Pura Vida! Volunteering for Olive Ridley Sea Turtle Conservation in Costa Rica

Hello readers!

My name is Reid Vender, and I am excited to be the Database Management & Website Development Assistant here at BIO this summer. I have just completed my second year at Western University in medical health informatics, where I’ll be using the computer skills I’ve learnt to spice up the BIObus blog and manage an all-new online database, cataloging body mass values for all the specimens collected at BIO. However, it’s another side of my passion for nature and biodiversity which I’ll be sharing with you in this post.

I descended through four cloud layers onto rolling hills, speckled with the peach terracotta of small villages lining the ridges which formed a network of grandiose mountains. Costa Rica is where I spent the month of May, volunteering at the Ostional National Wildlife Refuge with turtle conservation. This was my first experience out in the field, and my first experience immersed in Spanish culture!

Excitedly, we started our first day at 6:30 a.m. to beat the heat, which is regularly 40˚C. Shovel in hand, we trek to the untouched blanket of sand coating the glistening, morning beach. “1 m2 wide by 0.5m deep, dig and search,” is our pursuit for nests containing hundreds of turtle eggs from the last “arribada” (where thousands of turtles come ashore to nest and lay all at once). Our research is regarding the hatching success of Olive Ridley sea turtles, so our goal is to determine which stage of development each egg arrested in development, as all the nests dug up are past their incubation period. New nests are always re-covered to prevent disturbing the delicate balance of moisture and temperature that is necessary to hatching success. Mold and fungus-infested nests are common too, and these are chucked to the surface to degrade away from the new nests and cease the potential spread of these pesky substances.

A turtle egg arrested in stage 2 of development. The head and body begins to take shape.
A turtle egg arrested in stage 2 of development. The head and body begins to take shape.

In addition to these excavations, we go on scheduled patrols of the beach from 10 p.m. to 2 a.m. to search for turtles. There is no light pollution here, and a sheet of stars forms a cover poked with holes. The moon shines so brightly, we can see our shadows. The sand shines like black vinyl, and the white noise of the crashing waves is its only track. Surprisingly, turtle tracks stand out unbelievably darker than our surroundings and only with our torches off. We trace up the path to find our first turtle. In a trance, she practices soft, rhythmic breathing, and water streams slowly from her salt glands around her eyes, which gives the illusion of a mother crying tears of joy during birth. But we have to snap out of our trance because it is our job to record where the turtle is laying, measure nest depth, her dimensions, and the number of eggs which are laid. As soon as she is done, we quickly tag her fin; it is believed that a turtle returns to the same beach as the one which it hatches on.

Counting turtle eggs as they are hatched.
Counting turtle eggs as they are hatched.

Ostional is the only place in the world which still allows the harvesting of turtle eggs by the population there, and the Ostional National Wildlife Refuge aims to make this harvesting sustainable. Throughout their many years of research, it has been shown that the eggs laid in the early portions of arribadas have a very low hatching success due to other turtles, which come later, digging up these nests, and fierce competition between the millions of eggs which are laid on top of each other in these two days. It is these eggs which are the only eggs allowed to be harvested legally, and the process is highly regulated and documented. From my personal observation, it is a great practice which allows the small, local town to retain this massive part of their culture, nonetheless there is controversy regarding this tradition and I can respect both sides of the argument.

A nest of turtle eggs being laid.
A nest of turtle eggs being laid.

I had a profound, small taste of coastal, Costa Rican culture in my month spent in Ostional, and I’m excited to share more of my experience in my next post with you.

Until then fellow BIO buffs,

Reid

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