Feeding Honus

Green sea turtles (Chelonia mydas) spend their early life history stages in the open ocean where water depths are >200 m. Here they feed mainly on plankton, the tiny algae and microscopic animals that are at the base of the food chain in the open ocean. After several years of the early developmental stage, they leave the open ocean and come to live close to shore. Here, green sea turtles become vegetarians. In the Pacific ocean and in Hawaii in particular, they prefer seaweeds.

 

There are several good feeding areas for sea turtles in shallow water around Maui county. In these rocky intertidal zones, sea turtle congregate to graze on the algae.

 

We are designing a study of one of these feeding areas, located along the Ka'anapali coastline. Right now, we are testing our equipment, designing protocols for sampling, and trying to understand the best times of day to conduct the study. 

 

Our observations show that turtles come to the feeding areas in the afternoon. They feed on a preferred species of red alga, limu loloa (Pterocladiella), but they will eat other kinds of limu as well.

 

To get to the food source they actually fight the surge and hang on for dear life to the rocks to get to the precious algae. It is amazing to watch how determined these turtles are despite being tossed around by the waves. A person in the same situation would get bruised and cut and probably not fare as well as the turtles.

 

We photographed a large male braving the surf at our study site.