Draft Programmatic Environmental Impact Statement/Environmental Impact Report
San Francisco Estuary Invasive Spartina Project: Spartina Control Program
April 2003

 

Table 3.3-2: Summary of Mitigation Measures for Biological Resources

 

Mitigation

Manual
Removal
(Hand pulling and manual
excavation)

Mechanical
Removal
(Excavation, dredging, and shredding)

Pruning, Hand-mowing, and Smothering

Flooding
(Diking, drowning, and salinity
variation)

Burning

Herbicide
Application

BIO-1.1: Saltmeadow and English cordgrass. Minimize vehicle and foot access pathways.  Restrict equipment working in marsh to mats and geotextile fabric covers.  Stockpile non-viable excavated non-native cordgrass and excavated sediment and remove from marsh.  Stabilize smothering geotextile mats.  Cover non-target vegetation, or pre-treat non-target vegetation with protective films. Use optimal combinations of treatment to minimize repeat entry to marsh.

Applicable

Applicable

Applicable

Not Applicable

Applicable

Applicable

BIO-1.2: Atlantic Smooth cordgrass. Minimize vehicle and foot access pathways.  Restrict equipment in working in marsh plains to mats and geotextile fabric covers.  Stockpile non-viable excavated non-native cordgrass and excavated sediment and remove from marsh.  Cover non-target vegetation with fabric adjacent to areas sprayed with herbicide, or pre-treat with protective films of silt-clay.  Stabilize smothering geotextile mats.  Use optimal combinations of treatment to minimize repeat entry to marsh and re-treatment.  Minimize herbicide spray dose requirements by pre-treatments.  Use removal methods rather than helicopter applications of herbicide whenever feasible and less environmentally damaging.  Use non-spray application techniques to reduce herbicide dose and minimize non-target contact.

Applicable

Applicable

Applicable

Applicable

Not Applicable

Applicable

BIO-1.3: Chilean cordgrass. Identical with Mitigation BIO-1.1.

Applicable

Applicable

Applicable

Not Applicable

Not Applicable

Applicable

BIO-1.4: Submerged aquatic plant communities. Remove large deposits of mown cordgrass during the growing season; or install temporary water-permeable debris barriers around vulnerable pans.  Avoid transporting tanks of spray solution near pans.

Not Applicable

Not Applicable

Applicable

Not Applicable

Not Applicable

Applicable

BIO-2: Special-status plant species. Conduct pre-project spring surveys for sensitive plants and instruct field crews to avoid and protect sensitive populations.  Require qualified, experienced on-site botanical supervision if sensitive plants occur in the vicinity. If sensitive plant populations occur near the high tide line, rake and remove large deposits of mown cordgrass during the growing season.  Refrain from burning in marshes supporting sensitive plant species.  Stabilize smothering geotextile mats.  Cover non-target vegetation, or install spray-drift barriers.  If accidental exposure to spray drift occurs, thoroughly irrigate affected plants with silt-clay suspensions. Refrain from rapid replanting of Pacific cordgrass until Atlantic smooth corgrass pollen and see rain is minimal.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-3: Shorebirds and waterfowl. For work within 1,000 feet of mudflats, schedule eradication activities to avoid peak fall and spring Pacific Flyway stopovers.  Mobilize crews to project sites before mudflats emerge. Use optimal combinations of treatment to minimize repeat entry.  Avoid helicopter applications of herbicide to mudflat colonies within 1,000 feet of major habitual roosting or foraging sites.  As a last resort, haze shorebirds and waterfowl within 1000 feet of spray operations. Remediate small volumes of spilled solutions on mudflats.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-4.1: Salt marsh harvest mouse and tidal marsh shrew subspecies. Minimize vehicle and foot access pathways in potential tidal marsh habitat. Restrict equipment working in marsh to areas with mats and geotextile fabric covers.  Use optimal combinations of treatment to minimize repeat entry re-treatment.  Schedule work in suitable habitat soon after natural mass-mortality events caused by extreme high tides.  Compensatory measures for incidental take include restoration of optimal habitat within large tidal marsh restoration projects.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-4.2: Resident San Francisco Bay harbor seals. Minimize vehicle and foot access pathways in marsh within 1,000 feet of seal haul-outs, and avoid approaching haul-outs within 2,000 feet, or any distance that elicits vigilance behavior when pups are present. Consult with marine mammal experts to determine seasonal variation in sensitivity to disturbance.  Restrict equipment working in marsh to prescribed paths.  Use optimal combinations of treatment to minimize repeat entry to marsh and re-treatment. Refrain from use of low-flying helicopters within 2,000 feet of seal haul-outs. Transport any pre-mixed solutions of herbicide in double-lined containers.  Remediate spilled solutions on mudflats to the greatest extent feasible.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-5.1: California clapper rail. To minimize or avoid indirect impacts of eradication operations on clapper rails, follow "best management practices" in EIS/R Appendix G, as modified by the US Fish and Wildlife Service's Biological Opinion.  These protocols are based on (1) current survey and map data to determine distribution and abundance of rails in relation to project sites, and local behavior of rails in occupied habitats; (2) training and expert biological supervision of field crews to detect clapper rails and identify habitat; (3) modification of timing and within-site location of operations to minimize or avoid disturbances to clapper rails.  In addition, the mitigation measures generally used to minimize disturbances in MITIGATION BIO-1.2 and BIO-4.1 also apply.

For unavoidable significant impacts due to eradication of Atlantic smooth cordgrass and hybrids which provide habitat currently occupied by clapper rails, proportional compensatory mitigation is necessary.  Primary components of compensatory  mitigation include: (1) large-scale, rapid restoration of suitable tidal salt marsh habitat (including all essential habitat components for colonization by clapper rails) in advance of large-scale habitat destruction,  and within the same subregion as impacts, but at locations with low invasion pressure from non-native cordgrasses; (2) significantly increasing reproductive success of clapper rails within the same subregion as impacts, through management which reduces predation from non-native red fox, and enhances flood refugia (cover for rails during extreme high tides).

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-5.2: California black rail. Adapt protocols for minimization and avoidance of California clapper rails (Appendix G) for work in infested marshes known to support populations of California black rails (currently one: Southhampton Marsh, Benicia), emphasizing pre-project surveys (call detection), minimization of marsh disturbance (MITIGATION BIO-1.2), and avoidance of occupied habitat during the breeding season.

Applicable

Potentially
Applicable

Applicable

Not Applicable

Not Applicable

Applicable

BIO-5.3: Tidal marsh song sparrow subspecies and salt marsh common yellowthroats. Adapt protocols for minimization and avoidance of California clapper rails (Appendix G) for work in infested marshes known to support populations of Alameda song sparrows, San Pablo song sparrows, Suisun song sparrow, and the salt marsh common yellowthroat, emphasizing pre-project surveys, minimization of marsh disturbance (MITIGATION BIO-1.2), and avoidance of occupied habitat during the breeding season.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-5.4: Western snowy plovers and California least terns. Prior to levee access in areas where snowy plovers and least terns may breed, levee routes should be surveyed for potential nests, including nests in salt pond beds near levee roads. Dredging and excavation of cordgrass should be conducted either after least terns have migrated out of San Francisco Bay, or during middle to lower tidal stages that allow navigation of barge and crane operations, while exposing the maximum extent of cordgrass above standing tides.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

BIO-5.5: Birds of prey in tidal marshes. Minimize use of helicopters to apply herbicides over marshplains where raptors forage.

Not Applicable

Not Applicable

Not Applicable

Not Applicable

Not Applicable

Applicable

BIO-6.1: Chinook salmon and steelhead (anadromnous salmonids).  Dredging of infested intertidal channels should be limited to: (1) tidal stages when target areas are emerged above water level, and (2) during seasons when winter- and spring-run Chinook salmon and steelhead migration times minimize their risk of exposure at project sites, particularly juveniles. Intakes for impoundments should be limited to tides above mean high water to minimize entrainment and trapping.  Alternatively, fish screens could be installed on new tidegates used to impound and drown large cordgrass-infested marshes in former diked baylands. Herbicide methods should be minimized or avoided near channels and mudflats during migration periods of winter-run and spring-run Chinook salmon and steelhead. Minimize glyphosate/surfactant spray application requirements by pre-treating target cordgrass stands with mechanical methods that reduce cordgrass biomass and density, increase receptivity and coverage of spray, and increase mortality response to glyphosate.  In case of herbicide/surfactant solution spill, remediate small volumes of spilled solutions on mudflats to the greatest extent feasible by suction of surface muds, using portable wet vacuum or pumping equipment.

Not Applicable

Applicable

Not Applicable

Applicable

Not Applicable

Applicable

BIO-6.2: Delta smelt and Sacramento splittail. For work in infested North Bay marshes where delta smelt or Sacramento splittail may occur (currently one: Southhampton Marsh, Benicia), eliminate impoundment techniques and minimize spray drift near tidal creeks (MITIGATION BIO-1.1, 1.2).  Restrict any intertidal excavation or dredging in tidal creeks to tidal stages when target areas are emerged above water level.

Not Applicable

Applicable

Not Applicable

Applicable

Not Applicable

Applicable

BIO-6.4: Shallow-water estuarine fish. Dredging of infested intertidal channels should be limited to tidal stages when target areas are emerged above water level. Water intakes for impoundments should have invert elevations limited to tides above mean high water to minimize entrainment and trapping.  Alternatively, fish screens could be installed on new tidegates used to impound and drown large cordgrass-infested marshes in former diked baylands. Herbicide methods should be minimized near channels. Minimize glyphosate/surfactant spray application requirements by pre-treating target cordgrass stands with mechanical methods that reduce cordgrass biomass and density, increase receptivity and coverage of spray, and increase mortality response to glyphosate.  In case of herbicide/surfactant solution spill, remediate small volumes of spilled solutions on mudflats to the greatest extent feasible by suction of surface muds, using portable wet vacuum or pumping equipment.

Not Applicable

Applicable

Not Applicable

Applicable

Not Applicable

Applicable

BIO-8: Mosquito production in tidal marshes. Monitor access routes in marshes to detect formation of undrained depressions in tire ruts or foot trails.  Backfill access-related shallow marsh depressions or incise narrow drainages so they do not impound small, sheltered areas of standing water.  Where impoundments are used, design impoundments of sufficient size and depth to minimize mosquito breeding habitat.

Applicable

Applicable

Applicable

Applicable

Applicable

Applicable

Note:  Due to summarization, there may be textual differences between the measures in this summary table and the text in the section. The actual mitigation measure is in the text.