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Midwater Ecology Expedition Summer 2019 – Log 4

Vanessa Stenvers, left, and Rondi Robison look at a zooid that has been placed under a microscope. The actual size of these tiny little animals that make up the pyrosome is about as long as a sesame seed.

Midwater Ecology Expedition Summer 2019 – Log 4

Vanessa Stenvers, MBARI summer intern
Rondi Robison, manager, Ocean Sciences Department, University of California, Santa Cruz

We have been out for six days on the midwater ecology summer expedition. During this voyage we have been using the ROV Doc Ricketts to observe and sample life in the deep sea. Some dives have had specific missions to collect animals or to identify techniques and ways to observe animals to answer important science questions. We have had a chance to look at species in their natural environment from 200 to 3,000 meters (660 feet to almost two miles) deep.

From Rondi:

The excitement among the participants when we come upon a creature is infectious. Throughout my participation in the cruise my curiosity was piqued in a number of areas that I would not have expected. I was drawn to the excitement of the researchers. One in particular, Vanessa, was willing to share with me examples and knowledge about a couple of tunicates ( Pyrosoma atlanticum and Doliolula equus) we observed and sampled. Although both animals are tunicates, they are very different. I was struck by the firm structure of the pyrosome compared to the delicate doliolid. Both are colonial animals. Pyrosomes only survive as colonies; doliolids are only colonial for part of their life cycle.

First we observed these two animals through the ROV cameras, then the pilots and scientists expertly collected samples so we could observe them firsthand on the ship. By taking a closer look at their structures, many additional questions came out of these initial observations, which are helping Vanessa to identify her summer internship project with the Midwater Ecology Group.

I’m impressed with the knowledge and cooperation in which the scientists, pilots, and ship’s crew work together to make expeditions like this so successful. The data and information that have been collected on this journey will continue to provide insights into this weird and wonderful world.

From Vanessa:

During this cruise we not only got to observe midwater animals in their natural environment, but also got a chance to take an even closer look by bringing them up into the lab.

Many of the animals I had already seen in MBARI’s Deep-Sea Guide and in videos, or read about in academic literature, but being able to see them live (both in the ROV control room and the lab) is truly exciting. I am particularly interested in gelatinous zooplankton, with special emphasis on pyrosomes, as I studied these before coming to MBARI. Seeing pyrosomes bioluminesce (which they do very brightly) and observing their anatomy under the microscope have been a few of the highlights I experienced on this cruise. Moreover, talking to the researchers and pilots on the Western Flyer, who have already answered so many questions about the midwater zone, has provided me with many new insights and made me realize many more research possibilities. Everyone shares a fascination for what lies beneath the ocean’s photic zone, providing an inspiring environment for collaboration and research.

It has been incredible to see how MBARI operates and provides unique information about a difficult-to-reach environment like the deep sea and I could not be more thankful or excited to be part of this research group.