But shipwrecks and other artificial reefs created as substitutes for eroding natural reefs can support concentrated populations of these predators, a new study finds. In fact, predator densities were as much as five times greater at 14 artificial reefs analyzed in the study compared to 16 nearby natural reefs. Shipwrecks were their favorite. They particularly liked those that rose between 4 and 10 meters (13 to 32 feet) up into the water column, which is the column of water from the bottom of the sea up to the surface. Researchers found that in some areas, shipwrecks supported predators at densities 11 times greater than natural reefs or low-profile artificial reefs that were made of concrete. #shipwrecks #reefs #marinelife #oceans https://www.treehugger.com/how-shipwrecks-support-marine-predators-5078330