Japanese Loggerheads Released off of Kochi, Japan

Link to current trajectory map of #203 and #204


Turtle 204 continues to transmit locations very reliably.  It has been transmitting for 208 days now and has traveled roughly 8000 km.  Given that 208 days represents 4992 hours, 204 has been traveling/swimming at a rate of approximately 1.6 km/hour.  Below is a short animation of the water currents and 204's track indicating where 204 is as of March 27, 2024.  


Turtle 203 stopped transmitting on 2/3/24 but 204 continues to transmit.  Below is the current location of 204.  It appears that 204 is riding around in a small current eddy that has branched off of the main Kuroshio current.  These eddys tend to concentrate food items and are know to be areas preferred by loggerheads.  

Above is an animation of the travels of #204 in the Eddy shown above from 1/13/24 to 2/29/24.  


Here is an animation of  203's and 204's trajectories after their release in September until February 2, 2024.  


While 204 remains if the "Kii Channel", 203 has moved further offshore out into the Kuroshio current and is currently in waters that are 20+ degrees C.  Below is an animation of the tracks of the two loggerheads and tracks of each slowed down a bit.

Loggerheads 203 and 204 current locations and approximate sea surface temperature (SST) are shown above.

Loggerhead turtles 203 (Red) and 204 (blue) trajectories and locations as of 12/6/2023.



Earlier,  Tomomi Saito (STRETCH team member) indicated that he thought Turtle 203 would have to move out of the Suo-Nada area of the Seto Inland Sea and it has done just that.  The water temperature in Suo-Nada is somewhere between 12 and 13 degrees centrigrade.  Turtle 203 has moved out of that area and is now moving into waters that are warmer (around 15 degrees C).  Perhaps she will continue to move in a southerly direction into warmer waters.

Turtle 203 has moved out of Suo-Nada and is moving along the coast into warmer waters.


Tomomi Saito, Professor at Kochi University and STRETCH team member, has intitiated a satellite tagging study of two adult loggerhead turtles (203 & 204) retrieved as bycatch from the Muroto Point net fishery in Japan.  The two turtles were transported from Muroto Point to Kochi University where Dr. Saito and his students attached the two Wildlife Computers satellite tags that were graciously donated to the project by the STRETCH Project.  The two adult loggerheads were released off of Kochi, Japan on Sept. 1, 2023.  Below is a video of their track from 9/1/2023 to 11/13/2023.  
Dr. Saido wrote recently:   "Both are not in the open ocean where the Kuroshio Current flows, but are located on either side of the inner bay area called the Seto Inland Sea area.
The water temperature in the Seto Inland Sea area will eventually drop. In January, the temperature can drop to 10℃ in Suo-nada (where 203 is) and 15℃ in Kii Channel (where 204 is). I think it will be too cold for them."
The implication is that they will probably move out of their current foraging grounds as the temperature drops.

Below is a detection and trajectory map of the two loggerheads satellite tagged and released by Dr. Tomomi Saito of Kochi University on Sept. 1, 2023.

The map below gives the daily updated map of turtles 203 and 204.


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