Bermuda is located about 1000 km east-southeast of Cape Hatteras and 1400 km from the nearest coral reefs in the Florida-Bahamas region. It is bathed by the warm waters of the Gulf Stream, where they eddy into the Sargasso Sea, and thus enjoys a sub-tropical climate rather out of place for such a latitude (32 degrees, 20 minutes North).
Bermuda's marine fauna and flora are derived from the Caribbean province by way of ocean currents. Faunal and floral diversity is considerably lower than in the Caribbean. The number of coral species, for instance is a mere 22 compared with the 72 known in the Caribbean. Nevertheless, the reefs are well developed and show many features comparable with Caribbean reefs. The most noticeable absence is the coral genus Acropora which is very prominent in the Caribbean and Pacific reefs.
What we see in Bermuda are young coral reefs dominated
by species which rose to prominence over a short span of evolutionary time
and in an isolated, semi-enclosed sea in conditions very much like the
present. Thus, despite the prolific life in the Caribbean reefs, the fauna
is considered impoverished as compared to older, larger and richer Pacific
fauna. For example, the Caribbean is known to have 27 genera and 48 species
of coral; The Pacific boasts 90 genera and some 600 species. The Caribbean's
geologic history also accounts for the prominence of certain species among
it's fauna, such as the gorgonian coral, the familiar sea whips, and sea
fans, species which are less significant in other seas.