The U.S. Coast Guard is donating about 70 concrete anchor blocks to the state Department of Land and Natural Resources, and they will be added to the artificial reef at Maunalua Bay today through Wednesday.

"Artificial reefs are important resource-enhancement opportunities," said department chairman Peter Young. "New coral and seaweed will grow on the blocks, which will provide additional habitat to new communities of reef fish."

Off East O'ahu, the Maunalua Bay artificial reef was created in 1961 by depositing large, solid objects such as barges, truck tires, concrete pipes and cars on the ocean floor to provide marine animals with a habitat. It covers about 74 acres. Even though the reef has a strong current, it has proven to be a popular spot with fishermen and divers.

The Coast Guard uses the concrete blocks to anchor its navigational aids (such as channel marker buoys) to the sea floor.

As the blocks are dropped, the area will be marked with surface floats to warn boaters, fishermen and divers to stay clear of the area.