Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.

Mass strandings of juvenile Kemp's ridley sea turtles (Lepidochelys kempii) occur annually on the shores of Cape Cod, Massachusetts, USA, during the months of Oct-Dec. Strandings have increased from dozens to hundreds per year in the past two decades, challenging recovery and management of this...

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Main Authors: Kathleen E Hunt, Elizabeth A Burgess, Constance Merigo, Adam E Kennedy, Danielle Dillon, C Loren Buck, Jodie Treloar, Katherine Graham, Simran Chambers, Teagan Tinuviel, Rosalind M Rolland, Charles Innis
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0325265
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author Kathleen E Hunt
Elizabeth A Burgess
Constance Merigo
Adam E Kennedy
Danielle Dillon
C Loren Buck
Jodie Treloar
Katherine Graham
Simran Chambers
Teagan Tinuviel
Rosalind M Rolland
Charles Innis
author_facet Kathleen E Hunt
Elizabeth A Burgess
Constance Merigo
Adam E Kennedy
Danielle Dillon
C Loren Buck
Jodie Treloar
Katherine Graham
Simran Chambers
Teagan Tinuviel
Rosalind M Rolland
Charles Innis
author_sort Kathleen E Hunt
collection DOAJ
description Mass strandings of juvenile Kemp's ridley sea turtles (Lepidochelys kempii) occur annually on the shores of Cape Cod, Massachusetts, USA, during the months of Oct-Dec. Strandings have increased from dozens to hundreds per year in the past two decades, challenging recovery and management of this critically endangered species. Most stranded turtles are suffering from "cold-stunning", a life-threatening hypothermia-like condition, and are brought to nearby marine animal veterinary clinics for treatment and rehabilitation. Though most individuals survive, some mortality does occur, and even among surviving turtles there can be prolonged deficits in health and behavior. Previous studies have indicated that upon admission, the adrenal stress hormone corticosterone is elevated approximately an order of magnitude above presumed baseline, while plasma thyroxine is often undetectable, suggesting that these two hormones show promise as markers of recovery from cold-stunning. In this prospective study, 106 cold-stunned Kemp's ridleys were monitored during rehabilitation, with serial blood sampling at 0, 3, 7, 18, 30, 60 and 80 days post-admission to compare plasma concentrations of corticosterone and thyroxine to mortality, mass gain, feeding and activity. Corticosterone and thyroxine normalized in 88% of turtles by approximately day 18, but 12% showed persistent elevations of corticosterone (typically 2-3x above baseline), and persistently low thyroxine. Elevated corticosterone at day 18 was found to be predictive of mortality after day 18. The endocrine profile of high corticosterone and low thyroxine is also associated with lower rates of gain in body mass over time and reduced feeding. As prolonged deficits in growth affect body size at release, low mass gain may affect the predation risk on these juvenile turtles subsequent to release. These results suggest that endocrine biomarkers are useful for monitoring recovery of turtles in rehabilitation, and that growth rates and mass gains during rehabilitation may warrant further investigation.
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spelling doaj-art-9d3d562dbca4443bbddf4bed501b837a2025-08-20T03:47:13ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01206e032526510.1371/journal.pone.0325265Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.Kathleen E HuntElizabeth A BurgessConstance MerigoAdam E KennedyDanielle DillonC Loren BuckJodie TreloarKatherine GrahamSimran ChambersTeagan TinuvielRosalind M RollandCharles InnisMass strandings of juvenile Kemp's ridley sea turtles (Lepidochelys kempii) occur annually on the shores of Cape Cod, Massachusetts, USA, during the months of Oct-Dec. Strandings have increased from dozens to hundreds per year in the past two decades, challenging recovery and management of this critically endangered species. Most stranded turtles are suffering from "cold-stunning", a life-threatening hypothermia-like condition, and are brought to nearby marine animal veterinary clinics for treatment and rehabilitation. Though most individuals survive, some mortality does occur, and even among surviving turtles there can be prolonged deficits in health and behavior. Previous studies have indicated that upon admission, the adrenal stress hormone corticosterone is elevated approximately an order of magnitude above presumed baseline, while plasma thyroxine is often undetectable, suggesting that these two hormones show promise as markers of recovery from cold-stunning. In this prospective study, 106 cold-stunned Kemp's ridleys were monitored during rehabilitation, with serial blood sampling at 0, 3, 7, 18, 30, 60 and 80 days post-admission to compare plasma concentrations of corticosterone and thyroxine to mortality, mass gain, feeding and activity. Corticosterone and thyroxine normalized in 88% of turtles by approximately day 18, but 12% showed persistent elevations of corticosterone (typically 2-3x above baseline), and persistently low thyroxine. Elevated corticosterone at day 18 was found to be predictive of mortality after day 18. The endocrine profile of high corticosterone and low thyroxine is also associated with lower rates of gain in body mass over time and reduced feeding. As prolonged deficits in growth affect body size at release, low mass gain may affect the predation risk on these juvenile turtles subsequent to release. These results suggest that endocrine biomarkers are useful for monitoring recovery of turtles in rehabilitation, and that growth rates and mass gains during rehabilitation may warrant further investigation.https://doi.org/10.1371/journal.pone.0325265
spellingShingle Kathleen E Hunt
Elizabeth A Burgess
Constance Merigo
Adam E Kennedy
Danielle Dillon
C Loren Buck
Jodie Treloar
Katherine Graham
Simran Chambers
Teagan Tinuviel
Rosalind M Rolland
Charles Innis
Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.
PLoS ONE
title Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.
title_full Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.
title_fullStr Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.
title_full_unstemmed Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.
title_short Relationships of corticosterone and thyroxine with mortality, mass gain, feeding and activity in Kemp's ridley sea turtles (Lepidochelys kempii) recovering from cold-stunning.
title_sort relationships of corticosterone and thyroxine with mortality mass gain feeding and activity in kemp s ridley sea turtles lepidochelys kempii recovering from cold stunning
url https://doi.org/10.1371/journal.pone.0325265
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