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CAY SAL ARRIVAL Mission Dispatch 4 - April 7, 2005 | Mark Schrope - @SEA Correspondent Elbow Cay, Cay Sal Bank Late last night we made it to Cay Sal through four to six foot seas. The area was first mapped by the Spanish in 1511, according to an article by Jeremy D'Entremont 
in Lighthouse Digest Magazine, and claimed for Spain
by Ponce de Leon two years later. I first read about this place 15 or so
years ago in Ned Deloach's invaluable Diving Guide to Underwater
Florida. He tacked on one page about Cay Sal to the end of older editions of
the book, but for some reason dropped it from the newer edition. The brief
description spoke of desolation, colorful reefs, sheer vertical walls,
underwater caves, and clear lagoons, and I have wanted to visit ever since.
The morning was pretty grey, which seemed to fit the place. The small islands here, at least the ones we can see now, are indeed desolate, all rock and almost no vegetation save for scrubby vines and a single patch of trees. On one island called Elbow Cay (not to be confused with the inhabited Elbow Cay in the northern Bahamas, which has a famous red and white striped lighthouse) are the remains of a lighthouse that was built in the 1800s. DESOLATE SPLENDOR "The bleak topside scenery contrasts sharply with the compelling underwater beauty," according to Deloach, and that is precisely what we have found. One team dove a shear wall this morning down to about 150 feet. The current was strong, and at that depth you can only stay for a short while--their dive was less than 20 minutes--but they found extremely healthy coral and huge blue iridescent vase-shaped sponges as well as a variety of sponge samples for processing. One of the few descriptions of dives in the area that we were able to find said whale sharks often visit the wall, but none showed this time around. 
In the afternoon, a second group took the small boat near one of the
islands for snorkeling. The rocky island had steep walls down to 20 feet
or so that harbored a variety of fish, sponges, and corals, including a
few elkhorn corals, which are now all but nonexistent in the Florida
Keys save for their skeletal remains. We've heard that some of the larger Cay
Sal islands have tunnels cutting into them that lead to small lagoons,
but at our location we found only caverns cutting up under the walls.
We were exploring on the ocean side of the islands, fairly protected from the 20-knot winds that have been blowing since we got here. Climbing up onto the island we were able to see the actual sandy Cay Sal bank, around which the islands fringe. The seas were pretty rough. however, the deeper water there, which is about 35 feet throughout the bank, was deep blue and inviting if the winds die down or switch direction. FIRST DEEP PEAK Deloach only had the pleasure of scuba diving, but his description notes that one of the walls plunged to 1,200 feet. As far as we have been able to tell, this morning's first Johnson-Sea-Link (JSL) submersible dive was the first time that anyone has ever been able to see the wall's deeper reaches face to face. Amy Wright was in the sphere with Don Liberatore for a dive to 1,000 feet, where they found some unusually gargantuan sponges as large as three or four feet in diameter. They also encountered heavy current, which makes it difficult to collect samples. 
In hopes of finding a deeper spot with less current, we spent the midday
running transects with the fathometer--which creates a detailed map of
the seafloor--looking for potentially interesting submerged terrain. The
chosen target was a bump in about 2,400 feet of water. There,
Shirley Pomponi and Don found a series of strange 20 to 40-foot-high features,
and a single 100 footer. The bumps were unusual, according to Shirley,
because they appear to be formed from the skeletal remains of shallow water
species such as brain corals, suggesting some kind of geological shift
in Cay Sal's past that buried old reefs in deep water.
PUFF THE NEW SPONGE SPECIES? The highlight of the dive was the discovery of a sponge that the group has never before seen in over 20 years of submersible exploration. The sponges look like a cross between a mushroom and a cotton puff, and seeing them on the bottom, Shirley thought they might be relatively common anemone-like organisms called zoanthids. However, as soon as she saw them at the surface she could see the telltale spicules, which are defensive structures that 
resemble glass fibers and are unique to each sponge species. Shirley,
Amy, and
John Reed spent several minutes with the samples on the table trying
to decide what they were. At this point, the species remains a mystery.
Ultimately the sponge could prove to be a new species, and the group is working
now to assess its biomedical potential.
Overall, a fine start to the Cay Sal portion of the expedition. 
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