Uses

Artificial Reefs

Why are old subway cars and army tanks littering our ocean floor? What purpose can these sunken relics serve? Societies have constructed artificial reefs out of obsolete objects or “trash” for thousands of years for everything from blockading pirate ships to benefiting algae farm productivity. An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom. Today, many reefs are built using objects that were designed for other purposes, such as oil rigs, highway bridge materials, or ships. Other artificial reefs are designed specifically from PVC or concrete. It’s important to note that these reefs are planned and permitted by state and federal government agencies, and it is illegal to dump anything in the ocean without a permit.   So what should ocean planners know about artificial reefs?

  1. Artificial reefs provide habitat. Algae and invertebrates, such as barnacles, corals, and oysters, attach to the reef’s hard surfaces; the accumulation of attached marine life in turn provides intricate structure and food for assemblages of fish.
  2. Artificial reefs are often important for the local economy. Because these reefs are generally areas of enhanced fish resources, they support jobs and people that earn a living from fishing and tourism associated with diving.
  3. Artificial reefs often develop around wind turbines. Preliminary studies on wind farms in other countries show that the foundation used to support wind turbines acts as an artificial reef and has increased the habitat and diversity in the area surrounding the turbines. This could create new feeding areas for turtles, birds, and marine mammals, which marine planners would want to be aware of.

Quick Caveats The artificial-reef data collected from the states did not have standardized attributes or a common update cycle. The MarineCadastre.gov team has standardized the attributes in the compiled data set and reviews for updates every year.

For questions, please contact info@marinecadastre.gov.