ENVIRONMENTAL SENSITIVITY INDEX: GEORGIAocean.floridamarine.org/ACP/SAVACP/Maps/GA_ESI/Intro.pdfOther Reptiles/Amphibians Reef Communities ELMR Shellfish The polygon or point color

ENVIRONMENTAL SENSITIVITY INDEX: GEORGIA

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INTRODUCTION

Environmental Sensitivity Index (ESI) maps have beendeveloped for the coastal zone of Georgia. The ESI maps includeinformation for three main components: shoreline and wetlandhabitats; sensitive biological resources; and human-use resources.Background information, as well as the methods of data collectionand presentation, are summarized in the following sections.

SHORELINE HABITAT MAPPING

The intertidal habitats of Georgia were originally mappedduring overflights conducted in the fall of 1984. They were updatedonto 1:24,000 U.S. Geological Survey (USGS) topographic maps by anexperienced coastal geologist in January 1997 using recent verticalaerial photographs from 1993-96 at various scales. Where appro-priate, multiple habitats were delineated for each shorelinesegment. Portions of the coast were flown in February 1997 to verifythe photointerpretation. The aerial surveys were carried out using afixed-wing aircraft, flying at elevations of 500-1,000 feet and slowair speed.

Prediction of the behavior and persistence of oil on intertidalhabitats is based on an understanding of the dynamics of the coastalenvironments, not just the substrate type and grain size. Thesensitivity of a particular intertidal habitat is an integration of thefollowing factors:

1) Shoreline type (substrate, grain size, tidal elevation, origin)

2) Exposure to wave and tidal energy

3) Biological productivity and sensitivity

4) Ease of cleanup

All of these factors are used to determine the relative sensitivityof intertidal habitats. Key to the sensitivity ranking is anunderstanding of the relationships between: physical processes,substrate, shoreline type, product type, fate and effect, and sedimenttransport patterns. The intensity of energy expended upon a shorelineby wave action, tidal currents, and river currents directly affects thepersistence of stranded oil. The need for shoreline cleanup activitiesis determined, in part, by the slowness of natural processes in removalof oil stranded on the shoreline.

These concepts have been used in the development of the ESI,which ranks shoreline environments as to their relative sensitivityto oil spills, potential biological injury, and ease of cleanup.Generally speaking, areas exposed to high levels of physical energy,such as wave action and tidal currents, and low biological activityrank low on the scale, whereas sheltered areas with associated highbiological activity have the highest ranking. A comprehensiveshoreline habitat ranking system has been developed for the entireUnited States. The shoreline habitats delineated in Georgia arelisted below in order of increasing sensitivity to spilled oil.

1B) Exposed, Solid Man-made Structures

3A) Fine-to Medium-grained Sand Beaches

3B) Scarps and Steep Slopes in Sand

6A) Gravel Beaches

6B) Riprap

7) Exposed Tidal Flats

8A) Sheltered Scarps in Mud

8B) Sheltered, Solid Man-made Structures

8C) Sheltered Riprap

9A) Sheltered Tidal Flats

9B) Vegetated Low Riverine Banks

10A) Salt- and Brackish-water Marshes

10B) Freshwater Marshes

10C) Swamps

10D) Scrub-Shrub Wetlands

Each of the shoreline habitats are described on pages 10-16, interms of their physical description, predicted oil behavior, andresponse considerations.

SENSITIVE BIOLOGICAL RESOURCES

Biological information presented in this atlas was collected andcompiled with the assistance of biologists and resource managers fromthe Georgia Department of Natural Resources (GA DNR) and otheragencies and groups. Information collected and depicted on the mapsdenotes the key biological resources that are most likely at risk inthe event of an oil spill. Seven major categories of biologicalresources are included in this atlas: marine mammals, terrestrialmammals, birds, reptiles/amphibians, fish, invertebrates, andhabitats/rare plants.

Spatial distribution of the species on the maps is represented bypolygons and points, as appropriate. Associated with each of theserepresentations is an icon depicting the types of species or habitattypes that are present. Species have been divided into groups andsubgroups, based on their behavior, morphology, taxonomicclassification, and spill vulnerability and sensitivity. The iconsreflect this grouping scheme. The groups are color coded, and thesubgroups are represented by different icons:

REPTILES / AMPHIBIANS

HABITATS/RARE PLANTS

INVERTEBRATES

Rare Plants and Communities

B iva lves

FishBIRDS

Diving Birds

Gulls and Terns

Waterfowl

Wading Birds

Shorebirds

Raptors

Passerine Birds

Turtles

MARINE MAMMALS

TERRESTRIAL MAMMALS

Manatees

Small Mammals

W h a l e s

FISH

Other Reptiles/Amphibians

Reef Communities

ELMR Shellfish

The polygon or point color and pattern are generally the same forall the species in each major group (e.g., birds are green), and matchthe icon colors. The exception is habitat/rare plants which haveseveral different colors in the Georgia atlas (purple for plants, hotpink and blue for different hardbottom reef communities). Alsoassociated with each biological polygon or point feature on the mapis a resources at risk identification number (RAR#), located undereach icon or group of icons. The RAR# references a table on thereverse side of the map with a complete list of species found in thepolygon or at the point, as well as the state and federal protectedstatus (T&E), concentration or abundance, seasonality, and life-history information for each species.

Location-sensitive data provided by the GA DNR NaturalHeritage Program (NHP) are not shown on the maps as polygons orpoints. Instead, only marker icons are shown in the vicinity ofresource occurrence sites. In these instances, the RAR#s under theicons are shaded yellow in order to identify NHP data that are notassociated with specific polygons or point features. In addition, thetabular data for species from NHP records does not list the commonname of the species in question. In place of the common name, ageneral “subelement-level” name is listed which also indicateswhether the species is rare, threatened, or endangered (e.g., endan-gered wading bird; rare turtle). “Rare” refers to species without T&Estatus, but which are still considered to be at risk of extirpation orextinction. The “rare” descriptor was used for species with global orstate conservation status ranks of vulnerable, imperiled, or criticallyimperiled (see Master, 1991). In addition to the difference in speciesname, “occurrence” is listed in the concentration column, identifyingthe site as an element occurrence record from the NHP program. In allother regards, the NHP data included in this atlas are depicted onthe maps and tables as described in the paragraph above. However,the NHP data are not included in the digital ESI database.

There are some species that are found throughout specificgeographical areas or habitat types. Displaying the polygons forthese species would cover large areas, making the maps very difficultto read. Thus, species which occur over the majority of certaingeographic areas or habitats are often identified in a small box onthe maps which states that they are “Present in ...” (e.g., “Present inAtlantic Ocean” or “Present in Wetlands”). This approach informsthe user of the presence of these species, while maintainingreadability of the map. In all instances, data for species listed as“Present in ....” exist as polygons in the digital coverages. The use ofthis strategy is implemented on a map per map basis, depending onthe location, size, and number of polygons present on each map.

MARINE MAMMALS

Marine mammals depicted in the Georgia atlas include manateesand whales. Bottlenose dolphins are not included due to widespreadabundance and an assumed low-sensitivity to spills. Bottlenosedolphins are likely to be present throughout nearly all estuarine andnearshore waters of the study area. Though not threatened orendangered, bottlenose dolphins are protected under the MarineMammal Protection Act, as are all marine mammals.

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Manatees areas depicted in the atlas are limited to known high-use areas which may be occupied in warmer months. In general,seasonal manatee high-use areas may include estuaries, rivers, andtidal creeks. Manatees in Georgia may feed on Spartina and algaegrowing in shallow areas or on floating objects. In addition to directspill impacts, spill response personnel should be aware of manateeconcentration areas including locations where slow or idle boat speedsare posted for manatee protection.

Whale locations depicted in the atlas are largely restricted to aseasonal calving and juvenile area for the endangered Northern rightwhale. The area mapped has been listed as Designated CriticalHabitat by the National Marine Fisheries Service (NMFS) under theEndangered Species Act (NMFS, 1994). This area roughly extendsfrom the mouth of the Altamaha River, Georgia to Jacksonville,Florida (from the Atlantic shoreline to 15 nautical miles offshore),and from Jacksonville to Sebastian Inlet, Florida (from the Atlanticshoreline to 5 nautical miles offshore). Additional whale data forseveral species are also included for the offshore area encompassedby Gray’s Reef National Marine Sanctuary. Though not included onthe maps, offshore whale distributions are generally described asfollows: Northern right whale, 0-30 miles offshore; humpbackwhale, 0-30 miles offshore; pygmy sperm whale, 5-200 milesoffshore; and fin whale, 5-200 miles offshore.

Marine mammal distributions are displayed on the maps as abrown hatch polygon. A brown icon with a manatee or whalesilhouette is used to indicate the presence of marine mammals. TheRAR# under the icon references a table on the reverse side of the map.In this table, the first column gives the species name. The secondcolumn denotes whether the species has been designated endangered(E) or threatened (T) on either the state (S) and/or federal (F) lists.The next column provides an estimate of the concentration of thespecies at the site. Concentration is usually indicated as “HIGH”,“MED”, or “LOW”. The species seasonality is shown in the nexttwelve columns, representing the months of the year. If the species ispresent at that location in a particular month, an “X” is placed in themonth column. The final columns list the time periods for sensitivelife-history stages or activities, such as calving for Northern rightwhales.

TERRESTRIAL MAMMALS

Terrestrial mammals were only mapped where NHP recordsindicated the presence of protected or rare species. Note that smallsemi-aquatic fur-bearing mammals such as river otter, beaver,muskrat, and mink were not mapped as a part of this atlas, due tolack of information. However, these resources are likely to occurthroughout much of the study area. Depending on the species, semi-aquatic fur-bearing mammals may occur where rivers, streams,estuaries, impoundments, and especially wetlands are present. Semi-aquatic fur-bearing mammals can be severely impacted by swimmingthrough oil slicks or coming into contact with oiled vegetation.

Protected and rare terrestrial mammals are displayed on themaps as brown marker icons with a small mammal silhouette. TheRAR# under the icon (with the yellow NHP box) references a table onthe reverse side of the map. In this table, the first column gives ageneral subelement-level name for the species. The second columnindicates whether the species is listed as threatened (T) orendangered (E) on either the state (S) and/or federal (F) lists. Thenext column provides the concentration of each species at the site,which is “OCCURRENCE” for NHP-derived data. The speciesseasonality is shown in the next twelve columns representing themonths of the year. If the species is present at that location in aparticular month, an “X” is placed in the month column.

BIRDS

Birds are divided into several species subgroups based ontaxonomy, morphology, behavior, and oil spill vulnerability andsensitivity. The species table lists all the birds included on themaps, sorted by subgroup. These species were included either becauseof their likelihood of impact by an oil spill, or their specialprotection status as threatened or endangered. Birds are a majorcomponent of the Georgia ESI atlas; however, large wide-spreaddistributions of offshore birds are not included since particularconcentration areas can vary greatly, both spatially and temporally.Offshore birds not included in this project include Northern gannet(diving pelagic bird), which may be widespread and locallyabundant from 0-20 miles offshore from December through March.Likewise, Lesser scaup (waterfowl) may occur in large rafts offshore(and in the open sounds) from November through March. Otherspecies with similar distributions include common loon, mergansers,and other diving ducks.

Waterfowl and diving birds (pelicans, cormorants, etc.) areusually at greatest risk during oil spills, because they spend nearlyall of their time on the water surface, and/or because they becomepartially or entirely immersed while feeding. Waterfowl can also becontaminated through contact with oiled wetland vegetation.Wading birds are usually at slightly lesser risk, primarily becausethey become oiled mainly on the legs and bill while wading for prey.

Wading bird feathers and upper body parts can be more extensivelycontaminated, however, by contact with oiled vegetation.Shorebirds may avoid oiling in many cases, but may be impacted byloss of feeding areas or intertidal prey, particularly during importantmigration periods. Gulls may be at risk because they are oftenattracted to and will feed on sick or injured prey. This behavior mayresult in oiling of feathers and the ingestion of oil. Terns areprimarily at risk when they dive for prey. Raptors may also prey onoiled or injured species and thus may be contaminated themselves oringest oil. Osprey may also be oiled while diving for fish. Passerinebirds are typically not at great risk during spills; however, responseactivities can disturb nesting or damage coastal habitat for thesespecies. Passerine birds of concern during spills include threatened,endangered and rare species, especially if they nest near theshoreline or in wetland habitats such as marshes.

Oiling of birds reduces the buoyancy, water repellency, andinsulation provided by feathers, and may result in death by drowningor hypothermia. Preening of oiled feathers may also result iningestion of oil resulting in irritation, sickness, or death. Bird oiling,particularly waterfowl and wading birds, may continue even afterfloating oil has been removed, depending on the extent of oiledvegetation and debris. Oiling can severely impact breeding andnesting success, especially if oiled adults contaminate the nest, eggs,or young. Disturbance during response activities can also reducenesting success.

Bird concentration areas are shown on the maps as polygons witha green hatch pattern. Certain nesting sites and similar areas such aswood stork roosts are displayed as point locations using a green dot.Data from NHP records are displayed as marker icons and a yellowRAR# box. A green icon with the appropriate bird silhouette(wading bird, raptor, etc.) is associated with the polygons, points, ormarkers. The RAR# under the icon references a table on the reverseside of the map. In this table, the first column gives the speciesname. The second column indicates whether the species is listed asthreatened (T) or endangered (E) on either the state (S) and/orfederal (F) lists. The next column provides an estimate of theconcentration of each species at the site. For the bird data,concentration is indicated as “VERY HIGH”, “HIGH”, “MED”, or“LOW”, or as a numerical value representing the number of nests in apoint or polygon, or the number of individuals occurring in a polygon.For data from NHP element occurrence records, concentration is listedas an “OCCURRENCE”. The descriptive concentration estimates aresubjective, based on local expert opinion on relative concentrations inthe area. The numerical concentration values are based on surveydata. Numerical concentrations at any particular site may fluctuateseasonally and annually based on local or regional conditions, orother factors. The species seasonality is shown in the next twelvecolumns representing the months of the year. If the species is presentat that location in a particular month, an “X” is placed in the monthcolumn. The last columns denote the nesting time-period for eachspecies, if nesting occurs in the particular area or site in question.Nesting refers to the entire nesting period, while laying, hatching,and fledging are discrete subsets of the nesting time period. For manyspecies there is a temporal shift in seasonality and reproductionalong with spatial changes in location. Temporal informationincluded in the tables is specific to the one polygon or point that itreferences.

REPTILES/AMPHIBIANS

Reptiles and amphibians depicted in the Georgia atlas includesea turtles, other turtles and tortoises, lizards, frogs, andsalamanders. American alligators are not depicted in the atlas dueto widespread abundance and an assumed low sensitivity to spills.Alligators can occur throughout freshwater and estuarine habitats inGeorgia, particularly in wetlands, coastal rivers, ponds, andimpoundments. Diamondback terrapins were not mapped, thoughthey may occur in estuarine habitats such as salt and brackishmarshes and tidal creeks.

Sea turtle areas displayed on the maps are limited to nestingbeaches and several well known in-water concentration areas.However, loggerhead, green, Kemp’s ridley, and leatherback seaturtles can occur throughout the coastal, estuarine, and marine watersof Georgia. Though not included on the maps, offshore sea turtledistributions are generally described as follows: loggerhead, green,and Kemp’s ridley turtles, highest concentrations from 0-5 milesoffshore, and further offshore in the vicinity of reef areas such asGray’s Reef; and leatherback turtles, 0-200 miles offshore. All seaturtles are protected as threatened or endangered species.

In addition to sea turtles, the threatened gopher tortoise wasmapped in only a few locations. Significant coastal populations ofgopher tortoises are known for Crooked River State Park, CumberlandIsland, and St. Catherines Island. Additional reptiles andamphibians were mapped from NHP records.

Sea turtle and gopher tortoise concentrations are depicted aspolygons with a red hatch pattern. Other reptiles and amphibiansare indicated using a marker icon only. A red icon with a turtle orother reptile/amphibian silhouette is used to indicate the presence

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of reptiles. The number under the icon references a table on thereverse side of the map. In the tables, the first column gives thespecies name. The second column denotes whether the species hasbeen designated as endangered (E) or threatened (T) on either thestate (S) and/or federal (F) lists. The next column provides anestimate of the concentration of the species at a site. Concentration isgenerally indicated as “HIGH”, “MED”, or “LOW”, except for NHPelement occurrence records, where concentration is listed as an“OCCURRENCE”. The species seasonality is shown in the nexttwelve columns, representing the months of the year. If the species ispresent at that location in a particular month, an “X” is placed in themonth column. For sea turtles, the last two columns indicate nestingand hatching time periods. Nesting refers to the time when adultsconstruct nests and deposit eggs. Hatching refers to the time whenyoung are hatching and emerging from the nests. For many speciesthere is a temporal shift in seasonality and reproduction along withspatial changes in location. Temporal information included in thetables is specific to the one polygon that it references.

FISH AND INVERTEBRATES

The fish and invertebrate species depicted in the Georgia ESIatlas include selected estuarine-dependent, anadromous, and marinespecies. Species of commercial, recreational, ecological, or conser-vation interest were chosen. The ESI maps and tables show thegeneral distribution of fish and invertebrates by seasonal salinityzones in the estuaries and for the 0-10 meter depth zone in thenearshore marine environment. The data for fish and invertebratedistribution were collected and compiled by NOAA’s StrategicEnvironmental Assessments Division with the assistance of GA DNR,under the Estuarine Living Marine Resources (ELMR) program. Fishand invertebrate distributions by salinity or depth zone are referredto below and in the legend as “ELMR data”.

In addition to the ELMR distribution data, special concentrationareas for selected species were also mapped, based on expert sourceinformation, maps, and other data provided by GA DNR. Specialconcentration areas include known high concentration areas, spawningsites, important juvenile nursery areas, sessile shellfish beds, etc.Special fish concentration areas were mapped for shortnose sturgeon,Atlantic sturgeon, red drum, spotted seatrout, tarpon, andsheepshead. For invertebrates, American oyster and quahog (hardclam) sites were mapped within recreational and commercial harvestareas only. In addition to the ELMR distribution data and specialconcentration areas, fish species were mapped by bottom habitat typefor Gray’s Reef National Marine Sanctuary (map number 38), based ondata and expert knowledge provided by sanctuary staff. A variety ofreef-associated and other offshore fish were linked with three majorhabitats within the sanctuary: hardbottom reef; hardbottom reefledges; and sand bottoms. In a few cases, data from NHP records aredisplayed on the maps for rare and endangered fish species. Thesedata include records for some fish of conservation interest which werenot included in the ELMR data or special concentration areas.

The general ELMR distributions of fish and invertebrates bysalinity zone or depth are depicted on the maps as polygons, boundedby black lines. Shading or hatch patterns were NOT used since theELMR data fills nearly all water bodies on the maps. The blackELMR boundaries represent seasonal isohalines (in the estuaries), thebreak between the estuarine and marine environment (at the inletmouths), or the 10 meter depth contour (offshore). ELMR polygonboundaries are not visible in most other instances since they followthe shoreline (except at state borders which mark the limit of thestudy area). For non-ELMR data, special concentration polygons aredepicted as polygons with a blue hatch pattern for fish, and anorange hatch pattern for sessile shellfish. For Gray’s Reef, fish areassociated with the bottom habitat polygons differentiated by solidfill colors (see legend associated with the Gray’s Reef map). ForNHP records, only a marker icon was used. In all cases, a blue iconwith a fish silhouette, and/or an orange icon with either a bivalve orgeneral ELMR invertebrate (crab) silhouette, are associated with thefish and invertebrate data.

The RAR# under the icon or icon group references a table on thereverse side of the map. In this table, the first column gives thespecies name. The second column denotes whether the species hasbeen designated endangered (E) or threatened (T) on either the state(S) and/or federal (F) lists. For non-ELMR data, concentration may belisted as HIGH, MEDIUM, or LOW, or as “OCCURRENCE” for NHPelement occurrence records. The concentration column is left blank forthe ELMR data because relative abundances are listed by month inthe seasonality columns. Under each month where an ELMR speciesis present, a number code indicates the species abundance (1 = noinformation, 2 = rare, 3 = common, 4 = abundant, 5 = highly abundant).The ELMR abundance codes usually refer to juvenile life stages, eventhough other life stages may be present. If juveniles are not present,the abundances refer to adults, or larvae if adults and juveniles arenot present. For non-ELMR data, seasonality is also listed by monthwith an “X” indicating the species presence in any particular month.The last columns indicate time periods for various life-history stagesor activities (fish = spawning [parturition for sharks], outmigration,larvae, juveniles, and adults; invertebrate = spawning, larvae,

mating, juveniles, and adults). For many species there is a temporalshift in seasonality and life-history along with spatial changes inlocation. Temporal information included in the tables is specific tothe one polygon or site that it references.

A thorough understanding of the maps and tables would not bepossible without a summary description of the ELMR program.Detailed information about ELMR methods and the fisheries andsalinity data in Georgia are provided below.

ELMR FISHERIES AND SALINITY DATA

Through NOAA’s ELMR program, a set of regional, consistentdatabases have been developed describing the distribution, relativeabundance, and life-history characteristics of selected fish andinvertebrates in U.S. estuaries. The spatial and temporal distribu-tion of ELMR’s categorical relative abundance data were assigned toGeorgia’s estuarine systems, based on information from the originalELMR data set (Nelson et al., 1991), regional and local fisheriesexperts, survey reports, peer-reviewed literature, and existingquantitative data. The relative abundance categories are intended toemulate the categories often used by fisheries biologists. Theseabundance estimates are then verified through an extensive peer-review process utilizing the knowledge and field experience offisheries biologists and managers. The data summaries represent thebest available source of information about the current distribution andabundance of the selected species. In addition to 31 species from theoriginal ELMR database, 14 other fish and invertebrate species wereincluded for the Georgia ESI. They are: knobbed whelk, Atlanticsharpnose shark, hickory shad, hardhead catfish, shortnosesturgeon, striped anchovy, tarpon, star drum, king mackerel,hogchoker, black sea bass, gag, silver perch, and Atlantic spadefish.

A primary factor affecting the distribution of estuarine-dependent fish and invertebrates is salinity. Seasonal estuarinesalinity zones are used in this atlas to organize and geographicallydepict the distribution and relative abundance of fish and inverte-brates in estuaries. The three estuarine salinity zones (depth-averaged and seasonal) used for the Georgia ESI atlas are: tidalfresh (0 - 0.5 parts per thousand [ppt]), mixing (0.5 - 25 ppt), andseawater (>25.0 ppt). Three salinity zones were used due to the highvariability of Georgia’s estuaries. Salinity variability in Georgiaestuaries is largely the result of their geomorphology (they aregenerally shallow) and tidal ranges (which are large, 2-3 meters).The estuarine salinity zones used were adapted and updated fromthose developed in Orlando et al. (1994). These salinity zones werereviewed and revised in 1996 by GA DNR personnel.

Salinity analysis for Georgia’s estuarine systems focused on twoperiods: the high salinity period (~ late summer-fall) and the lowsalinity period (~late winter-spring). The two transitional salinityperiods, roughly representing summer (transitional, increasing salin-ity) and winter (transitional, decreasing salinity periods) were alsoaddressed. These periods represent the typical high-, transitional-,and low-salinity conditions experienced under average seasonalfreshwater inflow conditions. The isohalines that define thesalinity zones shift seasonally due to environmental factors such asfreshwater inflow, evaporation, and wind. The monthly designationof high (H), transitional (T), and low (L) salinity time periods arespecified in the tables on the reverse side of each map, in the legend,in Table 1, and on the seasonal salinity zone map shown on page 5.

ELMR data and expert review were used to develop maps ofdistribution and relative abundance for 45 fish and invertebratespecies in Georgia’s estuaries and marine environment. For species inthe marine environment, the distributions are mapped into four,depth-defined polygons: 0-10 meters (m), 10-20m, 20-50m, and 50-200m. Note that only the 0-10m zone is included in the hardcopyatlas, representing the nearshore marine environment. For themarine data, it is also important to note that some species (e.g., gaggrouper, Atlantic spadefish, etc.) are structure- or reef-oriented anddo not occur throughout the depth range in which they are depicted.For species information in the estuaries, species distribution infor-mation are organized into the aforementioned seasonal salinityzones; however, it is important to note that most species and lifestages do not occur everywhere throughout an assigned zone at alltimes. For example, a map might show juveniles for one species in theestuarine mixing zone in May. However, these juveniles may onlyoccur at the bottom, near structure, in waters less than 3m, and only inlate May.

The salinity patterns for each Georgia estuary were analyzed todetermine the locations of seasonal isohalines. The salinitycharacteristics for each estuary are described below and illustratedon page 5. Salinity distributions in most Georgia estuaries aredominated by changes in seasonal freshwater inflows. For estuarinesystems with larger rivers (e.g., Savannah, Ossabaw, Altamaha, St.Andrew Sound, and St. Marys), freshwater input is typically highestfrom January-April and lowest during August-November. Accord-ingly, salinity is typically 5-15 ppt lower during February-Aprilthan during September-December. Freshwater also tends to set-uplocalized areas of vertical salinity stratification, especially duringhigh inflow periods.

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Other estuaries (i.e., St. Catherines, Sapelo, Wassaw, St. Simon,and Cumberland Sounds) are supported by small watersheds thatprovide little direct freshwater inflow. However, many of thesesystems are influenced by the major river systems in adjacent estuariesand still experience appreciable (though much reduced) seasonalsalinity changes. Consequently, salinity typically remains closer tofull seawater strength throughout much of the year and verticalstratification is less likely to occur or persist.

In all Georgia estuaries, the prevailing seasonal salinitypatterns and the degree of vertical stratification are affected bytides, shelf circulation, local precipitation, and wind. Of these, theeffect of tide is most apparent. Tides (and wind) are importantmechanisms for water column mixing and, therefore, typically reducevertical salinity stratification. In addition, tides can shift thelocation of isohalines, particularly in estuaries with large riverinputs. In these cases, salinity may occasionally span brackish tonear-ocean concentrations over a tidal cycle.

TABLE 1. Seasonal salinity time-periods for Georgia estuaries.

ESTUARY

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

Savannah River T L L L T T T T H H H T

Wassaw Sound T L L L T T T T T H H H

Ossabaw Sound T L L L T T T T T H H H

St. Catherines,Sapelo, andDoboy Sounds

T L L L T T T T T H H H

Altamaha River T L L L T T T T H H H T

St. Andrew and St.Simons Sounds

T L L L T T T T T H H H

St. Marys Riverand CumberlandSound

T L L L T T T T H H H T

Savannah River

This estuary includes the New River, Wright River, and severaldistributaries of the Savannah River (i.e., Front, Back, and MiddleRivers and South Channel). The average depth of the estuary isapproximately 5m at mid-tide level, although deeper navigationchannels (9-12m mean low water [MLW]) exist. The estuary receivesmost of its freshwater from the Savannah River; the head of tide islocated about 5 km upstream of the Highway 17 bridge. During the1970s and 1980s, a tide gate located in the Back River affectedcirculation and salinity in the upper estuary. The tide gate has notbeen operational since March 1989. Thus, salinity zones defined forthis ESI map reflect conditions after March 1989.

Salinity variability is dominated by seasonal fluctuations andcontrolled releases of freshwater from impoundments on theSavannah River and its tributaries. Throughout much of the estuary,salinity is about 5 ppt lower during February-April than duringSeptember-November, although these seasonal differences are lessapparent upstream of Hutchinson Island. Salinities are oftenvertically homogeneous, except for moderate stratification in thelower Savannah River. Tides are semi-diurnal and range from 2.0mat the entrance to the estuary to 2.5m in the Savannah River aboveElba Island.

Wassaw Sound

This estuary includes Wassaw Sound and its major tributaries:the Wilmington, Bull, and Half Moon rivers. The average depth ofthe estuary is approximately 8m at mid-tide level in the riverchannels, and averages 2m elsewhere. Due to its small watershed,this estuary receives limited freshwater inflow, primarily from theWilmington River. However, a connection to the Savannah River(South Channel) periodically supplements freshwater derivedlocally from the Wilmington River watershed during freshets. Nohead of tide can be identified, as tidal influence extends throughoutthe estuary.

Limited data available for this estuary suggests that WassawSound experiences very little seasonal salinity changes. In theabsence of significant freshwater inflow, salinities tend to be verti-cally homogeneous and near full seawater strength. Tides are semi-diurnal and average about 2.1m in the Sound and Wilmington River.

Ossabaw Sound

This estuary includes Ossabaw Sound and the Ogeechee, LittleOgeechee, Burnside, and Vernon Rivers. The average depth is about4m at mid-tide level, although naturally deep areas and shoals areinterspersed throughout the estuary. The Ogeechee River is thedominant freshwater source to the estuary; head of tide is located 52km upstream of the entrance to Ossabaw Sound.

Salinity variability is dominated by seasonal fluctuations fromthe Ogeechee River and its tributaries. Throughout much of theestuary, salinity is 5-10 ppt lower during February-April than duringOctober-December. The greatest seasonal salinity changes areapparent in the lower Ogeechee River, below Shad Island. Salinityis generally unstratified, but may be moderately stratified inOssabaw Sound and the lower Ogeechee River during the low salin-ity period. Tides are semi-diurnal and range about 2.1m throughoutOssabaw Sound and the lower regions of the major tributaries.

St. Catherines, Sapelo, and Doboy Sounds

This group of estuaries includes three sounds (St. Catherines,Sapelo, and Doboy) and numerous tidal creeks, including Bear,Medway, North and South Newport, and Sapelo. The average depthis about 4m at mid-tide level, although naturally deep areas andshoals are interspersed throughout the estuary. Due to their smallwatersheds, St. Catherines and Sapelo Sounds systems receivelimited freshwater inflow. However, freshwater input from theAltamaha River has a major influence on Doboy Sound, and theOgeechee River contributes some fresh water to St. Catherinessystem, via the Atlantic Intracoastal Waterway. The head of tidefor St. Catherines Sound is located on the Medway and NorthNewport Rivers, about 40 km upstream of the entrance to the sound.

Although these estuaries experience seasonal salinity varia-tions, they are not as pronounced as in other estuaries with largerfreshwater sources (i.e., Savannah and Altamaha rivers). However,the Doboy Sound system does exhibit more seasonal salinityvariation than do St. Catherines and Sapelo systems, mostly due toinputs from the Altamaha River. Except for weak vertical stratifi-cation in Doboy Sound and its tributaries, salinities throughout theestuary are often vertically homogeneous. Tides are semi-diurnal andaverage about 2-3m.

Altamaha River

This estuary includes the Altamaha River, Altamaha Sound,and several tidal creeks. The average depth of the estuary isapproximately 3m at mid-tide level, although naturally deep areasand shoals are interspersed throughout the estuary. The estuaryreceives most of its freshwater from the Altamaha River, formed bythe confluence of the Ocmulgee and Oconee Rivers; the head of tide islocated about 39 km upstream of the entrance to Altamaha Sound.Freshwater from the Altamaha River also has a dominant influenceon the Hampton River.

Salinity variability is dominated by seasonal fluctuations of theAltamaha River and its tributaries. Dams that form reservoirs onthe Ocmulgee and Oconee Rivers have little impact on estuarinesalinities. Throughout much of the estuary, salinity is about 10 pptlower during February-April than during September-November.Moderate-to-high vertical stratification is common in the lowerAltamaha River (below Threemile Cut) and in the lower portion ofthe South Altamaha River. Tides are semi-diurnal and range 2.0m atthe entrance to the estuary.

St. Andrew and St. Simons Sounds

These estuaries include St. Andrew and St. Simons Sounds, as wellas the Satilla River, Little Satilla River, and several small tidalcreeks. The average depth of the estuaries is approximately 4m atmid-tide level. The Brunswick Harbor Channel (10m at MLW)extends from the entrance of St. Simons Sound to the city ofBrunswick; a smaller channel exists in the East River. The estuaryreceives most of its freshwater from the Satilla River; the head oftide is located about 80 km upstream of the entrance to St. AndrewSound. Limited additional freshwater is conveyed through theMackay River from the Altamaha River. Little water exchangeoccurs between the St. Simons and St. Andrews Sounds, althoughthese systems are adjacent.

Salinity variability is dominated by seasonal fluctuations of theSatilla River. Although St. Simons Sound lacks any comparabledirect freshwater inflow, exchanges with the Altamaha River viathe Frederica River appear to have periodic influence on salinityduring major freshets. Limited data available for Mackay River, St.Simons Sound, and Brunswick River suggest that salinities are highlyvariable and weakly stratified, particularly during the low salinityperiod (February-April). Tides are semi-diurnal and range 2.0m atthe entrances to the sounds, 2.2m near Brunswick, and 2.4m atHermitage Point.

St. Marys River and Cumberland Sound

This estuarine system includes the St. Marys, Crooked, andAmelia Rivers as well as Kings Bay, Cumberland Sound, andnumerous small tidal creeks. The average depth of the estuary isapproximately 6m at mid-tide level. Navigation channels (14m atMLW) extends from the entrance of St. Mary Sound to the Kings BayNaval Submarine Base. Smaller channels exists in CumberlandSound (9m at MLW), North River (9m at MLW), and through St.Marys River (5m at MLW). The estuary receives most of itsfreshwater from the St. Marys River, which originates in the

Georgia’s EstuarineSalinity Zones

Salinity ZonesTidal Fresh (0 0.5 ppt.)

Mixing (0.5 25 ppt.)

Seawater (>25 ppt.)

Transitional DecreasingSalinity Period

Altamaha RiverSavannah RiverSt. Marys River/Cumberland Sound

Ossabaw SoundSt. Andrew/St. Simons SoundsSt. Catherines/Sapelo SoundsWassaw Sound

Low SalinityPeriod

All estuary systems

Transitional IncreasingSalinity Period



High Salinity Period



Savannah River Savannah River

Savannah RiverSavannah River

Wassaw Sound Wassaw Sound

Wassaw SoundWassaw Sound

Ossabaw Sound Ossabaw Sound

Ossabaw SoundOssabaw Sound

St. Catherines &Sapelo Sounds




Altamaha River Altamaha River

Altamaha RiverAltamaha River

St. Andrew &St. Simons Sounds




St. Marys River &Cumberland Sound




--

Feb. - Apr.

-May - Aug.

May - Sep.

-

Dec. - Jan.

Jan.

Sep. - Nov.

Oct. - Dec.

GA - Page 6

Okefenoke Swamp; head of tide is located about 64 km upstream ofthe entrance to St. Marys Sound.

Salinity variability is dominated by seasonal fluctuations of theSt. Marys River and its tributaries. The largest seasonal salinitydifferences are apparent in the upper regions of the St. Marys andCrooked Rivers. Salinity in Cumberland Sound and lower St. MarysRiver is generally polyhaline to euhaline and tends to be verticallyhomogeneous. Tides are semi-diurnal and average about 1.8m at theentrance to St. Marys Sound.

HABITATS/RARE PLANTS

Habitats and plants depicted in the Georgia atlas includeprotected or rare plants, and hardbottom reef habitats associatedwith the Gray’s Reef National Marine Sanctuary. The majority ofrare plant data came from NHP records. Plant records wereidentified as terrestrial plants, wetland/aquatic plants, or uniqueplant communities. Submerged habitats for Gray’s Reef were mappedbased on side-scan sonar data and expert knowledge provided bysanctuary staff.

Plants are mainly depicted using marker icons (for NHP records).In a few cases, plants may be mapped as small polygons with a purplehatch pattern. Purple icons with a plant silhouette indicate rare orprotected plant species or communities. Habitats for Gray’s Reef aredepicted as polygons with a hot pink (high relief, hardbottom reefledges) or light blue (low relief, hardbottom reef) solid fill pattern.In the tables, the first column gives the name of the plant or habitattype. The second column denotes whether the plant species has beendesignated as endangered (E) or threatened (T) on either the state (S)and/or federal (F) lists. The final columns provide monthlyseasonality data. The plants and habitats mapped are all presentyear round.

HUMAN-USE FEATURES

The human-use features depicted on the maps are those thatcould be impacted by an oil spill or could provide access for responseoperations. All the features are represented by icons indicating thetype of human-use resource.

Coast Guard

Boat Ramp

Archaeological S i t e

Aquaculture

Airport

Water Intake

Wildlife Refuge

Beach

National Park

Diving

Marina

Access

Commercial Fishing

Marine Sanctuary

State Park

Recreational Fishing

Historical Site

Hazardous Waste Site

NOAA Data Buoy

Access—Location where it is possible to gain vehicular access to theshoreline or isolated coastal sites and islands. For some areas, suchas islands, vehicles and equipment would need to be transported toaccess sites on barges.

Airport—Location of airports, airfields, landing strips, etc., whetherthey are manned or unmanned. The locations were obtained fromUSGS topographic maps.

Aquaculture—Location of aquaculture sites and facilities. Aqua-culture locations were obtained from expert sources. When known, thesite name, owner/manager, emergency contact name, and telephonenumber are provided on the data tables for each map.

Archaeological Site—Location of known archaeological sites in thecoastal zone. This information was provided by the GA DNRHistoric Preservation Division (HPD). The exact location and extentof these sites are not represented on the maps due to their sensitivityto disturbance. Instead, generalized locations are depicted to indi-cate single or multiple site presence in the vicinity. For more specificlocational information, information on the type of site(s) present, andguidance during response operations, please contact: Mark Edwards,State Historic Preservation Officer, 404/651-5061 (office) and 404/993-2807 (home); Richard Clouse, Deputy State Historic PreservationOfficer, 404/651-5983 (office) and 770/469-4884 (home); W. Ray Luce,Supervisor, HPD Planning and Local Assistance Unit, 404/656-6461(office) and 770/998-6935 (home); Richard Alan Warner, 404/651-6775 (office) and 404/299-8565 (home); Ronnie Rogers, 404/657-1042(office) and 706/216-1077 (home); or Chip Morgan, 404/651-6433(office) and 770/475-7915 (home).

Beach—Location of recreational beaches used for activities such asswimming, sun-bathing, fishing, etc.

Boat Ramp—Location of boat ramps. This information was gatheredfrom overflight observations, aerial photographs, and expert sources.

Coast Guard—Location of Coast Guard facilities. This informationwas obtained from topographical maps.

Commercial Fishing—General areas where commercial fishingactivities take place. Commercial fishing types include shrimp,oyster, and hard clam harvest. Other commercial fishing activitiessuch as blue crab harvest, shad fishing, etc. may take place through-out the study area.

Diving—Location of recreational dive sites.

Hazardous Waste Site—Location of hazardous waste sites in thecoastal zone. GA DNR Environmental Protection Division contactsconcerning these sites are provided on the data tables for each map.

Historical Site—Location of historic sites in the coastal zone. Thisinformation was provided by the GA DNR HPD. These areas maycontain single sites or several sites, and may encompass largerhistoric districts. The exact location and extent of these sites are notrepresented on the maps due to their sensitivity to disturbance.Instead, generalized locations are depicted to indicate site presencein the vicinity. For more specific locations, detailed information onthe site(s) present, and guidance during response operations, pleaserefer to the same contacts listed for Archaeological Sites. In mostcases, historical site and district names are indicated on the datatables for each map.

Marina—Location of marinas. This information was gathered fromoverflight observations, aerial photographs, and expert sources.

Marine Sanctuary—Locations of areas managed by the NOAASanctuary and Reserves Division as National Marine Sanctuaries, orby NOAA and the state as National Estuarine Research Reserves.

National Park—Locations of areas managed by the National ParkService, including national parks, national seashores, and nationalmonuments.

NOAA Data Buoy—Location of central buoy for Gray’s ReefNational Marine Sanctuary. This buoy, maintained by the NationalData Buoy Center, provides real time wind speed and direction, seastate, and water temperature data.

Recreational Fishing—Location of recreational fishing sites.

State Park—Locations of areas managed by GA DNR as state parksand related properties.

Water Intake—Location of water intakes maintained by municipali-ties, power plants, industrial facilities, aquaculture sites, naturalresource agencies, etc. For most water intakes, the site name, owner/manager, contact person, and telephone number are provided on thedata table for each map.

Wildlife Refuge—Location of areas managed by the U.S. Fish andWildlife Service (USFWS) as National Wildlife Refuges or GADNR as State Wildlife Management Areas.

The names of the various management areas include:

NAME

MARINE SANCTUARIES & RESERVES (NOAA/GA DNR)Gray’s Reef National Marine SanctuarySapelo Island National Estuarine Research Reserve

NATIONAL PARK SERVICE (NPS)Cumberland National SeashoreFort Frederica National MonumentFort Pulaski National Monument

NATIONAL WILDLIFE REFUGES (USFWS)Blackbeard Island National Wildlife RefugeHarris Neck National Wildlife RefugeSavannah National Wildlife RefugeWassaw National Wildlife RefugeWolf Island National Wildlife Refuge

STATE PARKS (GA DNR)Crooked River State ParkFort King George State Historic SiteFort McAllister State Historic ParkHofwyl-Broadfield Plantation State Historic SiteSkidaway Island State ParkWormsloe Plantation State Historic Site

STATE WILDLIFE MANAGEMENT AREAS (GA DNR)Altamaha State Waterfowl Management AreaOssabaw Island State Wildlife Management AreaRichard J. Reynolds State Wildlife RefugeRichmond Hill State Wildlife Management Area

GA - Page 7

GEOGRAPHIC INFORMATION SYSTEM DATA

The entire atlas product is stored in digital form in a GeographicInformation System (GIS). The information is stored as geographiclayers and associated databases. The format for the data variesdepending on the type of information or features for which the dataare being stored. The three major formats are shoreline habitatclassification, biological resources, and human-use features.

Under separate cover is a metadata document which details thedata dictionary, processing techniques, and descriptive informationfor the digital data sets and maps that were used to create this atlas.Below is a brief synopsis of the information contained in the digitalversion. Refer to the metadata file for a full explanation of the dataand its structure.

SHORELINE HABITAT CLASSIFICATION

The shoreline habitat classification is stored as lines andpolygons with associated attributes. In many cases, a shoreline mayhave two or three different classifications. These multiple classifi-cations are represented on the maps by double and triple line patternsand in the database by ESI#1/ESI#2, where ESI#1 is the landward-most classification and ESI#2 is the seaward-most classification. Inaddition to the line features, tidal flats (ESI = 7, ESI = 9A) and thevarious wetland types (ESI = 10A, 10B, 10C, and 10D) are also storedas polygons.

SENSITIVE BIOLOGICAL RESOURCES

Biological resources are stored as polygons or points. Associatedwith each feature is a unique identification number which is linkedto a series of databases that further identify the resources. The firstdata set consists of a list of the species and the concentration of eachspecies. This dataset is then linked to datasets that describe the lifehistory of each species (temporal presence and reproductive/life-history time periods at month resolution) for the specified mapfeature. Other databases linked to the first data set are: the speciesidentification database, which includes common and scientific namesand NHP Global Conservation Status Ranks for all species; thespecies status database, which gives information for state and/orfederal threatened or endangered listings; and the sources database,which provides source metadata for each biological feature. Notethat element occurrence records for rare and endangered speciesprovided by the GA NHP are included only on the hardcopy maps,not in the digital data set.

HUMAN-USE FEATURES

Human-use features are represented as lines, points, or polygons.The resource name, the owner/manager, a contact person, and anemergency phone number are included in the database for aquaculturesites, water intakes, and other features, when available. Allmetadata sources are documented at the feature level. Note thatarchaeological site data provided by the GA DNR Historic Preser-vation Division are included only on the hardcopy maps, not in thedigital data set.

REFERENCES

Listed below are the major hardcopy reference materials usedduring this project. In some instances, reference materials were notdirectly used as source materials, but were instead used or interpretedby scientists or resource managers who provided expert knowledge orpersonal communication concerning resources depicted in the atlas.

Bryan, A.L., 1994, Wood stork roost sites in the coastal zone ofGeorgia and South Carolina in 1994. Savannah River EcologyLaboratory, Aiken, S.C.

Georgia Department of Natural Resources, 1981-1994, Numerousfishery assessment documents and reports. Complete citations forreferences used during the ELMR fisheries database developmentare available from NOAA’s SEA Division, Silver Spring, MD.

Georgia Department of Natural Resources, 1995, Georgia offshorefishing guide. GA DNR, Coastal Resources Division, Brunswick,GA.

Georgia Department of Natural Resources, 1996, Angler’s guide toGeorgia saltwater fishing access sites. GA DNR, Coastal ResourcesDivision, Brunswick, GA.

Georgia Natural Heritage Program, 1996, Special concern animals ofGeorgia. GA DNR, Wildlife Resources Division, Social Circle, GA.

Georgia Natural Heritage Program, 1996, Special concern plants ofGeorgia. GA DNR, Wildlife Resources Division, Social Circle, GA.

National Marine Fisheries Service, 1994, Designated critical habitatfor the Northern Right Whale. Federal Register 59(106):28793-28808.

Nelson, D.M., E.A. Irlandi, L.R. Settle, M.E. Monaco, and L. Coston-Clements, 1991, Distribution and abundance of fishes andinvertebrates in Southeast estuaries. ELMR Report No. 9, NOAA/

NOS Strategic Environmental Assessment Division, Rockville, MD,167 pp.

Orlando, S.P., Jr., P.H. Wendt, C.J. Klein, M.E. Patillo, K.C. Dennis.and G.H. Ward, 1994, Salinity characteristics of South Atlanticestuaries. NOAA/ORCA, Silver Spring, MD, 117 pp.

Parker, R., 1994, Video transect estimate of reef fish abundance.Fishery Bulletin 92:787-799.

Ruckdeschel, C., C.R. Shoop, and B. Winn, 1990, Brown pelicannesting in Georgia. The Oriole 55(4):65-68.

Southeast Monitoring Assessment Program (SEAMAP), 1986-1996,Survey and trawl data for fish and invertebrates off the southeastU.S. National Marine Fisheries Service, Southeast FisheriesCenter, Stennis Space Center, MS.

The Georgia Conservancy, 1993, Guide to the Georgia coast. TheGeorgia Conservancy and the Junior League of Savannah, GA. 201pp.

Wenner, C.A. and G.R. Sedberry, 1989, Species composition, distri-bution, and relative abundance of fishes in the coastal habitat offthe Southeastern United States. NOAA Technical Report NMFS79, 49 pp.

Whitted, J., 1980-1982, Guides to coastal fishing in Georgia (bycounty). University of Georgia, Marine Extension Service.

Wilkinson, P.M., S.A. Nesbitt, and J.F. Parnell, 1994, Recent historyand status of the eastern brown pelican. Wildlife Society Bulletin22:420-430.

ACKNOWLEDGMENTS

This project was supported by the National Oceanic and Atmo-spheric Administration’s Coastal Services Center (CSC) inCharleston, South Carolina and NOAA’s Hazardous MaterialsResponse and Assessment Division (HMRAD) in Seattle,Washington. The U.S. Coast Guard provided aircraft support andthe Georgia Department of Transportation provided access to aerialphotographs for the shoreline habitat mapping. Catherine Mainwith NOAA’s CSC and Brad Benggio with NOAA HMRAD (Miami,Florida) assisted greatly with project coordination and planning.

The biological and human-use data included on the maps wereprovided by many individuals within several divisions of GA DNR,as well as other agencies and groups including the Gray’s ReefNational Marine Sanctuary, NMFS, National Park Service, U.S.Army Corps of Engineers, USFWS, University of Georgia, and theSkidaway Institute of Oceanography. Catherine Main withNOAA’s CSC collected the biological and human-use data fromresource experts and assisted with compiling this data onto the maps.Tracy Gill, Ken Buja, Tony Lowery, and other contributors withNOAA’s SEA Division provided the salinity information andcollected and compiled the ELMR fish and invertebrate data withthe assistance of GA DNR fisheries experts.

Research Planning, Inc. (RPI), Columbia, South Carolina,produced the Georgia ESI atlas. At RPI, Scott Zengel was the projectmanager and ecologist. Shoreline habitat mapping was conducted byTodd Montello, coastal geologist. The biological and human-use datawere compiled onto basemaps and edited by Scott Zengel with theassistance of Kara Hastings and Christopher Locke. Kara Hastings(GIS coordinator), Christopher Locke, Zachary Nixon, Mark White,and William Holton entered the data and produced the final mapsunder the supervision of Joanne Halls. Systems administration wasconducted by William Holton. Graphics were provided by JoeHolmes. Dot Zaino prepared the final text and data tables.

GA - Page 8

SPECIES LIST*

Common Name Species Name

MAMMALS

MARINE MAMMALSFin whale Balaenoptera physalusHumpback whale Megaptera novaeangliaeNorthern right whale Eubalaena glacialisPygmy sperm whale Kogia brevicepsWest Indian manatee Trichechus manatus

TERRESTRIAL MAMMALSRare rodentThreatened rodent

BIRDS

DIVING BIRDSAnhinga Anhinga anhingaBrown pelican Pelecanus occidentalisDouble-crested cormorant Phalacrocorax auritusPied-billed grebe Podilymbus podiceps

GULLS AND TERNSBlack skimmer Rynchops nigerBlack tern Chlidonias nigerBonaparte’s gull Larus philadelphiaCaspian tern Sterna caspiaForster’s tern Sterna fosteriGull-billed tern Sterna niloticaHerring gull Larus argentatusLaughing gull Larus atricillaLeast tern Sterna antillarumRare ternRing-billed gull Larus delawarensisRoyal tern Sterna maximaSandwich tern Sterna sandvicensisThreatened tern

PASSERINEEndangered passerine birdRare passerine bird

RAPTORSAmerican kestrel Flaco sparveriusAmerican swallow-tailed kite Elanoides forficatusBald eagle Haliaeetus leucocephalusCoopers hawk Accipiter cooperiiEndangered raptorMerlin Falco columbariusNorthern harrier Circus cyaneusOsprey Pandion haliaetusPeregrine falcon Falco peregrinusRed-shouldered hawk Buteo lineatusRed-tailed hawk Buteo jamaicensisSharp-shinned hawk Accipiter striatus

SHOREBIRDSAmerican oystercatcher Haematopus palliatusBlack-bellied plover Pluvialis squatarolaBuff-breasted sandpiper Tryngites subruficollisCommon snipe Gallinago gallinagoDowitcher Limnodromus spp.Dunlin Calidris alpinaGreater yellowlegs Tringa melanaleucaKilldeer Charadrius vociferusLeast sandpiper Calidris minutillaLesser yellowlegs Tringa flavipesMarbled godwit Limosa fedoaPectoral sandpiper Calidris melanotosPeep Calidris spp.Piping plover Charadrius melodusRare shorebirdRed knot Calidris canutusRuddy turnstone Arenaria interpresSanderling Calidris albaSemipalmated plover Charadrius semipalmatusSemipalmated sandpiper Calidris pusillaSolitary sandpiper Tringa solitariaSpotted sandpiper Actitis maculariaStilt sandpiper Calidris himantopusUpland sandpiper Bartramia longicauda

SPECIES LIST*


BIRDS (continued)

SHOREBIRDS (continued)Western sandpiper Calidris mauriWhimbrel Numenius phaeopusWhite-rumped sandpiper Calidris fusciollisWillet Catoptrophorus

semipalmatusWilson’s phalarope Steganopus tricolorWilson’s plover Charadrius wilsoniaYellowlegs Tringa spp.

WADING BIRDSAmerican avocet Recurvirostra americanaBlack-crowned night heron Nycticorax nycticoraxBlack-necked stilt Himantopus mexicanusCattle egret Bubulcus ibisEndangered wading birdGlossy ibis Plegadis falcinellusGreat blue heron Ardea herodiasGreat egret Casmerodius albusGreen-backed heron Butorides striatusLittle blue heron Egretta caeruleaRare wading birdSnowy egret Egretta thulaTricolored heron Egretta tricolorWhite ibis Eudocimus albusWood stork Mycteria americanaYellow-crowned night heron Nyctanassa violacea

WATERFOWLAmerican coot Fulica americanaAmerican wigeon Anas americanaBlack duck Anas rubripesBlue-winged teal Anas discorsBufflehead Bucephala albeolaCanvasback Aythya valisineriaCommon moorhen Gallinula chloropusGadwall Anas streperaGreater scaup Aythya marilaGreen-winged teal Anas creccaHooded merganser Lophodytes cucullatusLesser scaup Aythya affinisMallard Anas platyrhynchosMottled duck Anas fulrigulaNorthern pintail Anas acutaNorthern shoveler Anas clypeataPurple gallinule Porphyrula martinicaRedhead Aythya americanaRing-necked duck Aythya collarisRuddy duck Oxyura jamaicensisWood duck Aix sponsa

REPTILES

AMPHIBIANSRare frogRare salamander

LIZARDSRare lizard

TURTLESGopher tortoise Gopherus polyphemusGreen sea turtle Chelonia mydasKemp’s ridley sea turtle Lepidochelys kempiiLeatherback sea turtle Dermochelys coriaceaLoggerhead sea turtle Caretta carettaThreatened turtle

FISH

ANADROMOUSAmerican shad Alosa sapidissimaAtlantic sturgeon Acipenser oxyrhynchusBlueback herring Alosa aestivalisEndangered anadromous fishHickory shad Alosa mediocrisShortnose sturgeon Acipenser brevirostrumStriped bass Morone saxatilis

* Threatened and endangered species are designated by underlining.

GA - Page 9

SPECIES LIST*


FISH (continued)

SPECIALAmerican eel Anguilla rostrataAtlantic croaker Micropogonias undulatusAtlantic menhaden Brevoortia tyrannusAtlantic sharpnose shark Rhizoprionodon terraenovaeAtlantic spadefish Chaetodipterus faberBar jack Caranx ruberBay anchovy Anchoa mitchilliBlack drum Pogonias cromisBlack seabass Centropristis striataBlue angelfish Holacanthus bermudensisBluefish Pomatomus saltatrixCobia Rachycentron canadumCocoa damselfish Pomacentrus variabilisCubbyu Equetus umbrosusGag grouper Mycteroperca microlepisGray snapper Lutjanus griseusGreat barracuda Sphyraena barracudaGreater amberjack Seriola dumeriliHardhead catfish Arius felisHogchoker Trinectes maculatusInshore lizardfish Synodus foetensKing mackerel Scomberomorus cavallaLadyfish Elops saurusLongspine porgy Stenotomus caprinusMackerel scad Decapterus macarellusMummichog Fundulus heteroclitusPearly razorfish Hemipteronotus novaculaPinfish Lagodon rhomboidesRare fishRed drum Sciaenops ocellatusRed porgy Pagrus pagrusRound scad Decapterus punctatusSand perch Diplectrum formosumScamp grouper Mycteroperca phenaxSeatrout (weakfish) Cynoscion regalisSheepshead Archosargus probatocephalusSilver perch Bairdiella chrysouraSlippery dick Halichoeres bivittatusSouthern flounder Paralichthys lethostigmaSouthern kingfish (whiting) Menticirrhus americanusSouthern stringray Dasyatis americanaSpanish mackerel Scomberomorus maculatusSpot Leiostomus xanthurusSpotfin butterflyfish Chaetodon ocellatusSpottail pinfish Diplodus holbrookiSpotted seatrout Cynoscion nebulosusStar drum Stellifer lanceolatusStriped anchovy Anchoa hepsetusStriped mullet Mugil cephalusSummer flounder Paralichthys dentatusTarpon Megalops atlanticusTomtate Haemulon aurolineatumYellow jack Caranx bartholomaei

INVERTEBRATES

BIVALVESAmerican oyster (eastern) Crassostrea virginicaQuahog spp. (hard clam) Mercenaria spp.

CRABSBlue crab Callinectes sapidus

GASTROPODKnobbed whelk Busycon carica

SHRIMPBrown shrimp Penaeus aztecusGrass shrimp Palaemonetes sp.Pink shrimp Penaeus duorarumWhite shrimp Penaeus setiferus

SPECIES LIST*


HABITATS

HABITATS/RARE PLANTSDense-flowered groundsel-tree Baccharis glomerulifloraRare communityRare terrestrial plantRare wetland/aquatic plantThreatened terrestrial plantThreatened wetland/aquatic plant

HARDBOTTOM/REEF LEDGESHardbottom reefHardbottom reef ledge

* Threatened and endangered species are designated by underlining.

Shoreline DescriptionsEXPOSED, SOLID MAN-MADE STRUCTURES ESI = 1BDESCRIPTION

• These structures are solid, man-made structures such asseawalls, groins, revetments, piers, and port facilities.

• Many structures are constructed of concrete, wood, ormetal.

• Often there is no exposed substrate at low tide, butmultiple habitats are indicated if present.

• They are built to protect the shore from erosion by waves,boat wakes, and currents, and thus are exposed to rapidnatural removal processes.

• Attached animals and plants are sparse to moderate.

PREDICTED OIL BEHAVIOR• Oil is held offshore by waves reflecting off the steep,

hard surface in exposed settings.• Oil readily adheres to the dry, rough surfaces above high

water, but it does not adhere to wet substrates.• The most resistant oil would remain as a patchy band at

or above the high-tide line.

RESPONSE CONSIDERATIONS• Cleanup is usually not required.• High-pressure water spraying may be conducted to:

- remove persistent oil in crevices;- improve aesthetics; or- prevent leaching of oil.

FINE- TO MEDIUM-GRAINED SAND BEACHES ESI = 3ADESCRIPTION

• These beaches are flat to moderately sloping andrelatively hard packed.

• They are composed of quartz sand and shell fragments andare common along the outer barrier island coastline.

• There can be heavy accumulations of wrack present.• They are utilized by birds for nesting, foraging, and

loafing and turtles for nesting.• Upper beach fauna include ghost crabs and amphipods;

lower beach fauna can be moderate, but highly variable.

PREDICTED OIL BEHAVIOR• Light oil accumulations will be deposited as oily swashes

or bands along the upper intertidal zone.• Heavy oil accumulations will cover the entire beach

surface; oil will be lifted off the lower beach with therising tide.

• Maximum penetration of oil into fine- to medium-grainedsand is about 10-15 cm.

• Burial of oiled layers by clean sand within the first weekafter a spill typically will be less than 30 cm along theupper beach face.

• Organisms living in the beach sediment may be killed bysmothering or lethal oil concentrations in the interstitialwater.

• Biological impacts include temporary declines in infauna,which can affect important shorebird foraging areas.

RESPONSE CONSIDERATIONS• These beaches are among the easiest shoreline types to

clean.• Cleanup should concentrate on removing oil and oily

debris once oil has come ashore.• Traffic through both oiled and dune areas should be

limited, to prevent contamination of clean areas.• Manual cleanup, rather than road graders and front-end

loaders, is advised to minimize the volume of sandremoved from the shore and requiring disposal.

• All efforts should focus on preventing the mixture of oildeeper into the sediments by vehicular and foot traffic.

• Mechanical reworking of lightly oiled sediments from thehigh-tide line to the upper intertidal zone can beeffective along outer beaches.

GA - Page 10

SCARPS AND STEEP SLOPES IN SAND ESI = 3BDESCRIPTION

• This shoreline type occurs where sandy bluffs are undercutby waves or currents.

• They normally form along embankments of sandy dredge-spoil material and at cutbanks in rivers; they also formwhere tidal creeks intercept old sandy beach ridgedeposits.

• Some scarps are fronted by narrow beaches, if the erosionrates are moderate and episodic.

• Trees growing at the top of these slopes are eventuallyundercut and the logs can accumulate at the base of thescarp.

• Biological utilization by birds and infauna is low.PREDICTED OIL BEHAVIOR

• Any stranded oil will concentrate at the high-water lineand may penetrate sandy sediments if a beach is present.

• Oil will also adhere to the dry surfaces of any logs thathave accumulated at the base of the scarp.

• There is little potential for burial except when majorslumping of the bluff occurs.

• Active erosion of the scarp will remove the oil.RESPONSE CONSIDERATIONS

• In most cases, cleanup is not necessary because of the shortresidence time of the oil.

• The need for removal of oiled sediments and debris shouldbe carefully evaluated because of the potential forincreased erosion.

• Closely supervised manual labor should be used so thatthe minimal amount of material is removed duringcleanup.

GRAVEL BEACHES ESI = 6ADESCRIPTION

• Gravel beaches in Georgia are composed almost entirelyof shell.

• They can be very steep, with multiple wave-built bermsforming the upper beach.

• Shell beaches are common near oyster reefs and along theintracoastal waterway where spoil mounds have beenreworked by boat wakes into steep shell berms.

• There are low densities of infauna because the coarsesediments dry out during low tide.

• They are important roosting areas for shorebirds,especially when high tide floods the marshes.

PREDICTED OIL BEHAVIOR

• Deep penetration of stranded oil is likely on shellbeaches because of their high permeability.

• Long-term persistence will be controlled by the depth ofroutine reworking by the waves.

• Along sheltered portions of the shorelines, chronicsheening and the formation of asphalt pavements islikely where accumulations are heavy.

RESPONSE CONSIDERATIONS

• Heavy accumulations of pooled oil should be removedquickly from the upper beach.

• All oiled debris should be removed.• Sediment removal should be limited as much as possible.• Low- to high-pressure flushing can be effective for fresh

liquid, making sure to recover all released oil withskimmers or sorbents.

• Mechanical reworking of oiled sediments from the high-tide line to the lower beachface can be effective in areasregularly exposed to wave activity; the presence ofmultiple storm berms is evidence of wave activity.

• In-place tilling may be used to reach deeply buried oillayers along the mid-intertidal zone on exposed beaches.

GA - Page 11

RIPRAP ESI = 6BDESCRIPTION

• Riprap structures are composed of cobble- to boulder-sizedblocks of granite or limestone.

• Riprap structures are common along shorelines exposed towave action (outer coasts, large bays and harbors,navigable channels) and are used for shoreline protectionand tidal- inlet stabilization (jetties).

• Attached biota are sparse to moderate on exposed riprap.PREDICTED OIL BEHAVIOR

• Deep penetration of oil between the blocks is likely.• Oil adheres readily to the rough surfaces of the blocks.• Uncleaned oil can cause chronic leaching until the oil

hardens.RESPONSE CONSIDERATIONS

• When the oil is fresh and liquid, high pressure sprayingand/or water flooding may be effective, making sure torecover all liberated oil.

• Heavy and weathered oils are more difficult to remove,requiring scrapping and/or hot-water spraying.

• It may be necessary to remove heavily oiled blocks andreplace them in high-use areas.

EXPOSED TIDAL FLATS ESI = 7DESCRIPTION

• Exposed tidal flats are broad intertidal areas composedprimarily of sand and minor amounts of shell and mud.

• The presence of sand indicates that tidal currents andwaves are strong enough to mobilize the sediments.

• They are usually associated with another shoreline typeon the landward side of the flat, though they can occur asseparate shoals; they are commonly associated withtidal inlets and are found at meander bends in large tidalcreeks/river channels.

• Biological utilization can be very high, with largenumbers of infauna, heavy use by birds for roosting andforaging, and use by foraging fish.


• Oil does not usually adhere to the surface of exposed tidalflats, but rather moves across the flat and accumulates atthe high-tide line.

• Deposition of oil on the flat may occur on a falling tide ifconcentrations are heavy.

• Oil does not penetrate water-saturated sediments, thoughit can penetrate drained burrows.

• Biological damage may be severe, primarily to infauna,thereby reducing food sources for birds and otherpredators.


• Currents and waves can be very effective in naturalremoval of the oil.

• Cleanup is very difficult (and possible only during lowtides).

• The use of heavy machinery should be restricted toprevent mixing of oil into the sediments.

SHELTERED SCARPS IN MUD ESI = 8ADESCRIPTION

• Sheltered scarps form by boat wake erosion of marshfronts or muddy substrates along navigable channels.

• There may be some fringing marsh at the base of the scarpalong the edge of the water; it is not significant enough tomap.

PREDICTED OIL BEHAVIOR• Oil will not adhere to the wet sediment surface but could

penetrate burrows if present and drained.• Stranded oil will persist because of low energy setting.

RESPONSE CONSIDERATIONS• Where the high-tide area is accessible, it may be

feasible to remove heavy oil accumulations and oileddebris.

• The muddy substrate cannot support heavy equipment,and even foot traffic could disrupt the sediments and mixoil deeper.

GA - Page 12

SHELTERED, SOLID MAN-MADE STRUCTURES ESI = 8BDESCRIPTION

• These structures are solid man-made structures such asseawalls, groins, revetments, piers, and port facilities.

• Most structures are constructed of concrete, wood, or metal.• These structures are found inside harbors and bays in

highly developed areas, sheltered from direct exposure towaves.

• Often there is no exposed beach at low tide, but multiplehabitats are indicated if present.

• Most of the structures are designed to protect a single lot,thus their composition, design, and condition are highlyvariable.

• Attached animal and plant life can be high.PREDICTED OIL BEHAVIOR

• Oil will adhere readily to the rough surface, particularlyalong the high-tide line, forming a distinct oil band.

• The lower intertidal zone usually stays wet (particularlyif algae covered), preventing oil from adhering to thesurface.


• Cleanup of seawalls is usually conducted for aestheticreasons or to prevent leaching of oil.

• Low- to high-pressure spraying at ambient watertemperatures is most effective when the oil is fresh.

SHELTERED RIPRAP ESI = 8CDESCRIPTION

• Riprap structures are composed of cobble- to boulder-sizedblocks of granite or limestone.

• These structures are found inside harbors and bays inhighly developed areas, sheltered from direct exposure towaves.

• Attached animal and plant life can be highly variable.PREDICTED OIL BEHAVIOR

• Deep penetration of oil between the boulders is likely.• Oil adheres readily to the rough surfaces.• If oil is left uncleaned, it may cause chronic leaching until

the oil hardens.RESPONSE CONSIDERATIONS

• High-pressure spraying may be required to remove oil foraesthetic reasons and to prevent leaching of oil from thestructure.

• Cleanup crews should make sure to recover all releasedoil.

SHELTERED TIDAL FLATS ESI = 9ADESCRIPTION

• Sheltered tidal flats are composed primarily of mud withminor amounts of sand and shell.

• They are present in calm-water habitats, sheltered fromwaves, and are frequently backed by marshes.

• The sediments are very soft and cannot support even lightfoot traffic in many areas.

• They can have heavy wrack deposits along the upperfringe.

• There can be large concentrations of invertebrates on andin the sediments.

• They are heavily utilized by birds for feeding.PREDICTED OIL BEHAVIOR

• Oil does not usually adhere to the surface of shelteredtidal flats, but rather moves across the flat andaccumulates at the high-tide line.

• Deposition of oil on the flat may occur on a falling tide ifconcentrations are heavy.

• Oil will not penetrate the water-saturated sediments, butcould penetrate burrows and desiccation cracks or othercrevices in muddy sediments.

• In areas of high suspended sediments, sorption of oil canresult in deposition of contaminated sediments on theflats.

• Biological damage may be severe.RESPONSE CONSIDERATIONS

• These are high-priority areas for protection because oflimited cleanup options.

• Cleanup of the flat surface is very difficult because of thesoft substrate; many methods may be restricted.

• Low-pressure flushing and deployment of sorbents fromshallow-draft boats may be helpful.

GA - Page 13

VEGETATED LOW RIVERINE BANKS ESI = 9BDESCRIPTION

• These are either low banks with grasses or low erodingbanks with trees and tree roots exposed to the water.

• The are flooded occasionally by high water.• These shorelines are generally found in fresh or brackish

water habitats.PREDICTED OIL BEHAVIOR

• During low water stages there is little impact, with theoil coating a narrow band of sediment at the water level.

• During high water, the oil can cover and coat the grassesand base of trees.

• Oiling may cause loss of the grasses, but the trees shouldsurvive unless oil penetrates and persists in the substrate.


• Low-pressure flushing of oiled areas is effective inremoving moderate to heavy accumulations of oil fromalong the banks.

• Sorbent and containment boom should be placed on thewater side of the cleanup operations to contain and collectoil outflow.

• Low- to high-pressure flushing can be used to remove oilfrom tree roots and trunks, if deemed necessary in high-useareas.

SALT- AND BRACKISH-WATER MARSHES ESI = 10ADESCRIPTION

• These are intertidal wetlands containing emergent,herbaceous vegetation.

• Width of the marsh can vary widely, from a narrowfringe to extensive areas.

• Sediments are composed of organic muds except on themargins of barrier islands where sand is abundant.

• Exposed areas are located along bays with wide fetchesand along heavily trafficked waterways.

• Sheltered areas are not exposed to significant waves orboat wakes.

• Resident flora and fauna are abundant with numerousspecies with high utilization by birds, fish, andinvertebrates.


• Oil adheres readily to intertidal vegetation.• The band of coating will vary widely, depending upon the

water level at the time oil slicks are in the vegetation.There may be multiple bands.

• Large slicks will persist through multiple tidal cyclesand coat the entire stem from the high-tide line to thebase.

• If the vegetation is thick, heavy oil coating will berestricted to the outer fringe, although lighter oils canpenetrate deeper, to the limit of tidal influence.

• Medium to heavy oils do not readily adhere to orpenetrate the fine sediments, but can pool on the surface orin burrows.

• Light oils can penetrate the top few centimeters ofsediment and deeply into burrows and cracks (up to onemeter).


• Under light oiling, the best practice is to let the arearecover naturally.

• Natural removal processes and rates should be evaluatedprior to conducting cleanup.

• Heavy accumulations of pooled oil can be removed byvacuum, sorbents, or low-pressure flushing. Duringflushing, care must be taken to prevent transporting oil tosensitive areas down slope or along shore.

• Cleanup activities should be carefully supervised toavoid vegetation damage.

• Any cleanup activity must not mix the oil deeper into thesediments. Trampling of the roots must be minimized.

• Cutting of oiled vegetation should only be consideredwhen other resources present are at great risk fromleaving the oiled vegetation in place.

GA - Page 14

FRESHWATER MARSHES ESI = 10BDESCRIPTION

• These are grassy wetlands composed of emergentherbaceous vegetation.

• They occur upstream of brackish vegetation along majorrivers.

• Those along major channels are exposed to strong currentsand boat wakes; inland areas are highly sheltered.

• The substrate is seldom exposed since daily water-levelchanges are low; greater changes occur during floods.

• Resident flora and fauna are abundant with numerousspecies.


• Oil adheres readily to the vegetation.• The band of coating will vary widely, depending upon the

water level at the time oil slicks are in the vegetation.There may be multiple bands.

• If the vegetation is thick, heavy oil coating will berestricted to the outer fringe, although lighter oils canpenetrate deeper.



• Natural removal processes and rates should be evaluatedprior to conducting cleanup.


• Cleanup activities should be carefully supervised toavoid vegetation damage.

• Any cleanup activity must not mix the oil deeper into thesediments. Trampling of the roots must be minimized.

• Cutting of oiled vegetation should only be consideredwhen other resources present are at great risk fromleaving the oiled vegetation in place.

SWAMPS ESI = 10CDESCRIPTION

• Swamps consist of shrubs and hardwood forestedwetlands, essentially flooded forests.

• The sediment tends to be silty clay with large amounts oforganic debris.

• They are seasonally flooded, though there are many low,permanently flooded areas.



• Oil behavior depends on whether the swamp is flooded ornot.

• During floods, most of the oil passes through the forest,coating the vegetation above the waterline, whichchanges levels throughout the flood event.

• Oiled woody vegetation is less sensitive than grasses tooil coating.

• Some oil can be trapped and pooled on the swamp floodplain as water levels drop.

• Penetration into the floodplain soils is usually limitedbecause of high water levels, muddy composition, surfaceorganic debris, and vegetation cover.

• Large amounts of oily debris can remain.• During dry periods, terrestrial spills flow downhill and

accumulate in depressions or reach waterbodies.RESPONSE CONSIDERATIONS



• Under stagnant water conditions, herding of oil withwater spray may be needed to push oil to collection areas.

• Oily debris can be removed where there is access.• Any cleanup activity must not mix the oil deeper into the

sediments. Trampling of the roots must be minimized.• Cutting of oiled vegetation should only be considered

when other resources present are at great risk fromleaving the oiled vegetation in place.

GA - Page 15

SCRUB-SHRUB WETLANDS ESI = 10DDESCRIPTION

• Scrub-shrub wetlands consist of woody vegetation lessthan 6m tall including true shrubs, small trees, and treesand shrubs that are stunted because of environmentalconditions.

• They are common in disturbed/modified areas such asdredge spoil mounds and along the edges of right-of-ways(utilities, pipelines, etc.) that cross channels.

• The sediment tends to be silty clay with large amounts oforganic debris.

• They are seasonally flooded, though there are many low,permanently flooded areas.



• Oil behavior depends on whether the wetland is floodedor not.

• During floods, most of the oil passes through the wetland,coating the vegetation above the waterline, whichchanges levels throughout the flood event.

• Oiled woody vegetation is less sensitive than grasses tooil coating.

• Some oil can be trapped and pooled on the wetlandfloodplain as water levels drop.

• Penetration into the floodplain soils is usually limitedbecause of high water levels, muddy composition, surfaceorganic debris, and vegetation cover.

• Large amounts of oily debris can remain.• During dry periods, terrestrial spills flow downhill and

accumulate in depressions or reach waterbodies.RESPONSE CONSIDERATIONS



• Under stagnant water conditions, herding of oil withwater spray may be needed to push oil to collection areas.

• Oily debris can be removed where there is access.• Any cleanup activity must not mix the oil deeper into the

sediments. Trampling of the roots must be minimized.• Cutting of oiled vegetation should only be considered

when other resources present are at great risk fromleaving the oiled vegetation in place.

GA - Page 16

Documents

ENVIRONMENTAL SENSITIVITY INDEX: GEORGIAocean.floridamarine.org/ACP/SAVACP/Maps/GA_ESI/Intro.pdfOther Reptiles/Amphibians Reef Communities ELMR Shellfish The polygon or point color