Hawksbill Sea Turtle (Eretmochelys imbricata) Blood and Eggs Organochlorine Pesticides Concentrations and Embryonic Development in a Nesting Area (Yucatan Peninsula, Mexico)

Abstract

Environmental contaminants with chemical origins, such as organochlorine pesticides (OCPs) have major impacts on the health of marine animals, including sea turtles, due to the bioaccumulation of those substances by transference throughout the food chain. The effects of environmental pollution on the health of marine turtles are very important for management strategies and conservation. During recent decades, the south Gulf of Mexico and the Yucatan Peninsula have suffered from increasingly frequent disturbances from continental landmasses, river systems, urban wastewater runoff, port areas, tourism, industrial activities, pesticides from agricultural use, and other pollutants, such as metals, persistent organic pollutants (POPs) and hydrocarbons (from the oil industry activities), which contaminate water and sediments and worsen the environmental quality of the marine ecosystem in this region. In this study, we assessed the concentrations of OCPs in the blood and eggs of 60 hawksbill turtles (Eretmochelys imbricata) nesting at the Punta Xen turtle camp, and their effects on the nesting population’s reproductive performance: specifically, maternal transfer and embryonic development were analyzed. Hematologic characteristics, including packed cell volume, white blood cell count, red blood cell count, and haemoglobin levels, and plasma chemistry values, including creatinine, blood urea nitrogen, uric acid, triglyceride, total cholesterol and glucose, were also measured. The general health of the turtles in this study, as well as their levels of urea, serum creatinine, glucose, uric, acid, cholesterol, and triglyceride, fell within normal ranges and was similar to other normal values, which could indicate the turtles’ good energy levels and body conditions for nest-building activity, with all of the turtles able to successfully come ashore to nest. All the same, the obtained results also indicate that OCPs affect the nesting and reproductive performance of the hawksbill turtles, as well as their fertility and the development of the population of eggs and reproductive performance, specifically in terms of maternal transference and embryonic development. There were significant differences in the concentrations of OCPs (ΣHCHs and ΣDienes) between maternal blood and eggs, indicating that these chemicals are transferred from nesting females to eggs and, ultimately, to hatchlings. OCPs may, therefore, have an effect on the health and reproductive performance of hawksbill turtles, both in terms of their fertility and egg development. Conservation strategies need to be species-specific, due to differences in feeding, and address the reasons for any decline, focusing on regional assessments. Thus, accurate and comparable monitoring data are necessary, which requires the standardization of monitoring protocols.

Fibropapillomatosis: A Review of the Disease with Attention to the Situation Northern Coast of Brazil

“…To prevent and control FP, it is necessary to prevent pollution, habitat degradation, and other human activities that can weaken sea turtle immune systems and increase their susceptibility to FP [ 7 , 8 , 9 , 10 ]. Moreover, implementing quarantine and biosecurity measures in sea turtle rehabilitation facilities and captive breeding programs to prevent the spread of FP, along with educating the public about the importance of sea turtle conservation and the risks of FP to help reduce human activities that can contribute to the spread of the disease are prospective solutions to curb the prevalence of FP [ 12 , 33 , 40 ].…”

“…This finding justifies the maintenance of conservation and monitoring programs for all species of sea turtles that occur off the Brazilian coast [ 3 , 4 , 5 ]. There are several factors that pose risks to sea turtles, such as incidental fishing, the ingestion of solid waste, interactions with fishing gear or boats, parasitic diseases, and fibropapillomatosis (FP), which is a debilitating disease of multifactorial nature that can be fatal [ 6 , 7 , 8 , 9 , 10 ]. Even with the efforts of the TAMAR-ICMBio Project and several other entities that continue to work and provide information on these animals along the Brazilian coast, there are still gaps in knowledge about the occurrence and health status of these species in some coastal regions, particularly in the northern region of the country [ 11 ].…”

Assessing and Screening of Female Fertility in Artificially Bred Asian Yellow Pond Turtles (Mauremys mutica) Based on Parentage Assignment

“…Fecundity is an important component of physical fitness in spawning-type animals [6]. Nutrition [7], living environment [8,9], population density [10], age [11] and genetic determinants [12] are the main factors influencing their fertility. Under conditions of artificial breeding, nutrition and management, variation in fecundity is largely influenced by individual genetics.…”