scholarly journals A long-term decline in the abundance of endangered leatherback turtles, Dermochelys coriacea, at a foraging ground in the California Current Ecosystem

2020 ◽  
Vol 24 ◽  
pp. e01371 ◽  
Author(s):  
Scott R. Benson ◽  
Karin A. Forney ◽  
Jeffrey E. Moore ◽  
Erin L. LaCasella ◽  
James T. Harvey ◽  
...  
Oryx ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 274-282 ◽  
Author(s):  
Marga L. Rivas ◽  
Carlos Fernández ◽  
Adolfo Marco

AbstractThe leatherback turtle Dermochelys coriacea, the only extant species in its family, is categorized as Vulnerable on the IUCN Red List. The protection of nesting beaches and the associated conservation efforts along the Western Atlantic coast of Central America have improved the population trends of some of the most important rookeries. Here we report the life history, ecology and population trends of leatherback turtles over 18 years (1994–2012, excluding 1998) of effective protection in the Pacuare Nature Reserve, on the Caribbean coast of Costa Rica. A mean density of 142 nests per km, probably the highest in Central America, indicates the importance of this rookery within the Caribbean region. Long-term conservation efforts at the Reserve have significantly reduced poaching and contributed to maintaining a high level of hatchling production. Long-term monitoring has also facilitated estimation of relevant demographic parameters of the population, such as nesting success (mean 69.8 ± SD 7.3%), clutch size (which is positively correlated with female size), hatching success (mean 55.2 ± SD 6.0%), remigration interval (2.5 years), and growth rate of remigrant females (mean 0.3 ± SD 1.0 cm per year), which is slightly faster than growth rates reported for Pacific leatherback turtles. Overall, efforts at Pacuare have been successful in protecting leatherback turtles and understanding their life history, highlighting the importance of long-term conservation projects for maintaining threatened leatherback populations.


Ecosphere ◽  
2011 ◽  
Vol 2 (7) ◽  
pp. art84 ◽  
Author(s):  
Scott R. Benson ◽  
Tomoharu Eguchi ◽  
Dave G. Foley ◽  
Karin A. Forney ◽  
Helen Bailey ◽  
...  

Ecosphere ◽  
2013 ◽  
Vol 4 (2) ◽  
pp. art25 ◽  
Author(s):  
Ricardo F. Tapilatu ◽  
Peter H. Dutton ◽  
Manjula Tiwari ◽  
Thane Wibbels ◽  
Hadi V. Ferdinandus ◽  
...  

2004 ◽  
Vol 118 (1) ◽  
pp. 72 ◽  
Author(s):  
Donald F. McAlpine ◽  
Stan A. Orchard ◽  
Kelly A. Sendall ◽  
Rod Palm

Marine turtles in British Columbia have previously been considered off course stragglers. Here we document 20 new reports for Green Turtles, Chelonia mydas, and Leatherback Turtles, Dermochelys coriacea, for the province. Until recently there had been no concerted effort to acquire data on marine turtle abundance or frequency off British Columbia. Observations presented here allow a reassessment of marine turtle status in British Columbia waters. We suggest Green Turtles and Leatherbacks should be considered rare vagrants and uncommon seasonal residents, respectively, off British Columbia and that they are a natural part of the British Columbia marine environment.


2021 ◽  
Author(s):  
Callie A. Veelenturf ◽  
Elizabeth M. Sinclair ◽  
Peter Leopold ◽  
Frank V. Paladino ◽  
Shaya Honarvar

Abstract Hatching success in sea turtles is hindered by a variety of biotic and abiotic factors. This study of the nesting ecology of leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles, investigated how several environmental factors and beach characteristics on Bioko Island, Equatorial Guinea influence sea turtle reproductive success. Average clutch hatching success was 40.4% for green turtles and 41.73% for leatherback turtles. For leatherback turtles, clutch elevation relative to the high tide line (HTL) was found to be the most influential factor in determining hatching success, highlighting the sensitivity of this species to sea level rise (SLR). Multiple linear regression analysis demonstrated that nest distance to vegetation and sand conductivity also played significant roles in leatherback clutch hatching success. For leatherback clutches, 33% percent of experimental nests were affected by inundation and 17% by predation. An optimum clutch elevation range for leatherback turtles was identified, where a distinct increase in hatching success was observed between -0.286 m to -0.0528 m above the HTL. For green sea turtles, 64% of experimental nests were affected by predation, confounding conclusions about the roles of environmental characteristics in green turtle hatching success. We propose further investigation into influential characteristics in green turtle nests and confirmation of the observed optimum elevation range on Bioko Island and other nesting grounds. Identified sensitivities of each species to SLR and beach characteristics will be used to encourage the government of Equatorial Guinea to consider the vulnerability of their resident turtle populations when planning for future coastal development.


2014 ◽  
Vol 11 (2) ◽  
pp. 2595-2621 ◽  
Author(s):  
T. M. Hill ◽  
C. R. Myrvold ◽  
H. J. Spero ◽  
T. P. Guilderson

Abstract. Deep-sea bamboo corals (order Gorgonacea, family Isididae) are known to record changes in water mass chemistry over decades to centuries. These corals are composed of a two-part skeleton of calcite internodes segmented by gorgonin organic nodes. We examine the spatial variability of bamboo coral organic node 13C/12C and 15N/14N from thirteen bamboo coral specimens sampled along the California margin (37–32° N; 792 to 2136 m depth). Radiocarbon analyses of the organic nodes show the presence of the anthropogenic bomb spike, indicating the corals utilize a surface-derived food source (pre-bomb D14C values of ∼ −100‰, post-bomb values to 82‰). Carbon and nitrogen isotope data from the organic nodes (13C = −15.9‰ to −19.2‰ 15N = 13.8‰ to 19.4‰) suggest selective feeding on surface-derived organic matter or zooplankton. A strong relationship between coral 15N and habitat depth indicate a potential archive of changing carbon export, with decreased 15N values reflecting reduced microbial degradation (increased carbon flux) at shallower depths. Using four multi-centennial length coral records, we interpret long-term 15N stability in the California Current. Organic node 13C values record differences in carbon isotope fractionation dictated by nearshore vs. offshore primary production. These findings imply strong coupling between primary production, pelagic food webs, and deep-sea benthic communities.


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