STRETCH UPDATES - COHORT 3

August 6, 2025

STRETCH Co-PI Jeff Polovina has shared an image of the SST anomaly published by NOAA and he wrote, "I've attached the latest SST anomaly plot for the Pacific and it's pretty interesting. Showing warmer than average water where our Cohort 3 turtles currently are and cooler than average waters off Baja. While we're currently in an ENSO neutral state, the equator is showing warm SST anomalies in the east, typical of El Nino, while tropical instability waves are seen in the central equatorial characteristic of La Nina."

Above is an image of Cohort III and the sea surface temperatures they are experiencing...

Below that is the Ca concentration for late July showing that the cohort has largely arrived at an area where there should be more food items available.

August 2, 2025

Cohort III turtles have traveled north from their release point (~500 km) and are now entering a zone of higher Chlorophyll a concentration and are turning east or west and remaining in the general area where the Ca is elevated and the water temperature is between 18-20 degrees C. The area they have reached is the Transition Zone Chlorophyll Front.... a favorite hangout for juvenile loggerhead turtles.

Darker green = higher Ca concentration

Cohort III turtles are in a more biologically productive area known as the transition zone chlorophyll front

July 31, 2025

Turtle Ehnally (Cohort III Splash 10 tagged loggerhead) continues to give good locations and, when compared with currents and Ca concentrations, it give us some idea about what it is doing in the area it has chosen.

Taking a look at Ehnally's current location relative to ocean currents and Chlorophyll a (Ca) concentrations (see below) one can see that Ehnally has passed through some strong currents and is meandering in a current eddy to the south of the major current stream. Ehnally's location is in an area where there is an elevated concentration of Chlorophyll a (higher productivity... more food) but, as mentioned in the last blog post, the temperature closer to the coast, where the Ca concentration is higher, may be above optimal for loggerheads.

Ehnally's track (blue) overlayed on the current pattern on 7/31/25.

Ehnally's track with Ca concentration overlay showing that Ehanlly is circleing in an area of elevated Ca concentration indicating an area of higher productivity and more potential food availability.

July 28, 2025

The animation below represents a look at the 3 Cohort III splash tagged turtles' (Moana Kai, Ehnally and Pericu) tracks from 3/1/25 to 7/28/25 with temperature overlays for March, April, June and July. The overlays are activated as the months change and represent the temperature during the middle of the month for a 7 day period.

The above image overlay shows that Moana Kai is currently in waters that are in the 19-20 degree C range, while Ehnally is in waters that are 22-23 degrees C and Pericu is in in waters that are slightly cooler at 21-22 degrees C. All three of them are remaining in a meandering pattern indicating that they have found forage in those areas.

It seems that the SST is getting to be pretty warm and I suggest that Ehnally and Pericu will be moving to the north a bit to find cooler waters... If you note the ycooler greenish color nearer BCP both Ehanlly and Pericu could move northeast into cooler waters.

July 25, 2025

The screen capture above shows the current tracks for Cohort II (white) and Cohort III (red). For Cohort III it is 382 days post release and for Cohort II it is16 days post release.

Below is a table showing distance traveled and the rate of travel for Cohort III turtles after 382 days post release.

July 23, 2025

All 28 Cohort III loggerheads are transmitting and giving good locations. Three of the TTT tags are transmitting at this time. The Cohort III turtles are still moving to the north and are in waters where the SST is 19-20 degrees C. All seems to be going according to expectations at this time.

July 21, 2025

Our three Splash 10 tagged turtles have given some diving and SST data that I have analyzed. There is data on the percent of time spent at particular depth (TAD, time at depth) and percent of time at temperature (TAT). Below are a series of bar graphs showing the temperature vs dive depth distribution (% of time) for four 6 hour time intervals- 1501 to 2100 h, 2101 to 0300 h, 0301 to 0900 h and 0901 to 1500 h. (the light blue color highlights the early evening and night time and the light gray hightlights the early morning and early afternoon hours).

While the number of data points is small (7/8-7/18/2025) at this point, it does appear that there is a definite diurnal pattern to the diving behavior with more diving activity occurring in the two time periods from 1501 to 0300 h. We don't know what they are doing during the time spent at depth or during the large amount of time they are spending at the surface (< 1 meter depth).

Turtle Seiran TAT and TAD for 7/8 to 1/18/2025

Turtle Ai TAT and TAD for 7/8 to 1/18/2025

Turtle Sora TAT and TAD for 7/8 to 1/18/2025

July 20, 2025

As our 28 Cohort III loggerheads and 17 of our Cohort II turtles continue to give good locations and four of our 5 experimental TTT tags are transmitting, our two turtle caretakers come to the end of their journey on board the Neptune Ace. They have disembarked in Panama and will make their way back to San Francisco and Monterey California for a visit to the Monterey Bay Aquarium. They have had and amazing journey and have done a wonderful job of caring for and releasing our Cohort III turtles.

From Koki-san, "This voyage has been the best adventure of my life! "

Below are a series of pictures taken by Yuki-san as they sailed south along the coast of central america. They saw lots of wildlife (fish, sharks, whales, dolphins, sea lions, sea turtles, sea birds, etc.) as the ship moved through those productive waters.

Sea lion.

Whale sounding.

Hammerhead shark.

Mating Olive Ridley turtles.

July 15, 2025

Cohort III loggerheads are moving north crossing the 19 degree C isotherm and moving towards their preferred 18 C temperature. The green line in the upper right hand corner is the 17 degree C isotherm.

Three of the 5 TTT tags are transmitting regularly (above). One of them is transmitting but has not given a good location since 7/14 and one of them is not currently transmitting.

July 14, 2025

Cohort III: All of the C III turtles gave good locations on July 13 except Cedros. We hope that Cedros is ok and we will see it back on line tomorrow when the tag is scheduled to transmit again. As expected, all of C III are heading north. They are currently in waters that are about 20 degrees C and seem to be on the edge of the Transition Zone Chlorophyll Front. As they move further north they should experience cooler waters and a higher concentration of Ca. This all leads to waters where there will be higher biological productivity, i.e., more food!

ABOVE: C III is moving to the north into cooler more biologically productive waters. They are currently in waters that are ~20 degrees C and should continue moving north until they experience water that is around 18 degrees C. This should place them in the area of the Transition Zone Chlorophyll Front. Green color is chlorophyll concentration (darker = higher concentrations-higher biological productivity). Dark blue represents areas that were lacking chlorophyll data.

Cohort II: Twenty members of C II gave good locations on July 13. They are not, as a group at least, headed in any particular direction. This is to be expected as they are widely separated and experiencing very different environmental conditions. Recall that the waters near Baja California are very productive and those animals that are likely to remain there until the waters warm up and drives the to the north and cooler waters. Those CII loggerheads that are further out in the eastern Pacific may move in a northerly direction sooner to remain in cooler waters and get into more productive areas.. of course, this is just speculation on my part.. we will see what they do in the coming weeks. Remember that this Cohort II has been transmitting for 370 days now... This is far-far better than we did with Cohort I which had an average battery life of 240 days!

July 10, 2025

We have received approval from MOL lines to publish a few photos of the release of Cohort III turtles. Many thanks to MOL and Masanori Mori for providing the photos and permission to post them.

Please visit MOL's press release on social media:

Neptune Ace Crew members carefully lower a junvenile loggerhead over the side.

Released from the basket a loggerhead gets its bearings and swims away from the ship.

The Captain and Officers of the Neptune Ace and our two turtle caretakers (Yuki and Koki). Without the generous cooperation and assistance of MOL and the Captain and crew of Neptune Ace, this project would not have been possible.

Placing a loggherad into a basket to be lowered over the side and released.

Free at last! A cohort III logherhead swims away from the Neptune Ace after being genly released.

Yuki and Koki in their STRETCH T shirts and giving a big thumbs up on the day of release.

A big thank you to the crew members of MOL Neptune Ace who successfully/safely lowered the entire 28 members of Cohort III juvenile loggerhead turtles into the northeastern Pacific Ocean to begin their journey.

July 8, 2025

It appears that all 28 members of STRETCH Cohort III loggerheads are now sending locations signals to the ARGOS satellites. It will take a few days for the algorithm to figure out the true locations so you may see some really weird locations for a few days.. Shortly, the system will figure out where they are actually located and the accuracy of the locations will improve dramatically. Please go to loggerheadstretch.org/map.html to see track data for all of Cohort III and the remaining Cohort II turtles.

July 7, 2025

The wonderful caretakers of our 28 Cohort III loggerheads (Yuki and Koki) report that the release from the Neptune Ace was successful and all 28 of the loggerheads are free and beginning their journey in the north east Pacific. So far only one is reporting but they will all begin transmitting in the next day or two according to their tag programming.

The first one to announce its position was turtle number 54 named Ai by MOL representative Ms. Miwako Ueno.

Today's release is the culmination of hardwork and care to raise the Kochi loggerheads, the work attaching the satellite tags to all 28 of the turtles, the care and transport of the turles to and on-board the Neptune Ace and the expert release of the turtles on July 7 between 1500 and 1600 local time on the Neptune Ace.

CONGRATULATIONS TO EVERYONE WHO CONTRIBUTED TO THE SUCCESS OF THE PROJECT SO FAR!!!!

Now we look forward to what out little loggerheads can teach us about their travels.

July 7, 2025

Today is Cohort III release day!!!! I have plotted the current location of three of our Cohort II turtles and they are at a similar latitude as the proposed release point indicating that the temperature at the proposed release point should be appropriate for the little loggerheads of Cohort III...

Fumi, Uzuki and Purutaui are at similar latitudes as the proposed release point for Cohort III.

July 6, 2025

The turtle caretakers (Koki and Yuki) continue to report that the 28 juvenile loggerheads of Cohort III are doing well. They report that the release day is near:

"The release time for the third cohort has been decided.The release will begin at 1:00 a.m. (UTC) on July 8.(This is 2:00 p.m. on July 7 local time.)

The estimated latitude and longitude at that time are as follows.
39°41.863' N
148°05.040' W"

The image above shows the release point for the first and second cohorts along with the proposed released point. The black box labels the currently proposed release point for Cohort III.

Windy.com website shows that the location where Cohort III is going to be releases is somehwere in the vicinity of 19 degrees C. This is well within their normal preferred temperature.

We anxiously await the release of our third Cohort of Juvenile loggerheads. We suspect that they will start moving in a northerly direction once they are rleased.. they should follow the 18 degree C isotherm as it moves north during the summer and, in the fall, they should move to the south as the warters cool.

July 2, 2025

Koki and Yuki continue to send us updates on their progress across the Pacific. Koki writes: "The ship is heading northeast, and the temperature has suddenly dropped.The 28 turtles are doing well as usual, but I’ll continue to take good care of them.

Early this morning, Yuki-san was looking out at the ocean and saw dolphins, whales, and even a sea turtle! Unfortunately, I was asleep and missed it...

Later in the afternoon, we got to see lots of seabirds and dolphins!

I was really surprised to see so much wildlife in the open sea, and we will keep watching!"

Follow the Neptune Ace at vessel finder.

June 30, 2025

Koki and Yuki (our turtle caretakers) report that they are doing fine and the turtles are eating well. They have left Yokohama and are on their way to Balboa, Mexico. You can follow the ship "Neptune Ace" by going to vessel finder. Below are a few images sent to us from Neptune Ace.

Thank you Koki and Yuki for taking good care of our 28 juvenile loggerheads!!!

They both claim the food is great. The chefs are Indian and they have been getting a fair share of curry!

The Japanese flag flies proudly over the Neptune Ace.

June 29, 2025

Below are some photos of the loading of Cohort III STRETCH loggerhead turtles on the "NEPTUNE ACE" of Mitsui O.S.K. Lines, Ltd. PNPA personnel and members of the STRETCH team loaded the turtles into a van for transport to the port of Nagoya where NEPTUNE ACE crew members along with the STRETCH team unloaded the turtles and moved them to an upper deck where they will be cared for by Koki and Yuki during their trip across the North Pacific Ocean.

Chief PNPA turtle curator Masanori Mori loading a satellite tagged juvenile loggerhead into the van for transport to Nagoya Harbor.

Loading is almost complete.

Turtle cartakers Yuki and Koki along with other members of the STRETCH tema and PNPA personnel arrive at the ship.

Unloading the turtles and transporting them to an upperdeck on the Neptune Ace.

Stern of the RORO ship "Neptune Ace" (Mitsui O.S.K. Lines, Ltd) that will carry our Cohort III turtles to their release point in the north east Pacific Ocean.

Neptune Ace crew member rolling Cohort III loggerheads to the elevator to get them to the upper deck.

Waiting at the elevator.

The Neptune Ace crew along with the STRETCH team and PNPA personnel pose for a photo after all of the Cohort III turtles have been loaded.

Twenty eight Cohort III juvenile loggerheads in their home for the next couple of weeks. They will be taken out of their carriers, cleaned, the carriers will be cleaned and filled with fresh sea water each day by Yuki and Koki. The turtles will be feed in the carriers several times each day.

June 28, 2025

19 members of Cohort II continue to transmit* and appear to be hanging around the same area for the last few weeks. The total time since release is 354 days and they will reach 1 year transmitting at about the time Cohort III is to be released.

*The three splash tagged turtles (Moana Kai, Ehnally and Pericu) are off line for the next couple of weeks as a result of the programming that we committed them to.

Cohort III Names and Tag numbers.

A note about the TTT tags. The TTT tags are experimental and have been deployed on the cohort III turtles to test how well they function at sea. They have been successfully used on Albatros and now are going to be tested on sea turtles. They are extremely small solar powered tags (7 g) and can be used on very small turtles in the future if they function well.

June 27, 2025

The 28 STRETCH turles of Cohort III are safely on the ship and Koki and Yuki are taking good care of them. We will keep up to date on their whereabouts as they begin their journey to the release point. The captain has suggested a release point approximately 1/2 way between the release points of Cohorts I and II and The water temperature in that area is ~23 degrees C which is a safe temperature for the release.

The MOL ship Neptune Ace has departed Nagoya and is currently on its way to Yokohama, Japan. Koki and Yuki are on board and caring for our 28 STRETCH Cohort III turtles! (information from: vesselfinder.com).

June 26, 2025

Today, the STRETCH team and the PNPA personnel transported the 28 juvenile loggerheads of Cohort III to the Port of Nagoya and loaded them onto the MOL ship Neptune Ace to begin their journey to release in the northeast Pacific Ocean.

Cohort III turtle number 62 carrying a Splash 10 tag and an experimental solar powered mini tag (posterior to the Splash tag) .

June 25, 2025

The STRETCH project, from its enception, has given the juvenile loggerheads released with satellite tags names that honor the countries and organizations that have a unique interest in the North Pacific Loggerheads. Mexico, United States, Japan, Hawaii, Port of Nagoya Public Aquarium, Kochi University and the Mitsui O.S.K. Lines, ltd all have provided support for this very large and important project.

This year, we asked Mitsui O.S.K. Lines (MOL) to provde 13 names of their choosing to honor their support of the project. Without their ships, we would never have been able to deploy the juvenile loggerheads out in the northeast Pacific Ocean.

Below is the list of names provided by MOL for 13 of the Cohort III loggerheads.

A note from Miwako Ueno (Marine Fuel GX Division) regarding the chosen Japanese names:

"For this naming project, I chose traditional Japanese names inspired by ancient shades of blue. These names reflect the graceful appearance and mysterious nature of the loggerhead sea turtles—guardians of the sea—and blend them with the delicate aesthetic sensibilities of Japanese culture.

Through names like Ruri, Ai, and Asagi, which evoke the beauty of the blue ocean, I hope more people will become aware of the importance of marine conservation, the preciousness of nature, and the interconnectedness of life. I wish for these names to inspire action to protect the future of our oceans."

Here are the names I gave to the 13 turtles:

Ai (藍) – A deep indigo blue, symbolizing the turtle’s strength and the calm of the deep sea.

Asagi (浅葱) – A refreshing blend of blue and green, reflecting the turtle’s graceful swimming and the clear ocean.

Gunjo (群青) – A vivid deep blue, representing hope for the future and the beauty of the deep sea.

Ruri (瑠璃) – A mystical, brilliant blue, expressing the turtle’s mysterious nature and the fantasy of the deep ocean.

Konpeki (紺碧) – A rich summer-sky blue, symbolizing vitality and the color of the summer sea.

Ama (天) – A clear sky blue, representing the turtle’s freedom and the vastness of the sea.

Seiji (青磁) – A soft blue-green, reflecting the turtle’s gentle features and the calmness of the ocean.

Mizu (水) – A pale, clear blue, symbolizing the turtle’s pure eyes and the clarity of the sea.

Sora (空) – A bright sky blue, expressing the turtle’s freedom and the brightness of the ocean.

Seiran (青藍) – A deep purplish blue, a fantastical name that reflects the turtle’s profound nature and the colors of the deep sea.

Hanada (縹) – A rich blue like a peaceful ocean, representing the turtle’s serene journey and the depth of the sea.

Heki (碧) – A greenish blue, expressing the turtle’s graceful swimming and harmony with nature.

Seigaiha (青海波) – A traditional wave pattern symbolizing peace and prosperity, reflecting the turtle blending into the waves and our wish for lasting harmony.

June 23, 2025

The team assemble at the PNPA for the third and final time this morning. We have 10 more to do and we will work them out this morning.

We arrived at the aquarium at 0900 h and got the last 10 turtles out and cleaned them. The team worked pretty efficiently and by 1100 h we had tags attached to all 10 juvenile loggerheads. They just needed to be painted with antifouling paint and they could be returned to their baskets. They will be loaded onto the Neptune Ace ship on June 26 to begin their trip to the northeast Central Pacific ocean where they will be released.

As of today there are 19 of the 28 Cohort II tags still transmitting And their current locations can be viewed on the map above and their entire tracks can be seen by going to loggerheadstretch.org/maps.html

The third day's attachment work is nearly completed. Here is the team that did the attachment work today.

June 22, 2025

Today markes the second day of tag attachment work at the PNPA.

Today we will work on attaching 10 more satellite tags to 10 juvenile loggerhead turtles of Cohort III.

We arrived at the PNPA and started work immediately. Our goal for the day was to attach two more Splash 10 + TTT (tiny turtle tags), 2 Spot 6 + TTT, and 6 more with just the Spot 6 tags.

We were successful in getting all of those tags attached and below are some images of our work today. We have completed tagging of 18 of 28 juvenile turtles. Tomorrow we will finish the last 10 and then they will be ready to board the ship for deployment on June 26.

The STRETCH team arrive at the PNPA for their second day of work.

Scrubbing the carapace and rinsing the juvile loggerheads.

Cleaning the turtles with the bridge to PNPA in the background.

Performing an oral exam.

Putting fiberglass cloth and polyester resin on to attach the satellite tag.

Attaching a Splash 10 tag.

Applying anti-fouling paint to prevent growth of algae and sessile inverts.

Cleaning up the tag and removing covers off of the contact points.

June 21, 2025

The STRETCH team assembled at 0800 and made our way to the PNPA to begin our work day. Today we will do 8 turtles in total, starting our with a Splash 10 tag and a Mini tag combo- through a special arrangement with Wildlife computers. We arrived at the aquarium at 0845 and began work by bring up the turtle for the Splash tag. Over the course of the day we were able to place satellite tags on 8 of the 28 juvenile loggerheads raised by PNPA.

Below are some pictures from the day's work:

Team members preparing the carapace for attachment of the tags.

Our first Splash 10 + Mini tag turtle.

Sanding the scutes in preparation for satallite tag attachment.

Recording the data / IDs for each of the 8 turtles.

Adding polyester resin to glass cloth to attach the satellite tag to the carapace of a juevenile loggerhead turtle.

Adding the final resin coating to the tags.

Adding a coat of anti biofouling paint to the tags.

Returning the satellite tagged turtles to their baskets for the night

Returning our tagged turtles to their baskets for the night.

Explaining the project to a Japanese TV news crew.

The STRETCH team at the end of the first day of satellite tag attachment.

Looking at how a WC mini tag might look on a one year old juvenile loggerhead.

June 20, 2025

The STRETCH Attachment team is assembling in Nagoya at this time. We are scheduled to gather together at our hotel and then travel as a team to the Port of Nagoya Public Aquarium.

We all meet at the Crown Plaza Hotel and made out way to the Port of Nagoya Public Aquarium and arrive there around 1400 h. Noah meet us and guided us to the aquarium to meet with Masanori Mori (Head Turtle Biologist for PNPA and the person who has raised all of our three cohorts of juvenile loggerhead turtles. We proceeded to go to take a look at the young turtles of Cohort IV that are being raised at PNPA for the 2026 release.