Navy divers assisting in the placement of used tires as an alternate reef material on the artificial reef site at Pokai Bay, Oahu. The tires did not stay in place because of the strong surge of the large Pacific swells at the site.

Navy divers assisting in the placement of used tires as an alternate reef material on the artificial reef site at Pokai Bay, Oahu. The tires did not stay in place because of the strong surge of the large Pacific swells at the site.

Tires being placed in an array to determine their effectiveness as habitat for fish.

Tires being placed in an array to determine their effectiveness as habitat for fish.

Tires being placed in an array to determine their effectiveness as habitat for fish.

Underwater writing slates were used to record the different species adhering to the top, side and interior roof of pipes over time.

Underwater tape recorders were used to record the number and size of each fish species on a set transect. A conversion table was used to convert estimated length of fish to estimated weight.

Underwater tape recorders were used to record the number and size of each fish species on a set transect. A conversion table was used to convert estimated length of fish to estimated weight.

Underwater writing slates were used to record the different species adhering to the top, side and interior roof of pipes over time.

Underwater writing slates were used to record the different species adhering to the top, side and interior roof of pipes over time. Counting the interior surface of pipes took considerable flexibility on the part of the diver.

Straightening out one of the underwater transect lines used for counting fish. All fish ten feet to each side of the line were counted.

A diver equipped with underwater tape recorder, wetsuit, watch for determining dive time.

Benthic samples were taken to identify the species associated with the artificial reef site.

Natural reef areas close to the artificial reef site were also sampled to determine the biomass and species composition of fish. You can see the portable transect line lying along the bottom.

Natural reef areas close to the artificial reef site were also sampled to determine the biomass and species composition of fish. You can see the portable transect line lying along the bottom.

Small coral colonies were collected on pipe surfaces of know age to determine growth rate of corals on the artificial reef.

Diver disentangling rope from regulator while getting ready to lay a transect line.

Small coral colonies were collected on pipe surfaces of know age to determine growth rate of corals on the artificial reef.

Ctenochaetus striogosus, surgeon fish and sea urchin, Echinothrix diadema.

Sea Cucumber, Stichopus chloronotus, and Ctenochaetus striogosus, surgeon fish in typical habitat where pipe meets the bottom.

A typical invertebrate grouping found on the interior roof of the pipes consisting primarily of bryozoa, tunicates and sponges over the top of oyster shells. Oysters could not survive long once the other fouling organisms covered them over.

Monotaxis grandoculis observed during a night dive on the artificial reef.

A typical school of the surgeon fish, Acanthurus olivaceus, grazing on algae during the time when filamentous algae were abundant. This period occurred soon after placement of the pipes and the red and green filamentous algae were replace with blue-green algae at a later stage.

A mixed school of surgeon fish grazing on algae during the time when filamentous algae were abundant. This period occurred soon after placement of the pipes and the red and green filamentous algae were replaced with blue-green algae at a later stage.

Surgeon fish, Naso unicornis, Acanthurus olivaceus, Acanthurus dussumieri, on reef during a low slightly greater turbidity episode.

A mixed school of surgeon fish grazing on algae during the time when filamentous algae were abundant. This period occurred soon after placement of the pipes and the red and green filamentous algae were replaced with blue-green algae at a later stage.

A typical invertebrate grouping found on the interior roof of the pipes consisting primarily of bryozoa, tunicates and sponges over the top of oyster shells. Oysters could not survive long once the other fouling organisms covered them over. You can see the tan colonies of erect bryozoa, Reteporellina sp. These colonies disappeared after strong storm surges.

A typical invertebrate grouping found on the interior roof of the pipes consisting primarily of bryozoa, tunicates and sponges over the top of oyster shells. Oysters could not survive long once the other fouling organisms covered them over. You can see the tan colonies of erect bryozoa, Reteporellina sp. These colonies disappeared after strong storm surges.

A typical invertebrate grouping found on the interior roof of the pipes consisting primarily of bryozoa, tunicates and sponges over the top of oyster shells.

Night time photo of nudibranch egg mass placed on the pipe surfaces within days of placement.

A permanent grid station showing outline of sample grid, stainless steel screw used to attach the nylon line, and the invertebrate community typical of the inside roof of pipe.

A permanent grid station showing outline of sample grid, stainless steel screw used to attach the nylon line, and the invertebrate community typical of the inside roof of pipe.

Holocentrus sp., squirrel fish, in typical habitat between pipes. Red areas on pipe are coralline algae.

Broyozoa, oysters, sponges on interior roof of concrete pipe. Community is characteristic of mature interior reef surface. You can see scrape marks from grazing fish on dark and light green colonies of bryozoa.

Bryozoa, oysters, corraline algae, sponges on interior roof of concrete pipe. Community is characteristic of mature interior reef surface.

Corraline algae and a colony of ahermatypic(no zooxanthellae algae in tissues and non-reefbuilding) coral , pink, Tubastraea sp.

Corralline algae, erect byrozoa(tan) Reteporellina sp. and ahermatypic(no zooxanthellae algae in tissues and non-reefbuilding) coral, on interior roof of pipe.

Newly colonized interior roof pipe surface with oysters and small white colonies of colonial tunicates (Didemnid sp.)

Mixed school of goatfish, Parupeneus multifasciatus, Parapeneus pleurostigma, and Chaetodon miliaris.

Surgeon fish, Acanthuris sp, in inside of pipe on artificial reef.

Intermediate age community of upright bryozoa, reteporellina sp., oysters ( mostly covered), and tunicates. The large, tan, upright bryozoa usually breakaway from the surface once they become too big.

Mixed school of butterfly fish and surgeon fish grazing on pipe surface.

Large single polyp of Fungia scutaria.

Individual polyps are extended in this colonial Pocillopora damicornis, coral.

Pocillopora damicornis, coral, showing gauls caused by the coral crab Trapezia wardi.

Colony of the ahermatypic coral, Tubastrea sp. With nudibranch that feeds on polyps of this coral.

Colony of the ahermatypic coral, Tubastrea sp.

Close up of the ahermatypic coral, Tubastrea sp.

Flatworm, Pseudoceros ferrugineus.

Nudibranch, Caloria indica, on purple sponge.