Leg 2: February 19, 2012

Day 3: Blue-water diving at Alarcon Seamount

You know it is going to be a nice blue-water dive when the ROV goes down and not only is the water blue, but the ROV video can still catch a glimpse of the Western Flyer from 25 meters (82 feet) down!

Steve Haddock gives a briefing for the divers and boat crew before the blue-water dive. Photo by Erik Thuesen

Steve Haddock gives a briefing for the divers and boat crew before the blue-water dive. Photo by Erik Thuesen

At 8:00 a.m. we got the okay from Captain George Gunther to go blue-water diving, and after a flurry of activity, Steve Haddock, Karen Osborn, Meghan Powers, and I loaded up the rigid hull inflatable boat (RHIB) and headed out to sea with Paul Ban and Craig Heihn as crew.

Meghan Powers double-checks her dive gear. Photo by Kyra Schlining

Meghan Powers double-checks her dive gear. Photo by Kyra Schlining.


The RHIB boat moves away from the Western Flyer with the divers and all their gear on board. Photo by Erik Thuesen

The RHIB boat moves away from the Western Flyer with the divers and all their gear on board. Photo by Erik Thuesen.

We deployed our lines (blue-water diving requires extra training and safety procedures as the bottom is 2,000 meters (6,500 feet) below us today) and hit the water with lots of empty jars.

George Matsumoto and Karen Osborn descend using a safety line. Image captured from video shot by Steve Haddock.

George Matsumoto and Karen Osborn descend using a safety line. Image captured from video shot by Steve Haddock.

By the time the dive was over (in an all-too-short 40 minutes) we had searched the water column from 25 meters (82 feet) to the surface and had filled up all our jars. We collect for all the scientists onboard, as not everyone is fortunate enough to go diving; we collected salps with amphipods for Rebeca Gasca, Sapphirina copepods for Erik Thuesen, and pteropods for Stephanie Bush. We also gathered a variety of other jellies, including Beroe, Haeckelia, Velamen, and Cestum. Researchers will observe these organisms in order to learn more about which genetic traits they are expressing (transcriptomics) and how closely they might be related to one another (population genetics).

Video frame grab from the ROV as it descends through a dense layer of Bathochordaeus. At around 30 meters (98 feet), it is just out of reach for our divers.

Video frame grab from the ROV as it descends through a dense layer of Bathochordaeus. At around 30 meters (98 feet), it is just out of reach for our divers.

My particular interest on this cruise is looking at the giant larvaceans (Bathochordaeus) that are found shallow here in the Gulf of California but deep in Monterey Bay. I hope to try and figure out how they are moving water through their inner filters using some dye and a video camera. Today they are just a little too deep (30 meters or 98 feet), so I will have to look again tomorrow.

—George Matsumoto

George Matsumoto waves from 25 meters (82 feet) down. Image captured from video shot by Steve Haddock.

George Matsumoto waves from 25 meters (82 feet) down. Image captured from video shot by Steve Haddock.


The ROV Doc Ricketts was also diving today. We recorded over 11 hours of deep-sea video to “mine” for data back at MBARI. And we weren’t the only ones diving out at Alarcón Seamount. A sperm whale was spotted off our stern this afternoon.

Thar she blows! Sperm whale off the stern. Photo by Kyra Schlining

Thar she blows! Sperm whale off the stern. Photo by Kyra Schlining.

—Kyra Schlining

MBARI's mapping AUV, the

Equipment

Gulf of California 2012 Expedition