For several years, watermen have been working with William & Mary’s Virginia Institute of Marine Science to remove thousands of abandoned crab traps around the Chesapeake Bay.
To find these “ghost pots,” crabbers use sonar units that identify objects on the seafloor.
But the technology has another benefit that local scientists are leveraging: It collects continuous data about the depth of the water.
Professor Kirk Havens, director of the Center for Coastal Resources Management at the Batten School & VIMS, said the information is extremely valuable. The project tends to focus on pots in shallower waters, where data is limited.
“We are woefully without shallow water bathymetry,” Havens said. “Those are the areas where it’s really important if you’re going to be modeling for storm surge or sea level rise that are associated with those near-shore landscapes.”
Bathymetry is often called “submarine topography,” referring to data about the depths and shapes of underwater terrain, according to the National Oceanic and Atmospheric Administration.
It allows scientists to accurately model impacts of changing water dynamics, Havens said.
The project is in partnership with the National Oceanic and Atmospheric Administration, which previously awarded VIMS $8 million to fund removal of marine debris in Virginia and beyond, including in Florida, California and the island nation of Palau.
In the Chesapeake Bay region, crabbers are paid in the winter off-season to remove traps. They have covered about 1,000 square miles and removed more than 37,000 pots.
NOAA and VIMS outfitted the crabbing boats with sonar units that ping every few seconds. They quickly realized the opportunities.
“We had so many people out there scouring the waterways, looking for these ghost pots, that they covered a lot of territory,” Havens said.
Years ago, it would’ve been virtually impossible to extract the data from the machines, he said. But computing advancements in recent years allowed scientists to get it in large batches and match the pings with information about times and tides.
The project has gathered about 5 million data points, which would have taken around 20 years and tens of millions of dollars to do on their own, Havens said.
Federal officials are also excited.
Rear Admiral Christiaan van Westendorp, director of NOAA’s Office of Coast Survey, said in a statement that the shallow-water data “is the missing puzzle piece for many of our coastal models and navigational charts.”
“Through harnessing commercial mariners' presence and expertise, we unlock a new data stream and are able to better identify recent seafloor changes in areas notoriously difficult to survey.”
VIMS and its partners are processing the data and plan to release it in batches available through a portal on NOAA’s National Centers for Environmental Information website. Officials hope it can be used by coastal researchers and to manage navigational safety.
Editor’s note: Derek Aday, director of VIMS and dean of the Batten School of Coastal & Marine Sciences at William & Mary, is a member of WHRO’s Board of Directors. The board is not involved in any editorial decisions.
