Learning about the respiration and metabolism of deep midwater animals is a priority of the Midwater Ecology Group. Studying an animal’s respiration (how much oxygen it consumes), helps us better understand how much energy (food) it needs to live. Understanding this relationship between oxygen consumption and energy requirements for different organisms gives scientists a better overall view of the midwater ecosystem and some insights on how this ecosystem may change with a changing climate.

The Midwater Respirometry System is a tool designed by scientists and engineers at MBARI to measure the respiration rates of midwater organisms under the natural conditions in which they live (at depth) instead of in the lab back on surface, where they may be stressed by conditions to which they aren’t adapted. Each day, we fill the MRS samplers with animals and then “hang” the system at various depths on a mooring over one or two nights. The system logs the oxygen consumption and other environmental data, which are downloaded when we retrieve the MRS.

When we aren’t filling the MRS with samples, we can explore the deep midwater above Monterey Canyon and collect animals for further research in the lab. The science team takes turns in the control room, spotting animals of interest, controlling the main science camera, taking frame grabs, and making observations using MBARI’s video-annotations system VARS. We also have husbandry staff from the Monterey Bay Aquarium onboard collecting animals for possible display at the aquarium.

This eight-day expedition has been successful thanks to the collaborative efforts of the science and ship’s crews as well as the ROV pilots. We’ve been lucky with the weather, diving the ROV all day every day, and studying some really amazing deep-sea animals in their natural habitat. Each expedition brings new discoveries and new questions and adds to what we know about this largely unexplored, but extremely diverse and productive, slice of ocean life.