GHOST NETS as depicted on the sonar screen: Another "nerd" topic dedicated to my friend Andrea Del Popolo.
Ghost nets are fishing nets that have been left or lost in the sea by fishermen, many of which often go unseen. These nets can be often found tangled on a rocky reef or drifting in the open sea.
Ghost fishing nets are the deadliest form of marine plastic as they unselectively trap wildlife, entangling marine mammals, seabirds, sea turtles, and other creatures, including the occasional human diver. Acting as they were designed for, the nets restrict movement, causing suffocation in those that need to return to the surface to breathe. Ghost fishing nets also damage critical marine habitats such as coral reefs. Additionally, they are responsible for the loss of commercially valuable fish stocks, undermining both the overall sustainability of fisheries as well as the people who depend on fish for food and for their livelihoods.
If you want to understand how the sonar works, go to https://freedivegreece.com/academy/sonar-academy/