Award: OCE-1803166

Storm surge is often considered the greatest threat to life and property associated with a hurricane. Studies of the ecosystem effects of storm surge often focus on exposed coastal areas such as beaches. However, the upstream delivery of salt water can have long-lasting effects and can result in the decline of valuable freshwater tidal areas, which provide habitat to fish and wildlife, protect and improve water quality, and store floodwaters. This is especially important given the fact that these areas are already facing potential loss due to upstream salt water intrusion as a result of sea level rise. Hurricane Irma, which passed over the US on Sept. 11, 2017, caused the highest storm surge ever recorded on the central Georgia coast and resulted in salt water moving much further upstream than usual. The NSF-sponsored Georgia Coastal Ecosystems Long Term Ecological Research Project (GCE-LTER) has long-term experiments and monitoring programs that provide ?before? data and a context for understanding the effects of this event. We anticipated that the salt water delivered by the storm surge will affect multiple components of intertidal wetland ecosystems, including plants, animals, water chemistry, and soil surface elevation. The overall goal of this project was to evaluate the effects of this storm surge on intertidal wetland ecosystems within the domain of the Georgia Coastal Ecosystems LTER. Our goals were to evaluate disturbance effects 1) along an estuarine salinity gradient; 2) in the context of disturbance history; and 3) in transitional areas. This is a collaborative project between the University of Georgia (UGA) and Georgia Southern University (GSU). This summary describes the results of the GSU-led effort to collect field data documenting plant habitat distributions. These observations will be used to create habitat maps from aerial photographs of the Altamaha River estuary, GA taken following Hurricane Irma to better understand how the storm surge affected tidal vegetation and to examine any shifts in vegetation type. In order to use aerial images to map changes in tidal habitats, it is first necessary to collect representative data on plant distributions on the ground when the imagery is collected. As part of this project, we collected extensive field data from sites distributed in habitats along the salinity gradient of the Altamaha River estuary, including tidal marsh (salt, brackish, tidal fresh) and tidal fresh forest environments. These data will be used as ground control points and ground reference data for habitat mapping. A total of 101 ground control points were collected in tidal habitats, with 26 in salt, 28 in brackish and 29 in tidal fresh marsh, and another 18 in tidal fresh forest. This information was used to create ground reference data in a Geographic Information System (GIS) to be used for habitat mapping. The results from this portion of the project will be used to provide the large number of ground reference required for the classification of imagery that are being collected by the University of Georgia, which has primary responsibility for this collaborative project. Last Modified: 11/05/2018 Submitted by: Christine Hladik