Journeying with green sea turtles and the Arribada Initiative

Today, a guest post: Alasdair Davies, co-founder of Naturebytes, ZSL London’s Conservation Technology Specialist and Shuttleworth Foundation Fellow, shares the work of the Arribada Initiative. The project uses the Raspberry Pi Zero and camera module to follow the journey of green sea turtles. The footage captured from the backs of these magnificent creatures is just incredible – prepare to be blown away!

Access to affordable, open and customisable conservation technologies in the animal tracking world is often limited. I’ve been a conservation technologist for the past ten years, co-founding Naturebytes and working at ZSL London Zoo, and this was a problem that continued to frustrate me. It was inherently expensive to collect valuable data that was necessary to inform policy, to designate marine protected areas, or to identify threats to species.

In March this year, I got a supercharged opportunity to break through these barriers by becoming a Shuttleworth Foundation Fellow, meaning I had the time and resources to concentrate on cracking the problem. The Arribada Initiative was founded, and ten months later, the open source Arribada PS-C green sea turtle tag was born. The video above was captured two weeks ago in the waters of Principe Island, West Africa.

The tag comprises a Raspberry Pi Zero W sporting the Raspberry Pi camera module, a PiRA power management board, two lithium-ion cells, and a rather nice enclosure. It was built in unison with Institute IRNAS, and there’s a nice user-friendly wireless charging case to make it easy for the marine guards to replace the tags after their voyages at sea. When a tag is returned to one of the docking stations in the case, we use to manage it, download videos, and configure the tag remotely.

The tags can also be configured to take video clips at timed intervals, meaning we can now observe the presence of marine litter, plastic debris, before/after changes to the ocean environment due to nearby construction, pollution, and other threats.

Discarded fishing nets are lethal to sea turtles, so using this new tag at scale – now finally possible, as the Raspberry Pi Zero helps to drive down costs dramatically whilst retaining excellent video quality – offers real value to scientists in the field. Next year we will be releasing an optimised, affordable GPS version.

green sea turtle Alasdair Davies Raspberry Pi Arribada Initiative

To make this all possible we had to devise a quicker method of attaching the tag to the sea turtles too, so we came up with the “pit-stop” technique (which is what the PS in the name “Arribada PS-C” stands for). Just as a Formula 1 car would visit the pits to get its tyres changed, we literally switch out the tags on the beach when nesting females return, replacing them with freshly charged tags by using a quick-release base plate.

To implement the system we first epoxy the base plate to the turtle, which minimises any possible stress to the turtles as the method is quick. Once the epoxy has dried we attach the tag. When the turtle has completed its nesting cycle (they visit the beach to lay eggs three to four times in a single season, every 10–14 days on average), we simply remove the base plate to complete the field work.

If you’d like to watch more wonderful videos of the green sea turtles’ adventures, there’s an entire YouTube playlist available here. And to keep up to date with the initiative, be sure to follow Arribada and Alasdair on Twitter.


Emma Ormond avatar

These are wonderful, the quality of the camera when the turtle breaks the surface is great.

Alex Bate avatar

I know. I’m so in love with these videos.

Alasdair Davies avatar

Delighted to be able to share these with you all. We tagged 5 turtles, and these videos are from the first to return, so we should expect the others to return over the Xmas period with new observational footage.

AndrewS avatar

I’ve got no idea if it’d be scientifically useful, but given that the camera is at a fixed position on the turtle’s shell, I guess you could use OpenCV to track the angle of the turtle’s head?

Alasdair Davies avatar

You certainly could, or detect objects from many hours of video clips that the turtle was eating (plastic injested etc) to help identify the scenes we need to watch. Now that we’ve got a stable and affordable camera tag we’re exploring the exact same questions. Ping us anything you think we should explore too.

AndrewS avatar

Should also be fairly easy to detect when the camera transitions from filming-underwater to filming-above-water and vice-versa, which might enable you to monitor dive-times etc. ?

Michael Peskett avatar

It never ceases to amaze me the phenomenal things people have been able to do with the raspberry pi.
Well done all for making it possible to do so many things. What can you put a raspberry pi on next. The video is amazing well done to you all.

Max Muster avatar

How long does the battery last averagely? What kind of batteries do you use for this project? How did you calculate the battery size during project development?

Alasdair Davies avatar

Hi Max,

We use two 3600mAh 18650 li-ion batteries so we can keep the tags rechargable. You could use primary cell batteries for extra capacity, but our objective is to release solutions that are as cost effective as possible (and so rechargable works best – from an environmental perspective too).

We get ~1 week of power and wake the Pi Zero to record footage at set intervals before shutting it down to conserve power. It is off during the night too. A tag can generate about 12 – 15 hours of footage and the turtles return after 11 – 14 days after being tagged on average as nesting green sea turtles will lay 4 – 5 clutches of eggs. We tag them on their second clutch usually and then remove the tag after we have collected the data before they finish their cycle.

Norbert Klär avatar

when will the turtle get rit of the batteries and equipment ?

Norbert Klär avatar

so, what will be the benefit of this project for animals and ocean ..?

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