"The Osborne Reef is an artificial reef project situated off the coast of Fort Lauderdale, Florida. It was one of many attempts in the 1970s and 80s to mimic the environmental benefits of coral reefs using old tires, but it has become an environmental disaster.

...It was approved by the U.S. Army Corps of Engineers, and the dumping operation was supervised by a U.S. Navy minesweeper.

In the years to follow, many of the tires — which were held together only with nylon rope and steel clips — came loose, making the “reef” useless as a habitat and, in some cases, damaging real coral reefs nearby.

Over the past two decades, groups both public and private have launched programs to remove the remaining Osborne Reef tires from the ocean.

...The state estimated that there were 650,000 tires remaining in 2016, and 4ocean estimates that there are still over 500,000 in 2022."