Introducing the 2018 Field Team: Tara Cousins

Howdy all,
My field season this year requires me to stay from June to mid-September in order to sample from the July, August and September arribadas. However, my students in the US (Ryota, Matti, Nicole and Alexis) all need to return to classes by the end of August. Luckily, I received very qualified applications from two recent graduates from Northern Ireland that could stay to help me through solitary nesting and September arribada sampling! They have been working with us for the last two weeks, and now I am pleased to introduce the first of our second stage team, Tara Cousins.

Hi, my name is Tara Cousins and I am a recent BSc Marine Science graduate from University of Ulster. I am extremely grateful to have this opportunity to assist Brie and her amazing team on their Olive Ridley sea turtle research project here in Costa Rica.

Introducing, the intrepid Tara Cousins!

 

Last year I was fortunate to gain a 7 month work experience in Tahiti, on the beautiful island of Moorea (French Polynesia) as a research technician. There I was able to acquire and develop the practical skills necessary for conducting Marine research both in fieldwork and Lab work. My project while I was there was to assess and monitor if the larval behavioural syndrome of the Amphiprioninae Chrysopterus (clownfish) was due to genetics or parental influences (nature vs nurture). To do this I had to acquire my sampling, I developed my diving skills and was able to become Sports diver certified as well as gain my boats licences.  As well as conducting my own research project, I was able to help other projects that were being conducted at the station: such as other clownfish projects involving hormone/stress balances, as well as helping with coral collection, assisting with catching, measuring, tagging, Identifying sex and DNA sampling of juvenile black tip reef and lemon sharks. I am very interested in animal cognition, behaviour and personality, as well as marine conservation. I have always been enthusiastic and intrigued by wildlife & Marine life, maybe like my research project in Tahiti this trait/drive I have is due to parental influences, as both my parents and my grandfather have an infectious passion for the sea.

I was drawn to this olive ridley turtle project as I currently have no experience working with Chelonioidea and wanted to develop my knowledge and skills with these magnificent creatures.  I am extremely excited to be a part of this team with Brie and to be gaining new insights from an expert in the field;  experiencing my first  Arribada, increasing my knowledge on turtle physiology,  mating and nesting habits as well as learning blood sampling and ultrasound imaging.  All this with a added bonus of experiencing a new culture and developing my very limited Spanish skills.

In October I will be commencing the next stage of my education at the University of Essex (Colchester) with a one year Master’s degree in Tropical Marine Biology. During this year I also hope to complete a Marine Mammal Medic training course with the British Divers Marine Life rescue as well as a Marine Mammal Observer Course, yes this will be a very busy year for me.  My ultimate goal is to eventually complete a PhD, but until then I will continue to do my part by volunteering, assisting, learning whenever and wherever I can.

The ocean contains many unanswered questions and I am on my journey to FIND my question to answer.

Ostional: Home of the Only Legal Sea Turtle Egg Harvest

One of my main goals as a mentor to my students is to offer them an opportunity to experience other cultures in an authentic way. When immersed in another culture, we often experience another way of thinking that can make us uncomfortable. I feel it is important to sit in that discomfort, and think deeply about why this situation makes us feel uncomfortable. Maybe even more important is to consider this other way of thinking while attempting to put one's own personal feelings aside. I think Matti Bradshaw has done a great job of fairly analyzing both sides of this issue, and she has presented some of the key issues that are being faced with the legal egg harvest in Ostional, Costa Rica in the following blog post. You can find out more about Matti here.


Costa Rica is a country rich in various customs that differ from those in the United States. The cultural exposure our team members have experienced in the last month has been eye-opening. Our host families and the town of Ostional have all been very welcoming and inclusive of us (even when our Spanish skills are slacking). The latest immersion experience was the Ostional Egg Harvest festival, which took place down the street from our houses. 

A large pile of olive ridley turtle eggs following cooking.

     The Egg Harvest Festival was filled with music, trampolines, cotton candy, a lot of Imperial (a local Costa Rican beer), and even traditional Costa Rican dances performed by some of the local children. Near the entrance of the festival there was a man selling plates of harvested sea turtle eggs to people as they walked by. The sight of so many sea turtle eggs in one place can be a little unsettling to a group of students dedicating their time to the conservation of the species, and I couldn’t help but wonder whether or not this practice is actually healthy for the population of Olive Ridleys. 

Brie learning to dance from the locals.

A few turtles remained the morning of July 5th. 

    To give a little bit of a background on Ostional, it is a seaside town that attracts many volunteers and tourists for the presence of its arribada beach. An “arribada” is a term used to describe the presence of mass nesting groups of Olive Ridley sea turtles that arrive once a month. During these mass nesting events thousands of sea turtles come ashore to lay their eggs. It is not known exactly what signals them to come ashore, but many believe it may be their ability to detect magnetic fields caused by moon cycles. The culture in Ostional is represented by sea turtles that appear on apparel, wall art, and in conversations constantly. Sea turtles are a way of life here.

     In the years prior to the turtle projects that have taken place in Ostional, the area was impoverished and the future appeared bleak. However, now due to the income from tourism in the last fifteen to twenty years there is a much higher quality of life and improved infrastructure. The tourism associated with the arribadas has produced many jobs for the people of this town. These jobs include tour guides, government officials related to running the Ostional Wildlife Refuge, Guardaparques that protect the beaches from poachers (this includes our host father, Pablito), and even income from harvesting the eggs. 

     The beach of Ostional has a very low success rate for hatchlings due to monthly arribadas that lead to anoxic conditions produced by the high number of eggs which decay in the sand, so during the first few days of the arribada locals are allowed to enter the beach and dig up eggs under the surveillance of the Guardaparques. Sea turtle eggs are a hot commodity in many Latin American countries, since they are believed to be an aphrodisiac that stimulates sexual potency in men. Many times, illegally harvested eggs from Leatherback sea turtles (Dermochelys coriacea) and Green sea turtles (Chelonia mydas) are sold in place of Olive Ridleys-whose eggs are noticeably smaller than many other species of sea turtle eggs. The argument that has been made is that allowing more of the less endangered Olive Ridley eggs to enter the market reduces poaching of the more endangered Green and Leatherback sea turtle eggs, since the believed presence of an aphrodisiac is not unique to a specific species.

     There is a lot of tension in Ostional when it comes to the discussion regarding the population of Olive Ridleys and whether or not the practice of harvesting eggs is sustainable. There are currently not any studies being done involving this topic, but it is estimated that around 5,000 eggs were collected when the July arribada was very short and probably did not exceed 10,000 eggs laid. The 5,000 eggs collected does not include the number of nests that are depredated upon by vultures and raccoons or the number that are lost to the anoxic conditions in the sand. As we left the beach each morning after a night of working the arribada, locals (including our host mother, Marilyn) walked in the opposite direction to begin harvesting eggs. The eggs are allowed to be harvested during the first seventy two hours after the arribada is announced, but arribadas in the wet season only last 3-5 days on average. The egg harvest period is not adjusted for these shorter arribadas, so locals are allowed to harvest the eggs after each night the mass nesting groups come ashore. Locals here claim that they only harvest 1% of eggs laid during arribadas, but there is not a lot of research to investigate this.

     Ostional is one of twelve Olive Ridley mass nesting beaches, so the species is not necessarily dependent upon the sustainability of this beach. However, hatchlings imprint on the beaches they are laid on, which will draw them back here in the future to lay their own eggs. If sea turtle eggs are being overexploited, there could be astronomical impacts that will not be known for years to come. 

Traditional Guanacaste dancing.

A large pile of empty turtle egg shells on the beach, likely depredated by vultures or dogs.

A batch of olive ridley turtle eggs cooking.

There is currently not enough research to support arguments for or against the harvest, so it is difficult to make suggestions on how the locals should control their own natural resources. Many locals believe that population estimates have been underestimated by researchers, so there is not a present worry regarding the sustainability of the arribadas. There are many positive and negative effects surrounding the egg harvest, but if the eggs are in fact being overexploited the way of life in Ostional will be forced to change dramatically. 

Arribada 1 and Special Visitors

One of the most critical parts of my project this summer is recapturing females on the nesting beach. We had a tough go of our first arribada due to the fact that it was very short lived and quite small, so we're hopeful to capture many more turtles in the August arribada. Alexis High and Ryota Masuko had a blast working the mass-nesting event and recount their experiences in the following blog, you can find out more about Alexis High here and Ryota Masuko here. 

            The arribada is a fantastic event that happens once a month on a dozen beaches across the world. This phenomenon is a large-scale nesting event where hundreds to thousands of sea turtles come out of the ocean to perform their motherly duties. By studying the arribada, we hope to find the females we caught during boat work. We will take and compare the data we obtained to later draw conclusions for Brie’s research.

Ready for night work! From left: Nicole, Ryota, Alexis and Matti with Brie in the front.

July 3^rd  Training day

            It was 9 pm, we were all filled with excitement as Brie lead us to the beach, where we found a female who recently came out of the ocean (stage 1 of 7 for the nesting process). Eventually, she finds the perfect spot and begins moving her back flippers- this is called body pitting (stage 2).

Soon after, she begins to dig her nest by scooping the sand out using her back flippers (stage 3). When we noticed that she was almost done digging, Matti laid down on her stomach and widened the nest to allow her to reach below the turtle’s cloaca to catch the eggs (stage 4). Then Matti caught ten eggs and laid them softly on wax paper for Nicole and Alexis to take the eggs’ mass and circumference. While Alexis and Nicole worked, Matti continued counting the eggs. Once the turtle laid twenty eggs, Brie (with the assistance of Ryota), took a blood sample while the turtle was fully in her trance. A trance is a mental state where a female will continue to lay her eggs and cover her nest even when we are working with her. After the turtle finished laying eggs, Alexis put the ten eggs back into the nest. The turtle then covered her nest by using her back flippers to fill the nest and moved her body side to side to pack down the nest (stage 5). Then we all took the weight, length, width, and circumference of the turtle. Next, the new mama moves all four flippers in a snow angel pattern in hopes to camouflage her new nest (stage 6). Once she successfully hides her nest, she goes back to the ocean (stage 7).

We all stayed on the beach till midnight, but Brie and Matti went back to the beach at three and found one of our tagged turtles from boat work.

July 4^th Day One of the Arribada

            The day started at 6pm, we searched and searched for our tagged turtles to no avail. Around 8pm, Chris, Dillon, and Dr. MacKenzie showed up to help us out. They happened to find one of our tagged turtles from the get go, and we all jumped into action performing the procedures stated above. Once we finished with collecting data from our first female of the night, we continued our search for more. We found many Ostional turtles (turtles tagged with Ostional tags) and a few solitary beach turtles (turtles tagged with solitary beach tags) but none of our own. We took measurements of the solitary turtles so Brie can look at their feeding patterns, and try to see why the female chose to lay her eggs during the arribada rather than as a solitary. In total we found one of our tagged turtles and many Ostional turtles.

            On a more personal note, it was a beautiful night; the moon was half full with very few clouds in the sky. The light of the moon helped to illuminate the shells of the turtles who had just come out of the ocean. That, and the random bursts of heat lightning would light up the area around you to allow you to see the hundreds of turtles that surrounded you at that moment. We ended the work day at 5am with the rising of the sun.  

July 5^th Day Two

            Again, we started the day at 6pm. Today, there were only a fraction of the turtles we saw the previous day. A lot of these turtles were handicapped in one way or another. Some were missing flippers and some had spinal cord issues making it very difficult to properly use their hind flippers. Due to their issues, they cannot properly form a nest and will not lay their eggs. These turtles will come back every day of the arribada to try and make a suitable nest, but eventually the females will get too tired and lay their eggs anyway. Sadly, these eggs will have no chance of survival. For a few of these turtles, we helped them build their nest to give her eggs a better survival rate.

            Due to the lack of turtles this night, Brie sent a few of us home early at midnight. This night we found a few Ostional turtles, but none of our own.

           

What’s next?    

Overall, this month we experienced a rather short arribada consisting of only a few days. We hope to have a larger arribada next month and find more of our tagged females. Working the arribada is a very exhausting process; however, seeing hundreds of female turtles come out of the ocean to do their part in the success of their species is absolutely beautiful. I am so proud to say I have had the luck to be able to see this amazing natural event, and I look forward to working the next arribada in August.

Stage One: Boat Work

Puerta de San Juanillo where we rent boats from the artesanal fisheries association (ASOPESJU)!

Post written by Alexis High! Learn more about Alexis here!

For the first stage of Brie’s project, we captured as many post-mating couples as we could from the ocean just off of the coast of Ostional. After getting the turtles onto the boat, we took measurements, ultrasound images and blood samples, and then painted the females with a large T (for Texas A&M) in hopes to find the females during the following arribada. For Olive Ridley sea turtles, the arribada is period once a month that all the nesting females come out of the ocean to lay their eggs in a mass nesting spectacle. For this blog I will lay everything out as if you were here with us and explain as we go, you ready! Let’s go!

            It is 5:20 AM, rise and shine, Matti and I wake up, shovel down our breakfast and meet up with everyone else. Everyone gets in the car and we are on our way to San Juanillo. After a short singing session to the Pokémon theme song and/ or Despacito, we make it. We unload all of the equipment and hurry to meet with the Capitan, Don Santiago and Justin (the local assistant that helps us catch the sea turtles). We get on the boat and here we go!

Justin, our tortuguero extraordinaire and excellent local assistant, Matti, Ryota and Brie with a male we recaptured!

            We search with excitement over the crashing waves to try and find a mating couple, we search for their shells slightly upright and their flippers up in the air as if they are waving at us. Don Santiago has the best eyes and always finds the turtles before any of us. He yells, “PAREJA! PAREJA!” (a pair!) and Justin and Ryota (or Justin and Matti) jump into action by putting on their scuba masks, jump in, and swim to the post-mating pair. First, they make sure that intromission is no longer occurring, and then one of them pries the male off of the female by gently removing his claw that is attached to his flipper that is hooked onto the female’s shell, which disconnects the two turtles. Then one person grabs the male and the other grabs the female and presses the carapace of the turtle’s shell to their torso and bringing the turtles mouth above the water. Then, they swim the turtles over to the boat and we gently set the turtles inside the boat, cover their face with a towel to calm them down, and we begin data collection.

Ryota and Matti move the post-mating couples toward the boat.

            First, we start with the male. One RA (research assistant) writes down all of the specific details of the capture such as the time we caught the pair, the GPS location, and all of the measurements later recorded. As the RA is writing that down, Brie starts out by taking a blood sample while another RA holds the head of the turtle in place. The blood is quickly put in the cooler filled with ice in hopes to keep the blood in the best condition for later testing. Then, a RA takes measurements such as carapace length, width, and circumference, while Brie takes an ultrasound in the shoulder region of the male to measure the size of his fat layer.

Brie assists with keeping the turtle restrained and calm.

The olive ridley takes a big breath.

We then weigh the turtle. Finally, we tag the turtle and set him free. Then we move on to the female where we use the same procedure, except that before we get a blood sample Brie takes a gonadal ultrasound of the female in her hip region to look for follicles, atretic follicles, and eggs. This tells Brie a bit about where the female is in her reproductive cycle. She also takes this ultrasound to see if the turtle has full intestines or not to see if the females are eating during the breeding season, which is a critical part of Brie’s hypothesis.

Brie takes a blood sample (permitted by IACUC, and CONAGEBIO!)

After that, we continue using the same procedures as we did for the male; blood, shoulder ultrasound, measurements, weight. Then we clean the females shell and paint it with non-toxic tree marking paint in hopes to find her during the following arribada. Once the paint dries, we tag her and set her free. ¡Hasta luego mamá! See you later! We take measurements of the females post-mating and during the arribada to compare her hormones and measurements between the two events, which is again a large part of Brie’s research.

Ryota measures the olive ridley.

            During the times we were searching for pairs we saw a variety of wildlife such as manta rays, dolphins, crabs, needle fish, and a sea snake-yikes. 

            Boat work was a success in that we far exceeded Brie’s goal and captured 64 turtles- 32 pairs! No one got bit and the only casualty of the boat work was my phone. May she rest in peace in the bottom of the ocean. With that aside, we were all extremely happy with our work and were rewarded with pizza and gelato. A pretty nice pay off if I do say so myself. Hopefully, we will see the 32 females later during the next arribada which will be in early July. Fingers crossed and knock on wood!

The crew prepares to release the turtle. From left to right: Nicole, Matti, Don Santiago, Ryota and Justin.

A needlefish accidentally jumped into our boat! We immediately released the fish after this photo.