Research - Sea turtle catch rates
Catch rate analysis forms the backbone of in-water sea turtle surveys conducted by the MRD. Monitoring changes in catch rates over time complements similar efforts to track trends in annual nest counts on beaches throughout the Southeast U.S., and as such, provides an important gauge for the relative success of conservation efforts since the 1970's.
Because sea turtles collected from coastal habitats are of an intermediate age between hatchling and adult, and because they have surpassed the steepest survival gauntlet , in-water catch rate trends provide a more refined indication of likely near-future nest count trends than simple projection (by ~30 years) of annual nest counts. Furthermore, in the absence of long-term nest count data it may not even be possible to extrapolate near-term nest count trends. For example, loggerhead sea turtles nesting for the first time in 2012 likely hatched around 1982, the first year of standardized "index" nesting beach surveys by the Marine Turtle Conservation Program.
Types of Surveys and Sampling Design Evaluations:
- Observer surveys
- Research surveys, shipping channels
- Research surveys, other coastal waters
- Sampling design evaluations
8 Conant, T.A., Dutton, P.H., Tomoharu, E., Epperly, S.P., Fahy, C.F., Godfrey, M.H., MacPherson, S.L., Possardt, E.E., Schroeder, B.A., Seminoff, J.A., Snover, M.L., Upite, C.M., Witherington, B.E., 2009. Loggerhead sea turtle (Caretta caretta) 2009 status review under the U.S. Endangered Species Act. Report of the Loggerhead Biological Review Team to the National Marine Fisheries Service, 222 p.