HRI Lecture Series - "Quantifying the effects of nest management and climate change on the Kemp’s ridley sea turtle population demography in Texas"

"Quantifying the effects of nest management and climate change on the Kemp’s ridley sea turtle population demography in Texas"

DR. DONNA SHAVER
CHIEF, DIVISION OF SEA TURTLE SCIENCE AND RECOVERY
TEXAS NESTING COORDINATOR, SEA TURTLE STRANDING AND SALVAGE NETWORK

Kemp’s ridley has been the focus of a bi-national recovery program to save the species from extirpation since 1978. Part of this program was to re-establish a secondary nesting colony of Kemp’s ridleys at Padre Island National Seashore (PAIS) to safeguard against species extinction in the event of a natural or human-caused disaster at the main nesting beach at Rancho Nuevo, Mexico. After more than four decades of conservation action, nesting has increased in Texas and PAIS has more Kemp’s ridley nests than any other US beach. The present study uses an integrated population model (IPM) analysis of the long-term mark recapture dataset (1994–2021) to look at the probability of persistence of the Texas nesting Kemp’s ridleys given specific futures regarding climate change (sea level rise and rising temperatures) and nest management scenarios. The IPM was used to estimate population parameters including adult survival, population growth rate, and abundance of nesting females in Texas. Currently, Texas nests are moved to protected incubation (corral or incubation facility). Analysis showed that future scenarios combining sea level rise where nest management levels included at least some nests moved to protected incubation resulted in stable or increasing growth. Alternatively, scenarios where all nests were left in situ resulted in population stability or decrease and probability of extirpation from Texas greater than 1 (p(N = 0 in 2100) = 0.25–0.73). With continuation of the current management practices, despite uncertainty in forecasted abundance and population growth rates, the IPM predicted stable or increasing population growth rates for the future. The IPM framework provides an example of how management scenarios can be critically evaluated to determine population changes under future environmental uncertainty.

Dr. Donna Shaver is the Chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore. She also serves as the Texas Nesting Coordinator and Coordinator of the U.S. Sea Turtle Stranding and Salvage Network. A leading expert on sea turtles, she has studied Texas sea turtles since 1980 and played a key role in the recovery of the critically endangered Kemp’s ridley sea turtle. She has secured over $14.6 million in funding, expanded the sea turtle program, and standardized data collection in Texas. Her research has influenced conservation efforts, and she has trained hundreds of biologists and volunteers. Recognized with numerous prestigious awards, including the 2021 Texas Distinguished Scientist and the International Sea Turtle Society’s Lifetime Achievement Award, she has also served on key recovery teams and led critical studies, such as the Natural Resources Damage Assessment after the Deepwater Horizon oil spill.