Meeting Abstract

P3.57  Sunday, Jan. 6  Quantifying Herbivory Pressure and Preference: Are Native or Invasive Macroalgae Preferred? CHULAKOTE, S.S.Y*; SMITH, C.M; University of Hawaii, Manoa; University of Hawaii, Manoa scottsyc@hawaii.edu

Although assessments of Hawai’i’s reef habitats have documented fish biomass and assemblage, few studies on herbivory pressure have been done. This experiment was done to quantify grazing pressure in four study sites (Waikiki Marine Life Conservation District (MLCD), Waikiki-Diamond Head Fisheries Management Area (FMA), and a nearshore and offshore site in the Paiko reef) and determine if there is a preference towards native or invasive macro algae using pairwise comparisons over multiple 24 hour experimental runs. Grazing pressure was moderately low for all macro-algal species across all sites while the only statistical differences in preference were seen in Acanthophora spicifera and Gracilaria salicornia over its native pairwise counterparts in the Waikiki-Diamond Head FMA. Previous studies that have indicated low fish biomass in conjunction with our observed low grazing pressure may suggest a lack in abundance of herbivores that are unable to prevent or reverse coral-algal phase shifts. Herbivore preference of two dominate invasive macro-algae seen in our study however may imply certain key herbivore species as viable biocontrol options for management.