Protecting Sea Turtles
Transcript( music ) Hello! My name is Meghan Balling. I’m a biologist in the Fish and Wildlife Inventory and Monitoring Program under the division of Resource Management at Biscayne National Park. Today, we will be taking a walk through the season in the life of a nesting sea turtle here in Biscayne. I hope you enjoy the footage, and at the end be sure to find out what you can do to help preserve these majestic animals. ( music ) Biscayne National Park was founded in 1968 and stretches 22 miles along the southeastern coastline of Florida. It is one of only two national parks in the United States comprised of 95% submerged resources. The park encompasses a diversity of ecosystems including coral reefs, seagrass beds, mangroves and hardwood hammock. It is home to a vast array of flora and fauna including many threatened and endangered species, such as the West Indian manatee, eastern indigo snake, American crocodile, Schaus' swallowtail butterfly, and 5 species of sea turtle. It has become the mission of park rangers to preserve and protect these natural resources and provide educational and environmentally friendly recreational activities for visitors. There are 7 species of sea turtles found throughout the world, 5 of which we see right here in Biscayne National Park. They are the Leatherback, Green, Hawksbill, Loggerhead, Kemp’s Ridley, Olive Ridley and the Flatback. The Olive Ridley and Flatback are only found in Pacific waters. Most sea turtles live to be around 50-80 years old, but are known to live even longer. These animals usually reach sexual maturity between 15-25 years of age, at which point they lay eggs every 2-4 years with up to 7 nests in a single season. In each of those nests 50-150 eggs are deposited, depending on species. The location of the nest is important and will determine the sex ratio of the offspring. During the two month incubation period, nests laid in full sun will reach higher ambient temperatures, resulting in greater numbers of female hatchlings. After a short juvenile stage in the shallows, sea turtles are pelagic and highly migratory, regularly traveling thousands of miles between cooler feeding grounds and warmer nesting grounds and exhibit various levels of philotropy, whereby mothers return to the same beach they hatched on to lay their eggs. There is a growing need for sea turtle conservation worldwide. Currently, all 7 species of sea turtle are listed under the Endangered Species Act. It is illegal to hunt most species in many countries, and many more areas are trying to implement regulations, but it seems that in some areas the local culture supersedes the law and traditional people still hunt the way their forefathers did. Sea turtles and their eggs are still harvested worldwide as a chief source of protein for coastal people. They are harvested for a number of other uses including tortoiseshell, a decorative ornamental material made from the scutes of Hawksbill turtles, which is highly coveted in Japan, China, Greece and Rome, and their skin, commonly used to make boots and other leather goods in Mexico. Other threats to turtles include entanglement in fishing gear, ingestion of litter and debris, coastal development and loss of nesting beaches and feeding habitat as well as boat injuries. Even with all the challenges facing these animals, they spend their days making beaches safer for human visitors by eating jellyfish. These venomous Cnidarians are not only a nuisance to swimmers but also to fisherman, whose catch is directly affected by how many larval fish are eaten by jellies before they reach harvestable size. Like the rest of the world, here in Biscayne the number of sea turtles that frequent our beaches is decreasing in number due to slow maturity and low survivorship. Even in the last few decades that Biscayne has been surveying turtle nesting beaches, the number of successful nests and the hatch success rate has decreased. On average, 1/1,000 to 1/10,000 eggs will develop into a reproductive adult. To put this into perspective, if there was no predation and 100% hatch success in Biscayne in any given nesting season, one mature adult would result. Biscayne’s Sea Turtle Protection Program began in 1980. Since then, surveying turtle beaches has been carried out with increasing frequency on Elliott Key. Green and hawksbill turtles are frequently seen around these nesting beaches, but to date only Loggerhead nestings have been recorded. Our turtle nesting season begins in late April and continues on until mid-October when the last nests are being excavated, with peak nesting in June-July. Park rangers are now doing a better job of inhibiting predation, but the numbers of hatchlings thought to be entering the Atlantic are still down from previous years. The number of false crawls this year far exceeds anything seen in the past. This may be an indication that nesters are becoming more discriminating with respect to nesting grounds or possibly that they are being disturbed during the act, suggesting possible predators nearby. The 11 beaches surveyed in Biscayne constitute a 1.9 mile stretch of nesting habitat, but the terrain is far from ideal. For anyone that has seen and compared these nests to those found on Ft Lauderdale or other nearby beaches, it is clear either that philotropy is a driving force or that our loggerheads are gluttons for punishment carrying themselves up over the sharp rocks, over the debris and through the dense vegetation in order to give the next generation a fighting chance. Before the season begins, Biscayne park rangers are accompanied by Alternative Spring Break students as well as our seasoned volunteers and interns to help clear the beaches of debris before nesting begins. Garbage accumulated on the beaches is removed in order to clear the beaches for the upcoming nesting activity. Marine pollution is truly a worldwide problem. Many of the items washing ashore on our beaches come from countries all over the world. What we’re looking for these crawls is freshly disturbed vegetation near the waterline. Since they are usually so close to the high tide line, we don’t usually get to see the turtle tracks left by the nesting mother, but by the time they are large enough to procreate and reproduce, they’re large enough to leave unmistakable prints left in the vegetation. ( waves ) What we usually see at the high tide line is a depression in the vegetation, approximately 1-2 meters wide, pressed down in two directions: one where the turtle came in, and one where the turtle went back out. As we move further inland, we’ll see a depression, or “body pit” made in the sand. This is an attempt by the nesting female to pull out all the surrounding vegetation before she digs a hole. In some cases this is all we’ll see, in other cases it’s clear there was an attempt to dig because there will be sand spray on the surrounding vegetation. From the amount of trash and debris that wash up on these beaches shortly after a beach cleanup event, its not difficult to see how turtles might have a hard time finding suitable nesting ground through these anthropogenically-induced barricades. ( waves ) Finally, we have noticed a great deal of raccoon tracks nearby all of the areas surveyed. Since raccoons are a recognized predator of sea turtle eggs and hatchlings, efforts have been made to remove as many as possible from nesting areas. However, with each new rain come fresh tracks in the sand, indicating that even if raccoons don’t impede nesting they may be awaiting the hatch and their numbers have been exploding likely due to receiving handouts from Elliott Key campers. When we find a crawl, we dig around in the areas we think they eggs may be buried. The terrain doesn’t always make this an easy task, but we dig by hand to make sure that we don’t damage any eggs and can successfully place the protective screen directly over the hole. This is where we place the screens and stake them in place over the nest area. You can see that there is a large screen with large mesh, and a small screen with finer mesh attached to it. The small screen is there initially to prevent raccoons from digging at the nest and is removed after 45 days. The large screen functions to prevent predation also, but has mesh large enough that the hatchlings can fit though and is left in place until the excavation date. The nests are checked daily and screens are modified or improved if there is attempted predation. The incubation period is usually about 60 days, so when we are reasonably sure every egg has hatched that was going to hatch, we excavate the nests after 70 days to determine the success. We count the number of hatchlings and empty, fully emerged from, eggshells, pipped eggs, these are the eggs which have small holes where the egg tooth has pierced the shell but the baby has failed to emerge, undeveloped eggs and predated eggs to determine the hatching and emergence success of the nest. We also document the location of the nest. As we mentioned before the temperature of the nest will determine the sex ratio of the offspring with nests in full sun generating a higher percentage of females. Additionally, we document if the nest failed for any obvious reasons including environmental conditions like hurricanes and inundations by high tides, predation or nest disturbance and poor location choice by mothers. For example, if the nest is too close to high tide or highly populated areas where ambient light confuses the babies’ march to the sea the nests tend to be less successful. No one knows what the future holds for these endangered animals but Biscayne is seeking to raise awareness of the situation and educate visitors about how they can contribute to the success of sea turtles in the park. Here are some things YOU can do to help protect these beautiful animals from extinction: Know your ocean. Use up-to-date nautical charts and stay away from shallow areas where sea turtles have no way to avoid an oncoming craft. Make sure you have someone on your boat looking for sea turtles or other animals resting on the surface to avoid collision. Be careful with fishing gear and free any turtles as quickly and carefully as possible to avoid drowning or injury. Throw away all garbage and debris into approved receptacles, especially plastic bags! Every year, rehabilitation centers see cases where sea turtles ingest all kinds of trash that makes them sick or kills them. As a general rule, pick up at least one piece of garbage, even if it’s not yours, every time you go to the beach. It may save a life. Do not purchase souvenirs or other items that are made from sea turtles or their parts. This will eliminate the need to poach. Turn your lights off at night if you live by the coast during nesting season between May-November. This will allow the hatchlings to make it safely to the ocean rather than into oncoming traffic. If you see an injured or stranded turtle contact the Sea Turtle Stranding and Salvage Network. Information can be found on the NOAA Southeast Fisheries Science Center website. Please visit us at www.nps.gov/bisc for more information about our 2011 turtle nesting season and about planning your visit to Biscayne National Park. I’m Meghan Balling and thanks for watching. ( music )
Protecting Sea Turtles in Biscayne National Park. Hosted by Meghan Balling.