Devil’s Island
We have transformed the M/S Endeavour into an enormous glass-bottomed boat! Not really of course, but our underwater digital video camera and I act very much like the glass in such a boat, creating a window for our guests to gaze through into the strange and wonderful world of the Antarctic seas. At every stop new and different vistas open up beneath us, another facet of this polar wilderness, as lovely and as endlessly variable as the terrestrial world.
Two days ago I dove in the South Shetland Islands, on a steep bouldery wall heavily grown with enormous kelp down to 100 feet and beyond. Exploring the rocky crevices under the large algae, I discovered a beautiful snow-white nudibranch and a pair of bizarre sea spiders. Yesterday it was Whaler’s Bay, inside the caldera at Deception Island, on a soft silty bottom carpeted with rose-colored sea urchins, writhing brittle stars and some very strange worms called flabelligerids. Today, much further south in the Weddell Sea, we had entered the land of ice and accordingly the undersea world was different yet again. Here, off the north shore of Devil’s Island, strong currents carry tremendous icebergs past in a never-ending procession. Grinding their keels against the bottom, even at considerable depth, these bergs plow up the sand and sediment, creating a no-man’s-land where only mobile or resistant creatures can survive. Descending a sloping bench through this ice scour zone, I observed scuttling isopods leaving the bottom to tumble in the current like flipped nickels. Juvenile rock cod zipped from hiding place to hiding place among the sparse red algae and tough-shelled limpets grazed over the exposed rocks. Most interesting of all was this crinoid, Pomachocrinus kerguelensis. Crinoids, also called feather stars, are well known from the warmer waters of the Caribbean and the Pacific; here there are not many species but this one is widely distributed in the south polar seas and is named after the sub-Antarctic island of Kerguelen. These animals are relatives of sea stars and sea urchins but use their feathery arms to feed from the current, assuming different postures such as fanned or bowl-shaped, depending on the direction of the current and the type of food it carries. Most amazing, they are able to survive in the scour zone by being quite mobile. They can walk from place to place and then cling to rocks or other perches by using their leg-like cirri, shown in the second photo.
Tomorrow will bring another new dive site and more wonders to discover and share; guess I’d better go get some rest!
