July 21, 2024

The U.S Fish and Wildlife Service (US FWS) proposed the listing of Texas mussel species found in the Colorado and other basins on the Endangered Species Act list of endangered species in 2021 Federal Register.  They took comments and worked with state and local entities to confirm their initial findings and to gain information about the species, their habitat requirements, what reaches of the rivers and tributaries should be listed as “critical habitat”.

In the July 5, 2024 Federal Register they published the agencies final decision regarding the listing of species and what portions of rivers and tributaries will be “critical habitat”.  I have selected portions of the Federal Register document below to provide a somewhat abbreviated version (with emphasis added bold within text, or within [ ] ) of the 97 page document

Executive Summary:

Why we need to publish a rule. Under the Act, a species warrants listing if it meets the definition of an endangered species (in danger of extinction throughout all or a significant portion of its range) or a threatened species (likely to become endangered within the foreseeable future throughout all or a significant portion of its range). If we determine that a species warrants listing, we must list the species promptly and designate the species’ critical habitat to the maximum extent prudent and determinable. We have determined that the Guadalupe fatmucket (Lampsilis bergmanni), Texas fatmucket (Lampsilis bracteata), Guadalupe orb (Cyclonaias necki), Texas pimpleback (Cyclonaias (=Quadrula) petrina), Balcones spike (Fusconaia (=Quincuncina) iheringi), and false spike (Fusconaia (=Quincuncina) mitchelli) meet the Act’s definition of endangered species, and the Texas fawnsfoot (Truncilla macrodon) meets the Act’s definition of a threatened species; therefore, we are listing them as such, finalizing a rule under section 4(d) of the Act for the Texas fawnsfoot, and designating critical habitat. Both listing a species as an endangered or threatened species and designating critical habitat can be completed only by issuing a rule through the Administrative Procedure Act rulemaking process (5 U.S.C. 551 et seq.).

The basis for our action. Under the Act, we may determine that a species is an endangered or threatened species because of any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence; we also take into account conservation efforts, such as Candidate Conservation Agreements with Assurances (CCAAs). We have determined that increased fine sediment, changes in water quality, and altered hydrology in the form of inundation and loss of flow and scour of substrate (Factor A), collection (Factor B), predation (Factor C), and barriers to fish movement (Factor E) are the primary threats to these species. These factors are all exacerbated by the ongoing and expected effects of climate change.

Section 4(a)(3) of the Act requires the Secretary of the Interior (Secretary), to designate critical habitat, to the maximum extent prudent and determinable, concurrent with listing. Section 3(5)(A) of the Act defines critical habitat as

(i) the specific areas within the geographical area occupied by the species, at the time it is listed, on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protections; and

(ii) specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination by the Secretary that such areas are essential for the conservation of the species.

Section 4(b)(2) of the Act states that the Secretary must make the designation on the basis of the best scientific dat available and after taking into consideration the economic impact, the impact on national security, and any other relevant impacts of specifying any particular area as critical habitat

Summary of Changes From the Proposed Rule (in part)

We made these and other changes as appropriate in this final rule. Inaddition to minor clarifying edits and incorporation of additional information on the species’ biology, populations, and threats, this final determination differs from the August 26, 2021, proposed rule in the following ways:

(3) For the critical habitat designation, we exclude proposed units TXFF–6 and TXPB–6 based upon the implementation of conservation measures completed by the Lower Colorado River Authority (LCRA) as part of their CCAA for the Texas pimpleback, Texas fawnsfoot, Texas fatmucket, and Balcones spike in the Lower Colorado River Basin below O.H. Ivie Reservoir (LCRA 2023, pp. 45–84; hereafter, the ‘‘LCRA Agreement’’)

I. Final Listing Determination (the following in italics is taken directly from the Federal Register)

Background of species found in the lower basin between Bastrop and Matagorda Counties

Texas fawnsfoot

The Texas fawnsfoot was originally described as Unio macrodon 1859 from a location near Rutersville, Fayette County, Texas (Lea 1859, pp. 154–155). Texas fawnsfoot is recognized by the scientific community as Truncilla macrodon (Williams et al. 2017, pp. 35, 44). Texas fawnsfoot is a small- to medium-sized (2.4 in (60 mm)) mussel with an elongate oval shell (Howells 2014, p. 111). For a detailed description, see Howells et al. 1996 (p. 143) and Howells 2014 (p. 111). Host fish species are not confirmed for the Texas fawnsfoot, but we expect they use freshwater drum (Aplodinotus grunniens; Howells 2014, p. 111), like other Truncilla species occurring in Texas and elsewhere (Ford and Oliver 2015, p. 8). Freshwater drum are molluscivorous (mollusk-eating) and become infested with glochidia when they consume gravid female mussels (Barnhart et al. 2008, p. 373). This strategy of host infestation may limit population size, as reproductively successful females are sacrificed (i.e., eaten by freshwater drum). Related species are bradytictic, brooding larvae over the winter instead of releasing them immediately (Barnhart et al. 2008, p. 384). Other species in the genus Truncilla from the Southeast and Midwest reach a maximum age ranging from 8 to 18 years (Haag and Rypel 2010, pp. 4–6), and we expect the lifespan of Texas fawnsfoot to be similar. Texas fawnsfoot are found in medium- to large-sized streams and rivers with flowing waters and mud, sand, and gravel substrates (Howells 2014, p. 111). Adults are most often found in bank habitats and occasionally in backwater, riffle, and point bar habitats, with low to moderate velocities that appear to function as flow refuges during high flow events (Randklev et al. 2017c, p. 137). Texas fawnsfoot occur in the lower reaches of the Colorado and Brazos Rivers, and in the Trinity River (Randklev et al. 2017b, p. 4) in seven populations: East Fork Trinity River, Middle Trinity River, Clear Fork Brazos River, Upper Brazos River, Middle/ Lower Brazos River, San Saba/Colorado Rivers, and Lower Colorado River [Colorado, Matagorda, and Wharton Counties] see also figure 5.7 in Service 2022, p. 101). Texas fawnsfoot was historically distributed throughout the Colorado and Brazos River basins (Howells 2014, pp. 111–112; reviewed in Randklev et al. 2017c, pp. 136–137) and in the Trinity River Basin (Randklev et al. 2017b, p. 11).

Texas Pimpleback

The Texas pimpleback was originally described as Unio petrinus from the ‘‘Llanos River’’ in ‘‘Upper’’ Texas (Gould 1855, p. 228). The species is now recognized as Cyclonaias petrina by the scientific community (Williams et al. 2017, pp. 35, 37). Burlakova et al. (2018, entire) recently described the Guadalupe orb (C. necki) from the Guadalupe River Basin as a separate species distinct from Texas pimpleback. Texas pimpleback are now considered to occur only in the Colorado River Basin of Texas. The Texas pimpleback is a small- to medium-sized (up to 4 in (103 mm)) mussel with a moderately inflated, yellow, brown, or black shell, occasionally with vague green rays or concentric blotches (Howells 2014, p. 93). Recent laboratory studies of the closely related Guadalupe orb suggest that channel catfish, flathead catfish, and tadpole madtom are host fish for the Texas pimpleback (Dudding et al. 2019, p. 2). Related species have miniature glochidia and also use catfish as hosts (Barnhart et al. 2008, pp. 373, 379). Additionally, related species can also produce conglutinates (Barnhart et al. 2008, p. 376) and tend to exhibit shortterm brooding (tachytictia; releasing glochidia soon after the larvae mature) (Barnhart et al. 2008, p. 384). Texas pimpleback are reproductively active between April and August (Randklev et al. 2017c, p. 110). Related species live as long as 15 to 72 years (Haag and Rypel 2010, p. 10). Texas pimpleback are known to occurin the Colorado River Basin in five isolated populations: Concho River, Upper San Saba River, Lower San Saba River/Colorado River, Llano River, and the Lower Colorado River [Colorado and Wharton Counties, TX]; see also figure 5.9 in Service 2022, p. 110). Only the Lower San Saba and Llano River populations are known to be successfully reproducing. Texas pimpleback was historically distributed throughout the Colorado River Basin (Howells 2014, pp. 93–94; reviewed in Randklev et al. 2017c, pp. 109–110)

Species Current Condition

Here we discuss the current condition of each known population, taking into account the risks to those populations that are currently occurring, as well as management actions that are currently occurring to address those risks. We consider climate change to be currently occurring, resulting in changes to the timing and amount of rainfall affecting streamflow, increased stream temperatures, and increased accumulation of fine sediments. In the SSA report, for each species and population, we developed and assigned condition categories for three population factors (occupied stream length, abundance, and reproduction) and three habitat factors (substrate, flowing water, and water quality) that are important for viability of each species. The condition scores for each actor were then used to determine an overall condition of each population: healthy, moderately healthy, unhealthy, or functionally extirpated. These overall conditions translate to our estimated probability of persistence of each population, with healthy populations having the highest probability of persistence over 20 years (greater than 90 percent), moderately healthy populations having a probability of persistence that falls between 60 and 90 percent, and unhealthy populations having the lowest probability of persistence (between 10 and 60 percent). Functionally extirpated populations are not expected to persist over 20 years or are already extirpated.

Texas Fatmucket

Overall, there are five known remaining populations of Texas fatmucket, all limited to the headwater reaches of the Colorado River and its tributaries. Historically, most Texas fatmucket populations were likely connected by fish migration throughout the Colorado River Basin, but due to impoundments and low water conditions in the Colorado River and tributaries, they are currently isolated from one another, and repopulation of extirpated locations is unlikely to occur without human assistance. Two of the current populations are moderately healthy, two are unhealthy, and one is functionally extirpated.

Onion Creek: Few live individuals of Texas fatmucket have been found in Onion Creek since 2010, and we consider this population to be functionally extirpated with little chance of persistence. The upper reaches of Onion Creek frequently go dry, and several privately owned lowhead in-channel dams currently exist along upper and lower Onion Creek, which further provide barriers to fish passage and mussel dispersal, preventing recolonization after low water events. Onion Creek is in close proximity to the City of Austin, and continued development in the watershed is expected to continue to degrade habitat conditions.

Texas Pimpleback

There are five known remaining Texas pimpleback populations, all in the Colorado River Basin. Historically, Texas pimpleback likely occurred throughout the basin with populations connected by fish migration, but due to impoundments and low water conditions, they are currently fragmented and isolated from one another, and repopulation of extirpated locations is unlikely to occur without human assistance. Three of the remaining Texas pimpleback populations are unhealthy and are not reproducing, and two of the populations are in moderate condition.

Lower Colorado River: Currently, the population of Texas pimpleback in the lower Colorado River is relatively abundant over a long stream length. However, because the species is a riffle specialist, the Texas pimpleback is especially sensitive to hydrological alterations leading to both extreme drying (dewatering) during low flow events, and to extreme high flow events leading to scouring of substrate and movement of mature individuals to sites that may or may not be appropriate, as evidenced by the August 2017 scouring flood event that substantially degraded the quality of the Altair Riffle in the lower Colorado River, a formerly robust mussel bed. While this population is in moderate condition, we expect this population to be at risk of extirpation due to these extreme flow events.

Texas Fawnsfoot

There are seven known remaining populations of Texas fawnsfoot, in the Trinity, Brazos, and Colorado River basins. Historically, Texas fawnsfoot occurred throughout each basin with populations connected by fish migration within each basin, but due to impoundments and low water conditions, they are currently isolated from one another, and repopulation of extirpated locations is unlikely to occur without human assistance. Four Texas fawnsfoot populations are moderately healthy, and three are unhealthy.

Lower Colorado River: The Texas fawnsfoot population in the lower Colorado River is expected to remain extant under current conditions, as this reach is expected to remain wetted, although with reduced flow. Despite increasing demands for municipal water, we expect that the lower Colorado River will continue to flow due to priority downstream agricultural and industrial water rights. Similar to the lower Brazos River population, Texas fawnsfoot in the Lower Colorado River are vulnerable to reduced flows and associated habitat degradation due to reductions in flow from upstream tributaries; because the species occurs in bank habitats that are likely to become exposed, the species will be subjected to desiccation, predation, and increased water temperatures as river elevations decline while the river still flows in its main channel. Currently, the Lower Colorado River Authority is implementing a water management plan that is alleviating this threat by providing consistent subsistence flows to the lower Colorado River Basin. Therefore, this population is moderately healthy

Future-Condition Scenarios for the Texas Fawnsfoot

Because of significant uncertainty regarding if and when flow loss, water quality degradations, extreme flooding and scour/substrate mobilizing events, or impoundment construction may occur, we have forecasted future viability for the Texas fawnsfoot in terms of resiliency, redundancy, and representation under four plausible future scenarios. Each scenario is projected across up to three time steps and considers the biological status of this species’ populations and habitats in ten, twenty-five, and fifty years. Ten years represents one to two generations of mussels, assuming an average reproductive life span of five to ten years. Twenty-five years similarly represents two to four mussel generations. Fifty years represents five or more generations of mussels and corresponds with the current planning horizon of the State Water Plans (from 2020 to 2070), a period of time for which the human population of the State of Texas is expected to grow 88%  rom 27 million to 51 million (TWDB 2017, p. 3) with much of the growth of human population occurring in the watersheds these seven species of mussels currently occupy (TWDB 2017, pp. 50–51). [If you want to read more about these scenarios, please refer to page 48058 of the Federal Register linked above were the agency provides a brief summary of each plausible future scenario; for more detailed information on these models and their projections, please see the SSA report (Service 2022, chapter 7)]

Determination of Status

Texas Fatmucket

Of the five remaining fragmented and isolated populations of Texas fatmucket, two are small in abundance and occupied stream length and have low to no resiliency (i.e., they are unhealthy), and one population is functionally extirpated. The other two current populations are moderately healthy. The upper/middle San Saba and Llano River populations are larger, with increased abundance and occupied stream length, but these populations are vulnerable to stream drying and overcollection. These very low flow events are expected to continue into the future, and both of these populations of Texas fatmucket are at risk of extirpation. Even if the locations of Texas fatmucket do not become dry, water quality degradation and increased sedimentation associated with low flows is expected. Additionally, the Llano River population does not appear to be successfully reproducing, further increasing the species’ risk of extirpation at this location. The Texas fatmucket has no populations that are currently considered healthy. Loss of populations at high risk of extirpation leads to low levels of redundancy and representation. Overall, these low levels of resiliency, redundancy, and representation result in the Texas fatmucket having low viability, and the species currently faces a high risk of extinction. Our analysis of the species current condition shows that the Texas fatmucket is currently in danger of extinction throughout all of its range due to the severity and immediacy of threats currently impacting the species

Texas Pimpleback

Of the five remaining Texas pimpleback populations, three are unhealthy and are not reproducing, and two are moderately healthy. The populations that are not reproducing are considered functionally extirpated, and the two moderately healthy populations are expected to continue to decline. The population in the middle Colorado and lower San Saba Rivers has very little evidence of reproduction and is therefore likely to decline due to a lack of young individuals joining the population as the population ages. The lower Colorado River population has very recently experienced an extreme high flow event (i.e., associated with Hurricane Harvey flooding in August and September of 2017) that vastly changed the substrate and mussel composition of much of its length, putting this population at high risk of extirpation. The Texas pimpleback has no healthy populations, and all populations are expected to continue to decline. Loss of populations at high risk of extirpation leads to low levels of redundancy and representation. Overall, these low levels of resiliency, redundancy, and representation result in the Texas pimpleback having low viability, and the species currently faces a high risk of extinction. Our analysis of the species’ current condition, as well as the conservation efforts discussed above, shows that the Texas pimpleback is currently in danger of extinction throughout all of its range due to the severity and immediacy of threats currently impacting the species.

Texas Fawnsfoot

Seven populations of the Texas fawnsfoot remain. Four populations are moderately healthy, and three are unhealthy or are functionally extirpated. Currently, unlike the other populations of this species, two of the moderately healthy populations are not subject to flow declines, due to increased flow returns in the Trinity River from wastewater treatment facilities and a lack of impoundments on the mainstemof the lower Brazos River. In the future, however, as extreme flow events become more frequent as rainfall patterns change, and increased urbanization results in reduced groundwater levels, we expect even these populations to be at an increased risk of extirpation. Future higher air temperatures, higher rates of evaporation and transpiration, and changing precipitation patterns are expected within the range of the Texas fawnsfoot in central Texas (Jiang and Yang 2012, pp. 234–239, 242). These future climate changes are expected to lead to human responses, such as increased groundwater pumping and surface water diversions, associated with increasing demands for and decreasing availability of freshwater resources in the State (reviewed in Banner et al. 2010, entire). Within 25 to 50 years, even under the best conditions and with additional conservation efforts undertaken, given the ongoing effects of climate change and human activities on altered hydrology and habitat degradation, we expect only one population to be in healthy condition, one population to remain in moderately healthy condition, four populations to be in unhealthy condition, and one population to become functionally extirpated. Given the likelihood of increased climate and anthropogenic effects in the foreseeable future, as many as three populations are expected to become functionally extirpated, leaving no more than four unhealthy  populations remaining after 25 years. After 50 years, we anticipated that as many as five populations are expected to become functionally extirpated, leaving no more than three unhealthy populations. In the future, we anticipate that the Texas fawnsfoot will have reduced viability, with no highly resilient populations and limited representation and redundancy. Thus, after assessing the best available information, we determine that the Texas fawnsfoot is not currently in danger of extinction but is likely to become in danger of extinction within the foreseeable future throughout all of its range. Our analysis of the species’ current and future conditions, as well as the conservation efforts discussed above, show that the Texas fawnsfoot is likely to become in danger of extinction throughout all or a significant portion of its range within the foreseeable future due to increased frequency of drought and extremely high flow events, decreased water quality, and decreased substrate suitability. We considered whether the Texas fawnsfoot is presently in danger of extinction and determined that endangered status is not appropriate. The current condition shows two of the populations in two of the representative units are not currently subject to declining flows or extreme flow events. While threats are currently acting on the species and many of those threats are expected to continue into the future, we did not find that the species is currently in danger of extinction throughout all of its range. According to our assessment of plausible future scenarios, the species is likely to become an endangered species within the foreseeable future of 25 years throughout all of its range. Twenty-five years encompasses about 5 generations of the Texas fawnsfoot; additionally, models of human demand for water (Texas Water Development Board 2017, p. 30) and climate change (e.g., Kinniburgh et al. 2015, p. 83) project decreased water availability over 25 and 50 years, respectively. As a result, we expect increased incidences of low flows followed by scour events as well as persistent decreased water quality to be occurring in 25 years. Thus, after assessing the best available information, we determine that the Texas fawnsfoot is not currently in danger of extinction but is likely to become in danger of extinction within the foreseeable future throughout all of its range

II. Final Rule Issued Under Section 4(d) of the Act

Background

Section 4(d) of the Act contains two sentences. The first sentence states that the Secretary shall issue such regulations as she deems necessary and advisable to provide for the conservation of species listed as threatened species. The U.S. Supreme Court has noted that statutory language similar to the language in section 4(d) of the Act authorizing the Secretary to take action that she ‘‘deems necessary and advisable’’ affords a large degree of deference to the agency (see Webster v. Doe, 486 U.S. 592 (1988)). Conservation is defined in the Act to mean the use of all methods and procedures which are necessary to bring any endangered species or threatened species to the point at which the measures provided pursuant to the Act are no longer necessary.

Additionally, the second sentence of section 4(d) of the Act states that the Secretary may by regulation prohibit with respect to any threatened species any act prohibited under section 9(a)(1), in the case of fish or wildlife, or section 9(a)(2), in the case of plants. Thus, the combination of the two sentences of section 4(d) provides the Secretary with wide latitude of discretion to select and promulgate appropriate regulations tailored to the specific conservation needs of the threatened species. The second sentence grants particularly broad discretion to he Service when adopting one or more of the prohibitions under section 9

III. Critical Habitat

Background

Section 4(a)(3) of the Act requires that, to the maximum extent prudent and determinable, we designate a species’ critical habitat concurrently with listing the species. Critical habitat is defined in section 3 of the Act as: (1) The specific areas within the geographical area occupied by the species, at the time it is listed in  accordance with the Act, on which are found those physical or biological features (a) Essential to the conservation of the species, and (b) Which may require special management considerations or protection; and (2) Specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species.

Our regulations at 50 CFR 424.02 define the geographical area occupied by the species as an area that may generally be delineated around species’ occurrences, as determined by the Secretary (i.e., range). Such areas may include those areas used throughout all or part of the species’ life cycle, even if not used on a regular basis (e.g., migratory corridors, seasonal habitats, and habitats used periodically, but not solely by vagrant individuals)

Under the first prong of the Act’s definition of critical habitat, areas within the geographical area occupied by the species at the time it was listed are included in a critical habitat designation if they contain physical or biological features (1) which are essential to the conservation of the species and (2) which may require special management considerations or protection. For these areas, critical habitat designations identify, to the extent known using the best scientific data available, those physical or biological features that are essential to the conservation of the species (such as space, food, cover, and protected habitat).

Under the second prong of the Act’s definition of critical habitat, we can designate critical habitat in areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species.

Section 4 of the Act requires that we designate critical habitat on the basis of the best scientific data available. Further, our Policy on Information Standards Under the Endangered Species Act (published in the Federal Register on July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106–554; H.R. 5658)), and our associated Information Quality Guidelines provide criteria, establish procedures, and provide guidance to ensure that our decisions are based on the best scientific data available. They require our biologists, to the extent consistent with the Act and with the use of the best scientific data available, to use primary and original sources of information as the basis for recommendations to designate critical habitat.

When we are determining which areas should be designated as critical habitat, our primary source of information is generally the information from the SSA report and information developed during the listing process for the species. Additional information sources may include any generalized conservation strategy, criteria, or outline that may have been developed for the species; the recovery plan for the species; articles in peer-reviewed journals; conservation plans developed by States and counties; scientific status surveys and studies; biological assessments; other unpublished materials; or experts’ opinions or personal knowledge.

We consider the following streams to be occupied by the Texas fatmucket at the time of listing: Bluff Creek, Lower Elm Creek, San Saba River, Cherokee Creek, North Llano River, South Llano River, Llano River, James River, Threadgill Creek, Beaver Creek, Pedernales River, Live Oak Creek, and Onion Creek (see Final Critical Habitat Designation, below).

We consider the following streams to be occupied by the Texas fawnsfoot at the time of listing: Upper Clear Fork of the Brazos River, Upper Brazos River, Lower San Saba River, and Upper Colorado River (see Final Critical Habitat Designation, below)

We consider the following streams to be occupied by the Texas pimpleback at the time of listing: Bluff Creek, Lower Elm Creek, Lower Concho River, Upper Colorado River, Lower San Saba River, Upper San Saba River, and Upper Llano River (see Final Critical Habitat Designation, below)

For areas outside the geographic area occupied by the species at the time of listing, we delineated critical habitat unit boundaries by evaluating habitat suitability of stream segments and retaining those segments that contain some or all of the PBFs to support lifehistory functions essential for the conservation of the species

Final Critical Habitat Designation

We are designating approximately 1,577.5 river mi (2,538.7 river km) in total, accounting for overlapping units, in 20 units (with a total of 32 subunits; see table 8 and map, below) as critical habitat for the central Texas mussel species: the Guadalupe fatmucket, Texas fatmucket, Texas fawnsfoot, Texas pimpleback, Guadalupe orb, Balcones spike, and false spike. All but four of the subunits are currently occupied by one or more of the species, and each of the 20 units contains the physical and biological features essential to the conservation of each species. Each species historically occurred in a different subset of watersheds in central Texas; therefore, there are large differences in the amount of critical habitat designated for each species. Texas surface water is owned by the State, as are the beds of navigable streams; thus, the actual critical habitat units (occupied waters and streambeds up to the ordinary high-water mark) are owned by the State of Texas (Texas Water Code, sections 11.021 and 11.0235). Adjacent riparian areas are in most cases, privately owned, and are what is reported in the discussion that follows, although these adjacent riparian areas are not included in the critical habitat designation. The critical habitat areas we describe below constitute our current best assessment of areas that meet the definition of critical habitat for the seven central Texas mussel species. Table 8 shows the critical habitat units and the approximate area of each unit.

Consideration of Impacts Under Section 4(b)(2) of the Act

Based on the information provided by entities seeking exclusion, as well as additional public comments we received, and the best scientific data available, we evaluated whether certain river mi in units TXFF–3, TXFF– 4,TXFF–6, TXFF–7, TXFF–8, TXPB–6, and BASP–1 are appropriate for exclusion from this final designation under section 4(b)(2) of the Act. This analysis indicates that the benefits of excluding areas from the final designation outweigh the benefits of designating those areas as critical habitat; thus, the Secretary is exercising her discretion to exclude the areas from the final designation. In the paragraphs below, we provide a detailed balancing analysis of the areas being excluded under section 4(b)(2) of the Act.

Benefits of Exclusion—LCRA Agreement Proposed Units TXPB–6 and TXFF–6: The benefits of excluding 108.9 river mi (175.2 river km) in the lower Colorado River Basin for the Texas pimpleback and 121.8 river mi (196.0 river km) in the lower Colorado River Basin for the Texas fawnsfoot under the LCRA Agreement from the designation of critical habitat are substantial and include: (1) Continuance and strengthening of our effective working relationship with partners to promote voluntary, proactive conservation of the Texas pimpleback, Texas fawnsfoot, and their habitats as opposed to reactive regulation; (2) allowance for continued meaningful collaboration and cooperation in working toward species recovery, including conservation benefits that might not otherwise occur; and (3) encouragement of developing additional conservation and management plans in the future for other federally listed and sensitivespecies. Additionally, partnerships with non-Federal landowners are vital to the conservation of at-risk species, especially on non-Federal lands; therefore, the Service is committed to supporting and encouraging such partnerships through the recognition of positive conservation contributions. In the case considered here, excluding these areas from critical habitat will help foster the partnerships the landowners and land managers in question have developed with Federal and State agencies and local conservation organizations; will encourage the continued implementation of voluntary conservation actions for the benefit of the Texas pimpleback, the Texas fawnsfoot, and their habitats on these lands; and may also serve as a model and aid in fostering future cooperative relationships with other parties here and in other locations for the benefit of other endangered or threatened species. Therefore, we consider the positive effect of excluding from critical habitat areas managed by active conservation partners to be a significant benefit of exclusion. 

DOCUMENTS