scholarly journals Site fidelity, ontogenetic shift and diet composition of green turtles Chelonia mydas in Japan inferred from stable isotope analysis

2014 ◽  
Vol 25 (2) ◽  
pp. 151-164 ◽  
Author(s):  
T Shimada ◽  
S Aoki ◽  
K Kameda ◽  
J Hazel ◽  
K Reich ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Site Fidelity ◽  
Diet Composition ◽  
Isotope Analysis ◽  
Chelonia Mydas ◽  
Ontogenetic Shift ◽  
Green Turtles

Diet and recruitment of green turtles in Fiji, South Pacific, inferred from in-water capture and stable isotope analysis

2020 ◽  
Vol 640 ◽  
pp. 201-213 ◽  
Author(s):  
S Piovano ◽  
GE Lemons ◽  
A Ciriyawa ◽  
A Batibasaga ◽  
JA Seminoff
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Green Turtle ◽  
Isotope Analysis ◽  
South Pacific ◽  
Chelonia Mydas ◽  
Iucn Red List ◽  
Mixing Model ◽  
Green Turtles ◽  
Prey Items

Green turtles Chelonia mydas are listed as Endangered on the IUCN Red List, yet in the South Pacific few conservation-relevant data are available for the species, especially relating to foraging and habitat use. Here, in situ observations and stable isotope analysis (δ13C and δ15N) were used to evaluate green turtle diet and recruitment patterns at Yadua Island and Makogai Island, Fiji. Juvenile green turtles (N = 110) were hand-captured, measured, and sampled. Stable isotope analysis was performed on skin samples and on putative prey items. ‘Resident’ turtles versus ‘recent recruits’ were classified based on their bulk skin tissue isotope values, which were compared with stable isotope values of local prey items and analyzed via cluster analysis. Green turtle diet composition was estimated using MixSIAR, a Bayesian mixing model. Recent recruits were characterized by ‘low δ13C/high δ15N’ values and ranged in curved carapace length (CCL) from 25.5 to 60.0 cm (mean ± SD = 48.5 ± 5.7 cm). Recruitment mostly occurred in summer. Green turtles identified as ‘residents’ had CCLs ranging from 43.5 to 89.0 cm (mean ± SD = 57.4 ± 9.0 cm) and were characterized by ‘high δ13C/low δ15N’ values; mixing model results indicate they fed primarily on invertebrates (40%), fishes (31%), and marine plants (29%). This study confirms the value of seagrass pastures as both an essential habitat and a primary food source for green turtles, and can serve as a baseline for evaluations of natural and anthropogenic changes in local green turtle aggregations.

Diet composition of Saunders's Gull (Larus saundersi) determined using stable isotope analysis at the Shuangtaihekou National Nature Reserve, China

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
王玄 WANG Xuan ◽  
江红星 JIANG Hongxing ◽  
张亚楠 ZHANG Yanan ◽  
陈丽霞 CHEN Lixia ◽  
宋常站 SONG Changzhan ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Diet Composition ◽  
Nature Reserve ◽  
Isotope Analysis ◽  
National Nature Reserve

scholarly journals Satellite tracking and stable isotope analysis highlight differential recruitment among foraging areas in green turtles

2017 ◽  
Vol 582 ◽  
pp. 201-214 ◽  
Author(s):  
PJ Bradshaw ◽  
AC Broderick ◽  
C Carreras ◽  
R Inger ◽  
W Fuller ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Satellite Tracking ◽  
Green Turtles

scholarly journals Stable Isotope Analysis of Ozark Hellbender (Cryptobranchus alleganiensis bishopi) Living and Preserved Museum Tissue Reveals a Shift in Their Generalist Diet Composition

Ecologies ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 187-202
Author(s):  
Waylon Hiler ◽  
Stanley E. Trauth ◽  
Benjamin Wheeler ◽  
Aimee Jimenez ◽  
Milica Radanovic ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Diet Composition ◽  
Isotope Analysis ◽  
Population Declines ◽  
Δ13c And Δ15n ◽  
Cryptobranchus Alleganiensis ◽  
N Isotopes ◽  
Generalist Diet ◽  
Stable Isotope Study

Ozark hellbenders (Cryptobranchus alleganiensis bishopi) have undergone marked population declines across their entire distribution. A variety of ecological life history research has been conducted to determine the cause(s) of the declines. Historically, hellbender diet studies used stomach content examination methods; however, alternative approaches such as less intrusive stable isotope analyses are now options for researchers. The goals of our study were to conduct stable isotope analysis on live and formalin-preserved museum specimen Ozark hellbender tissues to identify diet composition in the Eleven Point and Spring rivers, Arkansas. Also, we used stable isotope analysis to investigate if Spring River hellbender diets have changed over time. We sampled fish, live hellbenders (non-destructively), and formalin-preserved hellbender tissues from museum collections for stable isotope analysis. We sampled crayfish for assemblage composition and stable isotope analysis. The results of our stable isotope study revealed three main findings: (1) there were no statistically significant differences between hellbender δ13C and δ15N values among sites and hellbender stable C and N isotopes were correlated with body length; (2) traditional δ13C versus δ15N bi-plots and trophic discrimination values did not provide complete discernment in hellbender diets; however, Bayesian MixSIAR models revealed hellbenders to be generalists, and (3) the use of δ13C and δ15N values adjusted historic formalin-fixed and ethanol preserved hellbenders matched well with current crayfish and fish stable isotope values based on Bayesian MixSIAR models. These findings provide important diet information and a possible tool to examine dietary patterns from preserved specimens that may be used for hellbender conservation and management.

scholarly journals Stable Isotope Analysis of Specimens of Opportunity Reveals Ocean-Scale Site Fidelity in an Elusive Whale Species

2021 ◽  
Vol 2 ◽  
Author(s):  
Kerri J. Smith ◽  
Clive N. Trueman ◽  
Christine A. M. France ◽  
Jed P. Sparks ◽  
Andrew C. Brownlow ◽  
...  
Keyword(s):  
Population Structure ◽  
Stable Isotope ◽  
Atlantic Ocean ◽  
Stable Isotope Analysis ◽  
North Atlantic ◽  
Site Fidelity ◽  
North Atlantic Ocean ◽  
Isotope Analysis ◽  
Beaked Whale ◽  
Elusive Species

Elusive wildlife are challenging to study, manage, or conserve, as the difficulty of obtaining specimens or conducting direct observations leads to major data deficiencies. Specimens of opportunity, such as salvaged carcasses or museum specimens, are a valuable source of fundamental biological and ecological information on data-deficient, elusive species, increasing knowledge of biodiversity, habitat and range, and population structure. Stable isotope analysis is a powerful indirect tool that can be used to infer foraging behavior and habitat use retrospectively from archived specimens. Beaked whales are a speciose group of cetaceans that are challenging to study in situ, and although Sowerby's beaked whale (Mesoplodon bidens) was discovered >200 years ago, little is known about its biology. We measured δ13C and δ15N stable isotope composition in bone, muscle, and skin tissue from 102 Sowerby's beaked whale specimens of opportunity collected throughout the North Atlantic Ocean to infer movement ecology and spatial population structure. Median δ13C and δ15N values in Sowerby's beaked whale bone, muscle, and skin tissues significantly differed between whales sampled from the east and west North Atlantic Ocean. Quadratic discriminant analysis that simultaneously considered δ13C and δ15N values correctly assigned >85% of the specimens to their collection region for all tissue types. These findings demonstrate Sowerby's beaked whale exhibits both short- and long-term site fidelity to the region from which the specimens were collected, suggest that this species is composed of two or more populations or exhibits a metapopulation structure, and have implications for conservation and management policy. Stable isotope analysis of specimens of opportunity proved a highly successful means of generating new spatial ecology data for this elusive species and is a method that can be effectively applied to other elusive species.

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