SECTION NO. 6
Fluminicola n. sp. 20

Draft Management Recommendations for

Fluminicola new species 20, Lost Creek Pebblesnail,
a ROD Mollusk Species associated with creek habitats.

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: Fluminicola n. sp. 20 (Lost Creek pebblesnail)

Taxonomic Group: Mollusks (Phylum Mollusca; Class Gastropoda; Subclass Prosobranchia; Family Hydrobiidae)

ROD Components: Survey and Manage Strategies 1 & 2. This species is also listed in Standards and Guides for protection from grazing.

Other Management Status: None

Range: Fluminicola n. sp. 20 is a localized endemic is known from two sites in the Pit River system.

Specific Habitats: Fluminicola n. sp. 20 is found in creeks. It lives in swift flowing water, generally near shore, on sand-cobble substrates and aquatic macrophytes (usually Rorippa and Cicuta).

Threats:

• Chemical spills and other forms of water pollution (e.g., sewage contamination from recreational use, livestock use of channel bottoms) resulting in effects such as: 1. direct mortality of species as evidenced by the recent Cantara Spill (1991) on the Upper Sacramento River, and 2. deleterious habitat alterations resulting from factors such as eutrophication caused by excessive fertilization, reduced dissolved oxygen levels, and/or elevated water temperatures.
• Dam construction that slows current velocities, lowers the availability of oxygen, and allows fine sediments to accumulate. Existing dams on the Sacramento River (e.g., Shasta Dam, and dams creating Whiskeytown Reservoir and Siskiyou Lake) and the Pit River have already caused extensive destruction of suitable habitat.
• Reductions in water flow by water diversions, resulting in elimination and/or reduction of aquatic habitat for this snail.
• Excessive sedimentation from a variety of activities such as logging, mining, road and railroad grade construction, and grazing may smother preferred substrates and may impair egg-laying or survivorship of eggs or young.

Management Recommendations:

All known and newly discovered sites occupied by this species should be protected and monitored. Specific recommendations include:

1. Avoid all types of water pollution (e.g., chemical and sewage contamination, excessive fertilization).
2. Maintain water temperatures below 18^oC (65^oF) to avoid thermal stress and ensure adequate availability of oxygen. (The temperature of 18^oC represents the critical threshold for trout.)
3. Maintain and/or restore native riparian plant communities that aid in maintaining cool water temperatures (i.e., below 18^oC) by providing shade, reducing sedimentation impacts by providing a vegetative filter, and providing litter fall nutrients essential to energy pathways of the stream ecosystem.
4. Maintain dissolved oxygen levels at or near saturation levels.
5. Avoid and/or mitigate for activities (e.g., logging, grazing, mining, construction activities) that could increase sedimentation or potential for eutrophication of occupied sites.
6. Avoid water diversions and/or other activities that may reduce water flows below levels necessary to sustain viable populations. This level must be determined on a site-specific basis but this species needs flowing water.
7. Avoid and/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 and research is needed on habitat requirements of this species. Develop a collection of voucher specimens for appropriate administrative units within the range of this 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 are critical to this species' long-term survival. 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

Synonyms: None. This taxon may be present in museum collections or cited in past literature as Fluminicola turbiniformis, Lithoglyphus turbiniformis, Fluminicola seminalis, or Lithoglyphus seminalis; for description of these, see Hershler & Frest (1996).

B. Species Description

1. Morphology

See Frest & Johannes (1993a, fig. 3k; 1995, fig. 6k) for illustrations of this species. The moderately tall conic spire consists of about 4.5 whorls at maturity (about 3.4 mm in length). The apex is blunt (large, flat protoconch). There is a small open umbilicus and a moderate-sized basal crescent that does not extend to the base of the columella. The shell is rather thin, greenish, and is sometimes heavily streaked with white. The aperture is rounded; there is a narrow callus on the columella and parietal lip, but the rest of the lip is very thin and fragile. The body is gray on the upper surface; the mantle is black. This species resembles Fluminicola n. sp. 19 (q.v.) in its color, whitish streaks on the shell, apertural morphology, and open umbilicus. However, Fluminicola n. sp. 20 is smaller and more slender, has a less blunt apex, smaller umbilicus, and the body pigmentation is different. The verge (male copulatory organ) appears pigmented basally, in contrast to Fluminicola n. sp. 19 and most of the rest of the Upper Sacramento River system small Fluminicola species. This species was cited under the same name in Frest & Johannes (1993b) and as Fluminicola n. sp. 8 in Frest & Johannes (1993a, 1995).

2. Reproductive Biology

Information on life history is very sparse, but Fluminicola n. sp. 20 is 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.

3. Ecology

Fluminicola n. sp. 20 is a creek associate. It is a cold water, periphyton, and perilithon (i.e., the algal and microbial film on the submerged portions of macrophytes and rock surfaces, respectively) feeder, like most other Fluminicola species.

C. Range, Known Sites

It is currently known only from Lost Creek, a single spring-fed creek in Lassen National Forest, Shasta County, California. Lost Creek is presumably tributary to Hat Creek (Pit River tributary); it disappears underground into a lava tube. Two occupied sites have been located, both of which are on Forest Service lands. Private lands also occur in the Lost Creek drainage.

D. Habitat Characteristics and Species Abundance

This species lives in swift-flowing water, near shore, on sand-cobble substrate and aquatic macrophytes (generally Rorippa and Cicuta). No information on species abundance could be found.

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II. CURRENT SPECIES SITUATION

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

Fluminicola n. sp. 20 is considered rare since it occurs at only 2 highly localized sites in restricted habitats. It is endemic to the upper Sacramento River system. Historically (see IV. A), it has suffered from habitat degradation so it is appropriate to protect surviving populations. Because of these factors, the FEMAT analysis (USDA Forest Service and USDI Bureau of Land Management 1994) concluded that this species has a low likelihood of attaining stable, well distributed populations.

B. Major Habitat and Viability Considerations

Fluminicola n. sp. 20 is a localized endemic to the Upper Sacramento and Pit River systems. Historically, this area has experienced profound habitat destruction from logging, dam construction, water diversions, and hydraulic mining operation. Accelerated sedimentation of the Upper Sacramento has recently occurred (e.g., timber salvage following wildfires and other activities).

Fluminicola n. sp. 20 belongs 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, although this species is a stream associate. All hydrobiid snails have gills, which makes them dependent upon dissolved oxygen in the water column. Fluminicola species, like most hydrobiid snails, are highly sensitive to oxygen deficits (i.e., less than saturation levels), elevated water temperatures [i.e., above 18^oC (65^o F)], and sedimentation (i.e., smothering layers of fine sediment). Fluminicola n. sp. 20 is only found in creek reaches 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 this species.

A life history trait also puts it at risk: individuals appear to breed only once in a lifetime and then die. Usually 90 percent of the population turns over annually so any condition that impairs egg laying or survivorship of eggs or young may result in extirpation.

C. Threats to the Species

The sites on Hat Creek are generally in good condition, according to Frest and Johannes (1995). Threats to this species include:

• Chemical spills and other forms of water pollution (e.g., sewage contamination from recreational use, livestock use of stream channel bottoms), resulting in effects such as: 1. direct mortality of species [as evidenced by the recent Cantara Spill (1991) 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.
• Dam construction that slows current velocities, lowers the availability of oxygen, and allows fine sediments to accumulate. Frest and Johannes (1995) stated that there already has been small-scale hydropower development on Hat Creek. Existing dams on the Sacramento River (e.g., Shasta Dam, and dams creating Whiskeytown Reservoir and Siskiyou Lake) and the Pit River by Pacific Gas and Electric have caused extensive destruction of aquatic snail habitat in the past.
• Reductions in water flow by water diversions, resulting in elimination or reduction of aquatic habitat for snails.
• 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.

D. Distribution Relative to Land Allocations

The species currently occurs in Riparian Reserves in Lassen National Forest. 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 Taxa

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

B. Specific Objectives

• Maintain appropriate water quantity (as determined on a site-specific basis) and quality [e.g., high dissolved oxygen at or near saturated levels, stream temperatures below 18^oC (65^o F)] at levels suitable for sustainability of these species.
• Maintain native riparian plant communities to help maintain desired ecological attributes (see IV. C.).
• Maintain integrity of streambed substrates preferred by this species by minimizing sedimentation (i.e., avoid smothering of suitable substrates).

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IV. HABITAT MANAGEMENT

A. Lessons from History

Historically, over the last century the habitat of aquatic snails in northern California has suffered significant negative impacts from mining, logging, road and railroad grade construction, grazing, water pollution, and water manipulations. For example, hydraulic mining in the 1800s caused extensive damage by removal of riparian vegetation and 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 water flow - thus affecting the quantity and quality of habitat, as well as by livestock trampling of channel bottoms, resulting in sedimentation and other pollution (e.g., elevated nitrogen and phosphorus levels).

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

In July 1991 any remaining snail populations 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 to the lower 40 miles. Only the upper 3 miles were unaffected by the spill.

B. Identification of Habitat Areas for Management

All populations on Forest Service or BLM administered lands are considered important to the viability of this species. Management should be applied where this species currently exists. For existing sites, management would be appropriate in Hat Creek and Lost Creek, Pit River basin, California. Sites that are found 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 acre, 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

All sites occupied by this snail should be protected. Specific recommendations include:

1. Avoid all types of water pollution (e.g., chemical and sewage contamination resulting in excessive fertilization)
2. Maintain water temperatures below 18^oC (65^oF) to avoid thermal stress and ensure adequate availability of oxygen. (18^oC represents the critical threshold for the trout residing in the creek.)
3. Maintain and/or restore native riparian plant communities that aid in maintaining cool water temperatures (i.e., below 18^oC) by providing shade, reducing sedimentation impacts by providing a vegetative filter, and providing litter fall nutrients to energy pathways in the stream ecosystem.
4. Maintain dissolved oxygen levels at or near saturation levels.
5. Avoid or mitigate for activities that could significantly increase sedimentation or potential for eutrophication of occupied sites (e.g., logging, grazing, mining, damming, and construction activities).
6. Avoid water diversions or other activities that may reduce water flow below levels necessary to sustain viable populations. This level should be determined on a site-specific basis, but this species requires flowing water.
7. Avoid or mitigate for dam construction to minimize impacts (e.g., slowing of current velocities, lowering of dissolved oxygen, and increasing sedimentation).

D. Other Management Issues and Considerations

None 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

• Conduct surveys to locate populations in areas identified as potential suitable habitat. Surveys to reliably establish patterns of distribution have only recently been initiated (Frest and Johannes 1993a, 1995), so it is appropriate to conduct additional surveys in suitable habitats of the Sacramento River and Pit River basins prior to undertaking activities that may adversely impact this species.
• Conduct monitoring and research on habitat requirements of this species.
• Develop a collection of voucher specimens for appropriate administrative units within the range of this 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 are critical to this species' long-term survival.
• 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

• What is the formal description and type locality (as defined in the scientific literature) for this currently undescribed species?
• 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 this species?
• What are the specific habitat requirements of this species?
• How does this species respond to changes in water quality conditions and other disturbances?
• What implications, if any, does management for this species have on other species?

C. Monitoring Needs and Recommendations

Protocols for monitoring presently known populations and conducting surveys. At a minimum, variables that should be monitored to track habitat quality include: a. water temperature; b. dissolved oxygen; c. sedimentation; and d. current velocity at creek sites.

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VI. REFERENCES

Frest, Terrence J. and Edward J. Johannes. 1993a. Freshwater Molluscs of the Upper Sacramento System, California with Particular Reference to the Cantara Spill. Deixis Consultants, 1992 Yearly Report. Unpublished report prepared for the State of California, Department of Fish and Game, Contract #FG2016R1. 101 pp. and 2 appendices.

____________. 1993b. 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.

____________. 1995. 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.

Hershler, Robert and T. J. Frest. 1996. A Review of the North American Freshwater Snail Genus Fluminicola (Hydrobiidae). Smithsonian Contributions to Zoology. Number 583. 41pp.

USDA, Forest Service, and Department of the Interior, Bureau of Land Management. 1994. 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, OR.