ENVIRONMENTAL SENSITIVITY INDEX: GEORGIA INTRODUCTION Spatial distribution of the species on the maps is represented by polygons and points, as appropriate. Associated with each of these Environmental Sensitivity Index (ESI) maps have been representations is an icon depicting the types of species or habitat developed for the coastal zone of Georgia. The ESI maps include types that are present. Species have been divided into groups and information for three main components: shoreline and wetland subgroups, based on their behavior, morphology, taxonomic habitats; sensitive biological resources; and human-use resources. classification, and spill vulnerability and sensitivity. The icons Background information, as well as the methods of data collection reflect this grouping scheme. The groups are color coded, and the and presentation, are summarized in the following sections. subgroups are represented by different icons: SHORELINE HABITAT MAPPING MARINE MAMMALS REPTILES/AMPHIBIANS Manatees The intertidal habitats of Georgia were originally mapped Other Reptiles/Amphibians during overflights conducted in the fall of 1984. They were updated onto 1:24,000 U.S. Geological Survey (USGS) topographic maps by an Whales experienced coastal geologist in January 1997 using recent vertical Turtles aerial photographs from 1993-96 at various scales. Where appro- TERRESTRIAL MAMMALS priate, multiple habitats were delineated for each shoreline FISH Small Mammals segment. Portions of the coast were flown in February 1997 to verify the photointerpretation. The aerial surveys were carried out using a Fish BIRDS fixed-wing aircraft, flying at elevations of 500-1,000 feet and slow air speed. Diving Birds INVERTEBRATES Prediction of the behavior and persistence of oil on intertidal Gulls and Terns habitats is based on an understanding of the dynamics of the coastal Bivalves environments, not just the substrate type and grain size. The Passerine Birds sensitivity of a particular intertidal habitat is an integration of the ELMR Shellfish following factors: Raptors 1)Shoreline type (substrate, grain size, tidal elevation, origin) HABITATS/RARE PLANTS Shorebirds 2)Exposure to wave and tidal energy Wading Birds Rare Plants and Communities 3)Biological productivity and sensitivity 4)Ease of cleanup Waterfowl Reef Communities All of these factors are used to determine the relative sensitivity of intertidal habitats. Key to the sensitivity ranking is an The polygon or point color and pattern are generally the same for understanding of the relationships between: physical processes, all the species in each major group (e.g., birds are green), and match substrate, shoreline type, product type, fate and effect, and sediment the icon colors. The exception is habitat/rare plants which have transport patterns. The intensity of energy expended upon a shoreline several different colors in the Georgia atlas (purple for plants, hot by wave action, tidal currents, and river currents directly affects the pink and blue for different hardbottom reef communities). Also persistence of stranded oil. The need for shoreline cleanup activities associated with each biological polygon or point feature on the map is determined, in part, by the slowness of natural processes in removal is a resources at risk identification number (RAR#), located under of oil stranded on the shoreline. each icon or group of icons. The RAR# references a table on the These concepts have been used in the development of the ESI, reverse side of the map with a complete list of species found in the which ranks shoreline environments as to their relative sensitivity polygon or at the point, as well as the state and federal protected to oil spills, potential biological injury, and ease of cleanup. status (T&E), concentration or abundance, seasonality, and life- Generally speaking, areas exposed to high levels of physical energy, history information for each species. such as wave action and tidal currents, and low biological activity Location-sensitive data provided by the GA DNR Natural rank low on the scale, whereas sheltered areas with associated high Heritage Program (NHP) are not shown on the maps as polygons or biological activity have the highest ranking. A comprehensive points. Instead, only marker icons are shown in the vicinity of shoreline habitat ranking system has been developed for the entire resource occurrence sites. In these instances, the RAR#s under the United States. The shoreline habitats delineated in Georgia are icons are shaded yellow in order to identify NHP data that are not listed below in order of increasing sensitivity to spilled oil. associated with specific polygons or point features. In addition, the 1B)Exposed, Solid Man-made Structures tabular data for species from NHP records does not list the common name of the species in question. In place of the common name, a 3A)Fine-to Medium-grained Sand Beaches general “subelement-level” name is listed which also indicates 3B)Scarps and Steep Slopes in Sand whether the species is rare, threatened, or endangered (e.g., endan- gered wading bird; rare turtle). “Rare” refers to species without T&E 6A)Gravel Beaches status, but which are still considered to be at risk of extirpation or 6B)Riprap extinction. The “rare” descriptor was used for species with global or state conservation status ranks of vulnerable, imperiled, or critically 7)Exposed Tidal Flats imperiled (see Master, 1991). In addition to the difference in species 8A)Sheltered Scarps in Mud name, “occurrence” is listed in the concentration column, identifying the site as an element occurrence record from the NHP program. In all 8B)Sheltered, Solid Man-made Structures other regards, the NHP data included in this atlas are depicted on 8C)Sheltered Riprap the maps and tables as described in the paragraph above. However, the NHP data are not included in the digital ESI database. 9A)Sheltered Tidal Flats There are some species that are found throughout specific 9B)Vegetated Low Riverine Banks geographical areas or habitat types. Displaying the polygons for 10A)Salt- and Brackish-water Marshes these species would cover large areas, making the maps very difficult to read. Thus, species which occur over the majority of certain 10B)Freshwater Marshes geographic areas or habitats are often identified in a small box on 10C)Swamps the maps which states that they are “Present in ...” (e.g., “Present in Atlantic Ocean” or “Present in Wetlands”). This approach informs 10D)Scrub-Shrub Wetlands the user of the presence of these species, while maintaining Each of the shoreline habitats are described on pages 10-16, in readability of the map. In all instances, data for species listed as terms of their physical description, predicted oil behavior, and “Present in ....” exist as polygons in the digital coverages. The use of response considerations. this strategy is implemented on a map per map basis, depending on the location, size, and number of polygons present on each map. SENSITIVE BIOLOGICAL RESOURCES MARINE MAMMALS Biological information presented in this atlas was collected and Marine mammals depicted in the Georgia atlas include manatees compiled with the assistance of biologists and resource managers from and whales. Bottlenose dolphins are not included due to widespread the Georgia Department of Natural Resources (GA DNR) and other abundance and an assumed low-sensitivity to spills. Bottlenose agencies and groups. Information collected and depicted on the maps dolphins are likely to be present throughout nearly all estuarine and denotes the key biological resources that are most likely at risk in nearshore waters of the study area. Though not threatened or the event of an oil spill. Seven major categories of biological endangered, bottlenose dolphins are protected under the Marine resources are included in this atlas: marine mammals, terrestrial Mammal Protection Act, as are all marine mammals. mammals, birds, reptiles/amphibians, fish, invertebrates, and habitats/rare plants. GA - Page 1 Manatees areas depicted in the atlas are limited to known high- Wading bird feathers and upper body parts can be more extensively use areas which may be occupied in warmer months. In general, contaminated, however, by contact with oiled vegetation. seasonal manatee high-use areas may include estuaries, rivers, and Shorebirds may avoid oiling in many cases, but may be impacted by tidal creeks. Manatees in Georgia may feed on Spartina and algae loss of feeding areas or intertidal prey, particularly during important growing in shallow areas or on floating objects. In addition to direct migration periods. Gulls may be at risk because they are often spill impacts, spill response personnel should be aware of manatee attracted to and will feed on sick or injured prey. This behavior may concentration areas including locations where slow or idle boat speeds result in oiling of feathers and the ingestion of oil. Terns are are posted for manatee protection. primarily at risk when they dive for prey. Raptors may also prey on oiled or injured species and thus may be contaminated themselves or Whale locations depicted in the atlas are largely restricted to a ingest oil. Osprey may also be oiled while diving for fish. Passerine seasonal calving and juvenile area for the endangered Northern right birds are typically not at great risk during spills; however, response whale. The area mapped has been listed as Designated Critical activities can disturb nesting or damage coastal habitat for these Habitat by the National