Thirty years of leatherback turtle Dermochelys coriacea nesting in Espírito Santo, Brazil, 1988-2017: reproductive biology and conservation

L Vila-Verde,Ac Broderick,Lp Colman,Bj Godley,Jca Thomé,C Baptistotte,Fa Ribeiro,Adp Almeida,Pcr Barata

doi:10.3354/esr00961

Abstract

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 39:147-158 (2019) - DOI: https://doi.org/10.3354/esr00961 Thirty years of leatherback turtle Dermochelys coriacea nesting in Espírito Santo, Brazil, 1988-2017: reproductive biology and conservation Liliana P. Colman1,*, João C. A. Thomé2, Antônio de P. Almeida3, Cecília Baptistotte2, Paulo C. R. Barata4, Annette C. Broderick1, Flávia A. Ribeiro5, Lucas Vila-Verde5, Brendan J. Godley1 1Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, TR10 9EZ, UK 2Centro TAMAR-ICMBio, Vitória, ES, Brazil 29050-335 3ICMBio, Linhares, ES, Brazil 29900-979 4Fundação Pró-Tamar, Salvador, BA, Brazil 41185-135 5Fundação Pró-Tamar, Vitória, ES, Brazil 29050-256 *Corresponding author: l.p.colman@exeter.ac.uk ABSTRACT: In the southwestern Atlantic Ocean, leatherback turtles Dermochelys coriacea are only known to regularly nest in eastern Brazil, on the coast of the state of Espírito Santo. Here, we present an analysis of the nesting ecology, population trends and conservation status of this leatherback turtle colony between 1988 and 2017. We observed an increasing, although variable, trend in the annual number of nests, with the mean increasing from 25.6 nests in the first 5 yr of the study to 89.8 in the last 5 yr. Concurrently, there was also a significant decrease in the mean curved carapace length of the population, which we hypothesize was caused by recruitment of new females to the nesting population. Throughout the study period, nests were concentrated in the southern part of the 160 km long study area. No change was observed in the annual median nesting date. Mean annual hatching success was 66.0% and no significant variation in hatching success was detected after a major spill of mining tailings into the nesting area in 2015. We postulate that local conservation actions that started in the 1980s have contributed to the gentle recovery of this population; however, given the small population size and restricted nesting geographical distribution alongside the persistence of various threats—fisheries bycatch, climate change, pollution and coastal development—this population continues to be of conservation concern. KEY WORDS: Atlantic Ocean · Brazil · Conservation · Dermochelys coriacea · Leatherback turtle · Nesting biology · Population trend · Reproductive parameters Full text in pdf format Supplementary material PreviousNextCite this article as: Colman LP, Thomé JCA, Almeida AdP, Baptistotte C and others (2019) Thirty years of leatherback turtle Dermochelys coriacea nesting in Espírito Santo, Brazil, 1988-2017: reproductive biology and conservation. Endang Species Res 39:147-158. https://doi.org/10.3354/esr00961 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 39. Online publication date: June 27, 2019 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2019 Inter-Research.

Highlights

Leatherback turtles Dermochelys coriacea are highly migratory animals, often moving vast distances between nesting and foraging habitats (James et al 2005, Hays et al 2006, Shillinger et al 2008, Fossette et al 2014, Horrocks et al 2016)
The leatherback turtle is globally classified as Vulnerable by the International Union of Conservation of Nature (IUCN; Wallace et al 2013b)
We aimed to investigate possible effects of the mining incident on this population as well as to address a number of priority research questions (Rees et al 2016), including (1) estimation of the population trend, (2) analysis of reproductive parameters and (3) evaluation of the conservation situation of leatherback turtles nesting in Espírito Santo

Summary

Introduction

Leatherback turtles Dermochelys coriacea are highly migratory animals, often moving vast distances between nesting and foraging habitats (James et al 2005, Hays et al 2006, Shillinger et al 2008, Fossette et al 2014, Horrocks et al 2016). The Southwest Atlantic Ocean subpopulation is known to regularly nest only in eastern Brazil, on the coast of the state of Espírito Santo (Thomé et al 2007). This population, which is regionally classified as Critically Endangered by the IUCN (Wallace et al 2013b) and listed on the Brazilian government’s register of endangered species (Machado et al 2008), is genetically distinct from others in the Atlantic (Dutton et al 2013) and is considered a unique Regional Management Unit (Wallace et al 2010a). Occasional leatherback nests, possibly by turtles from subpopulations other than the Southwest Atlantic Ocean one, are recorded elsewhere along the Brazilian coast (Soto et al 1997, Barata & Fabiano 2002, Loebmann et al 2008, Bezerra et al 2014, Gandu et al 2014)

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