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Midwater Ecology Expedition Summer 2019

When the ROV dive ends, a “bucket brigade” of science team members quickly brings the samples from the vehicle into the lab. Kim Reisenbichler, right, hands off a sample to Tommy Knowles. Photo by Nancy Barr.

Midwater Ecology Expedition Summer 2019

The ethereal siphonophore, Erenna richardi, was spotted at 850 meters. The nectophores (swimming bells) were purple and the end of the tail (siphosome) was laden with eggs. We estimated it to be a whopping one meter (three feet) long! These gelatinous animals are armed with a battery of powerful stinging tentacles and have been observed ensnaring fish just above the seafloor.

MBARI Expedition #466

Expedition goal: The principal goal of this expedition is to measure oxygen consumption rates of select deep-sea animals using a custom-designed tool, the Midwater Respirometry System (MRS), at both shallow and deep locations. We will also be observing and collecting midwater animals to investigate their ecology, physiology, and behavior in conjunction with onboard collaborators from Stanford University and the Monterey Bay Aquarium.

Expedition dates: June 11- 17, 2019

Ship: R/V Western Flyer

Research technology:  ROV Doc Ricketts, Midwater Respirometer System

Expedition chief scientist: Bruce Robison

The Midwater Ecology Group will continue its research into the respiration rates (oxygen consumption) of deep-sea animals using the Midwater Respirometry System (MRS). The MRS allows the group to measure these animals’ metabolic rates where they live as opposed to in the laboratory at surface pressure. Understanding the energy requirements for these animals will allow a clearer understanding of the biological pump and the energy transfer from the surface, through the ocean’s midwaters to the seafloor. The group’s studies over the last three decades have shown the area of the deep ocean where the oxygen level is lowest is growing. The midwater team has documented the vertical expansion of the oxygen-minimum zone by 60-to 80-meters in relation to ocean warming. This expansion has fragmented the midwater community by shifting the distributions of some midwater animals. Long-term studies like this are necessary for first detecting shifts in communities and then predicting how communities will respond in the future to further changes in the environment

Midwater cruises also include exploration of this large habitat, where light does not penetrate from above, and the seafloor is not in sight below. Such explorations have led to many significant observations and discoveries about this habitat and the animals that live there—and their behavior.

About Midwater Ecology Expedition Summer 2019

June 11-17, 2019 – The Midwater Ecology Group is studying and collecting midwater animals in conjunction with collaborators from the Stanford University and the Monterey Bay Aquarium.