A Dall's porpoise (top) gives Michelle Ridgway in DeepWorker a sendoff before her dive to 1,700 feet at Zhemchug Canyon in this surreal looking image. Hundreds of Dall's porpoises were present around the ship during the expedition. (Video still by David E. Guggenheim)

The Esperanza began its 2-day steam south and endured gale-force winds and 15-foot seas along the way, but all are well and grateful for the successes along the way. The team achieved a total of 25 sub dives during the expedition, well-exceeding expectations for this part of the world where weather is typically unforgiving.

The team collected nearly a Terabyte (1,000 Gigabytes) of high-definition video, photographs and other data, now being archived, cataloged and distributed. Also collected were numerous coral, sponge, and other invertebrate samples which are being prepared for distribution to scientists around the world for further analysis.

Despite intense effort and late-night searching, the Esperanza was never able to locate the pinnacles reported to be in the Zhemchug Canyon area, pinnacles which are reported to rise within 20 feet of the surface. The team was prepared to scuba dive and video/photo-document these features, however this mystery will have to wait for a future expedition.

Zhemchug Canyon has revealed a diverse ecosystem with interesting and complex interrelationships. It’s also a location where large numbers of squid can be found at depth. Read more on David Guggenheim’s OceanDoctor blog.

The Esperanza is carrying two manned submersibles, a remotely-operated vehicle (ROV) and an international research team to the Bering Sea for a three week survey of Zhemchug and Pribilof Canyons,to map and document deepwater corals living at depths of more than 1,000 feet. The expedition was conceived of and is being led by Greenpeace.

Track the Bering Sea Expedition: Esperanza’s Current Location, Weather & Live Webcam

Trawl scar on bottom, DeepWorker 7 in background

Yesterday (Thursday) morning, Michelle Ridgway and I descended in the twin subs for our expedition’s penultimate dive on Pribilof Canyon. Michelle’s lights shone as tiny pinpoints in the distant green as the light from above slowly vanished and the cold darkness of Pribilof Canyon enveloped us. I had a rare moment amid the descent’s harried series of checks and radio transmissions to reflect on where I was, and Michelle’s lights reminded me of how tiny we were, trying to comprehend an enormous, complex tapestry in the darkness armed with only a pen light. But on this dive, some of those complexities began to tell a story.

Yesterday (Thursday) morning, Michelle Ridgway and I descended in the twin subs for our expedition’s penultimate dive on Pribilof Canyon. Michelle’s lights shone as tiny pinpoints in the distant green as the light from above slowly vanished and the cold darkness of Pribilof Canyon enveloped us. I had a rare moment amid the descent’s harried series of checks and radio transmissions to reflect on where I was, and Michelle’s lights reminded me of how tiny we were, trying to comprehend an enormous, complex tapestry in the darkness armed with only a pen light. But on this dive, some of those complexities began to tell a story.

The welcoming committee of squid was there to greet us en masse, larger squid this time, more abundant, and more aggressive. They rocketed through the water faster than anything I’ve seen, passing millimeters from the front of the light, causing a startling bright flash against their light bodies, before deploying a cloud of brownish ink, spreading their tentacles to reveal a hungry beak, convinced that the light that had drawn them to the sub meant food was near. Some latched on a appeared to try to take a bite. Others gave a menacing dance, another blast of ink, and rocketed into the darkness. Still others appeared in pieces, casualties of my thrusters. It was squid madness, and it was fascinating, even comical to watch. But it also was a vivid reminder of the predatory prowess of these animals — a small fish wouldn’t stand a chance, but at least the end would come in the blink of an eye.

The bottom arrived at 1,052 feet and I landed on what appeared to be some sort of geologic stratification — unusual layers and grooves of sediment in parallel lines across my path. I then realized I was looking at a trawl “scar,” the deep ridges in the bottom made by the wheels of a trawl net dragged across the bottom. A wide swath of bottom appeared as if it had been plowed like a cornfield, overturned sediment neatly piled along the long groove. I remembered that Michelle had told me some of the trawls used in these parts are as wide as a Boeing 737′s wingspan.

Sea whip (Halipteris willemoesi) coral

We began our transect, but shortly thereafter I was told to hold position — apparently the squid had won the last round against Michelle, causing one of her thrusters to blow a fuse. She surfaced for an early recovery while I continued the dive alone. I was excited to see a number of corals. The bottom was covered with tiny (an inch or two) white sea whips (Halipteris willemoesi), one of the corals we had seen elsewhere in Pribilof Canyon. But the sea whips we had seen elsewhere were much larger, 3 or 4 feet long. I only spied two or three that big in this location.

I moved along in the darkness, saw many snow crabs and flat fish, including the beautiful rex sole and equally dramatic sharp nose skate. I then spied a strange white ridge along the black horizon. As I approached I saw this ridge lay directly in my path, straight as an arrow. A geology professor of mine once gave our class a clue at identifying features in aerial photos by pointing out that straight lines are rare in nature. Sure enough, this was another trawl scar, larger than the first. I radioed to Sasha at the navigation station on the ship and asked that he note this location on his tracking computer. I continued and found many more linear features along my path, more trawling marks, no doubt, perhaps older ones.

As I continued ahead, some of the pieces I had been seeing in the tapestry during the week started to merge and suggest a pattern. Most of the tiny sea whips I had seen were roughly the same size, suggesting that they’re roughly the same age and most likely regrowth after a major disturbance, such as one that might be caused by dragging a massive object over the bottom…like a trawl. It’s gratifying to see an ecosystem demonstrating resiliency — little sea whips pushing up and trying to make a go of it. But knowing how important corals are to the health of marine ecosystems, it’s troubling to see such widespread impacts.

Rex sole (Glyptocephalus zachirus)

Continuing the transect, I enjoyed seeing the sole, halibut, skates and other flat fish. I’ve always been fond of these strange looking creatures and never appreciated the role they played in the tapestry until this dive. Shallow flat-fish-sized depressions cratered the soft bottom. But as I passed over these “flat fish holes,” the lights from the sub reflected off of hundreds of tiny eye balls looking back at me. These little depressions were teeming with little shrimp and other critters — colorful micro ecosystems moving in where a flat fish moved out.

This was an area of high current — maneuvering the sub was difficult — and I saw that these depressions offered the shrimp refuge out of the current on a silty bottom that was virtually devoid of rocks or other relief. I realized my flat fish friends were ecosystem engineers. The simple act of burying themselves in the silt and leaving a depression behind meant habitat for countless other creatures. NOAA scientist Bob Stone, aboard Esperanza for this expedition, smiled when I later mentioned this to him — he’s published a paper on the topic. I’ve seen a similar pattern in the Gulf of Mexico, where grouper dig enormous swimming pool-sized holes in the soft bottom sediment, exposing hard substrate for corals and sponges to grow and attracting many fish and invertebrates. So it’s troubling to me when we think of fish essentially as crops that we can simply harvest from the sea. Such a perspective ignores the critical point that fish themselves are part of the ecosystem and have important, often critical roles, in maintaining the health of the ecosystem. Removing fish from the ecosystem changes the ecosystem.

The call from Sasha came too soon, as it always does, “DeepWorker 6, at this time prepare the cabin for recovery.” As I ascended through the darkness, alone this time, I turned my lights off to gaze upon Pribilof Canyon in its true state and pondered how much of our planet’s life lives in complete darkness. My tiny sub had illuminated but a few new corners of this vast place. There lies so much more to see and discover, but with each tantalizing glimpse come new insights and a little more of the story the tapestry tells.

Thanks to great weather, state-of-the-art equipment and a top-notch crew, it has been a productive weekend for the team aboard Esperanza which arrived on site at Pribilof Canyon Saturday morning (July 28) when David Guggenheim and Michelle Ridgway made the first tandem dive in two DeepWorker submarines into Pribilof canyon to a depth of just over 1,000 feet and began to document a fascinating diversity of life, including a variety of corals, anenomes, sponges and fish. On Sunday, the ship visited a second site in Pribilof Canyon where John Hocevar and Timo Marshall completed a successful tandem dive, documenting more corals and successfully collecting a number of specimens with DeepWorker’s manipulator arm for analysis by scientists around the world.

John Hocevar (Greenpeace Senior Oceans Specialist) pilots DeepWorker at 1,100 feet in Pribilof Canyon (Video still by Timo Marshall – 29 July 2007)

Already, the Greenpeace-led team has accumulated nearly 16 hours of bottom time (8 hours per sub), more than all of the previous research done in this region combined. The subs’ high-definition video cameras have already collected over 120 Gb of data. The subs are performing linear transects which will then be analyzed on the video. Twin lasers spaced 20 cm apart allow accurate analysis of the size of organisms encountered.

The tumbling anenome, Liponema brevicornis, photographed here by David E. Guggenheim on Saturday, July 27 at a depth of 620 feet in Pribilof Canyon (The two red dots are from onboard lasers used to assist in estimating size. The lasers are 20 centimeters apart.)

The Esperanza is carrying two manned submersibles, a remotely-operated vehicle (ROV) and an international research team to the Bering Sea for a three week survey of Zhemchug and Pribilof Canyons,to map and document deepwater corals living at depths of more than 1,000 feet. The expedition was conceived of and is being led by Greenpeace.

Track the Bering Sea Expedition: Esperanza’s Current Location, Weather & Live Webcam