A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela

ABSTRACT Following classical literature in herpetology, we built two five-stage life tables for the endangered hawksbill sea turtle Eretmochelys imbricata in the Gulf of Paria, eastern Venezuela, using data from incidental captures by industrial trawl fisheries from 1991 until 2000, artisanal fisher...

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Autores principales: Balladares,Clemente, Gonzalez,María Fernanda, Rodriguez,Diego
Lenguaje:English
Publicado: Pontificia Universidad Católica de Valparaíso. Facultad de Recursos Naturales. Escuela de Ciencias del Mar 2020
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Acceso en línea:http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-560X2020000500739
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spelling oai:scielo:S0718-560X20200005007392020-11-18A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, VenezuelaBalladares,ClementeGonzalez,María FernandaRodriguez,Diego Eretmochelys imbricata hawksbill fecundity human interventions life tables survivorship Caribbean ABSTRACT Following classical literature in herpetology, we built two five-stage life tables for the endangered hawksbill sea turtle Eretmochelys imbricata in the Gulf of Paria, eastern Venezuela, using data from incidental captures by industrial trawl fisheries from 1991 until 2000, artisanal fisheries effect and regional stranding from 1999 to 2017, and a local conservation project with the nesting females from 2003 to 2018. We estimated the survivorship for the managed, translocated nests, and a portion of the natural in situ nests (≈31%). We used the resultant life graph and matrices to estimate the hawksbills population status in the region and determine differences in population growth rate and elasticity between translocated and in situ nests. Eggs/hatchlings (stage 1) and small juveniles of less than three years old (stage 2), had high mortalities. We controlled stage 1 mortality by translocating nests into a hatchery. The in situ nests suffered almost 88% predation or poaching. Conversely, these non-translocated nests' emergence success was greater than that of managed nests, but overall survivorship was the lower. We propose that fecundity could begin with sub-adults (stage 4) after the 7th year with 60 cm of curved carapace length. Finite rates of increase of both populations, managed and natural, were significantly higher than 1, and that of the managed population is significantly higher than that of the natural one, meaning that both populations would grow and that the managed one would grow faster than the natural one. Then protection of stage 1 is essential to the population of hawksbills in the region, although uncertainties of survivorship of stage 2 and fecundity of stage 4 were not properly confirmed locally. Notwithstanding, elasticity analysis indicated that the population growth rate was more affected by proportional changes in sub-adults and adults' fecundity than any other life-history element.info:eu-repo/semantics/openAccessPontificia Universidad Católica de Valparaíso. Facultad de Recursos Naturales. Escuela de Ciencias del MarLatin american journal of aquatic research v.48 n.5 20202020-11-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-560X2020000500739en10.3856/vol48-issue5-fulltext-2476
institution Scielo Chile
collection Scielo Chile
language English
topic Eretmochelys imbricata
hawksbill
fecundity
human interventions
life tables
survivorship
Caribbean
spellingShingle Eretmochelys imbricata
hawksbill
fecundity
human interventions
life tables
survivorship
Caribbean
Balladares,Clemente
Gonzalez,María Fernanda
Rodriguez,Diego
A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela
description ABSTRACT Following classical literature in herpetology, we built two five-stage life tables for the endangered hawksbill sea turtle Eretmochelys imbricata in the Gulf of Paria, eastern Venezuela, using data from incidental captures by industrial trawl fisheries from 1991 until 2000, artisanal fisheries effect and regional stranding from 1999 to 2017, and a local conservation project with the nesting females from 2003 to 2018. We estimated the survivorship for the managed, translocated nests, and a portion of the natural in situ nests (≈31%). We used the resultant life graph and matrices to estimate the hawksbills population status in the region and determine differences in population growth rate and elasticity between translocated and in situ nests. Eggs/hatchlings (stage 1) and small juveniles of less than three years old (stage 2), had high mortalities. We controlled stage 1 mortality by translocating nests into a hatchery. The in situ nests suffered almost 88% predation or poaching. Conversely, these non-translocated nests' emergence success was greater than that of managed nests, but overall survivorship was the lower. We propose that fecundity could begin with sub-adults (stage 4) after the 7th year with 60 cm of curved carapace length. Finite rates of increase of both populations, managed and natural, were significantly higher than 1, and that of the managed population is significantly higher than that of the natural one, meaning that both populations would grow and that the managed one would grow faster than the natural one. Then protection of stage 1 is essential to the population of hawksbills in the region, although uncertainties of survivorship of stage 2 and fecundity of stage 4 were not properly confirmed locally. Notwithstanding, elasticity analysis indicated that the population growth rate was more affected by proportional changes in sub-adults and adults' fecundity than any other life-history element.
author Balladares,Clemente
Gonzalez,María Fernanda
Rodriguez,Diego
author_facet Balladares,Clemente
Gonzalez,María Fernanda
Rodriguez,Diego
author_sort Balladares,Clemente
title A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela
title_short A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela
title_full A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela
title_fullStr A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela
title_full_unstemmed A matrix population model for the hawksbill sea turtle (Eretmochelys imbricata) in the Gulf of Paria, Venezuela
title_sort matrix population model for the hawksbill sea turtle (eretmochelys imbricata) in the gulf of paria, venezuela
publisher Pontificia Universidad Católica de Valparaíso. Facultad de Recursos Naturales. Escuela de Ciencias del Mar
publishDate 2020
url http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-560X2020000500739
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