Hydrological Barrier as a Cause of Salt Marsh Loss

• Published in: Journal of coastal research Vol. 77; no. sp1; pp. 88 - 96
• Main Authors: Huff, Thomas P., Feagin, Rusty A.
• Format: Journal Article
• Language: English
• Published: Fort Lauderdale Coastal Education and Research Foundation 01.04.2017; Coastal Education and Research Foundation, Inc. (CERF); Allen Press Inc
• Subjects: Bird watching; Construction; Ecology; Ecosystem disturbance; Ecosystems; Environmental factors; Environmental management; Estuaries; Fish ladders; Fishing; Hydrology; hypersaline; Imagery; Infiltration; Inlets; Inlets (topography); Inlets (waterways); Lakes; Land cover; marsh impoundment; Marshes; Nature conservation; Piles; Precipitation; Recreation; Salinity; Salinity data; Salinity effects; Salt marshes; Salt pans; Sanctuaries; Sea level; Sea level rise; Sediment; Soil erosion; Sustainability; tidal gauge; Tides; Trends; Wetlands; Wildlife
• ISSN: 0749-0208; 1551-5036
• DOI: 10.2112/SI77-009.1

Huff, T.P. and Feagin, R.A., 2017. Hydrological barrier as a cause of salt marsh loss. In: Martinez, M.L.; Taramelli, A., and Silva, R. (eds.), Coastal Resilience: Exploring the Many Challenges from Different Viewpoints. Journal of Coastal Research, Special Issue No. 77, pp. 88–96. Coconut Creek (Florida), ISSN 0749-0208. The Magic Ridge Marsh located along Magnolia Beach, Texas has rapidly degraded over the last few decades. This marsh is of great importance to wildlife and dependent recreational pursuits such as bird watching at the Magic Ridge Sanctuary and fishing in the marshes and adjacent bay. In this study, we decided to focus on the shell debris pile as aerial imagery, along with local knowledge, indicated that this was the point of hydrologic disturbance. In order to restore this ecosystem, the alterations to the hydrology had to be understood and thus the multi-stage approach was chosen to single out the environmental factors that influence the marsh. Land cover analyses were conducted in conjunction with analyses of precipitation and sea level rise data beginning in 1958 and ending in 2012. Tide and salinity data from March 2013 to August 2013 were obtained to determine tidal connectivity and salinity conditions within the marsh and bay. These data sets indicated that low marsh area decreased independently of sea level rise or precipitation. However, the tidal data showed the marsh was disconnected for extended periods of time resulting in increased salinity within the marsh. The lack of tidal exchange indicated that a blockage to tidal infiltration existed. However, during the period from 1958 to 2012, no new construction or man-made alteration to the inlets of the marsh occurred. This indicated that a separate entity was responsible for the impoundment, which would be a plug of sediment and shell that had accumulated in the Magnolia Inlet.