Utility of carapace images for long-term photographic identification of nesting green turtles

2021 ◽  
Vol 545 ◽  
pp. 151632
Author(s):  
Kohei Tabuki ◽  
Hideaki Nishizawa ◽  
Osamu Abe ◽  
Junichi Okuyama ◽  
Shigeo Tanizaki
Keyword(s):  
2014 ◽  
Vol 162 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Liliana P. Colman ◽  
Ana Rita C. Patrício ◽  
Andrew McGowan ◽  
Armando J. B. Santos ◽  
Maria Ângela Marcovaldi ◽  
...  

2013 ◽  
Vol 93 (7) ◽  
pp. 1991-2002 ◽  
Author(s):  
Maria Corsini-Foka ◽  
Gerasimos Kondylatos ◽  
Elias Santorinios

A total of 209 strandings of sea turtles (152 loggerhead turtles Caretta caretta, 42 green turtles Chelonia mydas, 15 unidentified) were recorded during the period 1984–2011 along the coasts of Rhodes (Aegean Sea, Greece). The proportion of dead to live individuals was different in the two species. Stranded Caretta caretta were larger than Chelonia mydas. The size range of stranded green turtles, usually juveniles, appeared to increase since 2000, including the largest specimens ever observed in Greek waters. For both species, a tendency to strand more frequently on the west coast of the island, along fishing ground areas, was noted. The higher incidence of loggerhead turtle strandings was observed in summer, while more green turtle strandings were documented in winter. Factors involved in the increased trend of stranding records of both species, along with the acceleration of this phenomenon in the last decade, are discussed. Data from Rhodes provide evidence that human activities detrimentally affect mainly larger-sized loggerhead turtles living in shallow waters.


1991 ◽  
Vol 57 (6) ◽  
pp. 1115-1120 ◽  
Author(s):  
Takeshi Umezu ◽  
Mamoru Murai ◽  
Makoto Miki ◽  
Yôji Kurata
Keyword(s):  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7570 ◽  
Author(s):  
Isis Gabriela Martínez López ◽  
Marloes van Den Akker ◽  
Liene Walk ◽  
Marieke M. van Katwijk ◽  
Tjisse van Der Heide ◽  
...  

In the Caribbean, green turtles graze seagrass meadows dominated by Thalassia testudinum through rotational grazing, resulting in the creation of grazed and recovering (abandoned) patches surrounded by ungrazed seagrasses. We evaluated the seagrass community and its environment along a turtle grazing gradient; with the duration of (simulated) grazing as a proxy for the level of grazing pressure. The grazing levels consisted of Short-term (4 months clipping), Medium-term (8 months clipping), Long-term grazing (8 months of clipping in previously grazed areas), 8-months recovery of previously grazed patches, and ungrazed or unclipped patches as controls. We measured biomass and density of the seagrasses and rhizophytic algae, and changes in sediment parameters. Medium- and Long-term grazing promoted a shift in community species composition. At increasing grazing pressure, the total biomass of T. testudinum declined, whereas that of early-successional increased. Ammonium concentrations were highest in the patches of Medium-term (9.2 + 0.8 μM) and Long-term grazing levels (11.0 + 2.2 μM) and were lowest in the control areas (4.6 + 1.5 μM). T. testudinum is a late-successional species that maintains sediment nutrient concentrations at levels below the requirements of early-successional species when dominant. When the abundance of this species declines due to grazing, these resources become available, likely driving a shift in community composition toward a higher abundance of early-successional species.


2018 ◽  
Vol 587 ◽  
pp. 217-234 ◽  
Author(s):  
CN Turner Tomaszewicz ◽  
JA Seminoff ◽  
L Avens ◽  
LR Goshe ◽  
JM Rguez-Baron ◽  
...  

Ecography ◽  
2002 ◽  
Vol 25 (3) ◽  
pp. 352-362 ◽  
Author(s):  
B. J. Godley ◽  
S. Richardson ◽  
A. C. Broderick ◽  
M. S. Coyne ◽  
F. Glen ◽  
...  

2002 ◽  
Vol 80 (7) ◽  
pp. 1299-1302 ◽  
Author(s):  
Graeme C Hays ◽  
Annette C Broderick ◽  
Fiona Glen ◽  
Brendan J Godley

Female green sea turtles (Chelonia mydas) nesting at Ascension Island (7°57'S, 14°22'W) in the middle of the Atlantic Ocean had a mean body mass (post oviposition) of 166.3 kg (range 107.5–243.5 kg, n = 119). Individuals lost mass slowly during the nesting season (mean mass loss 0.22 kg·d–1, n = 14 individuals weighed more than once). Gut-content analysis and behavioural observations indicated a lack of feeding. Females of equivalent-sized pinniped species that also do not feed while reproducing (nursing pups) on islands lose mass about 17 times faster. This comparatively low rate of mass loss by green turtles probably reflects their ectothermic nature and, consequently, their low metabolic rate. We estimate that a female turtle would lose only 19% of her body mass during the 143-day, 4400-km round trip from Brazil if she did not eat, laid 3 clutches of eggs, and lost 0.22 kg·d–1.


2021 ◽  
Vol 8 ◽  
Author(s):  
Lyndsey N. Howell ◽  
Donna J. Shaver

Knowledge of green turtle (Chelonia mydas) foraging ecology in the northwestern Gulf of Mexico (GOM) is critical as populations begin to recover from heavy harvesting in prior centuries. We present a comprehensive long-term assessment of green turtle diets from carcasses salvaged from 1987 to 2014 along the Texas coast. Digestive tract contents were examined from 420 green turtles, ranging in size from 7.3 to 86.0 cm in straight carapace length (SCLmax). Green turtles as small as 16.2 cm SCLmax recruit from the oceanic environment to nearshore foraging habitat in the northwestern GOM and consume macroalgae principally. A successive shift in diet and habitat to inshore seagrasses was evident by the seagrass-dominated diet of turtles larger than 30 cm SCLmax. Animal matter remained a frequently ingested diet item suggesting these immature green turtles are better classified as omnivores. The overall evidence indicates that Texas’ recovering green turtle assemblage is exhibiting foraging plasticity within seagrass meadows changing species composition and density.


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