AUV Dorado

AUV Dorado. The AUV Dorado is a sophisticated autonomous underwater vehicle developed and operated by the Monterey Bay Aquarium Research Institute for high-resolution seafloor mapping and water column survey missions. Designed as a modular, torpedo-shaped platform, it has been a critical asset for oceanographic research along the California Current and in other dynamic regions. Its operational history includes numerous expeditions that have advanced the understanding of benthic habitats, hydrothermal vent systems, and oceanographic processes.

Overview

The vehicle was conceived to address the need for detailed, repeatable surveys of the deep seafloor, complementing the capabilities of other platforms like the ROV Doc Ricketts and the RV Western Flyer. As part of the institute's fleet, it has participated in collaborative projects with organizations such as the National Oceanic and Atmospheric Administration and the United States Geological Survey. Its missions often support broader scientific initiatives like the Ocean Observatories Initiative, contributing to long-term environmental monitoring efforts in areas such as the Monterey Canyon.

Design and specifications

The Dorado's hull is constructed from aluminum and titanium alloys to withstand the pressures of the deep ocean, with a design depth rating exceeding 4,000 meters. Its propulsion system typically consists of a ducted thruster powered by lithium-ion batteries, providing an operational endurance of up to 24 hours depending on sensor payload and speed. The vehicle's modular payload section allows for the rapid integration of various scientific instruments, a design philosophy shared with other AUVs like those built by the Woods Hole Oceanographic Institution. Standard navigation relies on a combination of Doppler velocity logs, inertial navigation systems, and acoustic transponders for precise positioning underwater.

Operational history

Since its commissioning, the AUV Dorado has been deployed on numerous research cruises, including pivotal surveys of the Gorda Ridge and the Juan de Fuca Ridge to study hydrothermal plume dynamics. It played a significant role in the Monterey Accelerated Research System cable observatory site characterization, mapping potential installation locations. The vehicle has also been used in archaeological investigations, such as surveying historic shipwrecks within the Channel Islands National Marine Sanctuary. Key expeditions have been conducted from the RV Rachel Carson and other support vessels, often in coordination with surface assets and remotely operated vehicles.

Scientific contributions

Data collected by the AUV Dorado have been fundamental in publishing studies on submarine landslide frequency in Monterey Canyon, appearing in journals like *Geology* and *Journal of Geophysical Research*. Its high-resolution bathymetric maps have revealed previously unknown cold seep communities and intricate lava flow morphologies at Axial Seamount. The vehicle's water column surveys have directly contributed to models of carbon export in the California Current Ecosystem, informing research by institutions like the Scripps Institution of Oceanography. Its repeated surveys of specific sites have provided crucial time-series data for assessing changes in deep-sea coral habitats.

Technical systems and payload

The core sensor suite often includes a multibeam echosounder for bathymetry, a sidescan sonar for backscatter imagery, and a sub-bottom profiler for shallow stratigraphy. For water column studies, it can be equipped with a conductivity, temperature, depth profiler, fluorometers for chlorophyll detection, and optical sensors for measuring turbidity and dissolved oxygen. The vehicle's autonomy is managed by the MOOS-IvP software architecture, enabling complex mission planning and adaptive behaviors in response to environmental data. Payload integration has also included mass spectrometers for in situ geochemical analysis and specialized samplers developed in partnership with the University of Washington.