Sonnier Banks

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

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

Sonnier Banks (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 Banks

This fragile substrate has been impacted by anchoring and hurricanes. In fact, Sonnier Banks 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 Banks, 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 Banks
A spotted moray is stretched out across a sectio nof rocky reef by some fire coral and sponges
Habitat and wildlife at Sonnier Banks is very similar to that at Stetson Bank

A video of Sonnier Banks taken during ROV (remotely operated vehicle) and manned submersible explorations is available on our Northwest Banks Videos page.