According to my research and experience, using old tires as an artificial reef does not work so well.
From an article about a tire reef in Florida
The tires were unloaded there in 1972 to create an artificial reef that could attract a rich variety of marine life, and to free up space in clogged landfills. But decades later, the idea has proved a huge ecological blunder.
"The really good idea was to provide habitat for marine critters so we could double or triple marine life in the area. It just didn’t work that way," said Ray McAllister, a professor of ocean engineering at Florida Atlantic University who was instrumental in organizing the project. "I look back now and see it was a bad idea."
"We’ve literally dumped millions of tires in our oceans," said Jack Sobel, an Ocean Conservancy scientist. "I believe that people who were behind the artificial tire reef promotions actually were well-intentioned and thought they were doing the right thing. In hindsight, we now realize that we made a mistake."
From a study Broward County’s Department of Natural Resource Protection
’’We’re not really seeing any difference,’’ said Richard Spieler, a Nova University marine biologist hired by the county to study the structures.
No one can say with certainty why the idea doesn’t work, but one problem is that, unlike large ships that have been sunk for reefs, tires are too light. They can be swept away by the tides and powerful storms before marine life has a chance to attach. Some scientists also believe the rubber leaches toxins.
If you Google search for "tire reef"
and look at Images, most of the images are dark, gray, bleak, without plant life or aquatic life.