Protocol to control the invasive alga in a shallow Hawaiian reef flat.

Premise: A novel control technique was developed to mitigate an invasive siphonous green alga, (Dichotomosiphonaceae), within a shallow degraded reef flat in O'ahu, Hawai'i.

Methods And Results: Replicated treatments of 3% and 10% hydrogen peroxide (HO) were administered into individual basal attachments of the bed-forming invasive seaweed on the Paikō reef, O'ahu. Relative electron transport rate maxima (rETR) were measured using a Walz Diving Pulse Amplitude Modulated Fluorometer in two replicate 100-m plots in 2020.