Any solid structure that spends enough time in the ocean will eventually become a settling ground for various species of marine organisms. Oil and gas production platforms throughout the Gulf of Mexico are an excellent example of this. Their underwater support structures have become artifical reefs.
This video begins with a good look at the silhouetted support legs of High Island A389A, the gas production platform located within sanctuary boundaries and about 1 mile from the coral cap at East Flower Garden Bank. It is followed by up-close images of various animals that consider this platform home: sponges; whitespotted filefish; barracuda; and, scrawled filefish. SCUBA divers also enjoy diving under this platform because of the abundance of life that can be found here. (0:53)
Credit: FGBNMS/Hickerson