Coral Reefs
Santa Cruz
Hermatypic (reef-building) corals mostly surround the island. There are also dense aggregations (some mixed-species, some single-species) of massive corals not found in reefs around this island. These ahermatypic corals are mostly found in shady areas (Glynn & Wellington 1983).
Academy Bay is mostly harbors crustose coralline and brown fucoid algae because of the frequent tidal exposure in the months of June-December, but on the south side near Estrada Point one can find 8 hermatypic and 3 ahermatypic coral types. The reef-builders include Pavona varians, Pavona clavus, Pavona gigantea, Gardineroseris planulata, Pocillopora damicornis, P. elegans, Psammocora stellata, and Porites lobata. The ahermatypic corals are Tubastraea coccinea, Balanophyllia galapagensis, and Culicia rubeola. Gardineroseris planulata is only found around Santa Cruz within the archipelago. In Conway Bay there are subtidal pocilloporid patch reefs in a channel that has a strong current (Glynn & Wellington 1983).
Santa Fe
Around this island there is a lot of sand, rock, and shallow turf in the substrata. Coral is mostly found on the northeast shores, with the most development in areas with strong currents. There are a few colonies of Porites lobata that were up to one meter in diameter. There are also some 3-4m specimens of Porites lobata, Pavona gigantea, and Pavona clavus in the lee of the bay. It was found that the Eucidaris sea urchin did not live in these waters because the population of damselfish would remove it (Glynn & Wellington 1983).
Santiago
Around Boquerizo Point there is a lot of hermatypic coral sediment between the depths of 2-10m offshore. There live Porites lobata, Pavona clavus, Pocillopora damicornis, P.elegans, and a few individuals of Pavona gigantea ( Glynn & Wellington 1983).
Bartolome
This island has a lot of sand and rock offshore that is home to algae. There are calcerous sediments in the east and northeast. Coral reefs are found on the south and southwest shores. In the shallows pocilloporids, Porites lobata, and Pavona clavus can be found, but a lot of these colonies are dead due to exposure. At larger depths Pavona varians, Pavona gigantea, and Psammacora stellata are found (Glynn & Wellington 1983).
Cousin's Rock
Here a lot of ahermatypic corals are being overgrown and replaced with colonial ascideans, sponges, and crustose coralline algae (Glynn & Wellington 1983).
MIT