Coral Colonies Temporal Texture Study

(7/2020 – 6/2021)

In July 2020 the Friends of Hanauma Bay with the help of several members and volunteers started a yearlong Coral Colony Temporal Texture (CCTT) Study of coral colonies  of the inner reef at Hanauma Bay.  We would like to thank the Department of Land and Natural Resources (DLNR) and Hanauma Bay management for granting us the requisite permits during the COVID-19 pandemic, when Hanauma Bay was closed to the public. Our study is tracking changes in coral colonies along the inner reef over time. For our study, we selected 15 coral colonies which are in close proximity to the sites where we took water samples in May 2020.

This project was inspired by a similar project conducted by our friends at Kahalu’u Bay on the Big Island. Kahalu’u Bay has been facing multiple threats for years: sunscreen pollution, coastal inundation, sewage and runoff, homeless encampments, overcrowding and climate change among them. Staff and volunteers had observed the decline of corals without any bleaching events, so they started their own monitoring project. Starting in 2017, they took monthly photos of a number of Cauliflower corals (Pocillopora meandrina), selecting corals that were already showing small signs of die-off. The team was surprised to see how quickly some of these corals declined, and eventually completely died off. They named their first coral colony studied “Canary”, which died completely in less than two years. If you would like to see more examples of corals at Kahalu’uBay, please visit this website:

When our friend Cindi Punihaole, Director of the Kahalu`u Bay Education Center, shared with us that Kahalu’u Bay had lost 95% of its cauliflower coral and asked if we were seeing the same at Hanauma, we did not have any data to answer. The COVID-19 closure of Hanauma Bay offered a unique opportunity to start our own monitoring project. A small group of volunteers were trained by Dr. Craig Downs of the Haereticus Environmental Laboratory (yes, the same Dr. Downs who led our oxybenzone study back in 2017) in how to take photos of coral heads. This group of scuba divers and snorkelers started our temporal texture study on July 7, 2020. We go back to those same 15 coral heads every 4 to 6 weeks and take photos from the same angles to observe any changes.

Friends of Hanauma Bay members Michael Feeley and Anke Roberts had started an informal survey of a number of corals in the summer of 2019, and some of those corals are included in our scientific study as well. Unfortunately, we are seeing some degradation in some of the study corals, but that degradation is much slower than what has been documented for Kahalu’u Bay.

For each coral, photos are taken from five different angles during each survey. An L-ruler is used to indicate which direction in north, then photos are taken from each of the four compass directions, as well as from the top. However, Hanauma Bay’s inner reef has quite a few corals that do not grow on top of the reef, but along a side wall. In that case it is not possible to take photos from all angles.

Please click on the following link for timeline photos of each Coral Colony. We will continue to monitor progress and provide regular updates. We hope to lay a foundation for more research to be done to better understand what is impacting the health of our beautiful Cauliflower Coral (Pocillopora meandrina). Link to the Coral Colony Time-Lapse Images

If you would like to see all monthly survey photos for these corals, please contact

Mahalo to all the volunteers who have taken time to help with one or more of the monthly surveys: Anke Roberts, Glenn Roberts, Ken Staples, Cindy Staples, Shannon Murphy, Amy Kelley, Senator Chris Lee, Alex Kahn, and Michael Feeley.

To see photos of our volunteers in action, please browse through our photo gallery link: Volunteers In Action.