Mapping the Future of Fire Island

A team of researchers is using autonomous underwater vehicles and sonar to create digital “mosaics” of the seafloor.

I’m fascinated by the ebb and flow of the ocean and its impact on the environment, which is why I’m so envious of the team of scientists and students from the University of Rhode Island’s Graduate School of Oceanography (GSO) who are spending the summer mapping submerged habitats along the coast of Fire Island National Seashore on Long Island.

After Hurricane Sandy, a portion of Fire Island’s 26-mile barrier beach was submerged. Using high-tech equipment, the team is collecting data about the habitats that are now underwater and how this occurence may change the island ecosystem.

The technology in use includes high-resolution, side-scan sonar to create acoustic maps of the submerged habitats from the shoreline to about a mile into the Great South Bay. According to an article on the GSO webpage, the sonar can detect and differentiate physical features of the seafloor, such as eelgrass, shellfish beds, boulders and sand. The acoustic sonars, mounted to an autonomous underwater vehicle (AUV) or towed from a research vessel, send sound pulses to the seafloor. The sonars track the amount of time it takes for the sound to bounce back, which automatically calculates and collects measurements of water depth. It also produces an image of the seafloor.

Before Hurricane Sandy, very little baseline information existed that would allow researches to compare the before and after condition of submerged habitats, making it difficult to interpret how the storm affected various geological and biological features of the underwater ecosystems. The maps currently being developed will provide datasets the will help scientists plan for the future.