Hawksbill Sea Turtle Research in Costa Rica

Latest update December 3, 2018 Started on June 28, 2018

Hawksbill sea turtles are particularly threatened in the Eastern Pacific ocean, with only 500 nesting females left in the whole region. We have discovered that a small population of juvenile hawksbill sea turtles uses the rocky reefs around the waters of Costa Rica to feed and grow.

Join me as I explore the Pacific coast of Costa Rica, studying these animals, following their movements, and working with the local communities to ensure the survival of this species.

June 28, 2018
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Mission Underway


Today, i'm coming with great news!

My project has been selected to be part of next year's Student Conference on Conservation Science to be held at Cambridge University, UK, next March. I will be presenting a poster, showing an update on my project and on the hawksbill population of the area.

As a scientist and a biologist, it is an honor to be presenting at this prestigous university. Hawksbills of Costa Rica now have an international voice, aiming for their survival and conservation.

However, I need your help!! In order to cover travel expenses and fees, I'm raising funds through this small crowdfunding campaign, every donation above $100 will recieve a special present!!


Every dollar counts! And if you are not able to contribute financially, just sharing the website with your friends and fellow conservationists will be of great help. Help me and hawksbill sea turtles achieve our conservation goals!!

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The passing of a hawksbill

Today, I come with bad news. Studying endangered sea turtles can be a challenge, starting with the fact that the population of hawksbills that we are studying has declined abruptly in the last decades, with an estimate of only 500 female nesters in the region.

And what about the males? Studying male sea turtles is particularly hard because they dont come to the shores to nest as the females do. So, where are the male hawksbills in the eastern pacific spending their time and how much they are moving is still a mistery for biologists. This is why this information is so valuable, every time we have the chance to tag and track a male hawksbill we might me on the brink of discovering new behaviours.

This why the news of a male hawksbill sea turtle with one of my transmitters found dead on a beach close to our projects was specially shocking for me. The individual was found by Cindy, one of the managers of CIRENAS, a tropical research station near our site, while her team was patroling the beach looking for nesting sea turtles. It seems that a severe cause of red tide combined with very bad weather might be the cause of death, however we were not able to study the corpse as it was quickly taken away by locals, probably to preserve or sell the beautiful shell of the turtle.

After analyzing the pictures I could manage to identify the sea turtle as "Marcky", one of the first sea turtles tagged by my project back in March when I first got funding from EDGE and National Geographic. In fact, Marcky is the sea turtle shown on my iconic picture during this year's Explorer Festival while presenting on a panel called "Every animal deserves a story", ironically now i'm telling you Marcky's story with a sad ending. We hope that Marcky's tag was still transmitting when he washed on the shore and that once we recover our data from our receivers we might have a little bit more information on the movements of male hawksbills.

PS: If you look at the pictures below, you can see the dent at the right side of Marcky's carapace, this dent was a crucial on identifying the individual, which highlights the importance of taking good pictures of every side of the sea turtle during every encounter

Thanks for everything Marcky!! You will greatly contribute to the protection of your species in Costa Rica!

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That is hard to lose a turtle, especially one with limited numbers.

Proud new member of the SEE initiative!

Today I have great news!!

I have been selected as part of the SEE initiative, as consequence I will be receiving a brand new TRIDENT OpenROV to support my research on hawksbill ecology and behaviour in Costa Rica!!

With these new tool I will be able to study the foraging grounds of hawksbill sea turtles in a less invasive way, from a whole new perspective!

Stay in tune, since I'll be posting news regarding my new expeditions and amazing stuff that will be recorded with our new present.

Thanks again to everyone in Open Explorer and to every one of you who reads my posts and keeps updated with my work. Getting a Trident has been a dream since I saw David Lang's presentation at the Explorers Festival and now, that dream has come true thanks to you!


Daniel, this is such exciting news! So happy for you

Thank you Madeleine!! I'm very excited about everything that we can achieve!

Hola Daniel. Ya te llegó el Trident??

I look forward to reading more about what you discover!

Working with the world's largest youth-run organization

Today I will talk about my recent partnership with AIESEC(www.aiesec.org),,) the world's largest non-profit youth-run organization. AIESEC is composed by almost THIRTY thousand members across 127 countries. Earlier this year i was contacted by the leaders in Costa Rica, they where interested in starting a partnership, where they will look for young people around the world interested in protecting hawksbill sea turtles to work in my project.

As a pilot project, I hosted 3 volunteers: Jan (Germany), Julien (Belgium), and Leonardo (Brasil) for a 6-week program working in several projects of the organization, but focusing on the capture and tagging of hawksbill sea turtles at Cabo Blanco. During their stay we manage to watch olive ridley sea turtles nest and hatch, we captured one hawksbill sea turtle that was successfully tagged, we cleaned up a beach removing four giant bags of plastic trash.

When you work in conservation some things are clear, saving species from extinction is not easy, and it's not a conventional job, you never know how long you are going to be able to do it. But to think that people would come all the way from Europe to help me work, and go back to their countries caring for the ocean a little bit more, makes me feel that i'm doing the right job. I quote one of the volunteers:

"...I didn't expect to even live half of what i had the chance to live. I really hope you give the opportunity to discover the pura vida lifestyle to other people. I felt in love with this country and it's culture, absolutely mindblowing. I could not thank you enough for everything you allowed us to live."

I will receive six more volunteers from AIESEC during the next months.

If you have a project where you could use some volunteers, I really encourage you to get in contact with AIESEC in your region/country and start building a relationship, you will not regret it!

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That's pretty magical!

It really is!!

Coco's Island: Costa Rica's most precious treasure

From September 13th to 23rd, I had the chance to be part of the scientific crew aboard R/V Sharkwater alongside Randall Arauz and Mauricio Hoyos (world reknown shark biologists, they have appeared on Sharkweek! as part of the Shark Men series) on their expedition to Coco's Island, described by my hero Jacques Cousteau as the most beautiful island on the world.

Coco's island is one of the top attractions in the world for divers, as it is sometimes called "Shark island", the island is visited by a huge diversity and numerous schools of sharks, hammerheads, silkys, whitetip reef and tiger sharks are frequently observed on different island and pinnacles around the main island. In addition, Coco's island is part of a migratory swimway that connects the island with Galapagos and Malpelo in Ecuador and Colombia respectively, making the island a crucial hotspot to protect highly migratory species like sharks and sea turtles.

I have been told by scientists and tourists (since my first visit to the island was on 2012) that sea turtles were observed during every dive, that was before 2008 when a tiger shark was first reported on the island on more than 50 years. After that observation, tiger shark observations became more and more frequent, while sea turtle observations decline abruptly (Check out image). Since then, several videos have been recorded of tiger sharks attacking sea turtles, particularly green sea turtles and hawksbills.

It is still unknown if the tiger sharks have eaten the sea turtles or if the presence of sharks prevents them to stop at the island during their migrations. Therefore, our main goal as researchers is to study this relationship and figure out the ecological process and implications behind it. Right now, we are tagging all migratory animals with acoustic tags in order to follow their movements, as well as collecting tissue samples from animals in different trophic levels to run stable isotope studies that will provide us with a better understanding of the trophic relations in this magical place.

Would you like to join us on one of these expeditions??? Please contact me atdarauz18@gmail.comand let's talk!!

Check out the press release: http://www.prweb.com/releases/twotigersharkstaggedincocosislandnationalparkresearchersalsotaggedhammerheadsilkygalapagosandwhalesharks/prweb15796003.htm

I leave with a little video about our expedition, I have to add that we observed a green sea turtle, the first report made by divers in over three years (picture)!!

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The challenges of scientific diving

Diving is my favorite thing in the world. I have been a certified diver since 2011 and have already logged close to 200 dives in my journey from an open water diver to a professional dive master and scientific diver.

It has always been natural to me, for some reason, slowly moving underwater, controlling buoyancy using your lungs and cruising along the current while glancing and enjoying all the diversity that the ocean has to offer. Diving can be the most relaxing and exciting activity at the same time, it's really impressive.

When you are studying marine organisms, you need to take the most advantage of every opportunity that you have to be in the field, diving is not cheap, therefore, marine research that involves diving is not something that you can do every day. While diving in Punta Coyote during my last expedition, conditions were not the best, visibility was bad and there was a strong current, however that was the only chance that we had to retrieve the information from on of our receivers, and we took the challenge.

Here I will leave you with a small video made by my friend Dave Wise (http://thegreentraveller.trekandrun.com/#home)) who went on this challenging dive with Dominick and me, three crazy guys that could not refuse the chance to dive.

Day 8th-9th, July 11-12th: Cabo Blanco

For our final stop aboard the Sharkwater RV, we spent two days inside Cabo Blanco Absolute Natural Reserve. This place, is Costa Rica's first protected area, and the basis for the whole system of protected areas that we now have.

Nearly a year and a half ago, a research team from CREMA, including me, where exploring the coast looking for important rookeries and feeding grounds for both sea turtles and sharks. Without really knowing what we where going to get, we started deploying our sea turtle nets in small shallow tidepools that form when the tide is low.

For our surprise, we discovered a young and small population of juvenile hawksbill sea turtles that use this pools to feed and grow!! Up to this date we have identified around 30 different hawksbills that stay here for several years until they go to reproduce and lay eggs somewhere we still don't now,

As a main goal of my National Geographic Photo Ark EDGE Fellowship, I plan to track this individuals to learn more about their movements, as well as involving the local communities in the protection of this amazing animals!

During this expedition we managed to found the smallest individual that we have captured up to date, it was only 35 cm long! It was tagged with an acoustic transmitter and hopefully we will learn more about its movements in our upcoming field trips.

I want to thank Lush, and Fins Attached for making this trip possible. Right now, I'm heading back to San José to analyze the data gathered and start to get ready for our next field campaing. Stay Tuned!!!

Picture of Cabo Blanco Island with a majestic Brown Booby courtesy of my friend David Wise (http://thegreentraveller.trekandrun.com/#post0)

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Day 7th, July 10th: The Bongo River

As we cruise down south, we reach the southern part of the Nicoya Peninsula, here is where CREMA (www.cremacr.org ; the organization that I work with) has most of it's research and conservation projects.

For the next couple of days, we will be helping Elpis Joan M.Sc in wildlife conservation. She has been studying the movements of juvenile bull sharks that move along rivermouths in this region. One of our theories is that when they grow up, these sharks move to more pelagic waters to feed and reproduce, most likely, the Bat Islands and the area up there.

But, how do you track the movements of these animals??

As an organization, CREMA is part of MigraMar (www.migramar.org)) a network of organizations tracking ocean wildlife along the Eastern Pacific. All the organizations in MigraMar use acoustic telemetry to gather data on animal movements in the area.

Acoustic telemetry is very simple, you attach a tag to the object of study, this tag emits a sound at a specific frequency. Later, an acoustic receiver that is put in the areas of study will capture that signal, and let us know the time and date when the animal was swimming around that area. Since all the organizations use the same technology, all the data, and the receivers are shared between the researchers. In this area, we have 5 acoustic receivers deployed, we download the data every couple of months and we can know if any animals that we tag where swimming in this area.

Cool huh?

These are called presence/absence studies, since we can only know if the animal was present or not in the area at a specific time. With this data we can determine the areas of higher activity and therefore, pressure the local authorities to provide a better management of this region.

I will show a video where we tag a baby bull shark, i have to warn you that the video can be shocking, however, no animals where hurt during our research and all ethic guidelines where rightly followed.

Pictures: Acoustic receiver & Sea turtle with an acoustic tag on its carapace.

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Day 6th, July 9th: The Catalina Islands

As we travel south the Costa Rican Pacific coast, we stopped at the Catalina Islands to do a couple of dives and meet with some scientists that work in the area!

While we spend the day in the Catalinas, it was an honor to be joined by Mikki Mccomb, researcher from the Ocean First Institute (www.oceanfirstinstitute.org) and Ernst Van der Poll from Connect Ocean Academy & Dive Center (https://www.facebook.com/connectoceanaquaticacademy).

Together, they have not only started monitoring and tracking the sharks and rays the visit the area, but they are training the young local kids to become life guards, divers and ocean conservationists. It was really inspiring to talk to them about ocean conservations and the networks that have to be built between organizations, locals, and government stakeholders in order to succesfully preserve our oceans. Please follow their websites and social media if you want to learn more about them.

As part of the research we are doing, we are inventing and creating different parts of equipment to sucesffully gather data underwater. During this trip we are trying out the "Laser gun", a little plastic set up with two laser beams and a GoPro camera attached to it, knowing the distance between the beams, we are able to measure the size of the organisms in the videos (fish, sharks, rays, turtles, etc.). Here I attach a little Youtube video made by my great friend David Wise (http://thegreentraveller.trekandrun.com) where I explain a little bit how it works!

Tomorrow we will continue our way south and heading to Coyote and Cabo Blanco, where I have been monitoring hawksbill populations for the last year and a half, stay tuned!!

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Day 5, July 8th: The Big Scare

The next couple of posts are not going to be about sea turtles specifically, but hey, the ocean is more than just sea turtles right?

As I told you before, The Big Scare in the Bat Islands is one of the only places where you can dive with adult bull sharks (Carcharhinus leucas) in Costa Rica. CREMA (www.cremacr.org) has been studying bull shark nursering grounds in Costa Rica for a couple of year now, these sharks can tolerate freshwater and every year they return to the same estuary where they were born to give birth to their pups. We have been tracking juvenile bull sharks with acoustic telemetry in estuaries to know their movements alongside and in between estuaries.

Here in the big scare we had the chance to swim with the adult bull sharks we believe will go to the estuaries we study to give birth. We tried taking tissue samples for genetic studies, however sharks did not get close enough even though we could observe several of them.

Again, to show one more time how special the ocean in Costa Rica is, some of the divers in our group had the chance to experience one of the greatest and interesting spectales the ocean has to offer, a massive school of cownose rays cruising by during our safety stop.

Day 4th, July 7th (2/2): Colorada's Turtle Cemetery

I don't have to tell you that Costa Rica is a very special place, but our northern Pacific coast is really something else!

This region does not only provide the four species of endangered sea turtles that come to Costa Rica with beaches to nest, but it is also a critical hotspot in the conservation of the largest feline in the Americas, the mighty jaguar (Panthera onca).

In Guanacaste, many researchers have studied the relationship between these two endangered animals. Mainly because nesting sea turtles provide the jaguars with the proper meal to survive another day without to much effort.

Even though this process has been well documented in a couple of beaches in the area (Nancite & Playa Naranjo) jaguar distribution throughout Costa Rica is still unknown, with fragile populations suffering heavily from habitat loss and fragmentation. According to locals and colleagues, Playa Colorada near the Bat Islands is one of the most interesting places to study the interaction between jaguars and sea turtles, however, the place is really hard to reach, it can only be done on boats and it is considerably far from any civilization. Now, thanks to Sharkwater, we will have the chance to explore this beach, and think of ways to study it in the near future.

At the arrival, Colorada beach looks like a normal, beautiful beach in the Pacific, however you don't have to walk long to start observing very big paws printed in the sand, as well as ocassional sea turtle corpes piled up under the trees where they are eaten. During an hour walk, we registered more than 70 corpses of sea turtles (olive ridley and green turtles), none of them was a hawksbill, which tells us that they do not use this beach to nest, and so, the search for an important nesting beach for hawksbills in the Pacific Costa Rica still continues. We registered the GPS locations of the corpses we found and got back to the boat to analyze some pictures, in some of them you can look at the scratches an bitemarks on the shells!!

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Day 3, July 6th - Day 4th July 7th (1/2): The Bat Islands, San José Islands

After a succesfull turtle capture campaign in northern Costa Rica, we started to head south to our second pit stop: The Bat Islands.

The Bat Islands are located inside the Santa Rosa National Park, with a small marine protected area sorrounding the islands that are not too far from land. Here, recreational divers gather with the only purpose of diving in "The Big Scare", the only place in Costa Rica where you can watch adult bull sharks during a dive. However, I will leave that for a later post.

On our way to islands we stop in different dive spots to explore the area and look for more sea turtles, we found and caught a juvenile black sea turtle that was hanging around a black coral reef. Once we got to the island we took a relaxing hike around San José Island, the main island of the Bat archipielago.

During the next days, we will visit a sea turtle cemetery, we will dive with bull sharks, and continue on our way south while we look for more hawksbill foraging grounds! Stay tuned!

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Day 2, July 5th (2/2): Matapalito bay

The local workers for Equipo Tora Carey are great free divers, as they used to be fisherman before turning into conservationists. With their help, we manage to get our hands on five juvenile hawksbill sea turtles from different sizes!!

In the sea turtle life cycle, there is a stage that is usually called "the lost years". This is the time when hatchlings are roaming around the ocean, drifting in ocean currents with no routes or destiny. After several years roaming around, this young sea turtles will come back to coastal waters to feed and grow until they reach maturity (15-20 years) and start laying eggs on the same beach where they where born.

Until now, the whole stage where the sea turtle transforms from a small hatchling the size of the cookie to a 150 pound adult sea turtle its still really unknown. Therefore, when we have the chance of capturing and studying young individuals from a critically endangered population of hawksbill sea turtles, it is greatly satisfying!

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Day 2, July 5th (1/2): Matapalito Bay

Matapalito bay has proved to be one of the most important foraging grounds for green sea turtles and hawksbill sea turtles in the northern pacific coast of Costa Rica.

Sea turtle scientists have debated about the taxonomic classification of green turtles for decades. For some, Chelonia mydas should be considered a single species, even though its populations have different physical traits, the genetics is basically the same.

After several years of studying in-water sea turtle populations in the area, researchers from Equipo Tora Carey have discovered that Matapalito Bay is not visited only by Pacific green sea turtles (that we call black sea turtles, and some scientists consider a sub species of the green turtle) but its also visited by green sea turtles from the Indopacific Ocean, with a distinctive morph and colorations of their shell!!

During our research we had the chance to capture both a black turtle and an indopacific green turtle, we took tissue samples that will be used for genetic studies to help us solve the dilemma of the green turtle. Can you tell the difference?? (Look at pictures)

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Very cool! I didn't know about the black sea turtle. I love the patterns on the green sea turtles - those turtles are beautiful works of art!

I know!! The theory is that after the division of our continents and after the rise of central america, sea turtles in the eastern pacific had to shift their diets from strictly herbivorous to a more omnivorous one, changing the pigmentation on their shells and scales!

I am very sorry for the delayed update, on the field connection was not always available. Now that I'll be staying in the capital for a couple of days I'll be updating the exploration and giving you a very detailed description of the amazing things we encountered!

First of all, I want to thank Lush Cosmetics North America for making this trip happening as well as the crew from the Sharkwater, and the Fins Attached organization.

Day 1, July 4rd: El Jobo

El Jobo is a small community in northern Costa Rica, here the Equipo Tora-Carey (www.equipotoracarey.org)) has been working on foraging grounds and nesting beaches of Pacific green turtles and Hawksbill turtles.

We joined them as we went diving around the site, due to bad visibility we were not able to catch any turtles for our research, even though we did encounter a big female green sea turtle during our test dive.

Tomorrow we will go snorkeling with the locals at a site were sea turtles are frecuently caught as part of the team's research. Hopefully we will have the chance to find hawksbill sea turtles!!

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We have departed!!

The expedition aboard the Sharkwater has officially started!

Tomorrow we will dock at El Jobo, here, the Equipo Tora-Carey has been studying green turtles and ocasional hawksbill sea turtles at nesting beaches and foraging grounds. Barely a month ago, a nesting hawksbill sea turtle was tagged with a satellite transmitter by this team for the first time in Costa Rica! Hopefully they will share some cool information with us!

We will have two morning dives, and in the afternoon we will set up a sea turtle net in order to catch and monitor sea turtles at foraging grounds!

Stay tuned!!

Preparation Stage

For my next field campaign, I will have the support of the SharkWater research vessel. This incredible boat is owned by Fins Attached, and organization based in the United States.
Taken from their website (www.finsattached.org) : "Sharkwater is a 134-foot vessel that was originally built in Japan and used by Japanese fisheries but now has been repurposed for the good of our oceans through the marine research and conservation mission of Fins Attached. Sharkwater will be a host to many different professions within the field. Scientists, non-governmental organizations (NGOs), marine science students, and documentary crews will have the opportunity to conduct fieldwork, and to achieve the objectives of Fins Attached."

Getting very excited about this!

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Expedition Background


My name is Daniel Arauz, I'm a National Geographic Explorer part of the new Photo Ark EDGE fellows (www.edgeofexistence.com). For the past years I have been working with the Rescue Center for Endangered Marine Species (CREMA, www.cremacr.org)) on a recently discovered foraging site for the critically endangered hawksbill sea turtle in the Pacific coast of Costa Rica. My main objective is to track these animals using acoustic telemetry in order to find new feeding grounds, as well as engaging the local communities in the protection and conservation of this emblematic species.

I will be exploring the northern Pacific coast of Costa Rica, joining marine biologists and conservationists on their efforts to protect marine environments in my country. We will be looking for sea turtles, sharks, manta rays, and other marine fauna moving across different sites in order to strengthen the conservation efforts made by the local authorities.


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