Protocol for Monitoring Coastal Salt Marshes in the Southwest Alaska Network

Jorgenson, M; Miller, Amy

Sheltered salt marshes and tidal flats in the SWAN are important ecological features of the Lake Clark National Park and Preserve (LACL) and Katmai National Park and Preserve (KATM) coastlines because they support productive, high-quality forage and serve as important feeding and resting areas for brown bears (Ursus arctos horribilis), waterfowl, and shorebirds (Bennett et al. 2006). In recognition of these important features, salt marshes have been identified for monitoring under the ‘sensitive plant community’ vital sign. A variety of physical, chemical and biological attributes associated with salt marshes will be monitored under this protocol, independently of other ‘sensitive communities,’ due to the complex interactions that shape the vegetation in these salt marsh ecosystems. Accordingly, this protocol identifies the components of a comprehensive monitoring program and the standard operating procedures (SOPs) for each monitoring component, consistent with other national monitoring efforts of the National Park Service (Oakley et al. 2003). Development of a protocol for monitoring salt marshes in SWAN focuses on the major habitat characteristics that are important to other nearshore and terrestrial indicators (e.g., brown bears, seabirds, intertidal marine invertebrates, and algae), and on the major drivers of change. Salt marshes are highly dynamic systems with numerous important drivers that include erosional and depositional geomorphic processes associated with topography and hydrology; tidal fluctuations and storm surges; variable rates of sedimentation and erosion; and variation in salinity, physical disturbance and human impacts (Bird 2000). Tidal fluctuations and storm surges help control vegetation distribution by affecting water levels, sedimentation, and salinity. Sedimentation and erosion affect surface elevations, contribute nutrients, and can physically bury or disturb the surface. Winter ice-rafting can deposit sediments and disrupt levees. Salinity affects the osmotic potential of soil and is an important control over vegetation distribution (Vince and Snow 1984, Jorgenson 2000). Concerns about the potential effects of climate change on salt marsh ecosystems, particularly sea level rise, increased frequency and duration of storm events, and decreased sediment inputs as coastal glaciers recede, have elevated their status in the SWAN monitoring program. Salt marshes along Cook Inlet are also subject to oil spills and other contaminants from urban areas, oil platforms and pipelines, shipping, and military operations. Finally, the area is subject to tectonic uplift and severe earthquakes. In the SWAN, the primary goal of salt marsh monitoring is to describe long-term ecological change in response to environmental drivers (e.g., climate variables), and to document ecosystem response, as measured by responses of vegetation and small waterbodies (e.g., ponds), to short-term perturbations (e.g., tsunamis, volcanic eruptions, and large storm events) and/or acute disturbance (e.g., oil or chemical spills). Forage species of value to wildlife and waterfowl include, but are not limited to, Carex ramenskii (Carex subspathacea), Triglochin palustris, and Puccinellia phryganodes (Jeffries and Rockwell 2002; Person et al. 2003).

Protocol for Monitoring Coastal Salt Marshes in the Southwest Alaska Network

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