Pacific Turtle Tracks: Grupo Tortuguero
Grupo Tortuguero Tracking Project

Dataset credit

Data provider
Grupo Tortuguero Tracking Project
Originating data center
Satellite Tracking and Analysis Tool (STAT)

Contacts

RoleNameOrganization 
Primary contact Wallace Nichols Grupo Tortuguero Tracking Project
Data entry Michael Coyne seaturtle.org

Citation

Abstract

The oceanic movements of loggerhead turtles (Caretta caretta), green turtles (Chelonia mydas), and a Pacific ridley turtle (Lepidochelys olivacea) were monitored with satellite telemetry between 1996 and 2001 in the Pacific Ocean. During this time several turtles migrated across the Pacific Ocean, covering more than 11,500 km between Santa Rosaliita, Baja California, Mexico (28 40N, 114 14W), and Sendai Bay, Japan (37 54N, 140 56E). These findings are consistent with the hypothesis that loggerheads feeding in the eastern Pacific eventually return to nest on western Pacific beaches. Baja California loggerhead turtles have been shown, through molecular genetic analysis (Bowen et al. 1995) and flipper tag returns (Uchida and Teruya 1988, Resendiz et al. 1998), to be primarily of Japanese origin. We conclude that loggerhead turtles are capable of transpacific migrations and propose that the band of water between 25 and 30 degrees North latitude, the Subtropical Frontal Zone, may be an important transpacific migratory corridor. Recent findings (Polovina et al. 2000) indicate that juvenile loggerheads in the North Pacific move westward against weak (0.1-0.3 km/hr) eastward geostrophic currents, demonstrating that passive drift may not entirely explain the dispersal of loggerheads.

Juvenile loggerhead turtles, Caretta caretta, in the 20 - 85 cm straight carapace length (SCL) size range have been observed in the offshore waters along the Pacific coast of California, USA, and the Baja California peninsula, Mexico (Pitman 1990, Nichols, in press). Bartlett (1989) suggested that these turtles might be of western Pacific origin, migrating 10,000 km and feeding on pelagic red crabs (Pleuroncodes planipes) along the Baja California coast. Subsequently, Pacific loggerheads appear to utilize the entire North Pacific during the course of development in a manner similar to Atlantic loggerheads' use of the Atlantic Ocean (Bolten et al. 1998). After a period of more than 10 years (Zug et al. 1995), mature turtles evidently cross the Pacific Ocean from pelagic waters and foraging areas along the Baja California coast to return to natal beaches, a journey of more than 12,000 km in each direction. This is the first effort to document pelagic movements of North Pacific loggerheads from feeding grounds to nesting areas using satellite telemetry. Previous telemetry studies of loggerhead turtles have documented post-reproductive movements (Stoneburner 1982), pelagic movements (Polovina et al. 2000), home ranges (Renaud and Carpenter 1994), navigational abilities (Papi et al. 1997) and homing behavior (Luschi 1996). However, few studies of sea turtles have documented pre-nesting movements from feeding grounds to breeding areas. Notably, Renaud and Landry (1996) documented movement of a Kemp's ridley turtle (Lepidochelys kempii) from feeding grounds in Louisiana, USA, to its successful nesting in Rancho Nuevo, Mexico. A unique opportunity to track the movements of an adult-sized loggerhead turtle, rarely encountered along the Baja California coast, emerged in 1996. The turtle had been raised in captivity and used in the initial genetic analysis of Baja California loggerhead turtles (Bowen et al., 1995). Its mature size (Kamezaki and Matsui, 1997), genetic affinities with Japanese turtles, and the existence of a previous tag return from Japanese waters of a captive-raised, Baja California loggerhead turtle (Resendiz et al., 1998) were the deciding factors in choosing this particular turtle for the study. This turtle is included in the dataset as series 7667, named Adelita. The objective of the study was to monitor the oceanic movement, using satellite telemetry, of a Pacific loggerhead turtle initially captured on feeding grounds along the Baja California coast. Movement data also were examined with respect to oceanographic and meteorological information in an effort to gain insight into the navigational cues that guide adult sea turtles and to identify possible transpacific movement corridors.

Purpose

The objective of the study was to monitor the oceanic movement, using satellite telemetry, of a Pacific loggerhead turtle initially captured on feeding grounds along the Baja California coast. Movement data also were examined with respect to oceanographic and meteorological information in an effort to gain insight into the navigational cues that guide adult sea turtles and to identify possible transpacific movement corridors.

Supplemental information

Visit STAT's project page for additional information.

References

Attributes

Overview

Attributes described below represent those in the original dataset provided by the provider.
Only minimum required attributes are visible and downlodable online. Other attributes may be obtained upon provider's permission unless otherwise noted below.

Attributes in dataset provided

Attribute (table column)Description
project_idSTAT Project ID
prognumProgram number
tag_idPTT ID
datetime_utcDate and time in UTC
lcLocation class
iqQuality indicator
latitudeLatitude 1
longitudeLongitude 1
dir1Dir 1
nb_mesNumber of messages received
big_nb_mesdefinition not provided
best_levelBest signal strength in dB
pass_durationPass duration in seconds
nopcNumber Of Plausibility Checks successful (from 0-4)
calcul_freqCalculated frequency
altitudeAltitude used for location calculation
sensorsSensors
speciesSpecies name
sp_tsnITIS Taxonomic Serial Number
lc_filterParameters to location filtering
speed_filterParameters to speed filtering
distance_filterParameters to distance filtering
topo_filterParameters to topo filtering
time_filterParameters to time filtering
angle_filterParameters to angle filtering
life_stageLife stage of the animal
genderGender of the animal
wetdryWet or dry
wetdry_filterParameters to Wet or dry filterint
obs_datetimeDate and time (local time zone)
timezone_hTime difference from UTC
obs_countAnimal count (always 1)
OBIS-SEAMAP ID317
Seabirds0
Marine mammals0
Sea turtles2,234
Rays and sharks0
Other species0
Non spatial0
Non species0
Total2,234
Date, Begin1996-08-17
Date, End2001-08-29
Temporal prec.111111
Latitude11.38 - 39.84
Longitude140.92 - 273.92
Coord. prec.3 decimal digits
PlatformTag
Data typeTelemetry location
TracklinesYES (ID: 319)
Contr. throughSatellite Tracking and Analysis Tool
Registered2006-07-09
Updated2017-07-14
StatusPublished
Sharing policy Permission required
Also availalbe from None
See metadata in static HTML
See metadata in FGDC XML
See download history / statistics
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