Marine Operations

Papahānaumokuākea National Marine Sanctuary relies on a variety of tools and platforms to conduct research and support marine operations. This includes the research vessels Malolo and Kaku, open-circuit scuba diving, closed-circuit rebreather diving, uncrewed aerial systems, reliance on larger ships for expeditions, and various new tools for automated and remote sensing.

Research Vessels Kaku and Mālolo

These two research vessels are both 19-foot SAFE Boats equipped with twin 90 horsepower engines. They are designed to handle various ocean conditions, including the rough waters often encountered in Papahānaumokuākea National Marine Sanctuary. During marine operations, we usually have two to six personnel on each vessel as well as any scientific gear needed for the mission.

safeboat suspended on a crane launched from the side of larger vessel — Papahānaumokuākea National Marine Sanctuary's R/V *Kaku* launched from the side of the NOAA Ship Oscar Elton Sette. Photo: Pearl Thompson

researchers on safeboat — Papahānaumokuākea National Marine Sanctuary divers head out on R/V *Mālolo* for surveys at Kuaihelani (Midway Atoll). Photo: Sean Digre/NOAA

Expeditions Rely on Ship Time

Research expeditions to Papahānaumokuākea National Marine Sanctuary require a research crew to either secure a time block on a NOAA fleet ship such as Oscar Elton Sette, or charter a large ship through a third-party partner.

R/V Oscar Elton Sette docked for loading — NOAA Ship *Oscar Elton Sette* loads equipment for an expedition into Papahānaumokuākea National Marine Sanctuary. Photo: Chelsie Counsell/CIMAR

Scuba Diving

Scuba diving enables us to conduct in-water surveys along coral reef ecosystems of Papahānaumokuākea National Marine Sanctuary. An effective tool for in-water work from depths of 10 to 130 feet, divers train for specific data collection tasks like surveying reef fishes, while also maintaining a close eye on their buddy, remaining bottom time, and air resources. NOAA divers complete annual watermanship skill tests as well as regular first aid, CPR, and oxygen administration training to ensure they are ready to safely support one another during marine operations.

NOAA diver surveys the reef at Manawai (Pearl and Hermes Atoll) Photo: Nick Zachar/NOAA

two divers examining their equipment before going in the water — The tools divers bring with them depend on the mission. Powerful underwater cameras are an incredible tool for documenting interesting observations as well as capturing photogrammetry data to build high resolution 3D models of the reef habitat. Photo: Nick Zachar/NOAA

Closed-Circuit Rebreathers

Closed-circuit rebreather scuba diving is an advanced method of technical diving. It requires intensive training on the dive physiology of using mixed gases to dive deeper and stay on the bottom longer than traditional open-circuit scuba diving allows. Traditional scuba limits dive time because each exhale depletes a diver's air supply, while closed-circuit rebreather systems recycle exhaled air by removing carbon dioxide, extending underwater time and efficiency.

two divers underwater — NOAA divers Brian Hauk and Jason Leonard on closed circuit rebreathers use diver propulsion vehicles to survey for nuisance algae at Manawai. Photo: Nick Zachar/NOAA

Divers also undergo detailed training for the specific model of gear they will use. NOAA rebreather divers conduct regular proficiency dives to ensure familiarity with their gear and safety protocols. With rebreather technology, NOAA divers can conduct in-water surveys as deep as 300 feet (100 meters).

diver underwater — Papahānaumokuākea National Marine Sanctuary diver Jason Leonard conducts dive checks before descent. Photo: Nathan Eagle/ Civil Beat

group in scuba gear training on shore — Rebreather training is conducted in the field and classroom. Photo: Jason Leonard/NOAA

Remote Data Collection

Because Papahānaumokuākea National Marine Sanctuary is so remote and vast, sanctuary and NOAA researchers rely on uncrewed systems to collect data safely and efficiently across large areas. These technologies help scientists monitor wildlife, map and observe habitats, document marine operations in the field, and gather ocean and soundscape data while reducing risk to people, improving efficiency, and minimizing disturbance to sensitive species and

Uncrewed Aerial Systems

Uncrewed aerial systems enable researchers to collect aerial footage of the surface activities of marine protected species, ongoing marine operations in the field, shallow marine ecosystems, shorelines, and more. The Papahānaumokuākea National Marine Sanctuary team uses a few different uncrewed aerial system platforms, regularly training to maintain proficiency on each. We also practice launching and recovering them from the small boat, as most of our operations within the sanctuary occur from small boats.

team on a small boat at sea launching uncrewed aerial system — Papahānaumokuākea National Marine Sanctuary team practices an uncrewed aerial system launch and recovery from their 19-foot SAFE boat. Photo: Jason Leonard/NOAA

Remotely Operated Vehicles

Remotely operated vehicles, or ROVs, are tethered underwater robots controlled by operators from a ship. In Papahānaumokuākea, ROVs have been used during deep-sea expeditions to explore seamounts and other understudied seafloor areas, document biological communities, and collect samples, video, and other data from depths far beyond the reach of divers. Given the remote distance of Papahānaumokuākea National Marine Sanctuary from accessible ports, we are exploring the growing utility of remotely operated vehicles.

Autonomous Surface Vehicles

Autonomous surface vehicles can travel long distances while collecting data with minimal onboard human support. The Wave Glider is an autonomous surface vehicle made up of two parts: a float on the surface and a winged unit underwater, connected by a cable. In 2021, the Wave Glider traveled over 2,600 miles in 67 days while recording the presence of koholā (humpback whales) in Papahānaumokuākea as part of NOAA and the U.S. Navy’s Sanctuary Soundscape Monitoring Project (SanctSound).

an autonomous surface vehicle in the water. — The Wave Glider traveled 2,627 miles over 67 days (Jan. 8 to March 14, 2020). It was deployed with traditional ti leaves as it was blessed before leaving port. Photo: Jupiter Research Foundation

Listening in: Passive Acoustic Monitoring

Office of National Marine Sanctuary staff monitor long-term trends in natural biological sounds and human-generated noise in Papahānaumokuākea using passive acoustic methods. Acoustic tools that record underwater sound are important for monitoring biological activity in remote habitats because many fish, invertebrates, and marine mammals regularly produce sounds for communication and/or sensing their environment. Acoustic monitoring is also an effective way to detect human activities in a marine habitat, such as vessel traffic or the use of explosives in illegal fishing.

We use an ecological acoustic recorder (EAR), a low-power digital system designed to capture ambient underwater sound. At Manawai (Pearl and Hermes Atoll), recordings have documented some of the highest noise levels measured by an EAR in the Pacific, which may be linked to high biological productivity in the surrounding water. At Lalo (French Frigate Shoals), EAR recordings often capture dolphin and fish signals, as well as the songs of humpback whales (Megaptera novaeangliae).

three members of the field team on research vessel holding up an ecological acoustic recorder — Field team staff with an EAR that has just been recovered after over a year of collecting data in Papahānaumokuākea National Marine Sanctuary. Photo: Sean Digre/NOAA Dive Center.

field team member aboard research vessel programs ecological acoustic recorder — Marine Operations Coordinator Jason Leonard runs final checks on programming before deploying a new EAR within Papahānaumokuākea National Marine Sanctuary. Photo: Brian Hauk/NOAA