This project examined the results of the field manipulative experiment that has been set up to test the ecological effects of introduced roi on reef fish associations in West Hawaii. This on-going research project, which began in September 2010, evaluates the impact of roi removal by collaborating with local fishers to remove >90% of the roi from a patch reefs in Puako, West Hawaii. In situ observations of the introduced predatory grouper roi (Cephalopholis argus) were taken semi-annually within the coral reef ecosystem of Puako, northwest side of the Island of Hawaii October 2010 - July 2012. Visual fish transects were made at a depth range of 10-20 m. Tow board and standard visual belt transects were employed at control, reference, and treatment sites. Data include biometrics (length and weight) and biomass of roi, as well as an assemblage of other fish and feed guilds. Additional data on the movement of roi within the Puako area were collected using a fish tagging program followed by surveys for recapture and resighting. NODC Accession 0082197 contains similar data from November 2010 - June 2011. There is some overlap of data within 0082197 and the present accession.