Monterey Bay Aquarium Research Institute
2013 midwater ecology cruise

Day 3 – Deep midwater respirometry system (MRS) deployment
November 9, 2013

Overnight we transited to the deep MRS site (see yesterday's post and the cruise background for an introduction to the MRS). This site has a mooring in much deeper water than yesterday's site, about 3,000 meters. This mooring has hangers where we can deploy the MRS at multiple depths. The goal today was to collect deep-living animals (between 2,550 and 2,800 meters), hang the MRS on the 2,800-meter hanger, and measure the animals' respiration for two days.

The ROV quickly descended to 2,500 meters where we starting looking for animals large enough to measure their respiration in the MRS. Very small animals will not make any detectable changes in the oxygen content of the water in the sampler. There are eight chambers in the MRS and we collected four mysids (deep-sea shrimp-like animals) and two jellies called Poralia rufescens. The last two chambers were left without animals as controls for the experiment. Measuring the oxygen in the control will let Kim Reisenbichler know if anything went wrong with the experiment. Large changes in the control indicate a malfunction.

Left, a small Poralia rufescens and right, a mysid that were put in two of the MRS chambers.

People often think that nothing lives that deep in the ocean, but I can assure you there are plenty of interesting animals down there. After we deployed the MRS, we had the rest of the day to search for target species. We have a long list of animals that are of interest to the science team and their collaborators. Here are a few of the fascinating and rare animals we came across today:

Upper left: This cydippid comb jelly is about the size of a cantaloupe. Upper right: This beautiful jelly, Crossota millsae is somewhat rare—in 25 years we've only seen it approximately 70 times with our ROVs. It is named after one of our favorite jelly researchers, Dr. Claudia Mills. Lower left: Stygiomedusa gigantea is one of the largest jellies we see in the deep sea. The bell (in the center of the photo) was about 60 centimeters (nearly two feet) in diameter and the oral arms (trailing up and to the right in the photo) are many meters long. MBARI's ROVs have only seen this jelly eight times. Lower right: Atolla gigantea is a rare jelly only that we collected for our colleague at home George Matsumoto.

— Susan von Thun

Previous log Next log


Day 7 Day 7
November 13, 2013
Last day

Day 6 Day 6
November 12, 2013
Stayin' alive!

Day 5 Day 5
November 11, 2013
What's for dinner?

Day 4 Day 4
November 10, 2013
On the hunt for deep-living animals

Day 3 Day 3
November 9, 2013
Deep midwater respirometry system (MRS) deployment

Day 2 Day 2
November 8, 2013
Expansion of the oxygen minimum zone

whale's fluke Day 1
November 7, 2013
Why study the midwater and what the heck is OMZ?


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, 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.

Midwater respirometry system (MRS)

The MRS conducts oxygen consumption rate measurements in situ gauging the metabolism of animals without subjecting them to the stresses of transport to the surface. MRS has been modified to operate in deeper water with an expanded capacity, enabling respiration studies on animals that live deeper than 1,250 meters.

Detritus sampler

Detritus samplers are large plexiglass containers with lids that can be controlled by the pilot of the ROV and gently closed once an organism is trapped inside.


The CTDO is mounted on the ROV and takes in situ measurements of environmental parameters such as conductivity, temperature, depth, and oxygen concentration.

High frequency suction sampler

This sampler acts like a vacuum cleaner sucking up samples and depositing them into one of the 12 buckets.

 Research Team

bruce robison Bruce Robison
Senior Scientist, MBARI

Bruce Robison's research is focused on the biology and ecology of deep-sea animals, particularly those that inhabit the oceanic water column. He pioneered the use of undersea vehicles for these studies and he led the first team of scientists trained as research submersible pilots. At MBARI, his research group has focused on the development of remotely operated vehicles as platforms for deep-sea science.

kim reisenbichler Kim Reisenbichler
Research Specialist, MBARI

Kim's general area of interest is the study of midwater and deep sea animals. He has developed many tools and techniques to observe, manipulate, and collect these organisms, and to maintain the animals in the lab.

rob sherlock Rob Sherlock
Senior Research Technician, MBARI

Rob is interested in the ecology of midwater invertebrates. He has worked in the Robison lab and been involved with the Midwater Time Series since he came to MBARI in 1996, identifying and quantifying mesopelagic animals and the changes in that community over time and depth and relative to other physical factors.

kris walz Kris Walz
Research Assistant, MBARI

Kris works with the midwater ecology group, analyzing ROV video transects between 50 and 1,000 meters in depth to identify biological organisms from all taxonomic levels. Kris started working at MBARI in 1996 after finishing her master's degree at University of California, Santa Cruz. She's looking forward to going to sea this month to collect video transects and to search for deep-sea lobster larvae from the family Polychelidae.

susan von thun Susan von Thun
Senior Research Technician, MBARI

Susan works in the MBARI video lab, where her primary responsibility is to watch video taken with MBARI's remotely operated vehicles (ROVs) and make observations about the organisms, behaviors, equipment, and geological features that she sees. While annotating video, she's become adept at identifying numerous deep-sea organisms, specializing in midwater organisms. She works closely with the midwater ecology group and the bioluminescence lab to expand her knowledge of the fish, jellies, cephalopods, and other groups in the midwater.

Stephanie Bush
Postdoctoral Fellow, MBARI

Stephanie will be collecting squids and octopuses for the Monterey Bay Aquarium's upcoming cephalopod exhibit "Tentacles". She will also continue her research on deep-sea cephalopod behavior and population connectivity in planktonic animals.

goetz Freya Goetz
Museum Technician, Smithsonian Institution

Freya is collecting hyperiid amphipods, polychaetes and sampling of other animals for Karen Osborn at the Smithsonian Institution's National Museum of Natural History. The animals collected will be for a variety of projects including the study of amphipod eye structure, animal microbiomes and population genetics.

burford Ben Burford
Research Assistant

Ben's undergraduate degree encompassed terrestrial and aquatic zoology, ecology, and botany. He has become fascinated with and engrossed in the study of deep-sea ecology and behavior. This focus comes after recently completing an internship in the Robison Midwater Ecology Lab at MBARI where he examined the behavior of the deep-sea cephalopod, Chiroteuthis calyx.