This is an ongoing project with many stages. The first stage included the removal of the Hui Feng No. 1 ship wreck, which was completed in January 2014. The second stage of the project is to remove and control the corallimorph which has spread over the western terrace. The coral reefs at Palmyra Atoll National Wildlife Refuge (Palmyra) are under attack from an invasive corallimorph, Rhodactis howesii, an anemone like species that is out competing corals and smothering the reef. R. howesii were seen increasing in number on the western terrace of Palmyra after a long-line fishing vessel wrecked in the area in 1991. Available data including two surveys of the infestation in 2007 and 2011 suggests the vessel is fueling the growth of R. howesii perhaps by releasing iron, a limited element in seawater. The corallimorph is currently spreading over once pristine coral reefs, killing and smothering corals and turning an area once rich in species diversity into a monotypic blanket of corallimorph. Recent surveys in 2011 show that R. howesii has now spread over 250 acres of reef smothering corals across the western terrace and on the north and south fore reefs of the atoll. The speed at which the corallimorph is spreading poses a serious threat to the health of the reefs surrounding Palmyra and the coral reef ecosystem as a whole. In the past few years several control and eradication methods have been trialed, three of which have been proven successful. One of these (Tarp method) involves killing all organisms on the benthos using bleach and tarps and would be suitable for eradication in areas where corallimorph cover exceeds 60%. Pilot studies using this method show that once cleared from the substrate, corallimorph do not recover for at least a year. A second method (focal treatment) involves killing individual corallimorph using calcium bicarbonate and is more suited to eradication in areas where corallimorph cover is equal to that of corals (thereby limiting collateral damage). Pilot studies also reveal that reef fish will eat corallimorph. We hypothesize, therefore, that if large enough areas are treated, local predators will limit corallimorph densities and allow recovery of the reef.
