Uncategorized

The Battle: Sea Turtles vs. Predators!

Blogpost by Manuel Sanchez, Sea Turtle Conservation Program Coordinator

 

Nature is not always kind; sea turtles face a multitude of life threatening obstacles that reduce their chance of survival throughout their lives. Predation of eggs, hatchlings and adults by numerous predators is just one of the risks. Raccoons, coatis, opossums, crabs, dogs, birds and ants attack nests to indulge in an egg or a young sea turtle. Once the hatchling emerges from the nest, the challenge continues as hawks, pelicans, frigate birds, crabs and fish await a bite-size meal.  Once the hatchling defeats the odds of predation in their younger years, they reach adulthood where they are relatively safe from  such threats, excluding the occasional shark attack.

turtle-1

Photo by Manuel Sanchez of a sea turtle hatchling making its way into the ocean

In the Osa, the coati populations have increased largely because of a change in the ecosystem balance with a decline of apex predator populations due to habitat loss and hunting. As the number of coatis increases, more of them are taking to the beach in search of food and often finding sea turtle eggs for their dinner. This unbalanced ecosystem is having a cascading impact on the survival of these sea turtle nests and increasing the need for us to help protect these vulnerable nesting areas.

Photo by Janell Canon on predation by coati and birds

Photo by Janell Canon of predation by a coati and birds

Unfortunately, natural predation is only one of the factors contributing to sea turtle population decline. Human actions can also have more of a direct threat to sea turtle survival.  In many coastal communities, especially in Central America, sea turtle eggs and meat can be a source of food and income, although often illegal. During peak nesting seasons, turtle poachers have been known to raid the beaches at night looking to steal eggs from nests, which can unfortunately are often sold to those willing to pay. 

Here on Playa Piro and Peje Perro, sea turtle nests are threatened more by predation than poaching. Our Sea Turtle Conservation team works hard to reduce human-induced threats and to restore the natural ecosystem balance needed to save the sea turtles. This year, our sea turtle hatchery has already protected over 200 sea turtle nests and helped us to release over 7,000 hatchlings already this year! We are greatly appreciative of all our our conservation volunteers & visitors that help us protect these amazing and ancient creatures! Click here to learn more about volunteer opportunities with our Sea Turtle Conservation Program!

Sea Turtle Hatchery

Our Sea Turtle Hatchery in the Osa

 

Aquatic Health, Community Outreach, Uncategorized

Rios Saludables First Workshop in Colegio Puerto Jimenez

Blogpost by Hilary Brumberg, Ríos Saludables Program Coordinator 

Students in bright blue uniforms dip nets into a small stream and retrieve soggy masses of leaves, branches, rocks, and candy wrappers. They comb through the leaves with plastic spoons, and excitedly pluck small insects and crustaceans from the foliage and place them into the stream water filled ice cube tray  – our fancy specimen holder.

The students rush the specimens over to our identification station, a tree stump bearing a laminated booklet with dozens of pictures of aquatic critters. They methodically scan each page of the identification guide, enthusiastically pointing at pictures that look like their specimens. When these young scientists finally decide on the identity of the critter swimming around their tray, they return their specimen to the stream and begin fishing again. Other groups of teenagers wander around the stream in pursuit of litter, tossing snack wrappers in black trash bags to help clean the streams.

Students identifying macroinvertebrates

Students identifying macro invertebrates

These students attend Colegio Industrial Técnico Puerto Jiménez, one of two secondary schools on the Osa Peninsula and the closest one to our biological station. In the yard behind their school is Cacao Stream.  Students usually eat lunch alongside the stream, and often snack wrappers mysteriously make their way into the stream.

Today, these students are surveying the stream for macroinvertebrates, mini mighty organisms that are bio-indicators for river health. Many of the students had never thought twice about Cacao Stream, let alone the crustaceans and insects that call it home.

A group of students measuring the water

A group of students measuring the stream quality

This field activity is part of Rios Saludables’ first ever workshop with the Colegio Puerto Jiménez. Before heading to the stream to sample, I began the workshop with a presentation, assisted by one of the program’s community partners.

We discussed the importance of water and specifically rivers for nature and humans. Reasons they suggested included sources of drinking water, important ecological habitat, and nutrient transport.

One of my favorite parts of these presentations is to show a map of Osa’s expansive freshwater network. Rivers and streams expand like a spider web across the peninsula in every direction. Students always gasp when the map is projected, because they realize the extent that the peninsula’s ecosystems rely on rivers.

Hillary and some of the students

Hilary & students analyze their collections

A trademark Rios Saludables saying is “the problem with water on the Osa is not quantity, but rather quality.” This leads nicely into an explanation of the ways we determine water quality, namely water chemistry tests and macroinvertebrate surveys. These students had recently learned about pH and alkalinity  in their chemistry class, and I described what ranges indicate that a river is healthy. Then I passed around samples of macroinvertebrates I collected with community partners across the region, many from rivers close to students’ homes.

Now it is time for these newly ordained freshwater ecologists to head to Cacao Stream to practice these surveys.