Baseline Assessment of the Coral Reef Habitat in Kaloko-Honokōhau National Historical Park Adjacent to the Shores at Kohanaiki Development, 2006-2007 

Abstract

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.This study provides current-condition baseline data and long-term monitoring methodology for coral reef habitats within the northern portion of Kaloko-Honokōhau National Historical Park for 2006-2007. The Park contains approximately 596 acres of coral reefs, state-designated pristine coastal waters, and unique coastal aquatic ecosystems such as Hawaiian fishponds and anchialine pools. The Park is located on the rapidly urbanizing Kona Coast on the west side of Hawai'i Island and will be surrounded by large-scale developments that include a golf course; commercial, light industrial, and residential developments; and a possible harbor expansion resort complex. Coastal development in the Kailua-Kona area will also impact the Park's reefs through increases in fishing, anchoring, and recreational use. Worldwide, coastal development has had profound impacts on coral benthic communities, and is implicated in shifts from coral dominance to algal dominance with resulting loss of habitat for reef organisms. In response to the construction of the "Shores at Kohanaiki" development adjacent to the Park's north boundary, this study was initiated to establish a current baseline and to identify changes in percent coral cover, algal cover, and coral survival over time at two habitat zones within Kohanaiki Reef compared to two reference sites. In Spring 2006, Fall 2006, and Summer 2007, pre-development baseline data were collected on (1) randomly selected photo transects, (2) individual corals, and (3) macroinvertebrate densities to monitor coral reef health. Benthic cover at all three sites was primarily composed of coral, turf algae, and crustose coralline algae. Mean coral cover at Kohanaiki Reef as a whole remained stable throughout the 17-month study period, varying from 30.7 to 34.3%. Macroalgae were a minor component, comprising less than 1% cover at all sites on all survey dates except at Kohanaiki Reef vertical-wall sites where macroalgae were approximately 4.5% of benthic cover. Grazing urchin populations were present at all sites, averaging 6.0 urchins/m2 +/- SD 2.8. Acanthaster planci were present, but uncommon. Porites Tissue-Loss Disease was encountered on several Porites lutea colonies at the Kaloko Reference Site in the summer of 2006, and Porites Trematodiasis was observed throughout the study at all sites. Partial bleaching was widespread on Pocillopora meandrina heads at Kohanaiki Reef in October of 2005, but corals had recovered or died by the time of our surveys. Results indicate that the study design and survey methods are robust and have a good probability of correctly identifying >10% absolute change in coral cover over time.This study was funded by the National Park Service under Task Agreement # J8320050012 through the Hawai‘i-Pacific Islands Cooperative Ecosystem Studies Unit, Cooperative Agreement #H8080040012. We thank E. Brown, W. J. Miller, R. Steidl, and I. Williams for their assistance with sampling design and statistics. We thank R. Gmirkin for assistance in the field work and J. Beets for his support. We thank two peer-reviewers for their review and comments. This work was performed under Hawai‘i Division of Aquatic Resources Special Activity Permit number PRO-2006-84 and PRO -2007-16