SECTION NO. 4
Fluminicola n. sp. 2
Fluminicola n. sp. 3
Fluminicola n. sp. 11
Fluminicola n. sp. 19
Juga (Oreobasis) n. sp. 2
Lyogyrus n. sp. 1
Lyogryrus n. sp. 3
Vorticifex klamathensis sinitsini
Vorticifex n. sp. 1

Draft Management Recommendations
for
ROD Mollusk Species associated with springs and spring runs:
Fluminicola new species 2, 3, 11, 19;
Vorticifex new sp. 1, Vorticifex klamathensis sinitsini;
Juga (Oreobasis) new species 2; and Lyogyrus new spp. 1 and 3

v. 2.0

by

Joseph L. Furnish,
USDA Forest Service,
San Francisco, California

and

Roger W. Monthey
USDI Bureau of Land Management
Salem, Oregon

December 1998

TABLE OF CONTENTS

EXECUTIVE SUMMARY

Species: Freshwater snail species associated with springs and spring runs.

Taxonomic Group: Mollusks (Phylum Mollusca; Class Gastropoda; Subclasses Prosobranchia and Pulmonata; Families Hydrobiidae, Planorbidae and Pleuroceridae)

ROD Components: All species in this document are Survey and Manage Strategies 1 & 2. Fluminicola n. sp 11 and Fluminicola n. sp. 19 are also listed in the Standards and Guides for protection from grazing.

Other Management Status: The Oregon Natural Heritage Program (ONHP 1995) lists the following species as List 1 species (i.e., they are critically imperiled because of extreme rarity or are somehow especially vulnerable to extinction or extirpation, and typically have 5 or fewer occurrences): Fluminicola n. sp. 2, Fluminicola n. sp. 3, Juga (Oreobasis) n. sp. 2, Lyogyrus n. sp. 1 and Vorticifex klamathensis sinitsini. These same species are BLM Bureau Sensitive species in Oregon. Lyogyrus n. sp. 1 is on the Washington State Monitor Species List and is a BLM Bureau Tracking species in Washington.

Ranges: The distributions of all species are based on Frest and Johannes (1993, 1995a, b, c). These 9 species may be conveniently divided into 3 groups on the basis of geographic distribution. One group consisting of Lyogyrus n. sp. 1 and Juga (Oreobasis) n. sp. 2 is restricted to the Columbia Gorge. Another group is restricted to the Klamath Basin and is composed of Fluminicola n. sp. 2, Fluminicola n. sp. 3, Fluminicola n. sp. 11 and Vorticifex klamathensis sinitsini. The last group is endemic to the Pit River of northern California. Lyogyrus n. sp. 3, Vorticifex n. sp. 1 and Fluminicola n. sp. 19 define this group.

Specific Habitat: Species in this group are generally associated with springs and spring runs. Substrate material ranges in size from mud, silt, sand to gravel, cobble, and boulders. Specific habitat differences among species are found in the text.

Threats: A summary of the major threats for all species follows. See text for threats to specific species.

• Chemical spills and other forms of water pollution (e.g., livestock use of springs and spring runs, urban runoff, other agriculture, other industrial) resulting in effects such as: 1) direct mortality of species as evidenced by the recent (1991) Cantara Spill on the Upper Sacramento River, and 2) deleterious habitat alterations resulting from factors such as eutrophication caused by excessive nitrogen and phosphorus levels, reduced dissolved oxygen levels, or elevated water temperatures.
• Water diversions for such activities as irrigation and livestock watering, resulting in reduced spring flow and thus less habitat for these snails.
• Dam construction which submerges cold springs, slows current velocities, lowers the availability of oxygen and allows fine sediments to accumulate. For example, dams on the Columbia River have likely submerged formerly occupied sites.
• Excessive sedimentation from a variety of activities such as logging, mining, road and railroad grade construction, and grazing may smother substrates and may impair egg-laying or survivorship of eggs or young.

Management Recommendations: All sites occupied by these snails should be protected and monitored. Specific recommendations include:

1. Maintain water temperatures below 18^oC (65^oF) to avoid thermal stress and ensure adequate availability of oxygen. (18C represents the critical threshold for trout.)
2. Maintain dissolved oxygen levels at or near saturation levels.
3. Maintain and/or restore native riparian plant communities that aids in maintaining cool water temperatures (i.e. below 18^oC) by providing shade, reducing sedimentation impacts, and providing litter fall nutrients to energy pathways in the stream ecosystem.
4. Avoid or mitigate for activities that could significantly increase sedimentation, pollution, or potential for eutrophication of occupied sites (e.g., logging, grazing, mining, construction activities).
5. Avoid water diversions or other activities that may reduce water flow below levels necessary to sustain viable populations. This level must be determined on a site-specific basis, but these species generally need flowing water.
6. Avoid or mitigate for the construction of dams that could have the following negative impacts: submersion of cold springs, slowing of current velocities, lowering of dissolved oxygen, and increased sedimentation.

Information Needs - Additional surveys should be conducted to locate populations in areas with potential suitable habitat. More monitoring or research is needed on habitat requirements of these species. Develop a collection of voucher specimens for appropriate administrative units within the range of these species. Provide additional training opportunities for identifying mollusk species and conducting surveys within the appropriate administrative units. Monitor water temperatures and other environmental parameters (e.g., sedimentation, dissolved oxygen) that potentially affect this species. Determine the minimum instream flow requirements necessary to maintain environmental conditions within physiological limits.

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I. NATURAL HISTORY

A. Taxonomic/Nomenclatural History

Only one of these 9 species, Vorticifex (Parapholyx) klamathensis sinitsini (Baker, 1945), has been formally described in the scientific literature. However, Frest and Johannes (1993, 1995a, b, c) recognized the rest as distinct. Designation of undescribed species follows that given in the Record of Decision (ROD) for Amendments to Forest Service and Bureau of Land Management Planning Documents within the Range of the Northern Spotted Owl (1994). Common names are taken from Frest and Johannes (1993, 1995a, b, c). The following account is largely taken from information provided in these extensive reports that should be consulted for further details.

Although 8 of the 9 species in this species group are presently undescribed in the formal sense, specimens belonging to these genera have been recognized by various names in the scientific literature. The Fluminicola species are within the family Hydrobiidae, the "spring snails," and subfamily Lithoglyphinae. North American snails within this subfamily closely resemble some foreign groups. Similarities in the male reproductive system and shell led Taylor (1966, 1981) to consider these snails as representatives of the European genus Lithoglyphus. However, Thompson (1984), after detailed studies, concluded that Fluminicola is likely distinct, but there is still a need for more detailed anatomical and conchological examination.

Lyogyrus n. sp. 1 is within the Family Hydrobiidae, Subfamily Amnicolinae. It may be present in collections as L. greggi. The genus Lyogyrus has recently been split into subgenera (Thompson & Hershler, 1991; see also Hershler & Thompson, 1988). However, the detailed anatomy of all of the western and some of the eastern US species remains to be elucidated, and it is not clear if western species belong to any of the described subgenera.

Juga (Oreobasis) n. sp. 3 is a member of the family Pleuriceridae or the "river snails." This family differs from the family Hydrobiidae in that the males lack a verge (male copulatory organ). Juga is a genus that is distinct from eastern pleruocerid snails based on reproductive anatomy and egg mass characters (Taylor 1966). Juga species have been referred to in science literature as Goniobasis, Oxytrema, and Melania. In museum collections and literature citations, J. (O.) n. sp. 2 has been confused with J. bairdiana (Lea) and J. draytonii (Lea).

B. Species Description

1. Common Characteristics

Species are grouped because of their mutual affinity for springs and spring runs.

2. Morphology

Fluminicola n. sp. 2 (tall pebblesnail) - The tall conical (elongately conic) spire; small size (to 5 mm); evenly black body, tentacles, and mantle; and unpigmented alate penis are distinctive features. The distinctive verge (male copulatory organ) of this and several other Upper Klamath Lake drainage taxa may merit separation as a genus-level taxon.

Fluminicola n. sp. 3 (Klamath Rim pebblesnail) - This is a very small (to 1.5 mm length), broadly conic species with thin, almost transparent shell and light-greenish periostracum. Distinctive features of this taxon are the small size; rather evenly gray body and tentacles; and narrow, elongate, sickle-shaped penis.

Fluminicola n. sp 11 (Fredenburg pebblesnail) - This small (adults 2-3 mm in height) species has a globosely conic spire, greenish-yellow periostracum, light gray body, and more or less evenly but only slightly reinforced apertural margin, with a minor basal crescent. Cephalic tentacles and snout are slightly darker than general body color, and eye spots are slightly lighter than body color.

Fluminicola n. sp. 19 (umbilicate pebblesnail) - The spire is low conic, with a large flat protoconch and very blunt apex. The lower whorls are strongly convex, although the aperture is slightly flattened basally, and its shape is subovate, appearing small in comparison to the preceding whorl. The last quarter-whorl is deflected slightly downward in mature individuals. The shell is rather thin; there is a narrow columellar and parietal callus, but the basal lip and right side are very thin. There is a substantial open umbilicus, and a narrow basal crescent that is complete to the base of the columella. The shell is green with occasional distinct spiral whitish streaks on the early whorls. This species is about 4.3 mm in height at maturity, and has between 4-4.5 whorls at maturity. The body is black and the mantle is also very dark.

Juga (Oreobasis) n. sp. 2 (basalt juga) - Moderate-sized, somewhat low-spired Juga with barely convex whorls and shallow suture. Nacre white; shell with 3 numerous color bands, generally with 3 yellow and several brown, pink or tan; initial whorls smooth. This species may look much like Juga (Juga) n. sp. 2 (three-band juga) of Frest & Johannes (1995a) if the initial whorls are absent. However, that species generally has a much more consistent dark brown and yellow banding pattern, and generally retains enough of the early whorls that the plications, though weak, are easily visible.

Lyogyrus n. sp. 1 (Columbia duskysnail) - This small spring snail (length less than 1.5 mm) has a small flat protoconch, broadly domed upper whorls, oval aperture, black mantle, and evenly light gray body and tentacles. The shell is thin and partly opaque, its color generally off-white or slightly gray; the ornament has weak growth lines only, irregularly developed. The whorls are strongly convex, the suture deeply impressed, the spire ovately conic, and the umbilicus is small and open. Both penial lobes are unpigmented.

Lyogyrus n. sp. 3 (canary duskysnail) - This very small hydrobiid is less than 1.3 mm in length; has a very small, flat, strongly inclined protoconch; unpigmented body and lightly pigmented mantle (upper part of spire only); depressed conic spire; and canary yellow, semi-translucent shell. There is a distinct, open umbilicus and small, incomplete basal crescent placed wholly below the umbilical opening. The columellar callus is thin; there is also a weak parietal callus, but the rest of the apertural margin is thin. The margin is often irregular, but there is generally a distinct lip developed basally and another just to the right of the parietal margin. The aperture is nearly circular in side view. This species is mature at 4 whorls; the whorls (following the protoconch) are evenly convex. The shell is thin and partly transparent; ornament of weakly developed growth lines only.

Vorticifex klamathensis sinitsini (Sinitsin rams-horn) - The shell is similar to klamathensis but is smaller, more globose, more solid, and thicker. The spire is more elevated; aperture more rounded, not as effuse; columellar callus heavier; umbilicus closed or barely perforate. Color brownish horn; interior of aperture reddish-brown. Lip bordered internally by thin white callus. For more detail, see Baker (1945). This subspecies is smaller, has a thicker and more globose shell, and a higher spire than the nominate form.

Vorticifex n. sp. 1 (knobby rams-horn) - This rather unusual new species has a peripheral keel with short, spine-like protuberances and a heavily-ribbed shell with distinct varices. The juvenile is flat above (strong peripheral keel); the spire becomes moderately elevated with growth. The shell is thin and translucent; color ranges from green-brown to dark reddish-brown. Height is 1 cm or less. There is a small, straight columellar callus; the parietal callus is very thin, and the rest of the aperture is thin, somewhat irregular, easily damaged, and subovate in shape. The umbilicus is closed. The external morphology of the body is very similar to that of V. effusa effusa.

3. Reproductive Biology

Information on life history is very sparse, but the Fluminicola spp. and Lyogyrus spp. considered here are probably similar to other Fluminicola species that have been better studied. Typically, members of the family are dioecious (i.e., have separate sexes) and semelparous (i.e., breed only once in their lifetime and then die). Individuals have a life span of one year, with 90 percent or more of the population turning over annually. Surviving individuals are generally those that did not breed during their first year. Eggs are laid in the spring and hatch in approximately 2-4 weeks. Sexual maturity is reached by late summer after a few months of growth. Individuals overwinter as adults and do not disperse widely so populations remain very localized in their distribution.

The reproductive biology of Juga (Oreobasis) n. sp. 2 is unknown. However, based on the assumption that the biology of this species is similar to other, more studied species of Juga in the Pacific Northwest, the following generalities may be made. According to Hawkins and Furnish (1987) and Furnish (1990), Juga silicula (Gould) is an abundant species in creeks, streams, and small rivers of the Willamette Valley and Coast Range north to Puget Sound. In a small stream in the Oregon Coast Range, it reached sexual maturity in 3 years and adults usually lived 5-7 years. The species is dioecious and appears to be iteroparous (i.e., breeds several times after reaching sexual maturity). In late spring, egg masses containing about 150 individuals are laid on the undersides of cobble-sized substrates in shaded, running water. Young snails hatch in about one month.

Vorticifex klamathensis sinitsini (Sinitsin rams-horn) and Vorticifex n. sp. 1 (knobby rams-horn) are both pulmonate snails. Presumably, like all pulmonate snails, Vorticifex is hermaphroditic and capable of self-fertilization. As a general rule, pulmonates live for one year, lay eggs, and die.

3. Ecology

The 4 Fluminicola and 2 Lyogyrus species are rare aquatic snails belonging to the family Hydrobiidae. The common name for this family is "spring snails," which is an allusion to the type of habitat where they are primarily found. All hydrobiid snails (i.e., of the family Hydrobiidae) have gills that make them dependent upon dissolved oxygen in the water in which they live. Like most hydrobiid snails, the snails of this group are highly sensitive to water pollution, oxygen deficits, elevated water temperatures, and sedimentation. These 6 species are crenophiles (i.e., organisms living only in spring environments) and periphyton (organisms growing on submerged stems and other parts of aquatic macrophytes) or perilithon (organisms growing on stones) grazers. Major predators include waterfowl, amphibians, turtles, sculpins, and trout. Typically, many individuals are infected with trematode parasites.

Some ecological information for the various species is as follows:

1. Fluminicola n. sp. 2 (tall pebblesnail) - This endemic species is known from a single site at Harriman Spring. This site is a very cold, oligotrophic spring with a cobble-gravel bottom. Depths range from a few centimeters to a meter, depending mostly on the time of year. Large colonies (from 1-10 cms in diameter) of the blue-green alga Nostoc pruniformes occur in some areas. This snail is a crenophile and probably a periphyton-perilithon grazer.
2. Fluminicola n. sp. 3 (Klamath Rim pebblesnail) - Occurs only in one small, cold, spring run that is tributary to Upper Klamath Lake where the water is very shallow. The substrate is cobble and gravel and no macrophytes are present. The snail only occurs in shaded areas and may be photophobic. It is a crenophile and perilithon grazer.
3. Fluminicola n. sp 11 (Fredenburg pebblesnail) - This narrowly endemic species is only known from Fredenburg Spring, which is tributary to the middle Klamath drainage. The site has beds of Mimulus (monkey flower) and Rorippa (water cress). It is a crenocole and probably a perilithon grazer.
4. Fluminicola n. sp. 19 (umbilicate pebblesnail) - This species is a local endemic known from a single, cold, spring pool and outflow complex that is part of the source of Hat Creek and a tributary to the Pit River. It occurs among Rorippa (water cress) and Veronica beds on sandy-gravelly substrates. It is a crenocole and a perilithon and periphyton grazer.
5. Lyogyrus n. sp. 1 (Columbia duskysnail) - This species is known from 15 sites in springs and spring outflows in the Columbia Gorge. It prefers cold, well oxygenated water and occurs in shallow, slow flowing water with no macrophytes. It is probably a perilithon grazer. It co-occurs with other freshwater snails, such as Juga (Oreobasis) n. sp. and Pristinicola hemphilli, that are restricted to cold, pristine springs.
6. Lyogyrus n. sp. 3 (canary duskysnail) - This species is a crenophile known to occur in one very large, cold spring complex tributary to the Pit River, and in a spring-fed portion of the mainstem of the Pit River. Individuals are only found in shaded areas on the undersides of cobbles and boulders, and they appear to be photophobic. It is probably a perilithon grazer.

Juga (Oreobasis) n. sp. 2 (basalt juga) is a member of the family Pleuroceridae or "river snails." It is a crenophile restricted to cold springs that are tributary to the Columbia River at low elevations, and is a perilithon grazer. This species is dependent upon dissolved oxygen and, like the Fluminicola species, is sensitive to water pollution, oxygen deficits, elevated water temperatures, and sedimentation. It co-occurs with other freshwater snails, such as Juga (Juga) n. sp. and Pristinicola hemphilli that are restricted to cold, pristine springs.

The 2 Vorticifex species (V. klamathensis sinitsini and Vorticifex n. sp. 1) belong to the Family Planorbidae. Both species are crenophiles, living in large cold springs with coarse substrate. Both are also lithophiles and perilithon grazers. Associated mollusks include Fluminicola sp. and Lanx klamathensis.

Vorticifex n. sp. 1, the knobby rams-horn, occurs on red algae-encrusted cobbles and boulders.

C. Range, Known Sites

The distributions of all species are based on Frest and Johannes (1993, 1995a, b, c). These 9 species may be conveniently divided into 3 groups on the basis of geographic distribution. One group, consisting of Lyogyrus n. sp. 1 and Juga (Oreobasis) n. sp. 2, is restricted to the Columbia Gorge. Another group is restricted to the Klamath Basin and is composed of Fluminicola n. sp. 2, Fluminicola n. sp. 3, Fluminicola n. sp. 11, and Vorticifex klamathensis sinitsini. The last group is endemic to the Pit River of northern California: Lyogyrus n. sp. 3, Vorticifex n. sp. 1 and Fluminicola n. sp. 19. Distributions of all species are based on Frest and Johannes (1993, 1995a, b, c).

Distributions of individual species are as follows:

Fluminicola n. sp. 2 (tall pebblesnail) - This species is only known from Harriman Spring on private land adjacent to Winema National Forest lands in Klamath County, Oregon.

Fluminicola n. sp. 3 (Klamath Rim pebblesnail) - This species occurs at 2 sites in Klamath County, Oregon. One is on Medford District BLM lands.

Fluminicola n. sp. 11 (Fredenburg pebblesnail) - This species is found at a single site (Fredenburg Springs) on lands administered by Medford District BLM in Jackson County, Oregon.

Fluminicola n. sp. 19 (umbilicate pebblesnail) - This species is only known to occur at a single spring complex in Lassen National Forest in Shasta County, California.

Juga (Oreobasis) n. sp. 2 (basalt juga) - This species occurs sporadically in springs in the central and eastern portions of the Columbia Gorge in Hood River and Wasco counties, Oregon, and Klickitat and Skamania counties, Washington. Known sites occur within Mt. Hood National Forest and in the Columbia Gorge National Scenic Area. It is known to occur at 28 sites.

Lyogyrus n. sp. 1 (Columbia duskysnail) - This species occurs very sporadically in the central and eastern Columbia Gorge, Washington and Oregon. About a dozen sites are known from private lands and from the Columbia Gorge National Scenic Area, Gifford Pinchot National Forest, and Mt. Hood National Forest, in Klickitat and Skamania counties, Washington, and Multnomah and Hood River counties, Oregon. Some sites are in State parks (Beacon Rock, Benson, Wahkeena Falls).

Lyogyrus n. sp. 3 (canary duskysnail) - It is known from 2 sites in Shasta County, California; one near the present boundary of Shasta National Forest, and the other in a spring-influenced area in the Pit River. Other sites are possible in limited areas on Redding District BLM administered lands and in Lassen and Shasta National Forests in the vicinity of Fall River Mills.

Vorticifex klamathensis sinitsini (Sinitsin rams-horn) - It is known only from a single site on private land at Barkley Springs, Upper Klamath Lake, Klamath County, Oregon. There is probable occurrence on adjoining public lands in the Winema National Forest, and Upper Klamath Lake National Wildlife Refuge.

Vorticifex n. sp. 1 (knobby rams-horn) - This species is found at 2 sites in Shasta County, California, on private land adjoining Shasta National Forest. Limited numbers of additional sites are possible in Shasta National Forest, and on State owned lands near Fall River Mills.

D. Habitat Characteristics and Species Abundance

Much of the following habitat information is from Frest and Johannes (1995, 1996), and the FSEIS Appendix J2 (USDA Forest Service and USDI Bureau of Land Management 1994a). Information on species abundance is largely absent.

Fluminicola n. sp. 2 (tall pebblesnail) - This is an obligate spring dweller that may be photophobic (i.e., avoids light). The species occurs on pebbles and cobbles. Few macrophytes are present, except for local Veronica. In one site there are large numbers of Nostoc pruniforme (blue-green alga) colonies that cover substrate such as cobbles. It occurs in one large, very cold, undisturbed spring draining into Upper Klamath Lake.

Fluminicola n. sp. 3 (Klamath Rim pebblesnail) - This species only occurs in shaded areas and maybe photophobic. Its habitat is small, cold spring runs, in very shallow water with gravel-cobble substrate. No macrophytes were present.

Fluminicola n. sp 11 (Fredenburg pebblesnail) - It is known to occur only in one narrow, shallow, and small cold-spring run with cobble and gravel substrates. It is associated with Rorippa and Mimulus.

Fluminicola n. sp. 19 (umbilicate pebblesnail) - This species is a spring dweller that is abundant on submerged portions of emergent Rorippa and Veronica. It can be found on mixed silt, sand, gravel, and cobble substrates of spring pools and their outflows.

Juga (Oreobasis) n. sp. 2 (basalt juga) - This icrenophilic (i.e., prefers springs) species occurs in small, shallow undisturbed perennial springs tributary to the Columbia River. It occurs in large, cold springs and spring runs, with sand-gravel-cobble substrate, in forested areas, along with one or more endemic Fluminicola species. Occupied springs are often surrounded by basalt talus, and Rorippa is often present.

Lyogyrus n. sp. 1 (Columbia duskysnail) - It occurs in cold, well-oxygenated springs and spring outflows on soft substrates in shallow, slow flowing areas. It prefers areas with no macrophytes, but may occur in areas with Rorippa and Cicuta.

Lyogyrus n. sp. 3 (canary duskysnail) - This species is known to occur in one very large, cold spring and in a spring-fed portion of the Pit River. Individuals occur on the undersides of loose cobbles and boulders that are covered with an encrusting red alga. The species appears to be photophobic.

Vorticifex klamathensis sinitsini (Sinitsin rams-horn) - It is only known to occur in Barkley Springs, Upper Klamath Lake, a large, cold spring complex with coarse substrates and rapid current velocities. Common macrophytes in the springs include Rorippa, Mimulus, and Veronica. Water depth ranges from a few inches to 2 feet.

Vorticifex n. sp. 1 (knobby rams-horn) - This is a crenophilic species that occurs in a large, pristine, cold spring pool complex tributary to the Pit River. Individuals occur on the surface of cobbles and boulders that are mostly covered with an encrusting red alga. Elevation of the spring complex is 1010 m (3305 ft.)

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II. CURRENT SPECIES SITUATION

A. Why Species is Listed Under Survey and Manage Standards and Guidelines

Because of their rarity, occurrence in localized sites, and high degree of endemism, the FEMAT analysis (USDA, Forest Service and USDI, Bureau of Land Management 1994b) concluded that these species have low likelihood of attaining stable, well distributed populations. All 9 species are endemic to particular geographic areas. Historically, all species in this group have suffered from habitat degradation, so it is appropriate to protect surviving populations.

B. Major Habitat and Viability Considerations

The Fluminicola and Lyogyrus species are rare aquatic snails belonging to the family Hydrobiidae. A common name for this family is "spring snails," which is an allusion to the type of habitat where they are primarily found. All hydrobiid snails have gills that make them dependent upon dissolved oxygen in the water column. Fluminicola and Lyogyrus species, like most hydrobiid snails, are highly sensitive to oxygen deficits (i.e., less than saturation), elevated water temperatures (i.e., above 18^oC or 65^oF) and sedimentation (i.e., avoid smothering layers of fine sediment). These 6 hydrobiid species are only found in pristine springs that have cold, well oxygenated, clear water, generally with cobble and/or boulder substrates. Any activities that degrade these water quality parameters will adversely impact these species.

The life history traits of Vorticifex spp., Fluminicola, and probably also Lyogyrus species, puts them at risk. All species generally appear to breed only once in their lifetime and then die. Usually 90 percent of the population turns over annually so any condition (e.g., excessive sedimentation) that impairs egg laying, or survivorship of eggs or young may result in extirpation.

Juga (Oreobasis) n. sp. 2, like the Fluminicola sp. discussed above, is also a gilled snail that is sensitive to alterations in water chemistry, oxygen deficits, and fine sediments. It is believed to be relatively long-lived, with many individuals reaching an age of 5 to 7 years. Declining population trends may not become apparent for a few years unless recruitment into the population is monitored by looking for the appearance of young individuals.

C. Threats to the Species

The species restricted to cold springs in the Columbia Gorge [i.e., Lyogyrus n. sp. 1, Juga (Oreobasis) n. sp. 2 ] have been subjected to direct and indirect effects of habitat loss due to human activities, including disturbance to occupied spring sites. These disturbances include water diversions for irrigation, damming of the Columbia River, which has probably submerged formerly occupied sites, and road and railroad grade construction that destroy spring runs and disrupt spring flows.

The species restricted to cold springs in the Klamath Lake basin in southwestern Oregon (Fluminicola n. sp. 2, F. n. sp. 3, F. n. sp. 11, Vorticifex klamathensis sinitsini) have all been affected by grazing, water diversions, and road building. All species except F. n. sp. 3 occur in limnocrene habitats in or adjacent to Upper Klamath Lake where they have been exposed to additional disturbances like dredging, log storage and transport, and eutrophication and pollution associated with agricultural, urban, and industrial pollution. In 1994 habitat near the population of V. k. sinitsini was disturbed by addition of gravel, apparently to enhance endangered sucker spawning beds at Barkley Spring.

The habitats associated with the Pit River have been intensively modified by humans. Therefore, it is highly probable that the species in this area (Lyogyrus n. sp. 3, Vorticifex n. sp. 1, Fluminicola n. sp. 19) have suffered significant negative impacts from mining, logging, grazing, chemical pollution, road and railroad grade construction, and water diversions.

Dam construction on the Pit River by Pacific Gas and Electric has caused extensive destruction of suitable habitat. Dam construction submerges cold springs, slows current velocities, lowers the availability of oxygen, and allows fine sediments to accumulate. Existing populations have been decimated and become fragmented and isolated as a result.

Specific effects of threatening actions include:

• Chemical spills and other forms of water pollution (e.g., livestock use of springs and spring runs, urban runoff, other agriculture, other industrial) resulting in effects such as: 1. direct mortality of species as evidenced by the recent (1991) Cantara Spill on the Upper Sacramento River, and 2. deleterious habitat alterations resulting from factors such as eutrophication caused by excessive nitrogen and phosphorus levels, reduced dissolved oxygen levels, or elevated water temperatures.
• Water diversions for such activities as irrigation and livestock watering, resulting in reduced spring flow and thus less habitat for these snails.
• Dam construction that submerges cold springs, slows current velocities, lowers the availability of oxygen and allows fine sediments to accumulate. For example, dams on the Columbia River have likely submerged formerly occupied sites.
• Excessive sedimentation from a variety of activities such as logging, mining, road and railroad grade construction, and grazing may smother substrates preferred by these species and may impair egg-laying or survivorship of eggs or young.

A synopsis of some of the direct actions that threaten specific species include:

Fluminicola n. sp. 2 (tall pebblesnail) - Dredging, nutrient enrichment, irrigation, grazing, and sedimentation.

Fluminicola n. sp. 3 (Klamath Rim pebblesnail) - Grazing and spring diversions, road and railroad building.

Fluminicola n. sp 11 (Fredenburg pebblesnail) - Grazing, fire, and road building.

Fluminicola n. sp. 19 (umbilicate pebblesnail) - Road and railroad building, water diversions, and grazing.

Juga (Oreobasis) n. sp. 2 (basalt juga) - Road and railroad bed construction, fires. Historically logging and grazing probably impacted many formerly occupied sites.

Lyogyrus n. sp. 1 (Columbia duskysnail) - Water diversions, road construction, logging, fires, and recreation.

Lyogyrus n. sp. 3 (canary duskysnail) - Grazing and spring diversions, road and railroad construction.

Vorticifex klamathensis sinitsini (Sinitsin rams-horn) - Log storage and transport in Upper Klamath Lake, water diversions, eutrophication, and pollution.

Vorticifex n. sp. 1 (knobby rams-horn) - Road building and water diversions.

Vorticifex klamathensis sinitsini (Sinitsin rams-horn) - Log storage and transport associated with logging activities and water diversions associated with irrigation projects. Eutrophication and pollution associated with agricultural, urban, and industrial pollution. Most recently, adding gravel substrates to enhance the availability of sucker spawning habitat has smothered some habitat.

D. Distribution Relative to Land Allocations

Some of these populations are located in or near areas allocated as Late-Successional Reserves. Field offices should refer to the Survey and Manage database as well as maps of Late-Successional Reserves and other allocations in their administrative area to determine site locations in relation to specific land allocations.

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III. MANAGEMENT GOALS AND OBJECTIVES

A. Management Goals for the Taxon

The management goal for these species is to assist in maintaining species viability.

B. Specific Objectives

• Maintain appropriate water quantity (as determined on a site specific basis) and water quality (e.g., high dissolved oxygen at or near saturation levels, stream temperatures below 18^oC or 65^oF) at levels suitable for sustainability of these species.
• Maintain and/or restore native riparian plant communities that aids in maintaining cool water temperatures (i.e. below 18^oC) by providing shade, reducing sedimentation impacts, and providing litter fall nutrients to energy pathways in the stream ecosystem.
• Maintain integrity of streambed substrates by minimizing sedimentation (i.e., avoid smothering of suitable substrates).

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IV. HABITAT MANAGEMENT

A. Lessons from History

Historically, species in this group and their habitats have suffered significant negative impacts from mining, logging, road and railroad grade construction, grazing, water pollution, and water manipulations over the last century. For example, hydraulic mining in the 1800s caused extensive damage by removal of riparian vegetation and by bank destruction, resulting in elevated water temperatures and excessive sedimentation of aquatic habitats. In addition, the need for lumber to sustain mining operations increased logging activities resulting in similar effects. Road and railroad grade construction in riparian areas also added to these effects. Grazing operations have impacted aquatic habitat by diverting, channelizing, or damming spring flow, thus affecting the quantity and quality of habitat, as well as by livestock trampling of springs resulting in sedimentation and pollution.

Work initiated as part of the Central Valley Project (after 1937) and the California Water Project (in 1960) have resulted in major habitat modifications. Dam construction on the Sacramento River (e.g., Shasta Dam, and dams creating Whiskeytown Reservoir and Siskiyou Lake) and Pit River has caused extensive destruction of suitable habitat. Dam construction submerges cold springs, slows current velocities, lowers the availability of oxygen, and allows fine sediments to accumulate. Existing populations have been decimated and become fragmented and isolated as a result.

In July 1991 any remaining populations of snails in the Upper Sacramento River were apparently destroyed or greatly diminished when railroad cars carrying the herbicide metam sodium (Vapam) derailed at Cantara bend and spilled into the river, causing major impacts in the lower 40 miles of the river. Only the upper 3 miles were unaffected by the spill.

B. Identification of Habitat Areas for Management

At this time, all populations on Forest Service or BLM administered lands are considered important to maintain species habitats. Cold, perennial springs tributary to the Columbia and Pit Rivers, Upper Klamath Lake, and tributaries to the middle Klamath River are important habitat areas. Other sites on which populations are located in the future should also be managed.

Identify the habitat areas around known site locations, including all habitat features that contribute to the environmental conditions important to the species at the known site.

In most cases, the Riparian Reserve standards and guides for buffer widths and meeting Aquatic Conservation Strategy objectives will be sufficient for management within these areas. In situations where RRS and ACS do not apply or are not considered sufficient (e.g., wetlands less than 1 acres, springs and seeps) apply the standards and guides for perennial stream widths to determine the size of the area. Where wind firmness is a problem, habitat area widths may need to be increased to protect species habitat conditions.

C. Management Within Habitat Areas

1. Maintain water temperatures below 18^oC (65^oF) to avoid thermal stress and ensure adequate availability of oxygen. (18C represents the critical threshold for trout.)
2. Maintain dissolved oxygen levels at or near saturation levels.
3. Maintain and/or restore native riparian plant communities that aids in maintaining cool water temperatures (i.e., below 18C) by providing shade, reducing sedimentation impacts, and providing litter fall nutrients to energy pathways in the stream ecosystem.
4. Avoid or mitigate for activities that could significantly increase sedimentation, pollution, or potential for eutrophication of occupied sites (e.g., logging, grazing, mining, construction activities, fertilizing, herbicides).
5. Avoid water diversions or other activities that may reduce water flow below levels necessary to sustain viable populations. This level must be determined on a site-specific basis, but these species generally need flowing water.
6. Avoid or mitigate for the construction of dams that could have the following negative impacts: submersion of cold springs, slowing of current velocities, lowering of dissolved oxygen, and increased sedimentation.

D. Other Management Issues and Considerations

No other management issues and considerations are identified at this time.

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V. RESEARCH, INVENTORY AND MONITORING NEEDS

The objective of this section is to identify opportunities for additional information which could contribute to more effective species management. The content of this section has not been prioritized or reviewed as to how important the particular items are for species management. While the research, inventory, and monitoring information is not required, these recommendations should be addressed by a coordinating body at the Northwest Forest Plan level.

A. Data Gaps and Information Needs

The following items would enhance our knowledge of these species:

• Conduct surveys to locate populations in areas identified as potential suitable habitat. Surveys to establish reliable patterns of distribution have only recently been initiated (Frest and Johannes 1993, 1995a, b, c), so it is appropriate to conduct additional surveys in suitable habitats of the Columbia Gorge, and Upper Klamath and Pit River basins prior to undertaking activities that may adversely impact these species.
• Conduct monitoring or research on habitat requirements of these species.
• Develop a collection of voucher specimens for appropriate administrative units within the range of these species.
• Monitor water temperatures at or in the vicinity of occupied sites using continuous reading thermometers, or at least maximum-minimum thermometers, to assure compliance.
• Monitor other environmental parameters (e.g., sedimentation, dissolved oxygen) that potentially affect these species.
• Determine the minimum instream flow requirements necessary to maintain environmental conditions within physiological limits.
• Develop keys and descriptions that allow field offices to accurately identify these species.

B. Research Questions

• Are the survey and manage provisions effective? If not, why? What should be done differently?
• What is the condition of existing populations with regard to absolute size and density?
• What are the dispersal mechanisms of these species?
• What are the specific habitat requirements of these species?
• How do these species respond to changes in water quality conditions and other disturbances?
• What implications, if any, does management for these species have on other species?

C. Monitoring Needs and Recommendations

Protocols for monitoring presently known populations and conducting surveys are needed. At a minimum, variables that should be monitored to track habitat quality include: (1) water temperature, (2) dissolved oxygen, (3) sedimentation, and (4) discharge at springs.

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VI. REFERENCES

Baker, F. C. 1945. The Molluscan Family Planorbidae. University of Illinois Press, Urbana, IL. 530 pp.

Frest, T. J., and E. J. Johannes. 1993. Mollusc Species of Special Concern within the Range of the Northern Spotted Owl. Deixis Consultants, Final Report. Unpublished report prepared for the Forest Ecosystem Management Working Group, U.S.D.A. Forest Service; Pacific Northwest Region; Portland, OR. 98 pp. and 1 addendum.

______________. 1995a. Interior Columbia Basin Mollusk Species of Special Concern. Final Report prepared by Deixis Consultants for the Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA. Contract #43-0E00-4-9112. xi + 363 pp.

______________. 1995b. Freshwater Molluscs of the Upper Sacramento System, California with Particular Reference to the Cantara Spill. Deixis Consultants, 1994 Yearly Report. Unpublished report prepared for the State of California, Department of Fish and Game, Contract #FG2106R1. 175 pp. and 4 appendices.

______________. 1995c. Freshwater Mollusks of the Upper Klamath Drainage, Oregon. Final Report prepared by Deixis Consultants for the Oregon Natural Heritage Program, Portland, OR. Contract # ORFO 092094. v + 132 pp.

Furnish, J. L. 1990. Factors affecting the growth, production and distribution of the stream snail Juga silicula (Gould). Unpublished Ph.D. thesis, Oregon State University, 205 pp.

Hawkins, C. P. and J. K. Furnish. 1987. Are snails important competitors in streams? Oikos 49:209-220.

Hershler, R., and F. Thompson. 1988. Notes on Morphology of Amnicola limosa (Say, 1817) (Gastropoda:Hydrobiidae) with Comments on Status of the Subfamily Amnicolinae. Malacological Review 21:81-92.

Oregon Natural Heritage Program. 1995. Rare, Threatened and Endangered Plants and Animals of Oregon. Oregon Natural Heritage Program, Portland, Oregon. 84 pp.

ROD. 1994. Record of Decision for Amendments to Forest Service and Bureau of Land Management Planning Documents within the Range of the Northern Spotted Owl. Standards and Guidelines for Management of Habitat for Late-Successional and Old-Growth Forest Related Species Within the Range of the Northern Spotted Owl. U.S. Department of Agriculture, Forest Service, Portland, OR. ii + 74 pp.; vii + 143 pp.

Taylor, D. W. 1966. Summary of North American Blancan Nonmarine Mollusks. Malacologia 4:1-172.

______________. 1981. Freshwater Mollusks of California: A Distributional Checklist. California Fish and Game 67(3):140-163.

Thompson, F. G. 1984. North American Freshwater Snail Genera of the Hydrobiid Subfamily Lithoglyphinae. Malacologia 25:109-141.

Thompson, F., and R. Hershler. 1991. Two New Hydrobiid Snails (Amnicolinae) from Florida and Georgia, with a Discussion of the Biogeography of Freshwater Gastropods of south Georgia Streams. Malacological Review 24:55-72.

USDA, Forest Service and Department of the Interior, Bureau of Land Management. 1994a. Final Supplemental Environmental Impact Statement on Management of Habitat for Late-Successional and Old-Growth Forest Related Species within the Range of the Northern Spotted Owl, Appendix J2. Results of Additional Species Analysis.

______________. 1994b. Final Supplemental Environmental Impact Statement on Management of Habitat for Late-Successional and Old-Growth Forest Related Species within the Range of the Northern Spotted Owl, Appendix A, Forest Ecosystem Management: An Ecological, Economic, and Social Assessment. Portland, Oregon.