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SWFSC juvenile loggerhead sea turtle tracking 2002-2005
Howell, E.A., P.H. Dutton, J.J. Polovina, H. Bailey, D.M. Parker and G.H. Balazs. 2010. Oceanographic influences on the dive behavior of juvenile loggerhead turtles (Caretta caretta) in the North Pacific Ocean. Marine Biology. 157:1011-1026

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Archived data
Availability: Creative Commons License This dataset is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Notes: Only data aggregated per 1-degree cell are available through OBIS. The non-aggregated data are available through the OBIS-SEAMAP Portal

Satellite telemetry data from 17 juvenile loggerhead turtles (43.5-66.5 cm straight carapace length) were used in conjunction with oceanographic data to analyze the influence of regional and seasonal oceanography on dive behavior in the North Pacific Ocean.
These results will aid in our understanding of juvenile loggerhead dive behavior during their oceanic phase. An increased understanding of potential effects of oceanography on loggerhead dive behavior should assist in future conservation and bycatch studies working toward the reduction of loggerheads by longline fisheries in the North Pacific. more

Combined dive behavior for all individuals showed that turtles spent more than 80% of their time at 0-5 m depths, and more than 90% of their time at 0-15 m depths. Multivariate classifications of dive data revealed four major dive types, three representing deeper, longer dives, and one representing shallower dives shorter in duration. Turtles exhibited variability in these dive types across oceanographic regions, with deeper, longer dives in the Hawaii longline swordfish fishing grounds during the first quarter of the year, as well as in the Kuroshio Extension Bifurcation Region and the region near the Baja California Peninsula, Mexico. Turtles in the Kuroshio Extension Bifurcation Region also exhibited dive variability associated with mesoscale eddy features, with turtles making deeper, longer dives while associated with the strongest total kinetic energy. Turtles in the central North Pacific exhibited seasonality in dive behavior that appeared to reflect synchronous latitudinal movements with the North Pacific Subtropical Front and the associated seasonal, large-scale oceanography. Turtles made deeper, longer dives during the first quarter of the year within this region, the reported time and area where the highest loggerhead bycatch occurs by the longline fishery. These results represent the first comprehensive study of dive data for this species in this region. The increased understanding of juvenile loggerhead dive behavior and the influences of oceanography on dive variability should provide further insight into why interactions with longline fisheries occur and suggest methods for reducing the bycatch of this threatened species.

Biology > Reptiles
Marine, AE, North Atlantic, Caretta caretta

Geographical coverage
AE, North Atlantic [Marine Regions]

Temporal coverage
14 October 2002 - 7 July 2005

Taxonomic coverage
Caretta caretta (Linnaeus, 1758) [WoRMS]

Occurrence of biota

Federal Government of the United States of America; Department of Commerce; National Oceanic and Atmospheric Administration; National Marine Fisheries Service; Pacific Islands Fisheries Science Center (PIFSC), more National Oceanic and Atmospheric Administration (NOAA), moredata creator

Related datasets
Published in:
OBIS-SEAMAP: Spatial Ecological Analysis of Megavertebrate Populations, more

Based on this dataset:
Howell, E.A. et al. (2010). Oceanographic influences on the dive behavior of juvenile loggerhead turtles (Caretta caretta) in the North Pacific Ocean. Mar. Biol. (Berl.) 157(5): 1011-1026., more

Dataset status: Completed
Data type: Data
Data origin: Research: field survey
Metadatarecord created: 2015-03-24
Information last updated: 2015-03-24
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