Apparently this underwater cemetery helps rebuild reefs? Can cremated remains do that?

Artificial reef a novel way to create life after life
An artificial reef off of Key Biscayne acts as a final resting place for loved ones, and a source of new corals and other marine life.
Sunday Oct 10, 2009

The treasure hunt was part of a publicity campaign organized by the Plantation-based Neptune Society, which built the quarter-acre artificial reef two years ago as an underwater cemetery and home for marine life...

Indeed, the gated courtyard to Atlantis -- guarded by two lion statues and featuring a central podium -- is covered with algae and soft corals.
http://www.miamiherald.com/sports/story/1287817.html