Octocoral present at Joint Base Pearl Harbor-Hickam, Hawaii

The objective of this project is to evaluate hot water treatment as a method to control an invasive octocoral at Joint Base Pearl Harbor-Hickam (JBPHH). This species, along with other aquatic invasive species (AIS), clog water intake systems for naval vessels and cooling systems, leading to operational delays and costly repairs. Existing control methods, such as mechanical removal, chemical treatments, and biological controls, are costly and often ineffective. Hot water treatments offer a promising alternative by effectively killing a wide range of invasive species while enhancing biosecurity and minimizing operational impacts at JBPHH.

This project plans to use hot water to kill an AIS at JBPHH. Hot water will be deployed using a specially designed adaptation of commercially available units that deliver water for heated suits to divers who operate in cold water. The unit consists of an electric water pump that courses seawater through coils that are heated by a diesel burner and insulated hoses that deliver hot water directly to invasive coral. With sufficient flow rate and temperature, hot water has been shown in other settings to kill AIS in situ. The generator and heater are deployed on an appropriate platform (barge, ship) and a shipboard operator manages the generator and heater whilst divers below target hot water to AIS.

There are growing concerns among state and federal agencies that this octocoral and other aquatic invasive species could spread beyond JBPHH, threatening critical Department of Defense (DoD) infrastructure in the Indo-Pacific. The successful application of this innovative mitigation tool at JBPHH could serve as a model for addressing AIS on a larger scale at other DoD installations infestations are detected early. This approach promises more effective control with reduced infrastructure and financial impacts compared to current methods. Additionally, it could act as a fire break to prevent the spread of AIS from localized infestations. (Anticipated Project Completion - 2026)