Variability of cold-water coral mounds in a high sediment input and tidal current regime, Straits ofFlorida

Cold-water coral mound morphology and development are thought to be
controlled primarily by current regime. This study, however, reveals a general
lack of correlation between prevailing bottom current direction and mound
morphology (i.e. footprint shape and orientation), as well as current strength and
mound size (i.e. footprint area and height). These findings are based on
quantitative analyses of a high-resolution geophysical dataset collected with an
Autonomous Underwater Vehicle from three cold-water coralmound sites at the
toe of slope of Great Bahama Bank. The three sites (80 km2 total) have an average
of 14 mounds km)2, indicating that the Great Bahama Bank slope is a major coral
mound region. At all three sites living coral colonies are observed on the surface
of the mounds, documenting active mound growth. Morphometric analysis
shows that mounds at these sites vary significantly in height (1 to 83 m), area (81
to 6 00 000 m2), shape (mound aspect ratio 0Æ1 to 1) and orientation (mound
longest axis 0 to 180 ). The Autonomous Underwater Vehicle measured bottom
current data depict a north–south flowing current that reverses approximately
every six hours. The tidal nature of this current and its intermittent deviations
during reversals are interpreted to contribute to the observed moundcomplexity.