Nearshore neonate dispersal of Atlantic leatherback turtles (Dermochelys coriacea) from a non-recovering subpopulation

Abstract The cryptic ‘lost years’ of sea turtles challenge conservation efforts due to unknown movements and habitat utilisation of young life stages. Behavioural information strengthens dispersal and habitat utilisation models estimating unidentified movements. In this study, leatherback hatchlings were actively tracked with miniature acoustic tags off the east coast of Costa Rica for 83.15 min (± 9.12 SD) to determine their movements and swimming behaviour. Drifters were deployed throughout the tracking process to obtain surface current data. Hatchling (n = 42) over-ground and in-water swimming speed and bearing were calculated. Mean over-ground distance travelled was 2.03 km (± 0.71 km SD) with an over-ground average swim speed of 0.41 m/s (± 0.15 m/s SD). Mean bearing was 108.08° (± 20.19° SD) compared to the 137.56° (± 44.00° SD) bearing of nearshore ocean currents during tracking. Hatchling mean in-water swimming speed was 0.25 m/s (± 0.09 m/s SD). The lower in-water speed suggests hatchlings were advected by the currents, with overall movement strongly influenced by the current direction. This information can be assimilated into broader spatiotemporal distribution models to interpret the influence of directional swimming on ecosystem utilisation and help to achieve informed management decisions across all life stages of the population.

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Gap Filling of the CALYPSO HF Radar Sea Surface Current Data through Past Measurements and Satellite Wind Observations

International Journal of Navigation and Observation ◽

10.1155/2016/2605198 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Adam Gauci ◽

Aldo Drago ◽

John Abela

Keyword(s):

Oil Spills ◽

Surface Current ◽

Radar Data ◽

Current Data ◽

Hf Radar ◽

Sea Surface ◽

Machine Learning Techniques ◽

Learning Techniques ◽

Spatial Coverage ◽

Essential Components

High frequency (HF) radar installations are becoming essential components of operational real-time marine monitoring systems. The underlying technology is being further enhanced to fully exploit the potential of mapping sea surface currents and wave fields over wide areas with high spatial and temporal resolution, even in adverse meteo-marine conditions. Data applications are opening to many different sectors, reaching out beyond research and monitoring, targeting downstream services in support to key national and regional stakeholders. In the CALYPSO project, the HF radar system composed of CODAR SeaSonde stations installed in the Malta Channel is specifically serving to assist in the response against marine oil spills and to support search and rescue at sea. One key drawback concerns the sporadic inconsistency in the spatial coverage of radar data which is dictated by the sea state as well as by interference from unknown sources that may be competing with transmissions in the same frequency band. This work investigates the use of Machine Learning techniques to fill in missing data in a high resolution grid. Past radar data and wind vectors obtained from satellites are used to predict missing information and provide a more consistent dataset.

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Ecology and nest-site selection of leatherback turtles Dermochelys coriacea

Biological Conservation ◽

10.1016/0006-3207(83)90047-2 ◽

1983 ◽

Vol 26 (1) ◽

pp. 47-56 ◽

Cited By ~ 44

Author(s):

N. Mrosovsky

Keyword(s):

Site Selection ◽

Nest Site ◽

Nest Site Selection ◽

Dermochelys Coriacea ◽

Leatherback Turtles ◽

Selection Of

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Large-scale movements and high-use areas of western Pacific leatherback turtles,Dermochelys coriacea

Ecosphere ◽

10.1890/es11-00053.1 ◽

2011 ◽

Vol 2 (7) ◽

pp. art84 ◽

Cited By ~ 72

Author(s):

Scott R. Benson ◽

Tomoharu Eguchi ◽

Dave G. Foley ◽

Karin A. Forney ◽

Helen Bailey ◽

...

Keyword(s):

Large Scale ◽

Western Pacific ◽

Dermochelys Coriacea ◽

Leatherback Turtles

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Satellite tracking highlights difficulties in the design of effective protected areas for Critically Endangered leatherback turtles Dermochelys coriacea during the inter-nesting period

Oryx ◽

10.1017/s0030605308006947 ◽

2008 ◽

Vol 42 (02) ◽

Cited By ~ 28

Author(s):

Matthew J. Witt ◽

Annette C. Broderick ◽

Michael S. Coyne ◽

Angela Formia ◽

Solange Ngouessono ◽

...

Keyword(s):

Protected Areas ◽

Satellite Tracking ◽

Critically Endangered ◽

Dermochelys Coriacea ◽

Leatherback Turtles

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Status of Marine Turtles in British Columbia Waters: A Reassessment

The Canadian Field-Naturalist ◽

10.22621/cfn.v118i1.885 ◽

2004 ◽

Vol 118 (1) ◽

pp. 72 ◽

Cited By ~ 3

Author(s):

Donald F. McAlpine ◽

Stan A. Orchard ◽

Kelly A. Sendall ◽

Rod Palm

Keyword(s):

British Columbia ◽

Marine Environment ◽

Chelonia Mydas ◽

Marine Turtle ◽

Dermochelys Coriacea ◽

Concerted Effort ◽

Leatherback Turtles ◽

Marine Turtles ◽

Green Turtles

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.

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Do leatherback turtles Dermochelys coriacea forage during the breeding season? A combination of data-logging devices provide new insights

Marine Ecology Progress Series ◽

10.3354/meps322259 ◽

2006 ◽

Vol 322 ◽

pp. 259-267 ◽

Cited By ~ 42

Author(s):

AE Myers ◽

GC Hays

Keyword(s):

Breeding Season ◽

Dermochelys Coriacea ◽

Data Logging ◽

Leatherback Turtles

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The Effects of Nest Location and Beach Environment on Hatching Success for Leatherback (Dermochelys Coriacea) and Green (Chelonia Mydas) Sea Turtles on Bioko Island, Equatorial Guinea

10.21203/rs.3.rs-317848/v1 ◽

2021 ◽

Author(s):

Callie A. Veelenturf ◽

Elizabeth M. Sinclair ◽

Peter Leopold ◽

Frank V. Paladino ◽

Shaya Honarvar

Keyword(s):

Green Turtle ◽

Hatching Success ◽

Sea Turtles ◽

Chelonia Mydas ◽

Dermochelys Coriacea ◽

Equatorial Guinea ◽

Leatherback Turtles ◽

Nest Location ◽

Bioko Island ◽

Elevation Range

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.

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