Terra Nova

An iceberg seen near R/V Atlantis. Photo by Sam Dahlgren,
with the camera pointing through a pair of binoculars

My phone buzzed under my pillow, rousing me from a shallow sleep. I opened my eyes and checked my watch. It was a few minutes before 1 pm. With ROV dives taking place at night, I've been on a nocturnal schedule. My phone buzzed again, and I swiped on the screen to open it. There were two new messages on the expedition text thread. The first said simply "Land ho!" The second was a photo of an iceberg. 

I knew that Terra Nova sank close to Greenland. I had been told we would see the rocky, ice-laden island. But once we arrived, the land and the ice felt surprising all the same. Physically being in a place is so different from reading about it or watching it on video. 

The ROV team deployed our little robotic vehicle into the cold, clear sea. After a short descent, the vehicle arrived on the seafloor. It looked muddy, just like most of the ocean bottom. The ROV's forward-facing sonar showed a bright return - a solid object - dead ahead. The spot seemed too small to be the shipwreck, but we investigated anyway. Maybe it was an artifact that fell off the ship as it sank. As the ROV inched closer, the solid object came into view. It was rock. Everyone in the room sighed with disappointment. Except me. 

That rock had to be a glacial dropstone. Glaciers cover Greenland, and each of those glaciers would have stones frozen in the ice matrix. When icebergs calve off of glaciers, they carry the rocks with them. Then when the iceberg melts, the stones fall to the seafloor - dropstones. Dropstones are island-like hard-bottom habitats on the seafloor, oases of biodiversity in a sea of mud. As the Arctic basin warms with climate change, more and more dropstones are landing on the seafloor and reshaping biodiversity. 

The dropstones we observed around Terra Nova held an important message: the wreck might be largest island-like habitat in the region, but it's certainly not the only one. Larvae can easily disperse between the dropstones and the wreck, given their close proximity. The stones and wreck might function as one integrated metacommunity. 

As we survey Terra Nova, I will develop a deep understanding of this island-like shipwreck habitat. With exploration by night and sleep by day, we are accumulating an amazing dataset.