2009 Pacific Northwest Expedition

Leg 2 Logbook - Midwater Ecology
Day 2 — Our first dive
July 26, 2009

Latitude 46 degrees 10.1113 minutes N
Longitude 124 degrees 46.7728 minutes W

We launched the ROV Doc Ricketts at 6:30 this morning to commence our first dive in Astoria Canyon. Among our goals is the comparison of animals we encounter during this research cruise with those we observed in Astoria Canyon three years ago. We also want to differentiate animal diversity and abundance between Astoria and Monterey Canyons. Today’s dive site, situated at the head of the canyon, is the same as one of our dive sites from 2006.

As we flew deeper and the light diminished, we recognized many of the animals familiar to us from Monterey Bay. There are medusae, crustaceans, and pelagic worms among others. However, we also noticed several species were much more common here than in Monterey Bay. Some of these are ctenophores, gelatinous animals that propel themselves with rows of tightly spaced cilia and feed on zooplankton, including other ctenophores. The other relatively common animal is a squid that possesses a transparent body and arms, tentacles and eyes that become bright red when the individual is disturbed.

A ctenophore, Beroe abyssicola, which was quite abundant within Astoria Canyon.

Taonius sp. was the most commonly encountered squid on today’s dive.

We are especially interested in the animals that inhabit the oxygen minimum zone (OMZ). This is a depth range with oxygen levels so low that many deep-sea animals cannot inhabit this zone. Scientists have predicted that the OMZ of Monterey Bay is going to expand due to global climate change and part of our research seeks to understand how animal communities will change if this happens. The OMZ of Astoria Canyon is much more extensive than that in Monterey Canyon and by studying the former we may be able to predict how the latter could change.

For this reason we took our time exploring the water column before heading to the bottom at 1050 m. In 2006, oxygen levels were quite low all the way to the bottom and we found a “dead zone” with the remains of crabs and jellies littered across the benthos. While oxygen levels are similarly low this year, we did not observe any dead or dying animals when we reached the bottom.

—Stephanie Bush

Researchers Susan von Thun ‘the Hired Gun’ and Rob ‘Bobby Eddy’ Sherlock process a jelly sample.

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Leg 2

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.

High-frequency suction sampler

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

Detritus sampler

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


Used in combination with the High-Frequency Suction Sampler (HFSS) and Detritus Samplers, the spatulator flips items off the seafloor that are then vacuumed into the High Frequency Suction Sampler or collected with the Detritus Samplers.

Midwater acoustic current meter

The current meter is held by a small standalone fixture and measures the magnitude and direction of the currents about 1 meter above the seafloor.

 Research Team

Senior Scientist, Bruce Robison Bruce Robison
Senior Scientist, MBARI

Bruce Robison's research interests are centered on the biology and ecology of deep-sea animals, particularly those which inhabit the oceanic water column. He has pioneered the use of undersea vehicles for these studies and led the first team of scientists trained as submersible pilots for research in midwater. His midwater research program is presently addressing the ecology of gelatinous animals in the deep sea. This group includes ctenophores, medusae, and siphonophores, animals which cannot be investigated accurately with conventional sampling methods, but which play dominant roles in mesopelagic ecology. Related studies include trophic structure, physiology, and the behavior of midwater animals including fishes and squids. Behavioral studies are also investigating the ways that animals use bioluminescence in the deep sea, with both laboratory and in-situ observations.

Graduate Student, Stephanie Bush Stephanie Bush
Graduate Student, University of California, Berkeley

Stephanie is a doctoral candidate at UC, Berkeley, in the lab of Dr. Roy Caldwell. In collaboration with Bruce Robison and the MBARI Midwater Ecology lab, her dissertation research focuses on deep-sea squid ecology, particularly their defensive behaviors.

Senior Research Technician, Rob Sherlock Rob Sherlock
Senior Research Technician, MBARI

Rob studies the properties and organisms of the ocean's largest habitat, the midwater. His research group is learning more about the ecology of midwater organisms; their abundance and seasonal patterns, depth ranges and who eats whom. Rob enjoys watching mesopelagic animals with the HD (high definition) camera; animals that once would have come up as glop in a net can be seen to have delicate structure and complex behavior (e.g., squid inking or changing color, fish eyes that rotate to keep prey in sight, an amphipod carving up a pyrosome to make a home).

Senior Research Technician, Kim Reisenbichler Kim Reisenbichler
Senior Research Technician, 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.

Senior Education and Research Specialist, George Matsumoto George Matsumoto
Senior Education and Research Specialist, MBARI

George is interested in the open ocean and deep sea communities with particular emphasis on invertebrates. Specific areas of interest include ecology and biogeography of open ocean and deep sea organisms; functional morphology, natural history, and behavior of pelagic and benthic organisms; and systematics and evolution of ctenophores and cnidarians (molecular phylogeny). George also runs a wide variety of education programs at MBARI

Research Technician, Susan von Thun Susan von Thun
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.

Reseach Assistant, 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, most of which spend their entire lives in the oceanic water column. Kris started working at MBARI in 1996 after finishing her Master's at UC, Santa Cruz. She's looking forward to returning to sea for the first time since starting a family.