Daily Rules, Proposed Rules, and Notices of the Federal Government
This document consists of: (1) A final rule to list the Altamaha spinymussel (
Federal actions for this species prior to October 6, 2010, are outlined in our proposed rule (75 FR 61664), which was published on that date. Publication of the proposed rule opened a 60-day comment period, which closed on December 6, 2010. We reopened the comment period from May 12, 2011, through June 13, 2011, in order to announce the availability of and receive comments on a draft economic analysis (DEA), and to extend the comment period on the proposed listing and designation (76 FR 27629).
We received comments from the public on the proposed listing action and proposed critical habitat designation, and, in this rule, we respond to these issues in a single comments section. Below, we present the listing analysis first, followed by the analysis for designation of critical habitat.
The Altamaha spinymussel (
This species reaches a shell length of approximately 11.0 centimeters (cm) (4.3 inches (in)). The shell is subrhomboidal or subtriangular in outline and moderately inflated. As the name implies, the shells of these animals are adorned with one to five prominent spines. These spines may be straight or crooked, reach lengths from 1.0 to 2.5 cm (0.39 to 0.98 in), and are arranged in a single row that is somewhat parallel to the posterior ridge. In young specimens, the outside layer or covering of the shell (periostracum) is greenish-yellow with faint greenish rays, but as the animals get older, they typically become a deep brown, although some raying may still be evident in older individuals. The interior layer of the shell (nacre) is pink or purplish (Johnson 1970, p. 303).
Adult freshwater mussels are filter-feeders, siphoning phytoplankton, diatoms, and other microorganisms from the water column. For the first several months, juvenile mussels employ pedal (foot) feeding, extracting bacteria, algae, and detritus from the sediment (Yeager 1994, pp. 217-221; Cope
Although the life history of the Altamaha spinymussel has not been studied, the life histories of other mussels in the
This spinymussel is known only from Georgia in Glynn, Ben Hill, McIntosh, Telfair, Tattnall, Long, Montgomery, Toombs, Wheeler, Appling, Jeff Davis, Coffee, and Wayne Counties. This spinymussel is considered a “big river” species; is associated with stable, coarse-to-fine sandy sediments of sandbars, sloughs, and mid-channel islands; and appears to be restricted to swiftly flowing water (Sickel 1980, p. 12). Johnson (1970, p. 303) reported Altamaha spinymussels buried approximately 5.1 to 10.2 cm (2.0 to 4.0 in) below the substrate surface.
The historical range of the Altamaha spinymussel was restricted to the Coastal Plain portion of the Altamaha River and the lower portions of its three major tributaries, the Ohoopee, Ocmulgee, and Oconee Rivers (Johnson 1970, p. 303; Keferl 2001, pers. comm.). Large-scale, targeted surveys for the mussel have been conducted since the 1960s (Keferl 1993, p. 299). Recent surveys have revealed a dramatic decline in recruitment, the number of populations, and number of individuals within populations throughout the species' historic range (Stringfellow and Gagnon 2001, pp. 1-2; Keferl 1995, pp.
In a survey of the Ohoopee River, Keferl (1981, pp. 12-14) found at least 30 live specimens of the Altamaha spinymussel at seven of eight collection sites, in thinly scattered beds, in the lower 8 kilometers (km) (5 miles (mi)) of the river. Spinymussels were not found higher in the watershed, presumably because there are insufficient flows to support this species. By the early 1990s, however, only two live specimens were found at the same sites (Keferl 1995, pp. 3-6; Keferl 2008 pers. comm.; Wisniewski 2006, pers. comm.). Stringfellow and Gagnon (2001, pp. 1-2) resurveyed these sites using techniques similar to those used by Keferl (1981, p. 12), but did not find any live Altamaha spinymussels in the Ohoopee River. Therefore, the species is currently either extirpated from the Ohoopee River or present in such low numbers that it is undetectable.
The Altamaha spinymussel is known from the Ocmulgee River from its confluence with the Oconee River upstream to Red Bluff in Ben Hill County (approximately 110 km/68.3 mi). Early collecting efforts in the Ocmulgee River near Lumber City yielded many live Altamaha spinymussels. In 1962, Athearn made a single collection of 40 live spinymussels downstream of U.S. Highway 341 near Lumber City (Johnson
The lower Ocmulgee River was surveyed by Keferl in the mid 1990s, during 2000-2001 (Cammack
There are few historical records of Altamaha spinymussels from the Oconee River. Athearn collected 18 spinymussels, including 5 juveniles, at a site in Montgomery County near Glenwood in the late 1960s (Johnson
Most surveys for Altamaha spinymussels have been conducted in the Altamaha River. Although methodological differences preclude accurate comparison of mussel abundances over time, there is evidence that higher abundances of Altamaha spinymussels occurred in the Altamaha River historically. Early surveys at the U.S. Route 301 crossing documented 20 individuals in 1963, 7 in 1965, and 43 in 1970. Sickel sampled seven sites downstream of the U.S. Route 1 bridge in 1967. Sixty spinymussels were collected in one 500-square meters (m
From 1993 to 1996, Keferl surveyed 164 sites on the mainstem of the Altamaha River between the Ocmulgee-Oconee River confluence and the Interstate 95 crossing near the river's mouth (approximately 189 km/117 mi.). A total of 63 live Altamaha spinymussels were collected from 18 of these sites, located between the Oconee River and U.S. Route 301 (116 km/72 mi); however, no Altamaha spinymussels were collected below U.S. Route 301 (73 km/45 mi), suggesting absence or extreme rarity in the reach between U.S. Route 301 and the river's mouth (approximately 73 km (45 mi)). In addition, 10 of these sites were clustered within a 4-km (2-mi) reach upstream of the U.S. Route 301 crossing near Jesup; the remaining eight sites were isolated by long distances of habitat with no or sub-detectable numbers of live spinymussels.
O'Brien (2002, pp. 3-4) surveyed 30 sites on the Altamaha River from the confluence of the Ocmulgee and Oconee Rivers downstream to U.S. Route 301 during 2001, including the 18 known Altamaha spinymussel sites, reported by Keferl, within the reach. She collected a total of six live individuals from five different sites and freshly dead shells from two additional sites.
In 2003 and 2004, researchers surveyed 25 sites to collect specimens for host-fish trials (Albanese 2005, pers. comm.). Live Altamaha spinymussels were detected at only four sites. Five of the seven sites documented by O'Brien and all four sites documented during the host-fish surveys were clustered within a short reach (15 km/24 mi) of the Altamaha River just upstream of the U.S. Route 301 crossing near Jesup, Georgia.
To summarize, researchers were able to find 60 Altamaha spinymussels at a single site on the Altamaha River in 1967; in contrast, the largest number of Altamaha spinymussels observed from a single site on the Altamaha River during the 1990s or 2000s was nine (Albanese 2005, pers. comm.).
In 1994, researchers spent 128 search-hours throughout the Altamaha Basin to find 41 spinymussels (Keferl 1995, p. 3). From 1997 through 2006, researchers searched 233 sites throughout the basin to document 34 spinymussels in more than 550 hours of searching (Wisniewski 2006, pers. comm.); from 2007 to 2009, only 23 spinymussels were found from more than 110 sites (Wisniewski 2009, pers. comm.). In summary, the Altamaha spinymussel is considered extirpated from two rivers in its historical range, the Ohoopee (15 km (9 mi)) and Oconee Rivers (45 km (28 mi)), as well as the lower 73 km (45 mi) of the Altamaha River (Table 1). Since 1997, despite extensive survey efforts made by several different researchers, only 57 spinymussels have been observed from 7 sites in the Ocmulgee (110 km (68 mi)) and 15 sites in the upper Altamaha (116 km (72 mi)) combined, and while individual spinymussels have been found scattered throughout this stretch of river, most of these sites have been clustered in the 10 km (6 mi) immediately north of the U.S. Route 301 crossing.
Using Georgia Department of Natural Resources (GDNR)'s database, which included many of the surveys mentioned above, Wisniewski
During the open comment periods for the proposed rule (75 FR 61664) and draft economic analysis, we requested that all interested parties submit comments or information concerning the proposed listing and designation of critical habitat for the Altamaha spinymussel. We contacted all appropriate State and Federal agencies (including the State of Georgia, from whom we directly requested comments), county governments, elected officials, scientific organizations, and other interested parties and invited them to comment. Articles concerning the proposed rule and inviting public comment were published by the Associated Press, The Brunswick News and the Florida Times Union. An article was also published by the Center for Biological Diversity.
During the comment periods, we received a total of 79 comments. We received comments supporting the listing of the Altamaha spinymussel from the Georgia Department of Natural Resources-Wildlife Resources Division, the U.S. Army Corps of Engineers, three environmental groups, and 70 individuals including 9 letters and 65 postcards. We received two requests for an extension of the open comment period and notified requestors that the comment period would reopen for the Notice of Availability of the Draft Economic Analysis, published on May 12, 2011. We received no requests for, and therefore did not hold, a public hearing.
In accordance with our peer review policy published in the
We reviewed all comments received for substantive issues and new data regarding the spinymussel, its critical habitat, and the draft economic analysis. Written comments received during the comment periods are addressed in the following summary. For readers' convenience, we have combined similar comments into single comments and responses.
Nickel toxicity has been reported for juvenile unionids at 190 ug/L in a 96-hr test with soft water (hardness <50 mg/L). Acute and chronic nickel criteria should be lower than 190 ug/L (no citation provided).
Pyrene is a polycyclic aromatic hydrocarbon (PAH) that may be associated with pulp and paper mills among other industrial and urban sources. This PAH is toxic to unionid glochidia (24 h LC50) at 2.63 ug/L in the presence of UV light (no citation provided). Chronic criteria for persistent, bioaccumulative compounds like PAHs should be substantially lower than acute toxicity values.
Section 4(i) of the Act states, “the Secretary shall submit to the State agency a written justification for his failure to adopt regulations consistent with the agency's comments or petition.” Comments received from the State regarding the proposal to designate critical habitat for the Altamaha spinymussel are addressed below.
Because the comments of one peer reviewer (a State of Georgia employee) were adopted by the State, we are including them in our response to State comments. The State supports the designation of critical habitat for the occupied reaches of the Altamaha and Ocmulgee rivers as proposed, including the exclusion of the Altamaha River between U.S. Route 1 and the upper property boundary of Moody Forest Natural Area from proposed critical habitat. Georgia concurs with the Service that the designation of critical habitat in only the currently occupied reaches of the Altamaha and Ocmulgee Rivers would not adequately conserve the Altamaha spinymussel because this range is connected in a linear pattern that could be destroyed by a single event in the Ocmulgee, flowing downstream into the Altamaha. Therefore, the proposed designation of critical habitat in at least one additional tributary that historically harbored the Altamaha spinymussel is necessary to conserve the species.
In order to estimate the cost of consultation the Service contacted the National Marine Fisheries Service (NMFS) to see how many consultations they conduct for the shortnose sturgeon
We believe that the maximum temperature and the maximum daily temperature fluctuation criteria identified in PCE 3 are supported by the best available data generated from direct temperature measurements of the Altamaha River, as well as comparisons to three temperature gauge stations on the Savannah River, which is similar in size, hydrology, and proximity (Wisniewski 2011, pers. comm.). Therefore, a maximum temperature of 32.6 °C with no more than a 2 °C daily fluctuation appears justified. See the Physical or Biological Features discussion to see how these were derived.
Comments suggesting that dissolved oxygen in bottom layers of critical habitat may be lower than the PCE are not appropriate because spinymussels are found in the mainstem river in areas of moving water that does not stratify. Therefore, the water should be well-mixed and dissolved oxygen should be consistent throughout the water column.
For ammonia, 1.5 mg N/L is the criteria maximum concentration (CMC) and 0.22 mg N/L is the criteria continuous concentration (CCC). A review of mussel ammonia literature indicates that at least some juvenile mussels are sensitive to ammonia at concentrations as low as 0.093 mg NH3/L in 10-d assays (Newton
The Service attempted to determine the `central range' of pH values in the Altamaha River by generating the 10th and 90th percentiles (the point at which 10% and 90%, respectively, of the observed values fell) of pH. Because the causes of the decline of the spinymussel remain unidentified, and no data are available regarding the optimal pH for this species, it is reasonable to designate a PCE for critical habitat that does not include the extremes of any water quality parameter (Bringolf 2011, pers. comm.). Critical habitat must be supportive of the species, and it is reasonable to assume that extremes of any parameter could be detrimental to this species. Critical habitat PCEs should incorporate the most stable habitats.
Mussel toxicity to cadmium (Cd) is reported to occur at concentrations as low as 16 µg/L in 96-h tests with juveniles (Wang
The competition between the Asian clam (
In conclusion, there is not sufficient evidence to support the existence of potential populations of the Altamaha spinymussel in these floodplain lakes or tributaries.
Section 4 of the Act and its implementing regulations (50 CFR part 424) set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. A species may be determined to be an endangered or threatened species due to one or more of the five factors described in section 4(a)(1) of the Act. The five listing factors are: (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; and (E) other natural or manmade factors affecting its continued existence.
Bogan (1993, pp. 599-600 and 603-605) linked the decline and extinction of bivalves to a wide variety of threats including siltation, industrial pollution, municipal effluents, modification of stream channels, impoundments, pesticides, heavy metals, invasive species, and the loss of host fish. The Altamaha spinymussel lives within a large river drainage exposed to a variety of landscape uses. Habitat and water quality for the Altamaha spinymussel face degradation from a number of sources. Primary among these are threats from sedimentation and contaminants within the streams that the spinymussel inhabits.
Sickel (1980, p. 12) characterized the habitat of the Altamaha spinymussel as coarse-to-fine-grain sandbars, and suggested that this may make the Altamaha spinymussel susceptible to adverse effects from sediment (siltation). Sediments deposited on the stable sandbars required by the Altamaha spinymussel could make sandbars unstable, result in suffocation, or simply change the texture of the substrate, making them unsuitable for the species. Sedimentation, including siltation from surface runoff, has been implicated as a factor in water quality impairment in the United States and has contributed to the decline of mussel populations in streams throughout the country (Ellis 1936, pp. 39-41; Coon
Specific impacts on mussels from sediments include reduced feeding and respiratory efficiency, disrupted metabolic processes, reduced growth rates, increased substrata instability, and the physical smothering of mussels (Ellis 1936, pp. 39-41; Stansbery 1970, p. 10; Markings and Bills 1979, pp. 209-210; Kat 1982, p. 124; Aldridge
From 1700 to 1970, agricultural practices in the Southern Piedmont physiographic province resulted in extreme soil erosion, removing more than 17.8 cm (7 in.) of soil across the landscape (Trimble 1974, p. 1). The Ocmulgee, Oconee, and Ohoopee rivers all drain through the Piedmont and were directly affected by this erosion and resulting sedimentation. In 1938, van der Schalie (p. 56) reported the Altamaha River as being yellow in color, due to the large amount of suspended silt originating from intensive farming and road construction occurring in the headwaters. The sediment from these practices moved into stream channels and valleys, covering most of the original bottomlands (Trimble 1974, p. 26) and is now referred to as legacy sediment (Jackson
Studies of the fish populations in the Altamaha River Basin were conducted in 2000 by the GDNR Wildlife Resources Division (WRD). The Index of Biotic Integrity (IBI) and modified Index of Well-Being (IWB) rate fish populations as being in Excellent, Good, Fair, Poor, or in Very Poor condition, and were applied by the WRD to identify impaired fish populations in the Altamaha River. Stream segments with fish populations rated as Poor or Very Poor were listed as Biota Impacted. A lack of fish habitat due to stream sedimentation was generally the cause of a low IBI score.
Five Mile Creek (14.5 km/9 mi), Bullard Creek (12.8 km/8 mi), and Jacks Creek (14.5 km/9 mi) were rated as “Very Poor” and placed on the State of Georgia's 303(d) list of impaired waters due to a significant impact on fish (EPD 2007a, pp. 1-2). These three streams eventually feed into the mainstem of the Altamaha River via larger channels. As sediment moves through the basin, habitat is periodically buried. WRD recommends that there be no net increase in sediment delivered to the impaired stream segments so that these streams will recover over time (EPD 2007a, p. 26). Agriculture and roads were identified as the major sources of sediment with silviculture, mining sites, grazing, and urban development also contributing nonpoint sources of sediment (EPD 2007a, p. 9). Agriculture, including row crops, poultry farms, and pastures, constitute 15.5 percent of the land cover in the Piedmont and 32.7 percent of the land cover in the Coastal Plain (GDNR 2005, pp. 97, 132).
In addition to agriculture, there are numerous sources of sediment within the Altamaha River Basin, including silviculture, unpaved roads, kaolin mines, and construction sites. A threat assessment conducted by TNC (2004, p. 9) listed sediment from urban, industrial, and nonpoint sources (NPSs) as a threat to the spinymussel. The EPD (2007, p. v) reported that, while historical row crop-based land use contributes the majority of sediment in the Altamaha River (75 percent), that among other sources, approximately 17.3 percent of the total sediment load is from roads; 4.3 percent from grasses and wetlands; 1.5 percent from urban lands; and 1.0 percent from quarries, strip mines, and gravel pits. In addition, estimates of the contribution from construction could not be obtained, but could represent a comparatively high sediment load on a per -acre basis (EPD 2007, p. v).
Industrial forest management is practiced on approximately 8,000 hectares (40,000 acres) or 33 per