Loggerhead turtle movement off the coast of Taiwan

NOAA Pacific Islands Fisheries Science Center (PIFSC)

Satellite tags were attached to 34 non-reproductive loggerhead turtles (Caretta caretta) caught as bycatch in the Taiwanese coastal poundnet fishery from 2002 to 2008. Transmission durations ranged from 6 to 503 d (median 172 d), with 5860 d tracked in total. Horizontal track data were processed using the Bayesian state-space modelling to extract the most likely daily positions, taking into account ARGOS data quality and other forms of statistical error. A region of high occupancy in the East China Sea, covering 433 549 km2 of coastal and pelagic area next to Taiwan, China, Japan, and South Korea, was characterized from the tracking data. Various attributes of this hotspot are described using satellite tracks and remotely sensed data. The tracks were merged with oceanographic data, emphasizing a new global dataset characterizing mesoscale eddies from satellite altimetry data. A proximity-probability approach coupled with odds ratio testing was used to infer orientation to eddy features. Comparisons against random points, simulated particle tracks, and drifter buoys were used to demonstrate turtle differential responses to eddies inside and outside the hotspot, depending on eddy features (i.e. cyclonic vs. anticyclonic, edges vs. centres). Turtles inside the hotspot utilize fewer strong cyclonic eddy edges than those outside.

Define habitat use of loggerhead sea turtle, Caretta caretta in the Pacific Ocean Basin.

Metadata for individual animals / trackings including PTT Type, Duty cycle, Date deployed, Deployment location, Tag nos., Final location, Date terminated, Distance traveled, Transmitting days, Mean Speed of Travel, Capture status
are available upon request.

Overview

This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

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

Attributes in dataset

Attribute (table column)	Description
oid	Unique ID number (generated by OBIS-SEAMAP)
lon_360	Longitude in decimal degrees (0 - 360)
latitude	Latitude in decimal degrees
date_original	Date in original format (dd.mm.yy)
time	Time (UTC)
lc	Argos location class
argos_id	Tag ID
scl	SCL (cm)
ccl	CCL (cm)
sex	Sex (M: male; F: female; U: Unknown)
weight	Weight (kg)
longitude	Longitude in decimal degrees
obs_date	Date and time of the location (UTC)
species	Scientific name
sp_tsn	Taxonomic Serial Number added by OBIS-SEAMAP
count	Number of animals (always 1)
geom	Geometry field added by OBIS-SEAMAP