Curriculum Module

Oyster Reefs in Texas and the Gulf of Mexico
by Nan Crowson
Fall 97

Texas and the Gulf of Mexico do not have many natural oyster reefs, and efforts to help rehabilitate present ones have not been very successful. With oysters being a large cash crop, there are several programs in the works to augment the natural reefs with artificial ones. Houston Lighting and Power Company conducted an experiment that used ash from coal and lignite burning power plants and combined it with cement to form golf ball sized pellets. These pellets were distributed in six test beds close to shore in Galveston and Trinity Bays . These test beds were monitored for oyster attachment, and within six months the pellets were encrusted with oysters. Because this test was so successful, other experimental reefs were built. One test site, the size of a football field, was created in Galveston Bay near April Fool's Point. Texas A & M graduate students monitored the new reef for two years. Again, the reef was encrusted with oysters, barnacles, algae and sponges within a short time.

A large offshore artificial reef was constructed out of the ash and concrete mixture molded into four by four blocks. About 325 of the blocks were placed in 100 feet of water 30 miles off the coast of Freeport. One month after it was built, it was covered with spadefish and snappers. The power company produces 500,000 pounds of coal ash a year. Almost half of that is sold to be added to road base, but the rest is usually dumped into local landfills. With this new and successful technology, more landfill space will be freed up.

The reef project was concluded to be a biological and ecological success. The ash mixture costs about one third as much as regular concrete. Including the costs of transporting the reefs to sites, it was still economically favorable as opposed to placing the ash in landfills. The coal ash pellets will also enable scientists to help the oyster industry reestablish itself after severe storms such as hurricanes. Once the hard material is deposited, the oysters will attach to it and build a community. Hopefully, the quick reconstruction of a reef would minimize the damage to the local reef ecosystem.

The Texas Artificial Reef Advisory Committee monitors other options to build artificial reefs including the Rigs to Reefs program. Rigs that are no longer used may be taken apart and submerged to provide structures for reef communities to build upon. There is even a possibility that the Texas Clipper an old research vessel from A&M will be sunk and recycled into a reef. Many others companies are jumping on the band wagon. The Reef Ball company is producing various sizes of hollow concrete balls with holes in the surface. These are being sunk in the ocean with successful results in building a reef community.

All of the new artificial reefs will create new underwater ecosystems that Texans and others will enjoy through recreation, food and the benefits of recycling a large amount of 'ash trash'.

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