Decades ago, Arthur C. Clarke envisioned an “underwater telescope” that would allow users to look down from the surface of the ocean and enter its dark depths,media reported. Now, with existing technology, such capabilities are one step closer to reality. Typically, when scientists want to monitor ecologically important phenomena such as the proliferation of algae, they use satellite photographs. However, satellite cameras typically only “see” the ocean between 5 and 10 meters deep, according to researchers at the Bigelow Marine Science Laboratory in Bigelow, Maine.
To find a better alternative, the Bigelow team, led by Dr. Barney Balch, turned to the ship-borne lidar (LiDAR) unit. The technique is more common in robots and self-driving cars, where lidar devices work by emitting laser beams and then measure the exact time it takes for light to reflect back from any object. This method not only detects obstacles, but also detects their distance from the user and their contours.
Balch’s team, along with colleagues at Odomine University in Virginia, used the technology for a cruise study in the Gulf of Maine in 2018. In this way, they successfully gathered information about the outbreak.
These creatures protect themselves with calcium carbonate plates, which scatter reflected light in a unique way. As a result, scientists can determine the presence and amount of seaweed by analyzing reflected lasers.
In fact, the region is experiencing the largest outbreak of algae in the past 30 years. By using lidar, it can be three times as deep as it can be seen using satellite photos.
The technology has been successfully tested in other regions, such as the Matail Sea and the New York City coast. The researchers hope that lidar will eventually allow scientists to collect ocean data quickly, at a lower cost and easily, without having to stop ships to collect deep-sea samples.
“The use of a tool allows us to look deeper into the ocean, like having a new pair of eyes,” Balch said. “