Rediscovering Kemp’s Ridley Sea Turtle (Lepidochelys kempii): Molecular Analysis and Threats

Abstract

Sea turtles are reptiles that have inhabited the earth for 100 million years. These are divided into 2 families (Cheloniidae and Dermochelyidae) and 7 species of sea turtles in the world: the leatherback turtle (Dermochelys coriacea); hawksbill turtle (Eretmochelys imbricata); Kemp’s ridley (Lepidochelys kempii); olive ridley (L. olivacea); Loggerhead turtle (Caretta caretta); flatback sea turtle (Natator depressus) and green turtle (Chelonia mydas). In particular, Kemp’s ridley is included in the red list of IUCN categorized as “critically endangered”. The most important site around the Word is in Rancho Nuevo, Tamaulipas, Mexico. Where 80–95% of the world’s nesting is concentrated. Other nesting areas are Tepeguajes and Barra del Tordo, in Tamaulipas, and with less intensity in Veracruz (Lechuguillas and El Raudal beaches) and South Padre Island, Texas, USA. They deposit an average of about 90 eggs and hatching takes 40 to 60 days. Therefore, they are vulnerable to different anthropogenic activities and sources of pollution, such as heavy metals, which can cause toxic effects that are harmful to the turtles, damage their physiology and health. To understand the real situation about health and genetic parameters it is necessary to analyze biochemical and molecular factors in this species.

Confirmation of significant sea turtle nesting activity on a remote island chain in the Gulf of Mexico

“…Similar trends in Kemp's ridley nesting have been documented. After decades of apparent recovery, Kemp's ridley nesting declined significantly in 2010 and full recovery from that decline remains unclear as do the reasons for the declines (Galloway et al, 2016 ; Reyes‐López et al, 2021 ). Tagging studies in the northern Gulf of Mexico showed that these loggerheads exhibited extremely low nesting site fidelity (Hart et al, 2014 ; Lamont et al, 2014 ).…”

Genetic diversity of immature Kemp's ridley (Lepidochelys kempii) sea turtles from the northern Gulf of Mexico

“…By the mid‐1980s, nest numbers had declined to 700–800 deposited annually (Reyes‐López et al, 2021) and the population was estimated at approximately 300 nesting females (National Marine Fisheries Service, US Fish and Wildlife Service & SEMARNAT, 2011; Bevan et al, 2016). These declines have been attributed primarily to the mortality of Kemp’s ridleys in commercial fisheries and poaching of eggs for human consumption (National Marine Fisheries Service, US Fish and Wildlife Service & SEMARNAT, 2011; Reyes‐López et al, 2021). A bi‐national effort between the US and Mexico (Marquez, 1989), which included establishment of a secondary nesting population at Padre Island National Seashore in southern Texas and required the use of Turtle Excluder Devices on US fishing boats (National Marine Fisheries Service, US Fish and Wildlife Service & SEMARNAT, 2011), is credited with leading the Kemp’s ridley back towards recovery.…”

“…In 1947, more than 40,000 nests were documented in one day on the main nesting beach in Rancho Nuevo, Mexico, and it has been estimated that the population at that time consisted of more than 48,000 nesting females (Bevan et al, 2016). By the mid‐1980s, nest numbers had declined to 700–800 deposited annually (Reyes‐López et al, 2021) and the population was estimated at approximately 300 nesting females (National Marine Fisheries Service, US Fish and Wildlife Service & SEMARNAT, 2011; Bevan et al, 2016). These declines have been attributed primarily to the mortality of Kemp’s ridleys in commercial fisheries and poaching of eggs for human consumption (National Marine Fisheries Service, US Fish and Wildlife Service & SEMARNAT, 2011; Reyes‐López et al, 2021).…”

“…A bi‐national effort between the US and Mexico (Marquez, 1989), which included establishment of a secondary nesting population at Padre Island National Seashore in southern Texas and required the use of Turtle Excluder Devices on US fishing boats (National Marine Fisheries Service, US Fish and Wildlife Service & SEMARNAT, 2011), is credited with leading the Kemp’s ridley back towards recovery. By the 2011–2012 season, approximately 21,000 Kemp’s ridley nests were recorded at Rancho Nuevo (Reyes‐López et al, 2021). A second decline in nest numbers at Rancho Nuevo occurred from 2015 to 2019, when an average of 1,500 nests were documented annually.…”

“…A second decline in nest numbers at Rancho Nuevo occurred from 2015 to 2019, when an average of 1,500 nests were documented annually. However, the 2020 nesting season provided optimism when 15,210 nests were marked (Reyes‐López et al, 2021).…”