Summary

Description

Roi-Namur is located at the northernmost tip of Kwajalein Atoll, approximately 64 kilometers north of the U.S. Army Kwajalein Atoll(USAKA) central command post on Kwajalein Islet. Roi-Namur has a single sewage outfall, which is located at the northwestern corner of the islet. Originally, the outfall extended from shore to a point about halfway across the reef flat where the pipe ended abruptly as an upturned, uncapped elbow. Raw sewage was pumped through the pipe in pulses approximately every 15-20 minutes. Waves and shallow currents across the reef flat carried at least some of the effluent back toward shore and the lagoon, creating a potentially unhealthy situation. In order to correct this problem, USAKA implemented a plan to extend the original outfall all the way across the reef flat and into the open ocean where the predominant current flow would carry effluent-mixed waters away from the islet. Ultimately, the extended outfall was to be connected to a new sewage treatment facility that would discharge primarily treated effluent. Because of a concern that this discharge might adversely impact the coral-reef community surrounding the end of the new outfall, a baseline marine biological survey was to be conducted prior to start-up of the new sewage treatment facility. As planned, the results of this survey would provide a baseline against which the results of future surveys could be compared in order to determine whether a balanced community of indigenous species had been maintained at the site during operation of the facility. If not, conversion to secondary treatment at the facility would need to be considered. The first resurvey was planned to occur one year after start-up of the new sewage treatment facility with subsequent resurveys planned for every five years thereafter. In August 1997, biologists from the U.S. Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) conducted the baseline marine biological survey in the vicinity of the Roi-Namur outfall. For the National Oceanographic Data Center, interest in the report focuses on the marine element. Data tables from marine surveys of reef fishes, corals, other macroinvertebrates, and algae that exist in those habitats are provided.