In our first year (2007) our scientific goal was to search for “The Lost Experiments” – a set of recruitment, colonization and predation experiments that were started in the early 1960’s by Dr. Paul Dayton at Scripps Institution of Oceanography. Those were the earliest days of Scuba diving, when depth limitations had not been established, and Dr. Dayton’s experiments extended into 60 m water depth. Safety limits were later established at 40 m, so these experiments were never completed. The locations of these experiments were “lost” during the intervening years. In 2007, SCINI and a VideoRay ROV searched the seafloor and found every one of the experimental sites! Relocating this scientific underwater treasure trove opens the door to assessing decadal shifts in Antarctica, an important issue as we struggle with the increasing impacts of recent climate changes.
This year, our scientific goal is to expand the known ecological space in McMurdo Sound. We have three specific target locations, guided by intriguing hints that these places host special communities.
Target 1. Bay of Sails. This area is an “iceberg graveyard” where because of the combination of wind, currents, and bathymetry icebergs collect in high numbers. The first explorers to sight this area in the very early 1900’s thought the pointed outlines of the ‘bergs looked like the sails on their own ships, and so named it. The icebergs are driven by wind and currents and plow through the seafloor, destroying communities in their path – and opening up new areas for colonization. With SCINI, we will dive to 300m to trace the iceberg-driven patterns of destruction and rebirth on the seafloor.
Target 2. Cape Armitage. The southern point of Ross Island, where the annual sea ice contacts the permanent Ross Ice Shelf, was named after Lieutenant Armitage, part of Scott’s Discovery Expedition in 1901-1904. Here, currents are strong and bathymetry is steep, and divers have been tempted by glimpses of vast fields of the giant volcano sponge, Anoxycalyx joubini, in the depths beyond diving limits. These huge sponges are large enough to surround a diver, and are likely thousands of years old. SCINI will map the boundaries of the sponge field, and perhaps offer some clues to solve the mystery of why the sponges are in this location, but not in others.
Target 3. Heald Island. Embedded in the permanent Ross Ice Shelf, the ice surrounding the island is up to 200 m thick, but cracks form at stress points from tidal motion of the ocean water beneath. SCINI will dive through these natural access points to the mysterious depths below. Beneath permanent ice shelves remains one of the few unexplored regions of our planet; we have had only a few tantalizing peeks at what may live in the unending darkness there. Reports of massive, rapid scavenger response to baited traps placed through holes (Slattery and Oliver 1986), and notes on chemosynthetic communities under the recently disintegrated Larsen ice shelf (Domack et al. 2005) are intriguing hints that unexpected and perhaps novel communities remain undiscovered.