Salt Marsh Restoration

1. Salt Marsh Restoration Emily Wallis BioSc 413 Spring 2011

2. Basic Salt Marsh Ecology Salt marshes occur in intertidal zones of moderate to low energy shorelines Vegetation consists of various halophytic (salt tolerant) grasses, sedges, and rushes that are periodically flooded by estuarine waters

3. Basic Salt Marsh Ecology • Ecological values: • Primary production • Nutrient cycling • Habitat for fish, birds, and other wildlife • Stabilize shorelines • High macroinvertebrate diversity

4. Threats to Salt Marshes • Dredging • Waste discharge • Hazardous spills • Indirect effects of other activities, such as damming and agriculture • Salinity changes • Altered sedimentation rates • Nutrient pulses • Natural threats to salt marshes include hurricanes and changes in sea level

5. Restoration Challenges Salt marsh habitats are inherently variable in salinity, oxygenation, and velocity of incoming water due to slope Marshes occur on a wide variety of substrates Uncertainty of storm free periods that would be conducive to initiating a project

6. Restoration Challenges Mosquitoes Invasive species, such as Phragmites Minimizing human interference

7. Salt Marsh Restoration Strategies • Topographical studies • Slope of marsh must ensure adequate influx and efflux of salt water • Reestablishing hydrology • Modification of water control structures to reestablish historical tidal rushing regimes

8. Salt Marsh Restoration Strategies • Controlling invasive species • Phragmites can be drastically reduced by controlling tidal hydrology • If hydrological manipulation is not feasible or necessary, Phragmites can be controlled with herbicide, burning, or manual removal. These processes usually take several years

9. Salt Marsh Restoration Strategies • Planting native halophytic vegetation • Spartina- cordgrass • Salicornia- glassworts • Juncus- rushes • Cyperus- sedges • Open-water marsh management (OWMM) • Using tidal fishes to control mosquito populations

10. Why restore salt marshes? • Important areas for faunal biodiversity including fishes, macroinvertebrates, and birds • Salt marshes serve as natural transition zones for oceanic energy, allowing a reduction in water velocity before it reaches land • Flood protection

11. Why restore salt marshes? Crissy Marsh. San Francisco, CA Aesthetic appeal Global averages estimate a 30% loss in salt marsh habitat (Bostrom et al. 2011)

12. Works Cited Athearn ND, Takekawa JY, Shinn JM. “Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA.” Natural Resources and Environmental Issues 15.1 (2009): 77-86. Web. 10 April 2011. Bostrom C, Pittman S, Simenstad C, Kneib RT. “Seascape ecology of coastal biogenic habitats: advances, gaps, and challenges.” Marine Ecology Progress Series 427 (2011): 191-217. Web. 13 April 2011. Broome SW, Seneca, ED, Woodhouse WW. “Tidal salt marsh restoration.” Aquatic Botany 32 (1998): 1-22. Web. 10 April 2011. Johnston RJ, Magnusson G, Mazzotta MJ, Opaluch JJ. “Combining economic and ecological indicators to prioritize salt marsh restoration actions.” American Journal of Agricultural Economics 84:5 (2002): 1362-1370. Web. 10 April 2011. Rhode Island Habitat Restoration. “Restoration Strategy”. Web. Wolters M, Garbutt A, Bekker RM, Bakker JP, Care PD. “Restoration of salt marsh vegetation in relation to site suitability, species pool, and dispersal traits.” Journal of Applied Ecology 45 (2008): 904-912. Web. 10 April 2011.