Monitoring Demonstrates Increase in Parrotfish Biomass and Crustose Coralline Algae in Kahekili Management Area

The Kahekili Herbivore Fisheries Management Area (KHFMA) in Kaanapali, West Maui, was established by the State of Hawaii in July 2009. It involves a form of management that is unique within the state, namely protection of coral reef herbivores (i.e., surgeonfishes, parrotfishes, chubs, and sea urchins) within the boundaries of this fisheries management area. The goal of the KHFMA is to restore natural grazing processes and, therefore, to increase the local reef’s ability to resist and recover from excessive algal growth that occurred repeatedly on local reefs from the mid-1990s through the mid-2000s (see figures below). The KHFMA does not restrict fishing for other types of finfishes or invertebrates.

Examples of algal blooms at Kahekili in 2001 (left) and 2005 (right).
Examples of algal blooms at Kahekili in 2001 (left) and 2005 (right).
Trends in coral and macroalgal cover prior to creation of the Kahekili Herbivore Fisheries Management Area in July 2009.
Trends in coral and macroalgal cover prior to creation of the Kahekili Herbivore Fisheries Management Area in July 2009.

Since 2009, with funding from NOAA's Coral Reef Conservation Program, the PIFSC Coral Reef Ecosystem Division has partnered with the State of Hawaii, Department of Land and Natural Resources, Division of Aquatic Resources to conduct twice-annual surveys of fishes and benthos within the KHFMA. The survey design and methods are identical to those used for baseline surveys that began in January 2008, enabling continuity with data gathered at the reef prior to the creation of the KHFMA. The most recent surveys occurred during April 22-26, 2013 and monitoring is planned at current levels through autumn 2014.

Annual mean biomass of surgeonfishes and parrotfishes at the Kahekili Herbivore Fisheries Management Area in 2008-2012. Error bars 
        indicate ±1 standard error of the mean.
Annual mean biomass of surgeonfishes and parrotfishes at the Kahekili Herbivore Fisheries Management Area in 2008-2012. Error bars indicate ±1 standard error of the mean.

The full effects of the KHFMA on fishes and on relatively slow-growing corals will become evident only over a period that will be much longer than three years. However, initial results of the surveys include these findings: