Sombrero Reef by Michelle Burklund and Nathan Freeman

Bermuda Chub and Yellowtail Snapper Photo: Dr. Joshua Voss

Sombrero Reef is a barrier reef in the Atlantic off the coast of Marathon Key. The water on the reef was clear, though the wind made the surface choppy. Even beneath the surface, the system was still high energy, and tossed around divers. Barrier reefs like this one decrease wave energy as they approach shore, protecting the coastline from waves like the ones we experienced. Depths ranged from 2.5 to 3.5 meters. The bottom of the reef was sandy, with a diverse coral community. This sediment was finer than other sites visited, as it was created by bioeroders such as parrotfish feeding on the corals.

Dendrogyra cylindrus Photo: Dr. Joshua Voss

Palythoa caribaeorum on Sombrero Reef Photo: Dr. Joshua Voss

The reef provided a diverse habitat for many species of fish, including multiple species of Angelfish, Butterflyfish, and Damselfish, as well as others. Yellowtail snapper and Bermuda Chub were easy to observe because they swam right up to the boat to eat the results of numerous cases of seasickness. On the bottom, the corals included Dendrogyra cylindrus (Pillar coral), Montastrea cavernosa, and Sidastrea siderea, though in total there were around sixteen species. Competing with the coral for space was Palythoa caribaeorum, a hydrozoan which superficially appears similar to coral but does not calcify. The algal diversity was limited on the reef, but included some Sargassum, Halimeda, and various Cyanobacteria.