but specific sea turtles seem doomed to extinction because of negative human impacts. MORTALITY

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1 MORTALITY The large number of eggs laid by sea turtles attests to the number of hazards which keep most hatchlings from reaching maturity and reproductive age. Loggerheads are most vulnerable to normal causes of death during their juvenile stages. Once they reach maturity, they have few natural enemies except for sharks, toothed whales, and humans. The large numbers of eggs and the relatively small population of adults has been cited as evidence for a survival rate of something like 1 of every 1,000 hatchlings. Predation: Predators of sea turtles affect populations principally during early stages of development, particularly juvenile stages. Nests are commonly predated by mammals such as raccoons, feral pigs, or humans. Smaller predators such as birds and Ghost Crabs also predate nests. Upon emergence as a group, sea turtles often run a gauntlet of waiting predatory birds, crabs, fish, and toothed marine mammals. The swimming frenzy of hatchlings assures that they will rapidly disperse and be less vulnerable as a cohort to a few predators. Once reaching adulthood, sea turtles have few predatory enemies, but still have some as is indicated by bite marks and bitten off paddles. During this stage of their life, intentional and incidental human activities seem to be principal factors killing sea turtles. Age: The age of sea turtles is difficult to establish. Most age determinations are estimates. Colin Limpas recently reported tagging recapture data that indicated that Loggerhead sea turtles in Australian waters reach sexual maturity at cm curved carapace length. Most other researchers report sexual maturity in females as occurring at a carapace length of about 80 cm and have estimated the age of these turtles to be from 20 to 30 years old. Estimates of the normal life expectancy of sea turtles range from 50 to over 100 years. Regardless of the lack of precise knowledge of the life expectancy of sea turtles, it is clear that they live a very long time, reach maturity late in their life, and population dynamics are negatively affected by death of adult turtles which form the breeding stock for the future. but specific sea turtles seem doomed to extinction because of negative human impacts. Fishing: Fishing activities impinge upon sea turtles in all parts of the world. In many parts of the world indigenous people have traditionally captured and eaten sea turtles. Wherever these commercial fisheries occur, conservationists have attempted to allow a minimal take to maintain native tradition with minimal impact on sea turtles. Some countries have recognized that sea turtles constitute a significant population and have initiated and developed sea turtle fisheries. Cuba, for instance, harvests many tons of sea turtles per year. In addition to sea turtle fisheries, sea turtles have also been taken in increasing numbers [paralleling growth in human population and buying power] for curios, medicinal use, and for use in the manufacture of luxury items such as tortoise shell leathers, and other items. The Japanese have been most efficient in finding sources of Hawksbill turtles for use in jewelry and fashion items. Incidental catch from many fisheries are well documented. Trawling activities have been correlated with strandings of dead turtles on beaches around the world, including Georgia. Longline fisheries in the Mediterranean often hook sea turtles which consequently drown, are killed on deck, or are released in damaged condition. Turtles are increasingly being impacted by entanglement in discarded monofiliment line and are ingesting more and more plastic. Turtle Excluding Devices (Teds): The trawler fishery for shrimp in the United States is now required to trawl with Turtle Excluder Devices (TEDs), essentially escape hatches for sea turtles allowing them to escape from the trawl nets before the drown. The drowning or killing on deck of nearly mature sea turtles in, or near breeding age, has been addressed by shrimpers, installing TEDs in their nets (Fig. 39). This implementation of TEDs has been seen as one of the most hopeful conservation measures for sea turtles. Georgia shrimpers are to be applauded for their rapid adoption and use of TEDs. Interactions Homo sapiens: Because of the human population explosion, the advances in fishing and mechanical technology, and the increasingly egregious exploitation of the oceans fisheries, sea turtles have become significantly impacted by humans. In spite of conservation efforts to offset these negative impacts, populations of sea turtles are not only generally on the decline across the world, 29

2 ENDANGERED SPECIES ACT Figure 39 - Shrimp trawlers on the Georgia coast operate effective Turtle Excluder Devices (TEDs) which help decrease the incidental take of sea turtles. Dredging: It has become apparent recently, that dredging activities in shipping channels during seasons of turtle migration have begun taking a toll on adult populations. Efforts are now being made to define seasonal data to protect migrant, mating, and nesting sea turtles from hopper dredging activities. Strandings: Turtles that die or are sick or incapacitated are washed ashore (Fig. 40). These turtles are said to be stranded. The National Marine Fisheries Service operates a network of observers who watch for such strandings, seek help for live stranded turtles, and document dead turtles. Some workers are attempting to salvage skeletal remains for use by researchers in museums around the world. If you find a live turtle stranded on the beach - Report It Immediately - and then attempt to diagnose the problem. If you find a dead turtle on the beach, document it according to the Stranding Report form in Appendix D. Mark the turtle with spray paint, and, if possible, pull it over the dune and proceed into the salvage protocol. All sea turtles are endangered or threatened and fall under protection of the Endangered Species Act and international agreements. Unauthorized taking or harassment of sea turtles, dead or alive, or the taking of their eggs or disturbing of their nests is prohibited. Sea turtle Interns are working under permits granted to the Georgia Department of Natural Resources and granted as scientific collecting permits by the Georgia Department of Natural Resources. While on the Island, please do not act as a sheriff and attempt to interfere with other people s business, simply report unusual activity to Royce Hayes, Nancy Marsh, or Gale Bishop. The Beach as Critical Habitat for Nesting Shorebirds The beaches of the Georgia Coast, particularly those of undeveloped islands, provide nesting and living habitat to many organisms which may be negatively impacted by human presence, even that of a wellintentioned sea turtle intern. Developed areas from Maine to Florida have severely impacted the ability of several species of birds to nest and rear their young. Two species, the Piping Plover and the Least Tern, are now threatened with extinction. The undisturbed habitat provided by undeveloped islands such as St. Catherines provide critical habitat for many organisms including sea turtles and shore birds. Nine species of shore birds have been identified as nesting, or potentially nesting, on St. Catherines Island. One of the two known Georgia Brown Pelican rookeries is located on St. Catherines Bar where approximately 3,000 Brown Pelicans nested, loafed, and slept during Summer Shore birds most likely to be nesting on St. Catherines Island and other Georgia barrier islands include: Table 6. Shorebirds nesting in Georgia Figure 40 - Stranded loggerhead sea turtle on St. Catherines Island. Wilson s Plover Charadrius wilsonia Am. Oystercatcher Haematopus palliatus Willet Catoptrophorus semipalmatus Brown Pelican Pelicanus occidentalis Gull-Billed Tern Sterna nilotica Royal Tern Sterna mamima Sandwich Tern Sterna sandvincensis 30

3 Least Tern Black Skimmer Sterna antillarum Rynchops niger The Terns and Skimmers tend to nest on flat expanses of beach where the colonies, often numbering thousands of pairs in other areas, are extremely vulnerable to storms, spring tides, and humans. On St. Catherines, Terns and Skimmers sometimes nest on the flats at the northeastern tip of the Island [near St. Catherines Ebb Delta] on both sides of Seaside Inlet, McQueens Inlet, and Johnsons Inlet. American Oystercatchers and Wilson s Plovers, the two most common nesting shorebirds on St. Catherines Island, prefer to nest above the wrack line and particularly in the backbeach dunes. Willets have only been recorded nesting on the south side of McQueens Inlet in the high dunes and sedge wetlands to the south of these dunes. Sea turtle interns and researchers need to be aware of nesting birds and ever conscious of their potential deleterious impact on nesting birds. When nesting sites are discovered, they need to be marked on your patrol map and avoided as much as is possible. All these birds nest directly on the sand, except for pelicans, either building no nest at all or simply scooping out a depression in which to nest. Their eggs and chicks are extremely well camouflaged and difficult to see. The best way to identify a nesting site is by behavior and calls of the adults birds. Birds flying close to you, calling loudly, pretending to be injured by hopping or dragging a wing, or standing and allowing a close approach, are probably near a nest or chicks. Adult birds frightened off a nest for a short interval will eventually return. However, eggs left in the hot sun for even brief periods of time will overheat and die. Repetitive disturbances during incubation can lead to nest abandonment and reproductive failure for the season. Raccoons often follow human scent to forage for goodies left behind, so you may inadvertently lead this predator to a nest. If a shorebird nest is found, stay away! As soon as the sun sets, a raccoon may be the next to follow your tracks. Enjoy your work as a sea turtle intern, but please be aware of the incredible diversity of other animals dependent upon the beach ecosystems of the Georgia Coast. PROTOCOL for Human Interactions Protocol for Tours Because many people are interested in sea turtles. you will be asked on occasion to allow visitors to accompany you on evening turtle excursions to observe nesting or hatchling emergence. As a Sea Turtle Intern you are the person in charge, and should control the excursion to protect the turtles. Noise or lights will negatively affect gravid females that have not yet gone into nesting behavior. If you come upon a turtle emerging to deposit eggs, leave her alone. If you come upon a turtle depositing her eggs approach her with caution and respect and try to keep all people under control. Try to minimize noise and flash pictures. On urbanized islands, human-sea turtle interactions are likely to be less controllable and more common. Use common sense with both turtles and humans. Because you will be monitoring deposition of nests, you will know when each was deposited. You can add approximately 60 days to the day of deposition and thus estimate the time of probable emergence. This data can be used to control your presence or absence from specific nests, depending upon conditions or your particular circumstances. Emergent hatchlings apparently orient to beach slope, wave sound, and over the ocean starlight. Any local sources of light will rapidly disorient the hatchlings. We demand that flash pictures and flashlights not be allowed, if you choose to observe an emergence. It would be good to minimize the number of people allowed to observe this phenomenon. Tag Protocols When tags are seen on live turtles, you should record the tag number(s) and measure the carapace length and width, then document the observation in your notebook and transcribe it onto a Stranding Report form and send it in to Georgia DNR clearly marked as live turtle observation. When tags are found on dead turtles, document the stranded corpse on a Stranding Report, mark the turtle with spray paint, and remove the tag(s), reporting them on the Stranding Report. Check all dead stranded sea turtles for flipper tags, pitt tags, and biologic tags. FIELD METHODOLOGIES Beach Grid: The positioning of nests along the Island beaches is a significant parameter of sea turtle nesting behavior. In order to document the position of nests, it is necessary to tie the nest positions to a pre-surveyed beach grid or a GPS grid. A grid was 31

4 established in 1989 and modified in 1991 to accommodate the turtle monitoring survey. Using a 100 meter tape, and later a metric measuring wheel, stations were established at 100 m intervals along the beach and marked with pink flagging and 24 pink stake flags. Initially the stations were simply consecutively numbered from the beach entrance in either direction. This designation was changed in 1991 to number each station from an origin at the south end of the Island to the north end. Beginning at at the south end of the Island, kilometer posts (wood or PVC) were erected in the dunes behind the beach every kilometer along the beach. Between the kilometer markers, every 100 meters was marked with a pink stake flag and flagging tied to a tree, stump, or grass. Each station is identified as to its position relative to the last designated kilometer station + the last designated 100 meter stake + however many meters it is from he last stake. A station numbered is located north of kilometer stake 2, north of 100 m stake number 5, and 32 m north of that stake. Its position, is actually km north of the grid origin and represents a real location which can be plotted as a real number for analysis. Occasionally kilometer stakes, stake flags, or flagged objects are eroded away or disappear for other reasons. These stations can be easily reestablished by surveying them back from nearby stations which may still remain in place. This technique allowed the nests to be located accurately during each nesting season and from year to year. In 1999 we began taking GPS locations and abandoned the time consuming beach grid system. Beach Profiling: The slope of the beach can be easily determined by the following procedure (Sergio Rodriguez, personal communication). 1. Lay out a transect (line) running from the dunes to the low water line oriented perpendicular to the beach line and crossing the station that you are interested in. Profile stations will be marked with a starting point prior to the nesting season. 2. Beginning at the station of interest (kilometer stake, nest, etc..), measure along your line of profile with the tape measure [or measuring wheel] and mark each 10 m along the tape with a stake flag and each major change of topography [beach scarps, dunes, etc.]. 3. Using the two Jacob Staffs, begin at the landward end of your transect by planting the spiked Jacob Staff into the next to the last topographic station in a vertical position. Using the measuring Jacob Staff, place it on the landward station, sight across the top of the lower [seaward] Jacob Staff to the horizon. Read the intercept of the seaward Jacob Staff off the measuring Jacob Staff. This intercept represents a horizontal line from the horizon across the top of the lower [seaward] Jacob Staff onto the higher [landward] Jacob Staff. This intercept is the difference in elevation between the tops [and hence the bottoms] of the higher [landward] and lower [seaward] Jacob Staffs. If a runnel or trough is present, the higher and lower Jacob staff would be reversed and the two rods might have to be reversed [if only one person is available] or the field assistant might have to mark and measure the intercept on the seaward Jacob Staff. 4. Record the intercept on the data form and make a sketch map showing all stations and breaks in slope. Compute and sketch the profile while in the field to provide a check on yourself. Meteorology: One of the variables affecting nesting success is the weather, particularly storms that cool the beach sand. We keep a daily record of meteorological events with the intent of correlating them with erosional events, sudden temperature drops in nest chambers, or other aspects of turtle ecology. As you observe the weather, or are caught up in unusual local storms, please note them in your field notebook with as much detail as seems appropriate. Each days notes should also summarize meteorological conditions such as temperatures, clouds and cloud conditions, rain, fog, or other precipitation, wind direction and intensity and changes, sea conditions such as temperature, wave activity, turbidity, etc. Of particular importance to each of us will be survival. If you are caught in a thunderstorm, you must be especially cognizant of lightening as beaches have few points higher than people and the salt water in the substrate is extremely conductive. If possible, don t put yourself in jeopardy, but if you are, the safest action is to get off the beach into the massive forest and shelter inside your vehicle [with its rubber tires forming an insulator for you]. The best option, if caught far from your vehicle, would be to lie down to reduce your height and lightening attracting potential. The next most hazardous meteorological condition probably to be encountered will be solar radiation. Be sure to either wear clothing covering your skin or use a sun screen product to avoid sunburn and long range effects of exposure. We recommend Clinique oil-free sun screen sold at cosmetic counters at stores like Belk s. Begin your exposure with intensity SPF 15 and short exposures to the sun (Bishop has found 32

5 30 minutes is sufficient). As your melanin builds up you will be able to lengthen your exposure but not reduce your sunscreen. Wind intensity can be estimated using the Beaufort Wind Scale (Thurman 219) Figure - 42 South end of South Beach showing habitats including backbeache, dunes, washover fans, and erosional hammocks. >>>>>>>>>>>> Fig Beaufort Wind Scale and descriptors. 33