Costa Rica - One of the World's Richest Ecosystems (By Audry Dwyer, Chemistry & Environmental Sciences Instructor)

The leatherback sea turtles are critically endangered in 4 of their 7 distinct subpopulations! Only 1/1000 hatchling survive to adulthood. The main causes for the treat to the leatherback sea turtles survival are all human-caused: incidental capture from commercial fishing, habitat destruction, and egg harvesting. These massive reptiles can grow up to 6 feet long, weigh 1,200 pounds, and live up to 60 years. Out of the seven turtle species, the leatherback sea turtles are the largest and can be identified by the seven lines that run the length of the turtle's shell.

 

Last week I was basically a midwife for the sea turtles. At night our team of researchers and environmental teachers would dress in all dark clothing and under the star light go on on four hour beach patrols shifts. Headlamp lights can interrupt the female sea turtles' nesting, so we would walk the black sand coastline in search for tracks or lumps in the sand and water. Once a sea turtle was located, we would collect data on the length of the shell, width of the shell, inspect for injuries/tumors, and count the number of fertilized/unfertilized eggs. On average, sea turtles will lay around 80 fertilized/40 unfertilized eggs in their nest per clutch (5-7 clutches per season). Fertilized eggs are the size of billiard balls and have a strong rubbery shell to withstand the fall into the 70cm deep nest. Unfertilized eggs are visually smaller and can be as tiny as a pea. While the female is laying eggs, one of the scientists would hold the fins to be able to count the eggs. The turtles are in a trance during this process, so we were able to touch the turtle's shell and flipper. After the eggs are laid, the turtle carefully fills the hole with sand. Next, the turtle will spend some time to make false nests in order to trick predators. Being on the sand leaves the turtle vulnerable to predators, such as jaguars. Many of the turtles were injured. One turtle was so injured that she only had half a fin (possibly due to a shark attack) and needed assistance digging her nest. With another turtle, we had to relocate the eggs as the original site was in danger of being eroded by tides. 

 

In addition to sea turtles, I also saw a 2-toed sloth, 3-toed sloth, holler monkeys, white faced monkeys, crocodile, kayman, eye lash viper, keel bill tucan, bullet ants, cocoa plant, walking palm, crabs, giant toads, green/black poisonous dark frogs, blue jean poisonous dark frogs, green iguana, 4 species of bats, leaf-cutter ants, and much more. Out of these animals, the bats were the most fascinating. Bats are one of the most misunderstood mammals. They are not scary blood-sucking rabid animals. The Natural Texas class, which I will be teaching next year, will include a bat unit to educate our SMCA community on one of the earth's most unique mammals.