Deep Submergence Laboratory Research Articles

New records of the deep-sea anemone Phelliactis callicyclus Riemann-Zurneck, 1973 (Cnidaria, Actiniaria, Hormathiidae) from the Gulf of California, Mexico.

Specimens of a deep-sea anemone were observed in photographs and video footage taken with the Remotely Operated Vehicle JASON (WHOI Deep Submergence Laboratory) in the Gulf of California, Mexico, in May 2008. Comparison of our material with photographs and description of this species available in literature indicate that the sea anemones filmed during the JASON survey are most likely to represent Phelliactis callicyclus Riemann-Zurneck, 1973. This species has previously been reported from a locality in the Gulf of California near the present record. During the JASON survey, 28 specimens of P. callicyclus were spotted in 27 locations during six dives. The specimens occurred on angular rock outcrops along the escarpments of the transform faults of the Gulf of California, between depths of 993-2543 m and at temperatures ranging from 2.3 to 4.5°C. Based on these new records, Phelliactis callicyclus appears to be widely spread in the Gulf of California.

Workshop on ROVs and deep submergence

The deep‐submergence community has an opportunity on March 6 to participate in a unique teleconferencing demonstration of a state‐of‐the‐art, remotely operated underwater research vehicle known as the Jason‐Medea System. Jason‐Medea has been developed over the past decade by scientists, engineers, and technicians at the Deep Submergence Laboratory at Woods Hole Oceanographic Institution. The U.S. Navy, the Office of the Chief of Naval Research, and the National Science Foundation are sponsoring the workshop to explore the roles that modern computational, communications, and robotics technologies can play in deep‐sea oceanographic research.Through the cooperation of Electronic Data Systems, Inc., the Jason Foundation, and Turner Broadcasting System, Inc., 2‐1/2 hours of air time will be available from 3:00 to 5:30 PM EST on March 6. Twenty‐seven satellite downlink sites will link one operating research vessel and the land‐based operation with workshop participants in the United States, Canada, the United Kingdom, and Bermuda. The research ship Laney Chouest will be in the midst of a 3‐week educational/research program in the Sea of Cortez, between Baja California and mainland Mexico. This effort is focused on active hydrothermal vents driven by heat flow from the volcanically active East Pacific Rise, which underlies the sediment‐covered Guaymas Basin. The project combines into a single‐operation, newly‐developed robotic systems, state‐of‐the‐art mapping and sampling tools, fiber‐optic data transmission from the seafloor, instantaneous satellite communication from ship to shore, and a sophisticated array of computational and telecommunications networks. During the workshop, land‐based scientists will observe and participate directly with their seagoing colleagues as they conduct seafloor research.

Determination of fine-scale bottom roughness using combined optical and acoustical sensing.

Seafloor characterization work in progress at the Deep Submergence Laboratory takes advantage of a multiscale suite of optical and acoustic sensors deployed from towed and remotely operated vehicles. A long-term goal is the automated segmentation and classification of undersea terrain. Fine-scale data of small areal extent are used in the interpretation and ground truthing of coarser, larger scale data sets, which in turn are applied to other measurements of increasing scale and decreasing resolution: Camera and laser bathymetry are used for the ground truthing of high-frequency (e.g., 200–500 kHz) swath-bathymetric sidelook sonars; both optical and precision acoustical data serve for the interpretation and validation of intermediate-frequency sidelook data. Under development is an iterative technique, with the goal of improving classification results. At the first iteration, knowledge of sensor and seafloor geometry is combined with acoustic backscatter data to estimate a regional scattering function. This function is then applied to the raw amplitude data for removal of a deterministic component that depends on the bottom slope. The resultant map of acoustic albedo is segmented, a local scattering function is estimated within each segment, and the process is repeated until a measure of convergence is satisfied.