I have just returned from the Monterey Bay Aquarium Research Institute’s Northern Expedition to Axial Seamount on Juan de Fuca Ridge. This expedition was broken into two legs with two different research objectives. The goal of the first portion of the expedition was to study deep-sea chemistry and the purpose of the second leg was to study the seafloor lava flows. I was fortunate to participate on the second portion in order to collect and photograph acorn worms of the family Torquaratoridae and swimming acrocirrid polychaetes for Dr. Karen Osborn.
This was my first time on a deep-sea research trip and my first time visiting a mid-ocean ridge. We left out of Newport, OR on MBARI’s research vessel the Western Flyer that is home to the ROV Doc Ricketts. It took a day and a half to steam to the location of our first dive. Thankfully we had that time to set-up equipment and more importantly adjust to the motion of the boat! The Pacific Northwest can get pretty windy, but we were very lucky in regards to weather and it didn’t get too bad out there. While I have spent countless hours reading about and watching video of the deep-sea, there is nothing that compares to experiencing an ROV dive in real life. Watching Doc Ricketts lower through the “moon pool” for the first time I fully realized that I was about to witness a part of the world that few have had the opportunity to experience.
The ROV room has about 30 monitors and television screens in it. The four main screens display a live feed from the main HD camera on the ROV. The rest of the screens show information regarding the R/V location, the GIS information of the ROV and the R/V, the live feed from the camera on the bottom of the ROV and much more. Operating a deep-sea dive requires teamwork and dedication from everyone. The pilots are in constant communication with the captain of the vessel. On top of that, they also are communicating with the lead scientists as to where they would like the next sample collected and the plans for the dive.
There are two chairs for the ROV pilots in the front row and another chair where the lead scientist sits to control the camera on the ROV and to narrate the dive. The back of the room has four large chairs from an old airplane for the rest of the scientists to observe the dive from. There is a video monitoring station where screen grabs and notes are taken of each sample collected, of interesting geological structures and of animals observed. There is also a GIS station where a member of the research team records dive information so that there is a trail of “bread crumbs” that can be referenced after the dive is over and data analysis begins. Finally, there is the notes station where a researcher records similar information as the previous two stations. It may seem like a lot of repetitive work, however, after 8 days of 12-hour dives, it all starts to blend together so it is good to have as many records as possible.
My purpose on the boat was to collect biological specimens, however, I also had the opportunity to help out the geologists on board (and learn a bit about rocks!). When I wasn’t working at the GIS or notes station, I was watching the live feed for enteropneusts, polychaetes, and for any other interesting organisms.
Enteropneusts, commonly known as acorn worms, are closer relatives to vertebrates, (that’s us!), than one would think. Despite their gelatinous appearance they have three of the five anatomical characteristics that define the phylum chordate: a dorsal hollow nerve cord, notochord and pharyngeal gill pores. Previously, Enteropneusta consisted of three families and were thought to only inhabit the benthic substrate. In 2005 a fourth family, the Torquaratoridae was described. This family of enteropneusts live slightly off of the sea floor and some (maybe all of them) are capable of floating in the water column from one benthic foraging site to the next (Osborn et al. 2012). Enteropneusts found at Axial Seamount are primarily translucent with light pigmentation to their neck or intestinal region. They blend in with their surroundings very well and often the best way to see them is by the fecal trail left behind.
Several new species of enteropneusts have been seen on previous MBARI expeditions in the Axial area. Since their discovery, many have been recorded on video but few specimens have been collected for morphological and molecular study. They are very delicate organisms and often disintegrate during collection.
The acrocirrid polychaetes are more obvious to see but they swim fairly quickly so it is easy to lose them. Collecting deep-sea animals requires a lot of skill and dexterity and it is really amazing to watch the pilots work. For delicate organisms, the pilots use a suction sampler (similar to a vacuum) to collect them. After the collected animals make their long ascent to the surface, they are quickly removed from the ROV and put in the cold room. The suction sampler jars are carefully checked for symbiotic or parasitic organisms and then animal is gently transferred to a smaller container to be photographed. Finally, a tissue sample was taken for genetic analysis and the specimen was fixed for morphological study.
This research trip was the best experience I have ever had. I learned more than I could have hoped for, met truly amazing people and got to see the deep-sea firsthand. I am so thankful to Dr. Osborn for giving me this opportunity and to the team of scientists and the crew on board the Western Flyer. It was such a pleasure to work with everyone and I hope to have an opportunity to do this kind of work again in the future.
By Jessica Whelpley, independent contractor working on sorting and cataloguing the Museum's hydrothermal vent collection while applying to grad schools where she will hopefully work on some topic of deep sea conservation.
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