Tracking and filming marine animals with REMUSREMUS-100, with funding from Discovery Channel, has developemd the capability of tracking, following and filming great white sharks and other marine creatures that can be tagged. REMUS featured as SharkCam in Discovery Channel's SharkWeek show 'Return of Jaws' shows how well the technology worked in Cape Cod's turbid waters. Currently there are other ongoing efforts being made for REMUS to follow marine life.
Using REMUS Sidescan Sonar to Find and Identify Schools of Fish
Fish Cruise Video
Seaching for the Lost 8th Wonder of the World
Two Oceanographic Systems Laboratory, WHOI, REMUS-100 AUVs were used in February 2011 to search, map and classify the lake-floor of Lake Rotomahana (New Zealand) in hopes of locating the lost eighth wonder of the world, the Pink and White Terraces. The two vehicles known as Darter and Gudgeon (named after WW II submarines) were modified and outfitted with a unique suite of sensors to most efficiently and effectively characterize the lake's water properties as well as physical features.
Primary objectives for the WHOI-supplied instrumentation were to collect high-resolution bathymetric and side-scan sonar data of the lake bed with correlative water properties information including pH, Eh, temperature and turbidity, and 3-axis fluxgate magnetometer data. For the lake surveys, the REMUS 100 AUVs were fitted with mounting brackets to accept NOAA-PMEL ORP-MAPR sensors, to aid in characterizing the water properties and localizing any sources of hydrothermal activity. In addition, the REMUS AUVs were modified to accept SBE pH sensors.
Our long-term goal is to quantify ripple and ripple field properties in response to wave and current hydrodynamic forcing and grain size variability.
Spatial Surveys of Ripple Geometry:To obtain more detailed measurements of the large scale spatial variability of ripple morphology a REMUS AUV equipped with a sidescan and a small multibeam sonar will be used. The survey will cover the depth range of the fixed instrumentation, but will have a greater along shore spatial extent, which will be used to examine ripple variability that may be caused by gradients in wave energy or bottom characteristics. Using a REMUS AUV at SAX04 showed that the 900 kHz sidescan could measure the wavelength of large (50 cm+)and small ripples (15 - 20 cm minimum wavelength) when the vehicle was traveling parallel to the ripple crests, due to the geometry of the sidescan. A pencil beam sonar was also able to measure the height of large ripples (greater than 50 cmwavelength and greater than5 cmheight) when the vehicle was traveling perpendicular to the ripple crests. Thus height and wavelength measurements could not be conducted on the same ripples as the two measurements required different vehicle paths relative to the ripple crests.Since the SAX04 surveys low cost, lower power multibeam (sufficient to mount in a small REMUS AUV) have become available from Imagenex. This will allow simultaneous measurement of ripple wavelength over a relatively wide swath using the sidescan and ripple height using the multibeam while traveling parallel to ripple crests. It will also not require the use of a expensive and fragile inertial navigation system used with the narrow beam sonar in the SAX04 ripple height measurements.
Grouper Dynamics in Belize
GLOVER’S REEF, BELIZE—Nassau groupers are large, delicious, and easy to catch when they aggregate by the thousands to spawn on coral reefs in the Caribbean. To protect the species from overfishing, conservationists have proposed setting aside marine preserves, but they don’t know which areas are most critical because they don’t know enough about how the fish travel through the oceans from larval stages to adulthood.
In January 2006, WHOI scientists launched a novel collaborative study, funded by the Oak Foundation, on Glover’s Reef in Belize. To track fish from their birthplaces, biologist Simon Thorrold “tags” fish embryos with a nontoxic chemical marker that can be detected in the fish’s ear bones throughout their lives.
He is working with biologist Jesús Pineda and physical oceanographer Glen Gawarkiewicz, who uses a free-swimming robotic vehicle, REMUS, to obtain detailed measurements of currents that may sweep fish larvae on and off reefs. (Courtesy of Oceanus Magazine)
Seafloor Docking Oceanographic research of yesterday usually made observations in small slices making it expensive, time consuming and difficult to understand the big picture. Today, new generation AUVs have increased capabilities of going further in to the depths of our unexplored oceans. A remote underwater docking station designed here in the OSL will serve as an underwater garage where the vehicle can return to recharge its batteries, download its data and stand by for months waiting for instructions for its next mission. These dockings stations coupled with ocean observatories like LEO-15 will enable scientists to more readily study less known ocean events. The implementation of docking stations in remote areas may play a key role in learning about how our changing oceans affect climate change. These 'parked' vehicles can wake up during a geological event like an earthquake and inspect there impact on fault lines. Also, they can wake up when they sense a chemical plume and track it back to its source. Docking stations will save time, money but, will most of all, give us a more intimate look than we have ever had before into the mysteries of our oceans and their health.
Today we have successfully designed and built a REMUS docking station. Field tested in Woods Hole, we recently returned from a field operation where REMUS completed a mission, then docked itself in the underwater station where it recharged its batteries, downloaded its data and then preceded to undock itself for its next mission. Ultimately, REMUS docked successfully 100% and all systems were green!
Hydrodynamics of Tidal Flow Across A Submarine Sand Ridge
Middle Ground is a sand ridge that runs along the channel of Vineyard Sound just west of West Chop headland on Martha’s Vineyard.The ridge is situated in the channel at a slight angle to reversing tidal flow along the channel.This tidal flow is asymmetrical with respect to the ridge, with the ebb cycle stronger to the north of the ridge and the opposite true on the south side, resulting in a counterclockwise mean flow around the ridge.The goal of this study was to resolve the small-scale processes on and around the ridge that are responsible for its maintenance and shape.This was done by collection and analysis of in situ water velocity measurements and comparison of the data to a numerical model.Harmonic analysis was performed on a moored ADCP time series, which confirmed the ebb dominance on the north side of the ridge.A mean flow of 5-10 cm/s was found to flow in the direction of the ebb tide and was confirmed by the model.In order to extend the in situ observations to locations closer to the ridge, spatial transects across the ridge were obtained using the Autonomous Underwater Vehicle REMUS over a complete tidal cycle.Analysis of REMUS data showed a strong localized shearing of velocity over the ridge crest during the strongest currents.Comparison to the model indicated some spatial variability in the tidal asymmetry relative to the ridge.More field observations from both mooring and REMUS data are necessary to fully resolve the small-scale processes most relevant to Middle Ground.
Abstract by Tess Brandon.
Arctic REMUS aka ICEBOTIn March 2010 a team of WHOI experts emabarked on an Arctic expediton out of Barrow, Alaska.
Although the importance of the Arctic in global climate change is widely recognized, a critical component of the Arctic system has been largely overlooked: The inflow of Pacific Water and its role in maintaining the Arctic halocline. In particular, there is a need to understand the processes by which Pacific Water flowing through the Bering Strait is modified in the shallow Chukchi Sea and then transported to the western Arctic basin. The transport most important to halocline properties is that which occurs in winter beneath ice cover. This process establishes hydrographic conditions in the upper 200 m of the Arctic basin that determine the relative influence of Pacific and Atlantic water, and may profoundly affect the thickness and extent of Arctic sea ice. The narrow passage between Point Barrow, Alaska, and the flank of Barrow Canyon is a critical “choke point” of the system, where a significant portion of the Pacific Water inflow is concentrated subsequent to modification by shelf processes, but prior to exchange with Arctic waters. We set out to obtain high-resolution hydrographic transects across this choke point in winter, using REMUS-100.
A REMUS-100 was modified to operate under the ice and is referred to as the Icebot.
Hull & Harbor Surveys
REMUS 100 experimentation involves the development of new technologies that will involve: the performance of pier, harbor, and underwater hull surveys; the performance of near shore very shallow water mine counter measure operations from positions that are 10 km or more offshore; the performance of shallow water mine counter measure operations from a helicopter; and experimentation with these new capabilities during Naval exercises.
Delta-T Sonar Data
Data collected from our Hull & Harbor vehicle. Sonar imaging of 3D objects on the hull of a ship.