Concrete is ideal for artificial reefs because its uneven surface encourages the growth of algae, barnacles and soft corals, which attract fish. The holes, cut throughout the reef ball, give small fish shelter from predators. They are made by pouring concrete into a fiberglass mold containing an inflatable central bladder surrounded by various-size inflatable balls to make holes. The bladder can be left in the reef ball so the unit can be towed behind any size boat. At the artificial reef site, the bladder is deflated and removed.
Natural reefs come in various sizes and shapes.
Artificial reefs function better if they mimic nature. The seafood industry creates 40,000 jobs. Sixteen of Florida's 21 metropolitan areas are built around an estuary or lie at the mouth of a river where it flows into the sea. Boat registrations in Florida have approximately doubled in 15 years, a rate three times greater than the population increase. Florida's 735,000 boats represent one for every 18 residents or one for every eight Florida families.