National Park Service Pacific Island Network U.S. Department of the Interior

Life on the Decks of Sunken Ships coral Corals, fish, worms, algae, and have settled on the sunken hulls of WWII Valor in the Pacific National Monument Over 70 years ago the U.S.S. Arizona and the U.S.S. Utah were attacked and sunk in Pearl Harbor, Hawaii, taking

the lives of hundreds of men with them. fanworm

Nature invariably finds a way to overcome even the most egregious of human follies. Sabellastarte spectabilis Today, over 45 of grandis, was thespecies dominant found on both ships. marine organisms live and Invasive orange keyhole , flourish on the hulls of the two ships, according Porites compressa and Porites lobata. to a survey conducted by scientists at the Hawaii Institute Over 635 total corals were counted of Marine and measured on the U.S.S. Arizona Biology. and 60 corals on the U.S.S. Utah, most of them occurring on deck

Two species areas but also along the ships’ of sponges sides. Interestingly, no corals were reported on the U.S.S. Arizona in This finding suggests that the the 1986 survey or elsewhere in composition of the fish community a comprehensive survey of Pearl has changed substantially. Harbor conducted from 1971-73. It is likely that this recent coral Comparing the results of this 2011 Where surfaces of both ships growth is a positive response to the study led by Dr. Steve Coles from are not covered by silt or rubble, improved water quality and clarity the Hawaii Biological Survey of the they support a rich assemblage of that has been achieved in Pearl Bishop Museum in Honolulu, HI organisms dominated by sponges Harbor in the last 30 years. with those of a similar study in 1986, and worms. The Branchiomma sp. suggests that substantial changes in tubeworm was the most abundant At the present rates of coral the ocean life on both ships have organism reported on the U.S.S. accumulation it is possible that occurred in the last 35 years. Arizona in the 1986 survey, but it large sections of the U.S.S. Arizona appeared to be less abundant in and the U.S.S. Utah may become Twenty-one species of fish were 2011. This finding suggests that encased in coral. This may require identified on the U.S.S. Arizona lower organic particulate levels in a decision of whether to allow coral and 18 species on the U.S.S. Utah Pearl Harbor water have diminished accumulation to progress, or to in 2010. The fishes on both vessels the food source for this organism selectively remove coral to maintain were dominated by two species that relies on suspension feeding. the structural integrity of these of surgeonfish Acanthurids)( , historic ships. and by the sergeant major (A. The most significant finding of this –Corbett Nash, NPS abdominalis). Although similar study was the establishment of an numbers of fish species were found apparently thriving community Look for the full report soon at around the U.S.S. Arizona in 2010 of hard corals on both vessels. irma.nps.gov. as in the 1986 survey (25 species), They are dominated by Pocillopora Note: Pacific Coral Reef Program provided only eight species were found in damicornis and Leptastrea purpurea, partial funding to support this inventory when common between the two studies. and include a few large colonies of the program was administered by the PACN.

October 2013