The first weekend of May, a group of students aged 12-17 worked with the Latin American Sea Turtle (LAST) Association in the Osa Peninsula.

Early in the morning we start packing our stuff on the transportation that will take us to Osa Peninsula.

LAST is part of an international scientific network fighting for sea turtle conservation. With 11 members and a directive board of 5, LAST represents Costa Rica in WIDECAST, which coordinates efforts in more than 40 countries and territories of the Wider Caribbean Region. Their field teams include local assistants with unparalleled experience in sea turtle research and conservation, who coordinate with volunteers and environmental enthusiasts to put into action creative strategies to avoid the extinction of these species.

At Peninsula Osa, LAST Volunteers greet students and explain them their tasks.

The center in Puerto Jimenez focuses on two aspects of scientific research and conservation: 1) the conservation and study of mangrove plants; and 2) the conservation and study of sea turtle species.

Mangroves: An Aquatic Nursery

Mangroves are a type of genus of trees that survives in salty water.

Mangroves are a genus of trees which have the unique ability to survive in salt water. Salt water is a very difficult solution for plants, as the saltiness usually makes it very difficult for the plants to take water into their cells. Plants need to take water in through their roots and move it all the way to the leaves, where it is one of two ingredients required for photosynthesis, which allows plants to make sugars which they can then use for energy.

Mangroves roots provide natural hiding places for small or young aquatic organisms.

Mangroves’ survival in these conditions make them a valuable resource for small animals. When the tide is high, the exposed root systems of the mangroves can be fully submerged. This provides small, natural hiding places for small or young aquatic organisms. Perhaps you have already guessed this, but one aquatic animal that uses mangroves for shelter are none other than baby sea turtles! Costa Rica has several different species of mangroves, two of which are considered highly endangered.

Students work during the day to plant baby mangroves in nurseries.

At LAST, they collect propagules, which are “baby mangroves,” and plant them into pots, providing them with the best conditions for survival. Once they reach a certain size, volunteers take the saplings to the nearby mangrove forest and plant them where they believe they will have the highest chance of survival.

Students help track saplings’ growth.

Once planted, they record the exact location on their GPS, and measure the height and the number of leaves for each sapling. At set intervals, they return to each of the locations to track the saplings’ growth. With this data, LAST is beginning to understand the growth patterns and requirements of mangroves, which will aid reforestation efforts.


Tree of Life International School students volunteered and aided the reforestation process.

Six of seven turtle species found in Costa Rica

In Costa Rica, there are 6 different species of Sea Turtle: the Leatherback; Green; Olive Ridley; Hawksbill; Kemp’s Olive Ridley and Loggerhead. Interesting fact: there are only 7 species in the world, meaning Costa Rica provides a home for all but one species of sea turtles!


Turtles have a large appetite for coral and seagrass.

Every single species of sea turtles is considered Endangered and Protected by the Endangered Species Act. Sea Turtles are very peaceful creatures, but they have a large appetite for coral and seagrass and play a vital role in maintaining coral reefs and seagrass areas. They also provide food for large carnivores as well as small ‘cleaner’ fish who eat algae and parasites off them. The protection of Sea Turtles is very important for the future.

Students of Tree of Life International School go in search of turtles in Osa Peninsula.

Unfortunately humans have caused a lot of damage to their populations. From hunting them for their shells, to catching them as a by-product of fishing, to building hotels on the beaches where they would normally lay their eggs, we have made life harder for them and their populations have declined.

Sea turtle population has decreased due to human intervention in their habitats.

Organisations like LAST work to better understand the migratory patterns of Sea Turtles with the hopes that they can find more ways to protect them. They also provide much needed medical attention when they find a turtle that has been injured.


Tree of Life International School students earned their community work hours while taking pride in their positive impact on the environment.

While working with LAST, students had a chance to help out with the scientific studies. It was fantastic to see them working as a team, despite the wide range in age. The weather was hot and humid, the sun was harsh (anyone who saw my sunburn would understand!), yet the students took pride in making a positive impact on the environment. Following our trip, I have been talking with the LAST team to organise regular trips so we can continue the work we started this year.


Students of Tree of Life International School had the amazing experience of volunteering with LAST (Latin American Sea Turtle).

Text by Graham Jackson

Photographs by Leandro Natale