Cruise Background Continuing their 23-year-long time-series study of the coupling of open-ocean food supplies and the responses of seafloor communities, Ken Smith and his research team will retrieve and redeploy deep-sea observation equipment and the Benthic Rover at Station M, approximately 200 kilometers (125 miles) off the coast of Point Conception in the eastern North Pacific Ocean. The seafloor at Station M, 4,100 meters (13,500 feet) below the ocean's surface, is flat and muddy and composed of silty clay sediment and seasonal deposits of detritus. Time-lapse photography at Station M has revealed abundant evidence of bioturbation—the mixing of sediment by organisms burrowing into the seafloor—and other activity by animals living on and in the sediment such as trails, furrows, and mounds that can be centimeters to meters across. Smith and his colleagues will now have the opportunity to analyze a new set of time-lapse photographs taken by a camera mounted on the deep-sea observatory they deployed in June 2012 and will recover on this expedition. They will also process samples from the observatory's sediment traps to obtain values for organic carbon and nitrogen, as an estimate of the food supply to the benthic community. A sedimentation event sensor (SES) that photographs settling particles for comparison with the sediment traps will also be recovered. On this cruise, Smith's research team will once again deploy the free vehicle grab respirometer (FVGR) to measure the oxygen consumption of the seafloor sediment community. Additionally, the team will retrieve then redeploy the Benthic Rover to conduct similar measurements but in a linear transect. The Benthic Rover has been traversing the seafloor for the past five months. The remotely operated vehicle (ROV) Doc Ricketts will be used to conduct transects of the seafloor in order to assess the abundance and size of seafloor animals. The ROV will also be used to collect seafloor animals and place them in respirometers on the seafloor. The respirometers measure the animals' oxygen consumption, an indicator of how much food the animals consume. Related Links
The vast muddy expanses of the abyssal plains occupy about 60 percent of the Earth's surface and are important in global carbon cycling. Changes in the Earth's climate can cause unexpectedly large changes in deep-sea ecosystems. Based on 18 years of studies, MBARI's Ken Smith and his coauthors showed that such ecosystem changes occur over short time scales of weeks to months, as well as over longer periods of years to decades. This video shows a series of time-lapse still images of animals on the deep seafloor. The images were taken at one-hour intervals over a period of about three months in spring 2007. These images were taken at "Station M," a long-term research site about 4,000 meters below the surface and 220 kilometers west of Point Conception, on the Central California Coast. MBARI marine ecologist Ken Smith has been conducting research at Station M since about 1990.
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Logbook
Equipment
 R/V Western FlyerThe 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, the Gulf of California, and the Pacific Northwest.
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.
Sequencing conical sediment traps, each with an effective mouth opening of 0.25 m2, are moored at 600 meters and 50 meters above the bottom at 3,500- and 4,050-meter depths, respectively. Trap sequencers are programmed to collect sinking particulate matter in sampling cups every 10 days. In the laboratory, the collected particulate matter is analyzed in duplicate for total and inorganic carbon.
A push-core is a clear plastic tube with a rubber handle on one end. Just as its name implies, the push core is pushed down into loose sediment using the ROV's manipulator arm. As the sediment fills up the core, water exits out the top through one-way valves. When the core is pulled up again, these valves close, which (most of the time) keeps the sediment from sliding out of the core tube. When the cores are brought back to the surface, scientists typically look for living animals and organic material in the sediments.
The Benthic Rover is a mobile physiology lab. In a series of experiments, the rover measures how much oxygen seafloor animals are using. Precise motors lower two 30-centimeter-wide (12-inch) sample chambers into the sediment, where probes record oxygen levels. Two acoustic scanners use ultrasound (in 4-MHz pulses) to look 10 centimeters (four inches) deep into the sediment for large animals, such as worms.
This midwater toolsled contains a High-Frequency Suction Sampler (HFSS). You can see one of the 12 collection buckets in this image. This sampler acts like a vacuum cleaner sucking up samples and depositing them into one of the 12 buckets.
The benthic elevator allows us to carry more than the ROV itself can carry. Loaded with sediment enrichers, it is deployed from the ship before the dive and free-falls to the bottom where the ROV pulls the equipment from the elevator for use. After the ROV is recovered, the elevator anchor's acoustic release is triggered from the ship, and the elevator freely ascends to the surface and is recovered.
Oxygen consumption (a measure of biological activity) of the organisms living in the sediment is measured using a free vehicle grab respirometer (FVGR) which retrieves sediments for faunal examination and chemical analyses.
The Lagrangian Sediment Traps or LSTs are used to collect sinking material at specific depths. Once they are deployed they will sink to a programmed depth and float along with the current. After a few days the sample cups will close and the LST will activate its variable ballast system to rise to the surface to be recovered.
Research Team
Ken is an open-ocean ecologist with 40 of years experience going to sea and studying extreme ecosystems ranging from the deep ocean to Antarctic icebergs. The main thrust of his research is to understand the impact of a changing climate on deep-sea and polar ecosystems. On this cruise, he will coordinate the deployments of autonomous instruments to continue long time-series studies at Station M on the Monterey Deep-Sea Fan at 4,000 meters depth.
Alana specializes in instrumentation. On this cruise she will be deploying three instruments: the Benthic Rover, the time-lapse camera tripod, and Lagrangian sediment traps.
As lab technician, Jake's responsibility is to make sure everything runs smoothly so samples can be collected at sea and analyzed in the laboratory. He'll organize much of the equipment being taken to sea, and will ensure everything works during the cruise. Once ashore he'll take all the samples and analyze them in a variety of ways with the goal of achieving a better understanding of how the ocean works.
John will help with all the mechanical maintenance and repair of the Benthic Rover, the sediment traps, and the seafloor camera tripod.
Rich has been at MBARI since 2000 working on many types of projects, but mostly writing software for MBARI's autonomous vehicles. On this cruise Rich is responsible for the control system on the Benthic Rover. The Rover will be retrieved from the seafloor and then redeployed for six more months.
Crissy completed a post-doc in MBARI’s Midwater Ecology lab, after which she worked for Conservation International Indonesia supporting marine protected area monitoring efforts. She has just returned to MBARI, as a senior research technician in Ken Smith’s lab, and on this cruise is learning about the lab’s shipboard operations and instruments.
Paul specializes in underwater vehicles and instrumentation. On this cruise he'll help prepare, deploy, and recover the drifters, crawlers, and landers being used to study the deep ocean at Station M.
Researching the links between climate variation and deep-sea ecology has been a primary focus for Henry. In particular he's interested in understanding how changes in climate are related to the role of the deep ocean as a carbon sink. During the cruise he will be researching the abundance and distribution of animals on the seafloor, as well as their respiration rates using specialized chamber systems. Respiration is a good indicator of carbon utilization and provides key input into estimates of carbon flow and the importance of biodiversity at the seafloor.
Amanda studied plate sponges at Station M as an intern in the Smith lab. She is now pursuing a Ph.D. at the University of Alberta, studying the growth, energetics, and impacts of hexactinellid sponges that form reefs in the straits of western Canada. Her interests outside of research include scuba diving, martial arts, and science blogging.
Carola has worked for many years in the field of microscopy and volunteered on one of Ken Smith´s Sargasso Sea expeditions earlier in 2012. On this trip she will help in the lab. Her interests outside the work are photography and scuba diving. |
