Artificial Reef

History
The construction of artificial reefs is thousands of years old, although the historic usages were related to sea power rather than aquaculture. Ancient Persians blocked the mouth of the Tigris River to thwart Indian pirates by building an artificial reef, and during the First Punic War the Romans built a reef across the mouth of the Carthaginian harbor in Sicily to trap the enemy ships within and assist in driving the Carthaginians from the island.
The use of artificial reefs to increase fish yields or for algaculture also has a long history. During the 17th century reefs of building rubble and rocks were used in Japan to grow kelp, while the earliest recorded construction of artificial reef in the United States is from 1830s when logs from huts were used off the coast of South Carolina to improve fishing.