Sonnier Bank

Color bathymetric map of Sonnier Banks
There are 8 separate peaks at Sonnier Bank

Bottom Depth Range: 65-315 feet (20-96 meters)

Sonnier Bank (formerly known as Three Hickey Rocks and Candy Mountain) is located approximately 42 km (26 mi) north northeast of McGrail Bank, and 120 km (74 mi) northeast of East Flower Garden Bank. Like Stetson Bank, it is a mid-shelf bank made of uplifted siltstone and claystone.

There are eight separate peaks associated with this salt dome. Each is a nearly conical feature formed of uplifted sandstone, claystone, and siltstone and rising up to 30 m (98 ft) from the surrounding sea floor. Two of the peaks are within recreational diving depths.

A colony of brown sponge looks like miniature volcanoes encrusted on a rocky outcrop next to some fire coral
Sponges and fire coral dominate the crests of Sonnier Bank

This fragile substrate has been impacted by anchoring and hurricanes. In fact, Sonnier Bank sustained severe damage during the passage of Hurricanes Katrina and Rita in 2005.  It has been suggested that the level of damage from the hurricanes was directly related to earlier weakening of the substrate by chronic anchoring from vessels visiting the bank for diving and fishing activities.

The reef crests of Sonnier Bank, like Stetson Bank, are characterized as coral communities featuring fire coral, sponges and algae, as well as the invasive species, Tubastraea coccinea. Deeper habitats contain extensive mesophotic communities.

Sonnier Bank is a Habitat Area of Particular Concern (HAPC). It is named for Farley Sonnier, an offshore wildlife photographer.

Bright orange, brown and orange, and brown sponges cover a section of rocky reef amid a bunch of fire coral
More fire coral and sponges at Sonnier Bank
A spotted moray is stretched out across a sectio nof rocky reef by some fire coral and sponges
Habitat and wildlife at Sonnier Bank is very similar to that at Stetson Bank


The following video is a compilation of footage taken during ROV (remotely operated vehicle) and manned submersible explorations at Stetson Bank.

0:00 A bathymetric map of Sonnier Bank followed by a variety of footage in an area about 100-145 feet deep (30-44 meters):

0:08 Large patch of fire coral surrounding an orange cponge, bicolor damselfish, soldierfish, sergeant major, rocky reef, sponges, spotted drum, brown chromis, longspine squirrelfish, queen angelfish, rock beauty, wrasses, parrotfish.

0:38 Shark cruising overthe reef.

0:47 Four juvenile African pompano swimming with long trailing fins.

0:54 Abandoned fishing net on the sea floor.

1:02 Algal/sponge reef, ocean triggers, creolefish, rock beauty, spotfin hogfish, ling, snapper.

Video Length: 1:24

Credit: FGBNMS