Monterey Bay Aquarium Research Institute
2013 seafloor ecology expedition


Day 5—Squeezing in two dives on our last day
October 28, 2013

As expected, the wind rose last night and by 6:00 a.m., the start of our day, it was blowing between 25 and 30 knots – too windy and rough to launch ROV. The forecast was for the winds to drop through the day, so we decided to wait it out and hope for the best. It turned out that it didn’t take long. After only about an hour, we were able to start the dive, and by 8:30 a.m., we were working on the same urchin caging experiment at 1,000 meters that was the focus of our first day on this cruise.

urchins in jar

This sample jar holds deep-sea urchins and other animals collected from within one of the experimental cages that we placed on the seafloor two years ago.

Two years ago, we placed some urchins in mesh cages (six feet by six feet by one foot) on the seafloor at three depths to measure their rates of growth and to test whether they affect the smaller infaunal worms, crustaceans, and mollusks that live in the surface sediments nearby.

We placed sets of cages at depths of 200, 600, and 1,000 meters. At each depth, there were three cages with urchins and three without urchins. At the 600-meter site, we also placed three empty cage frames—cages without any mesh.

When the experiment was initiated, we collected a large number of sediment samples around the cages. This sediment was sieved through a fine mesh to remove the mud, allowing us to identify and count the animals in each sample. These samples allowed us to characterize the benthic macrofaunal community at the three sites.

Now, at the end of the experiment, we are taking sediment samples from within the cages to see if the macrofaunal community in cages with urchins has changed compared to cages without urchins.

chris with push cores

Chris Lovera carries a push core full of mud from the cold room (a walk-in refrigerator) to the wet lab on the Western Flyer.

We will also study communities in the cages with no mesh to test whether there is an effect of the cage itself on the benthic community. We expect that that cages do have an effect, because the cages slow currents a bit, leading to the accumulation of sediment inside the cages, compared to outside the cages.

Ultimately, we hope the results of this experiment will reveal how strongly urchins affect other seafloor animals on the muddy continental slope—and specifically how they affect the macrofauna.

As described in our October 24 cruise log, we also hope to learn something about how fast urchins grow. We’ve counted rings in the urchin’s calcium carbonate tests (shells), but we don’t know if these rings are created once per year – like tree rings – or at some other frequency.

During today’s first dive, we dove to the 1,000-meter site to collect urchins and animals from the three cages there. After about three hours of work on the bottom, we’d used up all of the sediment cores on the ROV, and had collected urchins and other animals from all of the cages. We then gathered all of the empty cages, tied them together with a long rope, and pulled them back up to the surface under the ROV. The ROV and the cages were on the surface by 1:00 p.m.

processing push cores

After collecting another two dozen push cores during our first dive today, we all pitched in to extract the sediment, filter out the fine material, and save the coarser sediment and animals from these cores. With lots of teamwork, we finished this work just in time for the second ROV dive of the day.

The Western Flyer wasn’t scheduled to arrive in Moss Landing until 6:00 p.m., and we wanted to make the most of the precious sea time we had available. We had just enough time to move the ship about eight kilometers toward Moss Landing, and complete a quick ROV dive at the urchin cage experiment at 600 meters depth.

We dove on the site and had about one hour to begin sampling the cages at this site. On the descent we passed through a massive school of juvenile hake – pretty cool. It was also exciting to revisit the cage experiment after not seeing it for two years.

The cages were heavily covered by brown mats of amphipod tubes. These little relatives of ‘sand fleas’ make mucous tubes. We watched them scurry around feeding and interacting with each other – sort of like a large amphipod “apartment complex.” The amphipods are probably an important source of food for a variety of predators that gather round the cages.

urchin frame at 600 meters

The urchin cages at 600 meters were covered with brown mats that turned out to be amphipod tubes. It was hard to tell if there were urchins inside the cages, but there were definitely a lot of them on the surrounding seafloor.

We collected video of each of the cages at 600 meters, and made plans for how to continue the experiment when we return to this site during our next cruise in December. Then we brought the ROV back up to the surface and headed for home.

It was about a two hour steam from the last dive site to Moss Landing. It is always nice to head home, with the wind at our backs. As we neared shore, there were about 20 or 30 humpback whales blowing all around, some breaching from time to time. You can never tire of such special treats.

approaching Moss Landing Harbor

Members of the crew of the Western Flyer stand on the bow of the ship during the approach to Moss Landing Harbor. Our research would not be possible without the dedication and diligence of the Western Flyer crew and the pilots of the ROV Doc Ricketts.

All in all, this was an excellent cruise. Nearly everything went off without a problem. The weather was mostly great, and the crew of the Western Flyer and the ROV Doc Ricketts pilots were cheerful, helpful, and efficient. It is always a pleasure to go to sea on MBARI ships. We completed as much as we could have expected, and look forward to our next chance to experience the deep sea.

—Jim Barry

Previous log

 Logbook

Day 5 Day 5
October 28
Squeezing in two dives on our last day


Day 4

Day 4
October 27
Collecting corn-bale animals and more logs


Day 3

Day 3
October 26
Corn stover and respiration experiments


Day 2

Day 2
October 25
Elevator to the seafloor


Day 1

Day 1
October 24
Urchin cages


 Equipment

R/V Western Flyer

The R/V Western Flyer is a small water-plane area twin hull (SWATH) oceanographic research vessel measuring 35.6 meters long and 16.2 meters wide. It was designed and constructed for MBARI to serve as the support vessel for ROV operations. Her missions include the Monterey Bay as well as extended cruises to Hawaii, the Gulf of California, and the Pacific Northwest.

ROV Doc Ricketts

ROV Doc Ricketts is MBARI's next generation ROV. The system breaks new ground in providing an integrated unmanned submersible research platform, with many powerful features providing efficient, reliable, and precise sampling and data collection in a wide range of missions.

Push cores

A push-core looks like a clear plastic tube with a rubber handle on one end. Just as its name implies, the push core is pushed down into loose sediment using the ROV's manipulator arm. As the sediment fills up the core, water exits out the top through one-way valves. When the core is pulled up again, these valves close, which (most of the time) keeps the sediment from sliding out of the core tube. When we bring these cores back to the surface, we typically look for living animals and organic material in the sediments.

Benthic respirometer system

Oxygen consumption (a measure of biological activity) of the organisms living in the sediment is measured using a benthic respirometer system (BRS). This instrument is used in situ (in place on the seafloor).

 Research Team

jim barry

Jim Barry

Senior Scientist
MBARI

Jim Barry's research program focuses on the effects of climate change on ocean ecosystems. In addition to climate change, his research interests are broad, spanning topics such as the biology and ecology of chemosynthetic biological communities in the deep sea, coupling between upper ocean and seafloor ecosystems in polar and temperate environments, the biology of deep-sea communities, and the biology of submarine canyon communities. Jim has helped inform Congress on ocean acidification, ocean carbon sequestration, and climate change by speaking at congressional hearings, briefings and meetings with congressional members.

kurt buck

Kurt Buck

Senior Research Technician
MBARI

Kurt Buck specializes in quantitative enumeration, ecology, and imaging of marine protists and bacteria. Upper water-column communities from Antarctic and Arctic sea ice to equatorial regions were his initial focus. He is currently working with deep-sea sediment communities including those from hypoxic zones.

patrick whaling

Patrick Whaling

Senior Research Technician
MBARI

Patrick has worked at MBARI since its beginning in the fall of 1987. Prior to his move to MBARI, he spent seventeen years at Duke University Marine Lab investigating heavy metals in the marine environment. He currently works with Jim Barry in the design and construction of sampling gear used on the ROV to collect benthic animals, in addition to processing benthic samples and conducting carbon-hydrogen-oxygen (CHN) analyses.

Chris Lovera

Chris Lovera

Senior Research Technician
MBARI

Chris supports Jim Barry's Benthic Biology and Ecology, and Free-Ocean CO2 Enrichment research projects. On this expedition, Chris's responsibilities are varied, from collection and curation of invertebrates used in Benthic Respiration System metabolic rate and manipulative oxygen and pH studies, to Geographic Information System work, to operation of the dissolved inorganic carbon analyzer. Chris's recent work focuses on the effects of ocean acidification on invertebrate behavior.

kim fulton-bennett

Kim Fulton-Bennett

Public Information Specialist
MBARI

Kim Fulton-Bennett works as a public information specialist at MBARI, writing articles and news releases for the institution's web site and working with members of the media on MBARI stories. During this cruise, he will be helping take digital notes about each dive, taking photos of the research activities on board, and helping prepare the daily expedition logs.

Craig McClain

Assistant Director of Science
National Evolutionary Synthesis Center




jenna judge

Jenna Judge

Postdoctoral Student
University of California, Berkeley

Jenna Judge is a doctoral student at University of California, Berkeley who is focusing on diversification patterns in chemosynthetic and biogenic habitats. Two years ago, she sank a collection of 10 different kinds of wood in Monterey Bay during a cruise with the Barry lab. On this trip, she hopes to recover all 28 wood bundles to see what animals have colonized them and whether there are differences between animal community richness and abundance for different wood types.

Rosemary Romero

Doctoral Student
University of California, Berkeley

Rosemary Romero is a doctoral student at University of California, Berkeley studying green tides in San Francisco Bay. She will be helping Jenna Judge recover sunken wood with Jim Barry and his lab members. She is excited for the opportunity to go to sea and to discover what animals have colonized the sunken wood since two years ago.