Underwater acoustics for mapping the water column
Underwater acoustics (ie. fisheries sonars) uses sound to detect and map the presence of fish and other organisms in the water column. An acoustic signal or ping is sent into the water column from an transducer. The strength of the return signal is measured and is correlated to the size of the fish target. The length of time (divided in half) that it takes for the sound wave to travel back to the transducer, indicates the range from the transducer (or depth) of the fish target. The resulting echogram displays the location and size of fish in the water column.
Acoustic surveys are integral to research and management of fishery stocks in Alaska, the Pacific Northwest and New England. Underwater acoustic sensors are also being deployed as part of integrated ocean observatories and energy development platforms (e.g., tidal and wind power facilities) in the mid-Atlantic and Pacific coasts. However, these advanced acoustic technologies have not been broadly applied in the southeast US, Gulf of Mexico or the Caribbean.
Southeast Regional Acoustics Consortium Workshop
The Southeast Regional Acoustics Consortium (SEAC) was conceived as a working group that would bring together academic institutions, federal and regional fisheries and environmental management agencies, and private industry – all vital partners in conducting acoustics research in the coastal ocean of the US from North Carolina to Texas and the US Caribbean – to advance the use of acoustic techniques for understanding the marine environment. A workshop was held at Florida International University March 13-15, 2012 to bring these regional partners together and kick-off the Southeast Acoustics Consortium.
The aim of the workshop was to discuss current research and management needs that can be addressed by employing emerging acoustic technologies. The three day workshop included presentations by leading scientists in the field of acoustics and fisheries science, including Dr. Michael Jech of NOAA’s Northeast Fisheries Science Center and Dr. John Quinlan of NOAA’s Southeast Fisheries Science Center. Discussions revolved around how best to apply these remote, non-invasive sampling techniques in the Southeast US and Caribbean to better manage fish species, protect essential fish habitat, and conduct science to support coastal ecosystem management.
A variety of applications demonstrating the use of acoustics to document fish behavior in mangroves, coral reef ecosystems, and shelf habitats in the Gulf of Mexico were presented. Discussions also included the potential for applying acoustic techniques to complement stock assessments and assist managers of National Marine Sanctuaries, highlighting the contribution that acoustic technologies can make to the management of fisheries resources and protected ecosystems. Hands-on demonstrations, by a variety of manufacturers, gave participants a chance to see this technology in action.
Partnerships for the Future
SEAC was founded by the National Centers for Coastal Ocean Science, along with NOAA Fisheries Southeast Fisheries Science Center, and the Marine Sciences Programs at Florida International University and Duke University. Partnerships such as this are extremely important when it comes to using new approaches to address the complexities of marine ecosystems. The Consortium will continue to be a focal point for scientists, resource managers, industry, and academics to share expertise and assets related to active acoustics, to inform regional managers on the state-of-the-science, and to identify data gaps and science needs for coastal ecosystem management that can be filled by advanced acoustic technologies.