So on my field trip for tropical marine biology, we traveled down to the Caribbean shore to snorkel on the only coral reef in Costa Rica.

Here you can see a large piece of brain coral and 2 black sea urchins stationed near it.

Along the coast we found a variety of marine life such as sargassums, sea hares, urchins, brain coral, parrot fish, and even a nurse shark!  Cahuita is a National Park in Costa Rica, meaning that it has laws and regulations stating that nobody can build land or do any type of human expansion on or in certain proximity of the area.  They made Cahuita a National Park to preserve the coral reef and the biodiversity it houses.

This sea hare can be found towards the bottom of the ocean in shallow waters, or attached to rocks by the shore.  Its defense mechanism is secretion of the jelly-like ink featured in the picture.  This occurred when my teacher proceeded to pick it up.


Before our first dive into the water we were given plastic underwater writing slates and Ticonderoga pencils (because “the mechanical pencils would not work” our teacher told us) on which we would take notes while in the ocean!  It was fascinating to be able to examine the creatures we had learned about and document our observations.

Here is a parrot fish I saw swimming in the shallow waters of Punta Uva

Along the shore of Cahuita National Park is white sand, but just a couple miles away in Puerto Viejo lay a black sand beach.  We went to visit it after snorkeling, and learned about the sulfur levels that cause the sand to turn black.  When you dug into the sand, all underneath was still darkly colored.  I had never been to a beach like this until I came here to Costa Rica.  The shore I was so deeply familiar with back at home felt like a world away as I stood in the tar-colored grain and gazed out into the Caribbean.


Black sand beach of Puerto Viejo