Padre Island National Seashore             

Kemp's Ridley Nesting and  Satellite Tracking

Following the Kemp’s ridley on their perilous trek from Padre Island National Seashore, TX, where they are re-establishing a nesting colony, to the Gulf of Mexico, is tricky business. Satellite transmitters are attached to a select number of females returning to the sea after laying eggs, their movements tracked by receivers picking up the signals emitted from their backpacks. This signal tells the scientists where the adults are feeding and resting before making their journey back to the island. The transmitters can last up to 24 months on their backs before failing or falling off. Information from the transmitter/receiver data shows that the turtles are primarily inhabiting shallower waters along the coastline along the Gulf of Mexico, including waters off the state of Tamaulipas, Mexico, and U.S. Gulf Coast states. In addition, necropsies of Kemp’s ridleys washed onshore verify that these adults are primarily feeding on crabs. Just knowing what areas of this Gulf coast that might need special protection is valuable information for wildlife authorities.

The scarcity of Kemp’s ridleys over 20 years ago prompted efforts to re-establish a nesting colony in the United States. From 1978-1988, an international project began with the intent to increase the number of Kemp’s ridley nesting on Padre Island National Seashore. This ambitious program had one grand goal - the conservation and recovery of this ancient sea species. Eggs were airlifted from Rancho Nuevo, Mexico to south Texas, and hatched in controlled conditions, and the resulting hatchlings were released along the south Texas shore of the Gulf of Mexico. Scientists hoped that turtles would eventually return to nest and re-establish a colony at Padre Island National Seashore where protection and care are available. Now, 10 to 15 year old mature Kemp’s ridley females are returning to the south Texas coast to nest. Many are found nesting on Padre Island National Seashore, identified by their coded markings from the hatching program. The first known female to return and nest was in 1996, hatched at Padre Island National Seashore in 1983.  Marked females from this program and other Kemp's ridleys have been nesting in increasing numbers during nearly every year since 1986.

Stretches of beach along the Gulf of Mexico near Rancho Nuevo, Mexico are the primary nesting sites for Kemp’s ridleys. Rancho Nuevo is located in the southern State of Tamaulipas. Prior to the project to re-establish the nesting colony at the National Seashore, a few nested sporadically to the north and south of Rancho Nuevo, on Mustang and Padre Islands, in Texas, and elsewhere in the States of Tamaulipas and Veracruz in Mexico. Known feeding grounds for adult Kemp’s ridley females are in the Gulf of Mexico, including the crab-rich shallow waters off Texas, Louisiana, around the Mississippi Delta, and Tabasco-Campeche, Mexico.

The Chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore led two cooperative studies of the movements of adult male Kemp’s ridley turtles captured by net fishermen in waters off Rancho Nuevo.  Prior to these studies, little was known about the movements, residency, and habitat utilization of adult males.  In the first study, movements of 11 adult males were monitored using satellite telemetry between 1999 and 2001 (Click this hyperlink to view the PDF file of the paper “Movements and Home Ranges of Adult Male Kemp’s Ridley Sea Turtles (Lepidochelys kempii) in the Gulf of Mexico Investigated by Satellite Telemetry”).  The majority of accepted locations were in near-shore waters, in 20 fathoms water depth or less.  One of the 11 turtles traveled northward and was last located offshore from Galveston, Texas, USA.  The other 10 remained within waters off Tamaulipas, Mexico.  To further investigate the possibility of year-round residency off the Rancho Nuevo nesting beach, the movements of 14 adult males captured during the non-nesting season were monitored using satellite telemetry between 2003 and 2005.  Again, most of the accepted locations were in near-shore waters of 20 fathoms water depth or less.  Thirteen of the 14 remained within waters off Tamaulipas, Mexico.  The other turtle traveled southward, offshore from Veracruz, Mexico during the tracking period, but returned to waters off Tamaulipas.  In contrast to previous findings for adult female Kemp’s ridley turtles, these results suggest that a significant proportion of the adult male Kemp’s ridley population may reside in the vicinity of nesting beaches in Tamaulipas, Mexico year-round.  Recovery programs for Kemp’s ridley turtles should incorporate considerations regarding year-round residency of adult males.  Further research is needed to investigate whether adult males also remain resident year-round in waters off south Texas nesting beaches. 

Kemp’s ridleys are not shy about laying their eggs. They amble onshore, dig a nest, and deposit the eggs in broad daylight, very different from other sea turtles that crawl ashore at night to lay their eggs. Also unique to their behavior, females often nest in large numbers at the same time in the same area called an “arribada.” A ridley’s nest will contain around 100 eggs, and research shows that females nest an average of 2.5 times during the same summer, and they prefer the Gulf of Mexico beaches from south Texas through Veracruz, Mexico. Even though sea turtles begin their life on land, they spend most of their life in water. But, for the newly hatched young, the water environment is a whole new world.

Young Kemp’s ridley sea turtles newly hatched from eggs in incubation boxes must make their way to the Gulf for the first time. This first journey is one of the most dangerous activities that the Kemp’s ridley must survive, entering a watery environment, although it is one that their genes are programmed to understand. The open sea, cold water, boat propellers, shrimp trawls, shark nets, and predators are just a few of the perils facing the hatchlings. But, for the Kemp’s ridley, just being a hatchling is a positive step towards population recovery, since successfully hatching eggs was not that common only a few years ago. Eggs are collected from nests discovered by trained people patrolling the Padre Island beaches watching for nesting activity. The eggs located at the National Seashore and northward along the Texas coast are incubated in a National Seashore laboratory under controlled conditions to ensure high survival rates. After hatching, the young ridleys are released on Padre Island National Seashore with the hopes of their return in 10 years or so to nest there, where Kemp’s ridley nesting is already increasing.

Nests from all five species of threatened and endangered sea turtles that nest in the Gulf of Mexico have been documented at the National Seashore.  The Padre Island National Seashore Chief of the Division of Sea Turtle Science and Recovery maintains records of sea turtle nests found on the Texas coast.  She also leads the investigation to determine the results of the effort to re-establish a Kemp's ridley nesting colony at the National Seashore, and to determine sea turtle nesting trends and distribution in Texas.

Various other studies of the nesting Kemp's ridleys and sea turtle eggs are conducted to gather data important to making management decisions and assessing impacts of management efforts.

Research Partners

Protecting Kemp’s ridleys is a cooperative venture of the National Park Service (Padre Island National Seashore), U.S. Fish and Wildlife Service, National Marine Fisheries Service, Texas Parks and Wildlife Department, Mexico’s Procuraduria Federal de Proteccion al Ambiente (PROF EPA), Gobierno de Tamaulipas (SEDUE), Secretaria de Media Ambiente y Recursos Naturales (SEMARNAT), National Fish and Wildlife Foundation, Shell Oil Company Foundation, National Park Foundation, Unilever,  HEART Sea Turtle Restoration Project, University of Texas, University of Charleston, University of Alabama, Norcross Wildlife Foundation, Western National Parks Association, Forever Resorts, H.E.B., Gladys Porter Zoo, Sea Turtle, Inc., and Seaspace.

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