Preliminary Results Available for Reef Fish Survey in the Main Hawaiian Islands
During August 1-23, 2013, scientists of the PIFSC Coral Reef Ecosystem Division (CRED) and partners conducted 1031 research dives around the islands of Hawaiʻi, Lānaʻi, Molokaʻi, Kauaʻi, Niʻihau, and Oʻahu as part of a Pacific Reef Assessment and Monitoring Program (RAMP) expedition in the main Hawaiian Islands. The NOAA Ship Hiʻialakai was the base of operations. The expedition, designated as PIFSC mission HA-13-04, was the fifth Pacific RAMP survey for the main Hawaiian Islands performed since the program began in 2000. Pacific RAMP is part of the National Coral Reef Monitoring Plan of NOAA's Coral Reef Conservation Program. It enables long-term monitoring of the status and trends of coral reefs in the U.S. Pacific and the physical and chemical processes that affect those ecosystems.
During RAMP surveys, teams of divers collect observations of fish, benthic organisms, and oceanographic conditions and deploy fixed biological and oceanographic monitoring stations. Much of the data collected can require extensive post-collection processing. However, data collected by the fish survey team is readily available for preliminary analysis immediately after data entry and quality checking. Here, we provide a summary overview of the survey effort and a preliminary evaluation of the data collected during the HA-13-04 expedition.
- Data were collected at 237 survey sites, including 58 at Hawaiʻi, 29 at Lānaʻi, 39 at Molokaʻi, 34 at Maui, 37 at Kauaʻi, 26 at Niʻihau, and 14 at Oʻahu.
- Niʻihau and Molokaʻi had the highest observed fish biomass. This finding was evident in the recorded estimates of total fish biomass as well as biomass of large fishes, piscivores, and primary consumers. The category of primary consumers includes herbivores such as parrotfishes (which eat plant material, like macroalgae) and detritivores such as surgeonfishes (which bottom feed on detritus).
- Similar to results from the visual surveys of reef fishes conducted by CRED off Oʻahu in September 2012, preliminary findings from the August 2013 expedition indicate that Oʻahu had the lowest fish biomass recorded in the main Hawaiian Islands. No fishes >50 cm in total length were observed during these surveys, and the lack of sightings of piscivorous reef fishes within the survey areas is notable.
