below reservoirs, whose water sand mining, particularly in the lower increase runoff, and trampling of levels are managed for various purposes river, and channel morphology changes riparian vegetation increases the that can cause water levels in the have been attributed to destabilization probability of erosion (Armour et al. reservoir or downstream to rise or fall in due to instream sand mining in the area 1994, p. 10; Brim Box and Mossa 1999, very short periods of time, such as when (USGS 2001, p. 27). The removal of sand p. 103). Additionally, much of the hydropower facilities release water from within the river creates sediment Brazos River basin is grazed or farmed during peak energy demand periods. traps during periods of high flow, which for row crops, which can contribute Drought can also severely impact causes scouring and erosion large amounts of sediment to the basin Texas fawnsfoot populations. Central downstream (USGS 2001, p. 27). A (Brazos River Authority 2007, p. 4). Texas, including the Colorado and gravel dredging operation in the Brazos Reservoir construction in the upper Brazos River basins, experienced a River has been documented as portion of the basin has been attributed major drought in the late 1970s (Lewis depositing sediment as far as 1.6 km (1 with the erosion and subsequent and Oliveria 1979, p. 243). Near record mile) downstream (Forshage and Carter sedimentation of the lower river (USGS dry conditions in 2008 followed by a 1973, p. 697). Accelerated stream bank 2001, p. 30), as sediment-poor tailwaters pattern of below-normal rainfall during erosion and downcutting of streambeds scour the riverbanks below the dam and the winter and spring of 2009 led to one are common effects of instream sand deposit sediment farther downstream. In of the worst droughts in recorded and gravel mining, as is the 2004, sedimentation was high enough in history for most of central Texas, mobilization of fine sediments during the Brazos River below Possum including the range of the Texas sand and gravel extraction (Roell 1999, Kingdom Reservoir to cause residents to fawnsfoot (Nielsen-Gammon and p. 7).

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00038 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62203

Within the current range of Texas 2010, flooding of holding ponds females and result in glochidial loss and fawnsfoot, TPWD has issued permits for adjacent to oil drilling operations leaked subsequent reproductive failure. four sand mining activities in the Brazos oil into Thompson Creek and Additionally, handling has been shown River basin (Austin, Bosque, and Fort subsequently into the Brazos River. to reduce shell growth across mussel Bend Counties) (TPWD 2004, p. 1; Also, in July 2010, oil pipelines burst species, including several species of 2007b, p. 1; 2008b, p. 1; 2010b, p. 1). All and released approximately 165 barrels Lampsilis (Haag and Commens-Carson of the permits allow for the repeated of crude oil into the upper Brazos River 2008, pp. 505–506). Repeated handling removal of sand and gravel at various (Joiner 2010, p. 1). by researchers may adversely affect locations within a stream. The lower Agricultural pesticides and emerging Texas fawnsfoot individuals, but these Brazos River, near where these mining contaminants are likely also present in activities are occurring rarely and are activities are occurring, contains a small streams inhabited by Texas fawnsfoot. not likely to be a threat to populations. Texas fawnsfoot population. There are 53 wastewater treatment Handling for scientific purposes The Texas fawnsfoot population in plants permitted to discharge into the contributes to the long-term the lower Brazos River is likely Brazos River basin (Valenti and Brooks conservation of the species. threatened by sand and gravel mining. 2008, p. 12); the outfalls from these We do not have any evidence of risks These activities occur over a long period treatment plants have not been tested to to the Texas fawnsfoot from of time, destabilizing habitat both determine if they contain contaminants overutilization for commercial, upstream and downstream, which of note. recreational, scientific, or educational decreases the likelihood of Chemical contaminants, such as oil, purposes, and we have no reason to recolonization after the activity has been ammonia, copper, mercury, nutrients, believe this factor will become a threat completed. Therefore, the effects of sand pesticides, and other compounds are to the species in the future. Based upon and gravel mining are an ongoing threat currently a threat to the Texas the best scientific and commercial to the Texas fawnsfoot. fawnsfoot. The species is vulnerable to information available, we conclude that acute contamination from spills as well Chemical Contaminants overutilization for commercial, as chronic contaminant exposure, which recreational, scientific, or educational For general information on the effects is occurring rangewide. purposes does not pose a significant of chemical contaminants on freshwater Summary of Factor A threat to the Texas fawnsfoot rangewide. mussels, please refer to ‘‘Chemical Factor C. Disease and Predation. Contaminants’’ under Factor A under The reduction in numbers and range Five-Factor Evaluation for Texas of the Texas fawnsfoot is primarily the Disease Fatmucket. result of the long-lasting effects of Little is known about disease in As with other freshwater mussels, the habitat alterations such as the effects of freshwater mussels. However, disease is Texas fawnsfoot is also affected by impoundments, sedimentation, sand believed to be a contributing factor in chemical contaminants. TCEQ data for and gravel mining, and chemical documented mussel die-offs in other 2010 indicated that 26 of the 98 contaminants. Impoundments occur parts of the United States (Neves 1987, assessed water bodies within Colorado throughout the range of the species and pp. 11–12). Diseases have not been River basin and 81 of approximately 124 have far-reaching effects both up- and documented or observed during any assessed water bodies within Brazos downstream. Both the Colorado and studies of Texas fawnsfoot. River basin did not meet surface water Brazos River systems have experienced quality standards and were classified as a large amount of sedimentation from Predation 303(d) impaired Water Bodies (Texas agriculture, sand and gravel mining, and Raccoons will prey on freshwater Clean Rivers Program 2010a, p. 5; TCEQ urban development. Sand and gravel mussels stranded by low waters or 2010c, pp. 1–106). These water bodies mining affects Texas fawnsfoot habitat deposited in shallow water or on bars were impaired with dissolved solids, by increasing sedimentation and following flooding or low water periods nitrites, nitrates, bacteria, low dissolved channel instability downstream and (Howells 2010c, p. 12). Predation of oxygen, aluminum, sulfates, selenium, causing headcutting upstream. Chemical Texas fawnsfoot by raccoons may be chloride, orthophosphorus, phosphorus, contaminants have been documented occurring occasionally but there is no Chlorophyll a, and low pH associated throughout the range of the species and indication it is a significant threat to the with agricultural, urban, municipal, and may represent a significant threat to the status of the species. industrial runoff. Of these, nitrates and Texas fawnsfoot. Based upon our review Some species of fish feed on mussels, low dissolved oxygen pose a threat to of the best commercial and scientific such as common carp, freshwater drum, Texas fawnsfoot, as discussed above. data available, we conclude that the and redear sunfish, all of which are In 2010, crude oil overflowed into present or threatened destruction, common throughout the range of Texas Keechi Creek in Leon County, a modification, or curtailment of its fawnsfoot (Hubbs et al. 2008, pp. 19, 45, tributary to Navasota River (National habitat or range is an immediate and 53). Common species of flatworms are Response Center 2010, p. 2). This ongoing threat of high magnitude to the voracious predators of newly location is upstream of one of the few Texas fawnsfoot. metamorphosed juvenile mussels of remaining Texas fawnsfoot populations. Factor B. Overutilization for many species (Zimmerman et al. 2003, Numerous other spills have occurred Commercial, Recreational, Scientific, or p. 30). Predation is a normal factor within the range of the Texas fawnsfoot. Educational Purposes. influencing the population dynamics of These can occur from on site accidents The Texas fawnsfoot is not a a healthy mussel population; however, (tank, pipeline spills) or from tanker commercially valuable species and has predation may amplify declines in small truck accidents within watersheds never been harvested in Texas as a populations primarily caused by other occupied by Texas fawnsfoot. For commercial mussel species (Howells factors. example, oil has spilled into the Brazos 2010d, pp. 9–10). Some scientific River a number of times. As much as collecting occurs but is not likely to be Summary of Factor C 320,000 L (84,000 gal) of crude oil was a significant threat to the species Disease in freshwater mussels is spilled in the Brazos River in 1991 because it occurs only rarely. However, poorly known, and we do not have any (Associated Press 1991, p. 1). In June handling mussels can disturb gravid information indicating it is a threat to

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00039 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62204 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

the Texas fawnsfoot. Additionally, with the limited ability of mussels to Additionally, these small populations predation is a natural ecological migrate, makes it unlikely that Texas are more vulnerable to extirpation from interaction and we have no information fawnsfoot can adjust their range in stochastic events, as the lack of indicating the extent of any predation is response to changes in climate (Strayer connectivity among populations does a threat to populations of Texas 2008, p. 30). Climate change could affect not permit nearby populations to fawnsfoot. Based upon the best the Texas fawnsfoot through the recolonize areas affected by intense scientific and commercial information combined effects of global and regional droughts, toxic spills, or other isolated available, we conclude that disease or climate change, along with the events that result in significant mussel predation is not a threat to the Texas increased probability of long-term dieoffs. While the small, isolated fawnsfoot. drought. Climate change exacerbates populations do not represent an Factor D. The Inadequacy of Existing threats such as habitat degradation from independent threat to the species, the Regulatory Mechanisms. prolonged periods of drought, increased situation does substantially increase the Existing regulatory mechanisms that water temperature, and the increased risk of extirpation from the effects of all could have an effect on threats to the allocation of water for municipal, other threats, including those addressed Texas fawnsfoot include State and agricultural, and industrial use. Climate in this analysis, and those that could Federal laws such as Texas Threatened change may be a significant stressor that occur in the future from unknown and Endangered Species regulations and exacerbates existing threats by sources. freshwater mussel sanctuaries, State and increasing the likelihood of prolonged Based upon our review of the best Federal sand and gravel mining drought. As such, climate change, in commercial and scientific data regulations, and regulation of point and and of itself, may affect the Texas available, we conclude that non-point source pollution. For more fawnsfoot, but the magnitude and fragmentation and isolation of small information on the effects of State and imminence of the effects remain remaining populations of the Texas Federal laws on the threats to freshwater uncertain. Based upon our review of the fawnsfoot are occurring and are ongoing mussels in central Texas, please refer to best commercial and scientific data threats to the species throughout all of Factor D under Five-Factor Evaluation available, we conclude that the effects of its range; these threats will continue. for Texas Fatmucket. climate change in the future will likely Further, stochastic events may play a exacerbate the current and ongoing magnified role in extirpation of small, Summary of Factor D threats of habitat loss and degradation isolated populations. Despite State and Federal laws caused by other factors, as discussed Nonnative Species protecting the species and water quality, above. the Texas fawnsfoot continues to For general information on the effects Population Fragmentation and Isolation decline due to the effects of habitat of nonnative species on freshwater destruction, poor water quality, For general information on the effects mussels in central Texas, please refer to contaminants, and other factors. The of population fragmentation and ‘‘Nonnative Species’’ in Factor E under regulatory measures described in Factor isolation on freshwater mussels in Five-Factor Evaluation for Texas D under Five-Factor Evaluation for central Texas, please refer to Fatmucket. As with other freshwater Texas Fatmucket have been insufficient ‘‘Population Fragmentation and mussels, the Texas fawnsfoot is to significantly reduce or remove the Isolation’’ in Factor E under Five-Factor threatened by nonnative species. threats to the Texas fawnsfoot. Based Evaluation for Texas Fatmucket. As Various nonnative aquatic species pose upon our review of the best commercial with many freshwater mussels, most of a threat to the Texas fawnsfoot, and scientific data available, we the remaining populations of the Texas including golden algae, zebra mussels, conclude that the lack of existing fawnsfoot are small and geographically and black carp. Of these, golden algae regulatory mechanisms is an immediate isolated and thus are susceptible to has been responsible for killing more threat of moderate magnitude to the genetic drift, inbreeding depression, and than two million fish in the Colorado Texas fawnsfoot. random or chance changes to the River since 1989 (TPWD 2010a, p. 1). Factor E. Other Natural or Manmade environment, such as toxic chemical Although mussel kills due to golden Factors Affecting Its Continued spills (Watters and Dunn 1995, pp. 257– algae have not been recorded, we expect Existence. 258) or dewatering. Historically, the golden algae to negatively affect mussel Natural and manmade factors that Texas fawnsfoot was once widespread populations through loss of host fish threaten the Texas fawnsfoot include throughout much of the Colorado and and direct toxicity. Zebra mussels and climate change, population Brazos River systems when few natural black carp do not currently occur within fragmentation and isolation, and barriers existed to prevent migration the range of the Texas fawnsfoot, nonnative species. (via host species) among suitable although both are found in Texas and habitats. The extensive impoundment of could be introduced to the Brazos and Climate Change the Colorado and Brazos River basins Colorado Rivers in the future. Based on For general information on the effects has fragmented Texas fawnsfoot population responses of other mussel of climate change on freshwater mussels populations throughout these river species that overlap with zebra mussels in central Texas, please refer to systems. and black carp in similar river ‘‘Climate Change’’ in Factor E under Small Texas fawnsfoot populations, conditions, we conclude that the Five-Factor Evaluation for Texas including those in the Brazos River, introduction of zebra mussels or black Fatmucket. Because the range of the Clear Fork Brazos River, Navasota River, carp into the range of smooth Texas fawnsfoot has been reduced to and Deer Creek, may be below the pimpleback would be devastating to the isolated locations, many with low minimum population size required to species. population numbers, in small rivers and maintain population viability into the Based upon our review of the best streams, the Texas fawnsfoot is future. These populations are more commercial and scientific data vulnerable to climatic changes that vulnerable to extirpation since they are available, we conclude that golden algae could decrease the availability of water. less likely to be able to recover through is an ongoing threat to the Texas The disjunct nature of the remaining recruitment from events that reduce but fawnsfoot, and other nonnative species, Texas fawnsfoot populations, coupled do not extirpate populations. such as zebra mussels and black carp,

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00040 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62205

are a potential threat to the Texas Texas fawnsfoot under the Act is imminent. These threats include habitat fawnsfoot that is likely to increase as warranted. We will make a loss and degradation from these exotic species expand their determination on the status of the impoundments, sedimentation, sand occupancy within the range of the Texas species as threatened or endangered and gravel mining, and chemical fawnsfoot. when we complete a proposed listing contaminants; other natural or determination. When we complete a manmade factors such as climate Summary of Factor E proposed listing determination, we will change, small, isolated populations, and The effects of climate change, while examine whether the species may be nonnative species; and the fact that the difficult to quantify at this time, are endangered or threatened throughout all threats to the species are not being likely to exacerbate the current and of its range or whether the species may adequately addressed by existing ongoing threat of habitat loss caused by be endangered or threatened in a regulatory mechanisms. Our rationale other factors, and the small sizes and significant portion of its range. for assigning the Texas fawnsfoot an fragmented nature of the remaining However, as explained in more detail LPN of 2 is outlined below. populations render them more below, an immediate proposal of a We consider the threats that the Texas vulnerable to extirpation. In addition, regulation implementing this action is fawnsfoot faces to be high in magnitude. nonnative species, such as golden algae, precluded by higher priority listing Habitat loss and degradation from currently threaten the Texas fatmucket, actions, and progress is being made to impoundments, sedimentation, sand and the potential introduction of zebra add or remove qualified species from and gravel mining, and chemical mussels and black carp are potential the Lists of Endangered and Threatened contaminants are widespread future threats. Based upon our review of Wildlife and Plants. throughout the range of the Texas the best commercial and scientific data We reviewed the available fawnsfoot and profoundly affect its available, we conclude that other information to determine if the existing habitat. Remaining populations are natural or manmade factors are and foreseeable threats render the Texas small, isolated, and highly vulnerable to immediate threats of moderate fawnsfoot at risk of extinction now such stochastic events. magnitude to the Texas fawnsfoot. that issuing an emergency regulation Under our LPN guidelines, the second criterion we consider in assigning a Finding for Texas Fawnsfoot temporarily listing the species under section 4(b)(7) of the Act is warranted. listing priority is the immediacy of As required by the Act, we considered We determined that issuing an threats. We consider the threats to the the five factors in assessing whether the emergency regulation temporarily Texas fawnsfoot as described under Texas fawnsfoot is threatened or listing the species is not warranted for Factors A, D, and E in the Five-Factor endangered throughout all of its range. the Texas fawnsfoot at this time, Evaluation for Texas Fawnsfoot section We examined the best scientific and because we have not identified a threat to be imminent because these threats are commercial information available or activity that poses a significant risk, ongoing and will continue in the regarding the past, present, and future such that losses to the species during foreseeable future. Habitat loss and threats faced by the Texas fawnsfoot. the normal listing process would destruction has already occurred and We reviewed the petition, information endanger the continued existence of the will continue as the human population available in our files, and other entire species. However, if at any time continues to grow in central Texas. The available published and unpublished we determine that issuing an emergency Texas fawnsfoot populations may information, and we consulted with regulation temporarily listing the Texas already be below the minimum viable recognized Texas fawnsfoot experts and fawnsfoot is warranted, we will initiate population requirement, which would other Federal and State agencies. this action at that time. cause a reduction in the number of This status review identifies threats to populations and an increase in the the Texas fawnsfoot attributable to Listing Priority Number for Texas species’ vulnerability to extinction. Factors A, D, and E. The primary threat Fawnsfoot These threats are exacerbated by climate to the species is from habitat destruction The Service adopted guidelines on change, which will increase the and modification (Factor A) from September 21, 1983 (48 FR 43098), to frequency and magnitude of droughts. impoundments, which scour riverbeds, establish a rational system for utilizing Therefore, we consider these threats to thereby removing mussel habitat, available resources for the highest be imminent. decrease water quality, modify stream priority species when adding species to Thirdly, the Texas fawnsfoot is a valid flows, and restrict fish host migration the Lists of Endangered and Threatened taxon at the species level and, therefore, and distribution of freshwater mussels. Wildlife and Plants or reclassifying receives a higher priority than Additional threats under Factor A species listed as threatened to subspecies, but a lower priority than include sedimentation, dewatering, endangered status. These guidelines, species in a monotypic genus. sand and gravel mining, and chemical titled ‘‘Endangered and Threatened Therefore, we assigned Texas fawnsfoot contaminants. Also, most of these Species Listing and Recovery Priority an LPN of 2. We will continue to threats may be exacerbated by the Guidelines’’ address the immediacy and monitor the threats to the Texas current and projected effects of climate magnitude of threats, and the level of fawnsfoot and the species’ status on an change (discussed under Factor E). taxonomic distinctiveness by assigning annual basis, and should the magnitude Threats to the Texas fawnsfoot are not priority in descending order to or imminence of the threats change, we being adequately addressed through monotypic genera (genus with one will revisit our assessment of the LPN. existing regulatory mechanisms (Factor species), full species, and subspecies (or While we conclude that listing the D). Because of the limited distribution equivalently, distinct population Texas fawnsfoot is warranted, an of this endemic species and its lack of segments of vertebrates). immediate proposal to list this species mobility, these threats are likely to lead As a result of our analysis of the best is precluded by other higher priority to the extinction of the Texas fawnsfoot available scientific and commercial listings, which we address in the in the foreseeable future. information, we have assigned the Texas Preclusion and Expeditious Progress On the basis of the best scientific and fawnsfoot an LPN of 2, based on our section below. Because we have commercial information available, we finding that the species faces threats assigned the Texas fawnsfoot an LPN of find that the petitioned action to list the that are of high magnitude and are 2, work on a proposed listing

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00041 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62206 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

determination for the species is finding is $39,276; for a 12-month activities nationwide. Therefore, the precluded by work on higher priority finding, $100,690; for a proposed rule funds in the listing cap, other than those listing actions with absolute statutory, with critical habitat, $345,000; and for needed to address court-mandated court-ordered, or court-approved a final listing rule with critical habitat, critical habitat for already listed species, deadlines and final listing $305,000. set the limits on our determinations of determinations for those species that We cannot spend more than is preclusion and expeditious progress. were proposed for listing with funds appropriated for the Listing Program Congress identified the availability of from Fiscal Year (FY) 2011. This work without violating the Anti-Deficiency resources as the only basis for deferring includes all the actions listed in the Act (see 31 U.S.C. 1341(a)(1)(A)). In the initiation of a rulemaking that is tables below under Preclusion and addition, in FY 1998 and for each fiscal warranted. The Conference Report Expeditious Progress. year since then, Congress has placed a accompanying Public Law 97–304 statutory cap on funds that may be (Endangered Species Act Amendments Preclusion and Expeditious Progress expended for the Listing Program, equal of 1982), which established the current Preclusion is a function of the listing to the amount expressly appropriated statutory deadlines and the warranted- priority of a species in relation to the for that purpose in that fiscal year. This but-precluded finding, states that the resources that are available and the cost cap was designed to prevent funds amendments were ‘‘not intended to and relative priority of competing appropriated for other functions under allow the Secretary to delay demands for those resources. Thus, in the Act (for example, recovery funds for commencing the rulemaking process for any given fiscal year (FY), multiple removing species from the Lists), or for any reason other than that the existence factors dictate whether it will be other Service programs, from being used of pending or imminent proposals to list possible to undertake work on a listing for Listing Program actions (see House species subject to a greater degree of proposal regulation or whether Report 105–163, 105th Congress, 1st threat would make allocation of promulgation of such a proposal is Session, July 1, 1997). resources to such a petition [that is, for precluded by higher priority listing Since FY 2002, the Service’s budget a lower-ranking species] unwise.’’ actions. has included a critical habitat subcap to Although that statement appeared to The resources available for listing ensure that some funds are available for refer specifically to the ‘‘to the actions are determined through the other work in the Listing Program (‘‘The maximum extent practicable’’ limitation annual Congressional appropriations critical habitat designation subcap will on the 90-day deadline for making a process. The appropriation for the ensure that some funding is available to ‘‘substantial information’’ finding, that Listing Program is available to support address other listing activities’’ (House finding is made at the point when the work involving the following listing Report No. 107–103, 107th Congress, 1st Service is deciding whether or not to actions: Proposed and final listing rules; Session, June 19, 2001)). In FY 2002 and commence a status review that will 90-day and 12-month findings on each year until FY 2006, the Service has determine the degree of threats facing petitions to add species to the Lists of had to use virtually the entire critical the species, and therefore the analysis Endangered and Threatened Wildlife habitat subcap to address court- underlying the statement is more and Plants (Lists) or to change the status mandated designations of critical relevant to the use of the warranted-but- of a species from threatened to habitat, and consequently none of the precluded finding, which is made when endangered; annual ‘‘resubmitted’’ critical habitat subcap funds have been the Service has already determined the petition findings on prior warranted- available for other listing activities. In degree of threats facing the species and but-precluded petition findings as some FYs since 2006, we have been able is deciding whether or not to commence required under section 4(b)(3)(C)(i) of to use some of the critical habitat a rulemaking. the Act; critical habitat petition subcap funds to fund proposed listing In FY 2011, on April 15, 2011, findings; proposed and final rules determinations for high-priority Congress passed the Full-Year designating critical habitat; and candidate species. In other FYs, while Continuing Appropriations Act (Pub. L. litigation-related, administrative, and we were unable to use any of the critical 112–10), which provides funding program-management functions habitat subcap funds to fund proposed through September 30, 2011. The (including preparing and allocating listing determinations, we did use some Service has $20,902,000 for the listing budgets, responding to Congressional of this money to fund the critical habitat program. Of that, $9,472,000 is being and public inquiries, and conducting portion of some proposed listing used for determinations of critical public outreach regarding listing and determinations so that the proposed habitat for already listed species. Also critical habitat). The work involved in listing determination and proposed $500,000 is appropriated for foreign preparing various listing documents can critical habitat designation could be species listings under the Act. The be extensive and may include, but is not combined into one rule, thereby being Service thus has $10,930,000 available limited to: Gathering and assessing the more efficient in our work. At this time, to fund work in the following categories: best scientific and commercial data for FY 2011, we plan to use some of the Compliance with court orders and available and conducting analyses used critical habitat subcap funds to fund court-approved settlement agreements as the basis for our decisions; writing proposed listing determinations. requiring that petition findings or listing and publishing documents; and We make our determinations of determinations be completed by a obtaining, reviewing, and evaluating preclusion on a nationwide basis to specific date; section 4 (of the Act) public comments and peer review ensure that the species most in need of listing actions with absolute statutory comments on proposed rules and listing will be addressed first and also deadlines; essential litigation-related, incorporating relevant information into because we allocate our listing budget administrative, and listing program- final rules. The number of listing on a nationwide basis. Through the management functions; and high- actions that we can undertake in a given listing cap, the critical habitat subcap, priority listing actions for some of our year also is influenced by the and the amount of funds needed to candidate species. In FY 2010, the complexity of those listing actions; that address court-mandated critical habitat Service received many new petitions is, more complex actions generally are designations, Congress and the courts and a single petition to list 404 species. more costly. The median cost for have in effect determined the amount of The receipt of petitions for a large preparing and publishing a 90-day money available for other listing number of species is consuming the

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00042 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62207

Service’s listing funding that is not to 12, depending on the magnitude of reclassify a species to endangered if we dedicated to meeting court-ordered threats (high or moderate to low), can combine this with work that is commitments. Absent some ability to immediacy of threats (imminent or subject to a court-determined deadline. balance effort among listing duties nonimminent), and taxonomic status of With our workload so much bigger under existing funding levels, the the species (in order of priority: than the amount of funds we have to Service is only able to initiate a few new monotypic genus (a species that is the accomplish it, it is important that we be listing determinations for candidate sole member of a genus); species; or part as efficient as possible in our listing species in FY 2011. of a species (subspecies, or distinct process. Therefore, as we work on In 2009, the responsibility for listing population segment)). The lower the proposed rules for the highest priority foreign species under the Act was listing priority number, the higher the species in the next several years, we are transferred from the Division of listing priority (that is, a species with an preparing multi-species proposals when Scientific Authority, International LPN of 1 would have the highest listing appropriate, and these may include Affairs Program, to the Endangered priority). species with lower priority if they Species Program. Therefore, starting in Because of the large number of high- overlap geographically or have the same FY 2010, we used a portion of our priority species, we have further ranked threats as a species with an LPN of 2. funding to work on the actions In addition, we take into consideration described above for listing actions the candidate species with an LPN of 2 by using the following extinction-risk the availability of staff resources when related to foreign species. In FY 2011, we determine which high-priority we anticipate using $1,500,000 for work type criteria: International Union for the Conservation of Nature and Natural species will receive funding to on listing actions for foreign species, minimize the amount of time and which reduces funding available for Resources (IUCN) Red list status/rank, Heritage rank (provided by resources required to complete each domestic listing actions; however, listing action. currently only $500,000 has been NatureServe), Heritage threat rank allocated for this function. Although (provided by NatureServe), and species As explained above, a determination there are no foreign species issues currently with fewer than 50 that listing is warranted but precluded included in our high-priority listing individuals, or 4 or fewer populations. must also demonstrate that expeditious actions at this time, many actions have Those species with the highest IUCN progress is being made to add and statutory or court-approved settlement rank (critically endangered), the highest remove qualified species to and from deadlines, thus increasing their priority. Heritage rank (G1), the highest Heritage the Lists of Endangered and Threatened The budget allocations for each specific threat rank (substantial, imminent Wildlife and Plants. As with our listing action are identified in the threats), and currently with fewer than ‘‘precluded’’ finding, the evaluation of Service’s FY 2011 Allocation Table (part 50 individuals, or fewer than 4 whether progress in adding qualified of our record). populations, originally comprised a species to the Lists has been expeditious For the above reasons, funding group of approximately 40 candidate is a function of the resources available proposed listing determinations for the species (‘‘Top 40’’). These 40 candidate for listing and the competing demands Texas fatmucket, golden orb, smooth species have had the highest priority to for those funds. (Although we do not pimpleback, Texas pimpleback, and receive funding to work on a proposed discuss it in detail here, we are also Texas fawnsfoot is precluded by court- listing determination. As we work on making expeditious progress in ordered and court-approved settlement proposed and final listing rules for those removing species from the list under the agreements, listing actions with absolute 40 candidates, we apply the ranking Recovery program in light of the statutory deadlines, and work on criteria to the next group of candidates resource available for delisting, which is proposed listing determinations for with an LPN of 2 and 3 to determine the funded by a separate line item in the those candidate species with a higher next set of highest priority candidate budget of the Endangered Species listing priority (i.e., candidate species species. Finally, proposed rules for Program. So far during FY 2011, we with LPNs of 1). reclassification of threatened species to have completed delisting rules for three Based on our September 21, 1983, endangered species are lower priority, species.) Given the limited resources guidelines for assigning an LPN for each because as listed species, they are available for listing, we find that we are candidate species (48 FR 43098), we already afforded the protections of the making expeditious progress in FY 2011 have a significant number of species Act and implementing regulations. in the Listing Program. This progress with a LPN of 2. Using these guidelines, However, for efficiency reasons, we may included preparing and publishing the we assign each candidate an LPN of 1 choose to work on a proposed rule to following determinations:

FY 2011 COMPLETED LISTING ACTIONS

Publication date Title Actions FR Pages

10/6/2010 ...... Endangered Status for the Altamaha Spinymussel Proposed Listing Endangered ...... 75 FR 61664–61690 and Designation of Critical Habitat. 10/7/2010 ...... 12-Month Finding on a Petition to list the Sacramento Notice of 12-month petition finding, Not war- 75 FR 62070–62095 Splittail as Endangered or Threatened. ranted. 10/28/2010 ...... Endangered Status and Designation of Critical Habitat Proposed Listing Endangered (uplisting) ...... 75 FR 66481–66552 for Spikedace and Loach Minnow. 11/2/2010 ...... 90-Day Finding on a Petition to List the Bay Springs Notice of 90-day Petition Finding, Not sub- 75 FR 67341–67343 Salamander as Endangered. stantial. 11/2/2010 ...... Determination of Endangered Status for the Georgia Final Listing Endangered ...... 75 FR 67511–67550 Pigtoe Mussel, Interrupted Rocksnail, and Rough Hornsnail and Designation of Critical Habitat. 11/2/2010 ...... Listing the Rayed Bean and Snuffbox as Endangered Proposed Listing Endangered ...... 75 FR 67551–67583

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00043 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62208 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

FY 2011 COMPLETED LISTING ACTIONS—Continued

Publication date Title Actions FR Pages

11/4/2010 ...... 12-Month Finding on a Petition to List Cirsium wrightii Notice of 12-month petition finding, War- 75 FR 67925–67944 (Wright’s Marsh Thistle) as Endangered or Threat- ranted but precluded. ened. 12/14/2010 ...... Endangered Status for Dunes Sagebrush Lizard ...... Proposed Listing Endangered ...... 75 FR 77801–77817 12/14/2010 ...... 12-Month Finding on a Petition to List the North Notice of 12-month petition finding, War- 75 FR 78029–78061 American Wolverine as Endangered or Threatened. ranted but precluded. 12/14/2010 ...... 12-Month Finding on a Petition to List the Sonoran Notice of 12-month petition finding, War- 75 FR 78093–78146 Population of the Desert Tortoise as Endangered or ranted but precluded. Threatened. 12/15/2010 ...... 12-Month Finding on a Petition to List Astragalus Notice of 12-month petition finding, War- 75 FR 78513–78556 microcymbus and Astragalus schmolliae as Endan- ranted but precluded. gered or Threatened. 12/28/2010 ...... Listing Seven Brazilian Bird Species as Endangered Final Listing Endangered ...... 75 FR 81793–81815 Throughout Their Range. 1/4/2011 ...... 90-Day Finding on a Petition to List the Red Knot Notice of 90-day Petition Finding, Not sub- 76 FR 304–311 subspecies Calidris canutus roselaari as Endan- stantial. gered. 1/19/2011 ...... Endangered Status for the Sheepnose and Proposed Listing Endangered ...... 76 FR 3392–3420 Spectaclecase Mussels. 2/10/2011 ...... 12-Month Finding on a Petition to List the Pacific Wal- Notice of 12-month petition finding, War- 76 FR 7634–7679 rus as Endangered or Threatened. ranted but precluded. 2/17/2011 ...... 90-Day Finding on a Petition to List the Sand Ver- Notice of 90-day Petition Finding, Substantial 76 FR 9309–9318 bena Moth as Endangered or Threatened. 2/22/2011 ...... Determination of Threatened Status for the New Zea- Final Listing Threatened ...... 76 FR 9681–9692 land-Australia Distinct Population Segment of the Southern Rockhopper Penguin. 2/22/2011 ...... 12-Month Finding on a Petition to List Solanum Notice of 12-month petition finding, War- 76 FR 9722–9733 conocarpum (marron bacora) as Endangered. ranted but precluded. 2/23/2011 ...... 12-Month Finding on a Petition to List Thorne’s Notice of 12-month petition finding, Not war- 76 FR 9991–10003 Hairstreak Butterfly as Endangered. ranted. 2/23/2011 ...... 12-Month Finding on a Petition to List Astragalus Notice of 12-month petition finding, War- 76 FR 10166–10203 hamiltonii, Penstemon flowersii, Eriogonum ranted but precluded & Not Warranted. soredium, Lepidium ostleri, and Trifolium friscanum as Endangered or Threatened. 2/24/2011 ...... 90-Day Finding on a Petition to List the Wild Plains Notice of 90-day Petition Finding, Not sub- 76 FR 10299–10310 Bison or Each of Four Distinct Population Seg- stantial. ments as Threatened. 2/24/2011 ...... 90-Day Finding on a Petition to List the Unsilvered Notice of 90-day Petition Finding, Not sub- 76 FR 10310–10319 Fritillary Butterfly as Threatened or Endangered. stantial. 3/8/2011 ...... 12-Month Finding on a Petition to List the Mt. Notice of 12-month petition finding, War- 76 FR 12667–12683 Charleston Blue Butterfly as Endangered or Threat- ranted but precluded. ened. 3/8/2011 ...... 90-Day Finding on a Petition to List the Texas Kan- Notice of 90-day Petition Finding, Substantial 76 FR 12683–12690 garoo Rat as Endangered or Threatened. 3/10/2011 ...... Initiation of Status Review for Longfin Smelt ...... Notice of Status Review ...... 76 FR 13121–13122 3/15/2011 ...... Withdrawal of Proposed Rule to List the Flat-tailed Proposed rule withdrawal ...... 76 FR 14210–14268 Horned Lizard as Threatened. 3/15/2011 ...... Proposed Threatened Status for the Chiricahua Leop- Proposed Listing Threatened; Proposed Des- 76 FR 14126–14207 ard Frog and Proposed Designation of Critical Habi- ignation of Critical Habitat. tat. 3/22/2011 ...... 12-Month Finding on a Petition to List the Berry Cave Notice of 12-month petition finding, War- 76 FR 15919–15932 Salamander as Endangered. ranted but precluded. 4/1/2011 ...... 90-Day Finding on a Petition to List the Spring Pygmy Notice of 90-day Petition Finding, Substantial 76 FR 18138–18143 Sunfish as Endangered. 4/5/2011 ...... 12-Month Finding on a Petition to List the Bearmouth Notice of 12-month petition finding, Not War- 76 FR 18684–18701 Mountainsnail, Byrne Resort Mountainsnail, and ranted and Warranted but precluded. Meltwater Lednian Stonefly as Endangered or Threatened. 4/5/2011 ...... 90-Day Finding on a Petition to List the Peary Car- Notice of 90-day Petition Finding, Substantial 76 FR 18701–18706 ibou and Dolphin and Union population of the Bar- ren-ground Caribou as Endangered or Threatened. 4/12/2011 ...... Proposed Endangered Status for the Three Forks Proposed Listing Endangered; Proposed 76 FR 20464–20488 Springsnail and San Bernardino Springsnail, and Designation of Critical Habitat. Proposed Designation of Critical Habitat. 4/13/2011 ...... 90-Day Finding on a Petition to List Spring Mountains Notice of 90-day Petition Finding, Substantial 76 FR 20613–20622 Acastus Checkerspot Butterfly as Endangered. 4/14/2011 ...... 90-Day Finding on a Petition to List the Prairie Chub Notice of 90-day Petition Finding, Substantial 76 FR 20911–20918 as Threatened or Endangered. 4/14/2011 ...... 12-Month Finding on a Petition to List Hermes Copper Notice of 12-month petition finding, War- 76 FR 20918–20939 Butterfly as Endangered or Threatened. ranted but precluded. 4/26/2011 ...... 90-Day Finding on a Petition to List the Arapahoe Notice of 90-day Petition Finding, Substantial 76 FR 23256–23265 Snowfly as Endangered or Threatened.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00044 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62209

FY 2011 COMPLETED LISTING ACTIONS—Continued

Publication date Title Actions FR Pages

4/26/2011 ...... 90-Day Finding on a Petition to List the Smooth-Billed Notice of 90-day Petition Finding, Not sub- 76 FR 23265–23271 Ani as Threatened or Endangered. stantial. 5/12/2011 ...... Withdrawal of the Proposed Rule to List the Mountain Proposed Rule, Withdrawal ...... 76 FR 27756–27799 Plover as Threatened. 5/25/2011 ...... 90-Day Finding on a Petition to List the Spot-tailed Notice of 90-day Petition Finding, Substantial 76 FR 30082–30087 Earless Lizard as Endangered or Threatened. 5/26/2011 ...... Listing the Salmon-Crested Cockatoo as Threatened Final Listing Threatened ...... 76 FR 30758–30780 Throughout its Range with Special Rule. 5/31/2011 ...... 12-Month Finding on a Petition to List Puerto Rican Notice of 12-month petition finding, War- 76 FR 31282–31294 Harlequin Butterfly as Endangered. ranted but precluded. 6/2/2011 ...... 90-Day Finding on a Petition to Reclassify the Notice of 90-day Petition Finding, Substantial 76 FR 31903–31906 Straight-Horned Markhor (Capra falconeri jerdoni) of Torghar Hills as Threatened. 6/2/2011 ...... 90-Day Finding on a Petition to List the Golden- Notice of 90-day Petition Finding, Substantial 76 FR 31920–31926 winged Warbler as Endangered or Threatened. 6/7/2011 ...... 12-Month Finding on a Petition to List the Striped Notice of 12-month petition finding, War- 76 FR 32911–32929 Newt as Threatened. ranted but precluded. 6/9/2011 ...... 12-Month Finding on a Petition to List Abronia Notice of 12-month petition finding, Not War- 76 FR 33924–33965 ammophila, Agrostis rossiae, Astragalus ranted and Warranted but precluded. proimanthus, Boechera (Arabis) pusilla, and Penstemon gibbensii as Threatened or Endangered. 6/21/2011 ...... 90-Day Finding on a Petition to List the Utah Popu- Notice of 90-day Petition Finding, Not sub- 76 FR 36049–36053 lation of the Gila Monster as an Endangered or a stantial. Threatened Distinct Population Segment. 6/21/2011 ...... Revised 90-Day Finding on a Petition to Reclassify Notice of 90-day Petition Finding, Not sub- 76 FR 36053–36068 the Utah Prairie Dog From Threatened to Endan- stantial. gered. 6/28/2011 ...... 12-Month Finding on a Petition to List Castanea Notice of 12-month petition finding, Not war- 76 FR 37706–37716 pumila var. ozarkensis as Threatened or Endan- ranted. gered. 6/29/2011 ...... 90-Day Finding on a Petition to List the Eastern Notice of 90-day Petition Finding, Substantial 76 FR 38095–38106 Small-Footed Bat and the Northern Long-Eared Bat as Threatened or Endangered. 6/30/2011 ...... 12-Month Finding on a Petition to List a Distinct Pop- Notice of 12-month petition finding, Not war- 76 FR 38504–38532 ulation Segment of the Fisher in Its United States ranted. Northern Rocky Mountain Range as Endangered or Threatened with Critical Habitat. 7/12/2011 ...... 90-Day Finding on a Petition to List the Bay Skipper Notice of 90-day Petition Finding, Substantial 76 FR 40868–40871 as Threatened or Endangered. 7/19/2011 ...... 12-Month Finding on a Petition to List Pinus albicaulis Notice of 12-month petition finding, War- 76 FR 42631–42654 as Endangered or Threatened with Critical Habitat. ranted but precluded. 7/19/2011 ...... Petition to List Grand Canyon Cave Pseudoscorpion .. Notice of 12-month petition finding, Not war- 76 FR 42654–42658 ranted. 7/26/2011 ...... 12-Month Finding on a Petition to List the Giant Notice of 12-month petition finding, Not war- 76 FR 44547–44564 Palouse Earthworm (Drilolerius americanus) as ranted. Threatened or Endangered. 7/26/2011 ...... 12-Month Finding on a Petition to List the Frigid Notice of 12-month petition finding, Not war- 76 FR 44566–44569 Ambersnail as Endangered. ranted. 7/27/2011 ...... Determination of Endangered Status for Ipomopsis Final Listing Endangered, Threatened ...... 76 FR 45054–45075 polyantha (Pagosa Skyrocket) and Threatened Sta- tus for Penstemon debilis (Parachute Beardtongue) and Phacelia submutica (DeBeque Phacelia). 7/27/2011 ...... 12-Month Finding on a Petition to List the Gopher Notice of 12-month petition finding, War- 76 FR 45130–45162 Tortoise as Threatened in the Eastern Portion of its ranted but precluded. Range. 8/2/2011 ...... Proposed Endangered Status for the Chupadera Proposed Listing Endangered ...... 76 FR 46218–46234 Springsnail (Pyrgulopsis chupaderae) and Proposed Designation of Critical Habitat. 8/2/2011 ...... 90-Day Finding on a Petition to List the Straight Notice of 90-day Petition Finding, Not sub- 76 FR 46238–46251 Snowfly and Idaho Snowfly as Endangered. stantial. 8/2/2011 ...... 12-Month Finding on a Petition to List the Redrock Notice of 12-month petition finding, Not war- 76 FR 46251–46266 Stonefly as Endangered or Threatened. ranted. 8/2/2011 ...... Listing 23 Species on Oahu as Endangered and Des- Proposed Listing Endangered ...... 76 FR 46362–46594 ignating Critical Habitat for 124 Species. 8/4/2011 ...... 90-Day Finding on a Petition to List Six Sand Dune Notice of 90-day Petition Finding, Not sub- 76 FR 47123–47133 Beetles as Endangered or Threatened. stantial and substantial. 8/9/2011 ...... Endangered Status for the Cumberland Darter, Rush Final Listing Endangered ...... 76 FR 48722–48741 Darter, Yellowcheek Darter, Chucky Madtom, and Laurel Dace. 8/9/2011 ...... 12-Month Finding on a Petition to List the Nueces Notice of 12-month petition finding, Not war- 76 FR 48777–48788 River and Plateau Shiners as Threatened or En- ranted. dangered.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00045 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62210 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

FY 2011 COMPLETED LISTING ACTIONS—Continued

Publication date Title Actions FR Pages

8/9/2011 ...... Four Foreign Parrot Species [crimson shining parrot, Proposed Listing Endangered and Threat- 76 FR 49202–49236 white cockatoo, Philippine cockatoo, yellow-crested ened; Notice of 12-month petition finding, cockatoo]. Not warranted. 8/10/2011 ...... Proposed Listing of the Miami Blue Butterfly as En- Proposed Listing Endangered Similarity of 76 FR 49408–49412 dangered, and Proposed Listing of the Cassius Appearance. Blue, Ceraunus Blue, and Nickerbean Blue Butter- flies as Threatened Due to Similarity of Appearance to the Miami Blue Butterfly. 8/10/2011 ...... 90-Day Finding on a Petition to List the Saltmarsh Notice of 90-day Petition Finding, Substantial 76 FR 49412–49417 Topminnow as Threatened or Endangered Under the Endangered Species Act. 8/10/2011 ...... Proposed Listing of the Miami Blue Butterfly as En- Proposed Listing Endangered and Similarity 76 FR 49408–49412 dangered, and Proposed Listing of the Cassius of Appearance. Blue, Ceraunus Blue, and Nickerbean Blue Butter- flies as Threatened Due to Similarity of Appearance to the Miami Blue Butterfly. 8/10/2011 ...... Emergency Listing of the Miami Blue Butterfly as En- Emergency Listing Endangered and Simi- 76 FR 49542–49567 dangered, and Emergency Listing of the Cassius larity of Appearance. Blue, Ceraunus Blue, and Nickerbean Blue Butter- flies as Threatened Due to Similarity of Appearance to the Miami Blue Butterfly. 8/11/2011 ...... Listing Six Foreign Birds as Endangered Throughout Final Listing Endangered ...... 76 FR 50052–50080 Their Range. 8/17/2011 ...... 90-Day Finding on a Petition to List the Leona’s Little Notice of 90-day Petition Finding, Substantial 76 FR 50971–50979 Blue Butterfly as Endangered or Threatened. 9/01/2011 ...... 90-Day Finding on a Petition to List All Chimpanzees Notice of 90-day Petition Finding, Substantial 76 FR 54423–54425 (Pan troglodytes) as Endangered. 9/6/2011 ...... 12-Month Finding on Five Petitions to List Seven Spe- Notice of 12-month petition finding, War- 76 FR 55170–55203 cies of Hawaiian Yellow-faced Bees as Endangered. ranted but precluded. 9/8/2011 ...... 12-Month Petition Finding and Proposed Listing of Notice of 12-month petition finding, War- 76 FR 55623–55638 Arctostaphylos franciscana as Endangered. ranted; Proposed Listing Endangered. 9/8/2011 ...... 90-Day Finding on a Petition to List the Snowy Plover Notice of 90-day Petition Finding, Not sub- 76 FR 55638–55641 and Reclassify the Wintering Population of Piping stantial. Plover. 9/13/2011 ...... 90-Day Finding on a Petition to List the Franklin’s Notice of 90-day Petition Finding, Substantial 76 FR Bumble Bee as Endangered. 9/13/2011 ...... 90-Day Finding on a Petition to List 42 Great Basin Notice of 90-day Petition Finding, Substantial 76 FR and Mojave Desert Springsnails as Threatened or and Not substantial. Endangered with Critical Habitat.

Our expeditious progress also statutory timelines, that is, timelines a lower priority if they overlap includes work on listing actions that we required under the Act. Actions in the geographically or have the same threats funded in FY 2010 and FY 2011 but bottom section of the table are high- as the species with the high priority. have not yet been completed to date. priority listing actions. These actions Including these species together in the These actions are listed below. Actions include work primarily on species with same proposed rule results in in the top section of the table are being an LPN of 2, and, as discussed above, considerable savings in time and conducted under a deadline set by a selection of these species is partially funding, when compared to preparing court. Actions in the middle section of based on available staff resources, and separate proposed rules for each of them the table are being conducted to meet when appropriate, include species with in the future.

ACTIONS FUNDED IN FY 2010 AND FY 2011 BUT NOT YET COMPLETED

Species Action

Actions Subject to Court Order/Settlement Agreement

4 parrot species (military macaw, yellow-billed parrot, red-crowned parrot, scarlet macaw) 5 ...... 12-month petition finding. 4 parrot species (blue-headed macaw, great green macaw, grey-cheeked parakeet, hyacinth 12-month petition finding. macaw) 5. Longfin smelt ...... 12-month petition finding.

Actions with Statutory Deadlines

Casey’s june beetle ...... Final listing determination. 5 Bird species from Colombia and Ecuador ...... Final listing determination. Queen Charlotte goshawk ...... Final listing determination. Ozark hellbender 4 ...... Final listing determination. Altamaha spinymussel 3 ...... Final listing determination. 6 Birds from Peru & Bolivia ...... Final listing determination.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00046 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules 62211

ACTIONS FUNDED IN FY 2010 AND FY 2011 BUT NOT YET COMPLETED—Continued

Species Action

Loggerhead sea turtle (assist National Marine Fisheries Service) 5 ...... Final listing determination. 2 mussels (rayed bean (LPN = 2), snuffbox No LPN) 5 ...... Final listing determination. CA golden trout 4 ...... 12-month petition finding. Black-footed albatross ...... 12-month petition finding. Mojave fringe-toed lizard 1 ...... 12-month petition finding. Kokanee—Lake Sammamish population 1 ...... 12-month petition finding. Cactus ferruginous pygmy-owl 1 ...... 12-month petition finding. Northern leopard frog ...... 12-month petition finding. Tehachapi slender salamander ...... 12-month petition finding. Coqui Llanero ...... 12-month petition finding/Proposed listing. Dusky tree vole...... 12-month petition finding. Leatherside chub (from 206 species petition) ...... 12-month petition finding. Platte River caddisfly (from 206 species petition) 5 ...... 12-month petition finding. 3 Texas moths (Ursia furtiva, Sphingicampa blanchardi, Agapema galbina) (from 475 species 12-month petition finding. petition). 3 South Arizona plants (Erigeron piscaticus, Astragalus hypoxylus, Amoreuxia gonzalezii) (from 12-month petition finding. 475 species petition). 14 parrots (foreign species) ...... 12-month petition finding. Mohave Ground Squirrel 1 ...... 12-month petition finding. Western gull-billed tern ...... 12-month petition finding. OK grass pink (Calopogon oklahomensis) 1 ...... 12-month petition finding. Ashy storm-petrel 5 ...... 12-month petition finding. Honduran emerald ...... 12-month petition finding. Eagle Lake trout 1 ...... 90-day petition finding. 32 Pacific Northwest mollusks species (snails and slugs) 1 ...... 90-day petition finding. Spring Mountains checkerspot butterfly ...... 90-day petition finding. 10 species of Great Basin butterfly ...... 90-day petition finding. 404 Southeast species ...... 90-day petition finding. American eel 4 ...... 90-day petition finding. Aztec gilia 5 ...... 90-day petition finding. White-tailed ptarmigan 5 ...... 90-day petition finding. San Bernardino flying squirrel 5 ...... 90-day petition finding. Bicknell’s thrush 5 ...... 90-day petition finding. Sonoran talussnail 5 ...... 90-day petition finding. 2 AZ Sky Island plants (Graptopetalum bartrami & Pectis imberbis) 5 ...... 90-day petition finding. I’iwi 5 ...... 90-day petition finding. Humboldt marten ...... 90-day petition finding. Desert massasauga ...... 90-day petition finding. Western glacier stonefly (Zapada glacier) ...... 90-day petition finding. Thermophilic ostracod (Potamocypris hunteri) ...... 90-day petition finding. Sierra Nevada red fox 5 ...... 90-day petition finding. Boreal toad (eastern or southern Rocky Mtn population) 5 ...... 90-day petition finding. Alexander Archipelago wolf 5 ...... 90-day petition finding.

High-Priority Listing Actions

20 Maui-Nui candidate species 2 (17 plants, 3 tree snails) (14 with LPN = 2, 2 with LPN = 3, 3 Proposed listing. with LPN = 8). 8 Gulf Coast mussels (southern kidneyshell (LPN = 2), round ebonyshell (LPN = 2), Alabama Proposed listing. pearlshell (LPN = 2), southern sandshell (LPN = 5), fuzzy pigtoe (LPN = 5), Choctaw bean (LPN = 5), narrow pigtoe (LPN = 5), and tapered pigtoe (LPN = 11)) 4. Umtanum buckwheat (LPN = 2) and white bluffs bladderpod (LPN = 9) 4 ...... Proposed listing. Grotto sculpin (LPN = 2) 4 ...... Proposed listing. 2 Arkansas mussels (Neosho mucket (LPN = 2) & Rabbitsfoot (LPN = 9)) 4 ...... Proposed listing. Diamond darter (LPN = 2) 4 ...... Proposed listing. Gunnison sage-grouse (LPN = 2) 4 ...... Proposed listing. Coral Pink Sand Dunes Tiger Beetle (LPN = 2) 5 ...... Proposed listing. Lesser prairie chicken (LPN = 2) ...... Proposed listing. 4 Texas salamanders (Austin blind salamander (LPN = 2), Salado salamander (LPN = 2), Proposed listing. Georgetown salamander (LPN = 8), Jollyville Plateau (LPN = 8)) 3. 5 SW aquatics (Gonzales Spring Snail (LPN = 2), Diamond Y springsnail (LPN = 2), Phantom Proposed listing. springsnail (LPN = 2), Phantom Cave snail (LPN = 2), Diminutive amphipod (LPN = 2)) 3. 2 Texas plants (Texas golden gladecress (Leavenworthia texana) (LPN = 2), Neches River rose- Proposed listing. mallow (Hibiscus dasycalyx) (LPN = 2)) 3. 4 AZ plants (Acuna cactus (Echinomastus erectocentrus var. acunensis) (LPN = 3), Fickeisen Proposed listing. plains cactus (Pediocactus peeblesianus fickeiseniae) (LPN = 3), Lemmon fleabane (Erigeron lemmonii) (LPN = 8), Gierisch mallow (Sphaeralcea gierischii) (LPN = 2)) 5. FL bonneted bat (LPN = 2) 3 ...... Proposed listing. 3 Southern FL plants (Florida semaphore cactus (Consolea corallicola) (LPN = 2), shellmound Proposed listing. applecactus (Harrisia (=Cereus) aboriginum (=gracilis)) (LPN = 2), Cape Sable thoroughwort (Chromolaena frustrata) (LPN = 2)) 5.

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00047 Fmt 4701 Sfmt 4702 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2 62212 Federal Register / Vol. 76, No. 194 / Thursday, October 6, 2011 / Proposed Rules

ACTIONS FUNDED IN FY 2010 AND FY 2011 BUT NOT YET COMPLETED—Continued

Species Action

21 Big Island (HI) species 5 (includes 8 candidate species—6 plants & 2 animals; 4 with LPN = Proposed listing. 2, 1 with LPN = 3, 1 with LPN = 4, 2 with LPN = 8). 12 Puget Sound prairie species (9 subspecies of pocket gopher (Thomomys mazama ssp.) Proposed listing. (LPN = 3), streaked horned lark (LPN = 3), Taylor’s checkerspot (LPN = 3), Mardon skipper (LPN = 8)) 3. 2 TN River mussels (fluted kidneyshell (LPN = 2), slabside pearlymussel (LPN = 2)) 5 ...... Proposed listing. Jemez Mountain salamander (LPN = 2) 5 ...... Proposed listing. 1 Funds for listing actions for these species were provided in previous FYs. 2 Although funds for these high-priority listing actions were provided in FY 2008 or 2009, due to the complexity of these actions and competing priorities, these actions are still being developed. 3 Partially funded with FY 2010 funds and FY 2011 funds. 4 Funded with FY 2010 funds. 5 Funded with FY 2011 funds.

We have endeavored to make our Continuing review will determine if a from the Clear Lake Ecological Services listing actions as efficient and timely as change in status is warranted, including Field Office (see ADDRESSES). possible, given the requirements of the the need to make prompt use of Authors relevant law and regulations, and emergency listing procedures. constraints relating to workload and We intend that any proposed listing The primary authors of this notice are personnel. We are continually determination for Texas fatmucket, the staff members from the Southwest considering ways to streamline golden orb, smooth pimpleback, Texas Region of the U.S. Fish and Wildlife processes or achieve economies of scale, pimpleback, and Texas fawnsfoot will Service. such as by batching related actions be as accurate as possible. Therefore, we together. Given our limited budget for will continue to accept additional Authority implementing section 4 of the Act, these information and comments from all The authority for this section is actions described above collectively concerned governmental agencies, the section 4 of the Endangered Species Act constitute expeditious progress. scientific community, industry, or any of 1973, as amended (16 U.S.C. 1531 et Texas fatmucket, golden orb, smooth other interested party concerning this seq.). pimpleback, Texas pimpleback, and finding. Texas fawnsfoot will be added to the list Dated: September 26, 2011. of candidate species upon publication of References Cited Rowan W. Gould, this 12-month finding. We will continue A complete list of references cited is Acting Director, Fish and Wildlife Service. to evaluate these species as new available on the Internet at http:// [FR Doc. 2011–25471 Filed 10–5–11; 8:45 am] information becomes available. www.regulations.gov and upon request BILLING CODE 4310–55–P

VerDate Mar<15>2010 16:27 Oct 05, 2011 Jkt 226001 PO 00000 Frm 00048 Fmt 4701 Sfmt 9990 E:\FR\FM\06OCP2.SGM 06OCP2 mstockstill on DSK4VPTVN1PROD with PROPOSALS2