Sea Turtle Conservation Program
What is Biscayne National Park doing to promote conservation of the loggerhead and other sea turtles?
Every summer, Biscayne National Park conducts a sea turtle nest monitoring project, which aims to survey and monitor sea turtle nesting beaches within the park to protect nests from natural predation and unintentional damage by park visitors. Efforts are concentrated on five beaches that have a long history of nesting activity, but other beaches are also often checked for nesting activity.
In addition to summertime nest monitoring, park staff and volunteers work year-round on habitat restoration activities to improve the quality of nesting beach habitats available to nesting sea turtles. Each day, assorted debris is washed ashore and over time, this debris accumulates on the nesting beaches. Sea turtles can have a difficult time traversing over the increasing amounts of debris on the beach and too much trash makes it hard for sea turtles to find suitable nesting spots. By periodically cleaning the beaches, we improve the quality of nesting grounds for sea turtles and increase the chances of successful nesting events.
What does sea turtle nest monitoring involve?
During turtle nesting and hatching season, Biscayne National Park resource managers and volunteers patrol the beaches daily in search of signs of new nesting activity (e.g. turtle tracks in the sand, evidence of nesting cavities, trampled vegetation). Since loggerhead sea turtles typically nest at night, beach surveys are completed early in the morning in order to more easily identify signs of the previous night's nesting activity. Newly discovered nests are covered with a self-releasing wire mesh screen that prevents raccoons from being able to dig into the nest, but still allows the small hatchlings to get through when it is time and find their way to the ocean. The mesh screen also provides a way to mark the nest to prevent park's visiting beachcombers from accidentally stepping on the nest.
Nesting beaches are consistently monitored from May through October of each year. Efforts are focused on finding new nests during May through August, followed by monitoring hatching activity and completing post-hatchling nest assessments in August through October. Loggerhead nesting peaks in June and July, but can span from May to September. A female can nest more than once during each nesting season.
Baby sea turtles (hatchlings) can emerge as soon as 45 days after the eggs are deposited in a nest. The incubation period might reach 95 days, however, depending on incubation temperature. The nest is monitored closely for hatching activity from Day 45 until evidence of hatchling emergence is found. Hatchlings emerge from the sand and find their way to the sea using the reflection of the moonlight on the ocean to guide them to the water. For this reason, in heavily developed coastal areas with many lights, confused hatchlings often fail to make it to sea because they mistakenly follow lights from inland houses, buildings, and cars. These confused hatchlings are much more vulnerable to predation as well as heat-related mortality.
Sea turtle conservation efforts (nest monitoring and habitat restoration) in Biscayne National Park have been occurring since 1984, and each year, the program is improved. For example, the self-releasing screens are a relatively new idea first applied in 2000. Before then, nest predation by raccoons was reported to be responsible for 100% of the observed nests each season. The percentage of nests predated has remained over 50% since the year 2000, and reached a peak of 75% of predated nests in 2006 when a tropical storm closed the park down for one week, thereby halting monitoring efforts. Predation remains a threat because raccoons, being very numerous and fairly aggressive, actively seek out sea turtle nests and sometimes find a nest before park staff or volunteers can protect it with the mesh screen. The park has now learned that consistent daily monitoring is the best way to reduce predation levels. We are happy to report that in 2007, predation levels dropped to 0%, likely resulting from the frequent and consistent monitoring efforts (six times per week with no storm-related park closures). Based on post-hatchling nest assessments, park staff believe that the successful protection of 100% of nests found in 2007 resulted in about 300 loggerhead hatchlings entering the Atlantic Ocean.
For ways in which you can contribute to sea turtle conservation, click here