Even though fly ash may release small quantities of arsenic and selenium, these amounts do not exceed EPA drinking-water standards, so that successful reefs have also been constructed of this material. Liberty vessels and barges constructed of steel can withstand corrosion underwater for 50-100 years. However, to meet Environmental Protection Act requirements, ships must be thoroughly cleaned, including detoxification of hazardous materials from the hulls. Likewise, steel petroleum platforms have been successful as reef structures, each providing a surface area of more than 100,000 square feet. Although Florida has the most active artificial reef program in the Gulf of Mexico, Texas and Louisiana use oil and gas platforms almost exclusively for reef construction.
Rigs are unique artificial reefs in that they extend vertically through the water column.
As in natural systems, various photic zones may exist as species compositions change with depth. Importance of Artificial Reef Structures Artificial reefs are an economically and environmentally sound way of disposing of petroleum platforms. Local commercial and recreational fishing enterprises benefit as marine ecosystems are enhanced. However, If removal and positioning of rigs are not done properly, there may be a loss of valuable habitat for shrimp, and destruction of shrimping gear during trawling. Also, any structures that are utilized must not pose navigational hazards or interfere with shipping lanes.