Sea Turtle Nesting: What Is Known and What Are the Challenges under a Changing Climate Scenario

Raquel A M São Miguel,Mário J Pereira,Rita Anastácio

doi:10.4236/oje.2022.121001

Abstract

The rate of climate change experienced globally in recent decades may compromise sea turtles’ survival; especially temperature increase, which is particularly fast, impacts life history characteristics, such as temperature-dependent sex determination (TSD), late maturity and sea turtles highly migratory nature. This review aims to identify and summarize the information that has been collected from 2009-2020 in order to aid future empirical studies that seek to fill these and other knowledge gaps, and subsequently assist conservationists in making multilevel decisions to protect sea turtle populations and species. In a summarized way the general knowledge acquired so far on the influence of environmental abiotic and biotic factors on nesting behaviour and hatching, emergence and survival successes of sea turtle hatchlings, was gathered. To accomplish this work, a search on Web of Science, Science Direct, NCBI/PubMed, and Google Scholar was carried out using the terms “sea turtles + climate change”. Published articles in the period 2009-2020 were selected, related to the nesting ecology of 5 species of sea turtles: Caretta caretta, Eretmochelys imbricata, Dermochelys coriacea, Chelonia mydas, Lepidochelys olivacea. Emphasis was also placed on geographical information and on population location (e.g. climatic conditions during the nesting season). These articles (N = 126) were analysed giving relevance to researcher’s data interpretations, comparisons with other researches, and the reached conclusions. An attempt was made to represent all 5 species of sea turtles when selecting articles on each of the environmental factors that influence sea turtle nesting: temperature, humidity, nesting substrate, gases, depth of the nest, sea surface temperature (SST), nest location on the beach, nesting phenology and geographic distribution of nesting habitats. The interaction between these parameters and their consequences on the terrestrial phase of reproduction are presented and discussed.

Highlights

The oldest fossil of sea turtles dates back to more than 120 million years, belonging, a species described under the name of Desmatochelys padillai, a vast group were dermochelyids, and cheloniids are included [1]
Mostly papers, from 2009-2020 on each of the abiotic parameters, temperature, humidity, soil type, gases and microorganisms were sought to give a general idea of what was known so far and to provide a framework on each topic. Those related to climate change were selected and many of them were selected as case studies to support ideas and conclusions throughout the text
It should be noted that some articles (N = 12) outside the 2009-2020 range were used to further clarify specific aspects of sea turtle nesting biology, terms on their ecology or climate/climate change aspects

Summary

Introduction

The oldest fossil of sea turtles dates back to more than 120 million years, belonging, a species described under the name of Desmatochelys padillai, a vast group were dermochelyids, and cheloniids are included [1]. Current changes in climate manifest themselves mainly through the unprecedented warming of air temperature and changes associated with the ocean-atmosphere system [4] Examples of these changes are irregularities in precipitation patterns [6] [7] and the increased intensity and frequency of cyclonic events and storms [8] [9]; sea-level rise (SLR); changes in ocean salinity and pH [10]. Their interconnection and the effect of changes in synergy are even more complex to study

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Conclusion