December 2024

Year in Review: 2024 Highlights from the Triton Initiative

The Triton Initiative aims to reduce barriers to permitting and facilitating the deployment of marine energy devices by contributing knowledge and data around potential environmental impacts. Each year, the projects and research efforts evolve, but the mission stays the same. In 2024, Triton’s research took the team around the country, conducting tank-based particle motion experiments at Pacific Northwest National Laboratory (PNNL), deploying tethered balloon systems in California, and addressing active acoustics knowledge gaps in New Hampshire. As we reflect on a productive year of research, fieldwork, lessons learned, and partnership building, here are some highlights from Triton in 2024. 

Advancing Acoustic Particle Motion Research 

The Acoustic Particle Motion team conducting dose response experiments with salmon at the “Big Blue” tank at Pacific Northwest National Laboratory-Richland. (Photos by Joe Haxel | Pacific Northwest National Laboratory). 

Triton’s Acoustic Particle Motion research team, led by Triton principal investigator Joe Haxel, aims to address knowledge gaps related to the potential impacts of ocean energy-generated acoustic particle motion and substrate vibration on fishes and invertebrates to better understand underwater noise effects for marine and aquatic species. 

Triton researchers, in collaboration with the Water Power Technologies Office, Bureau of Ocean Energy Management, and diverse subject matter experts, will conduct tank-based experiments with fish and crabs at PNNL research facilities to understand behavioral and physiological response of animals when exposed to acoustic particle motion and substrate vibration from offshore energy. 

In 2024, the Triton team started experimental design and setup for these exposure experiments. Using physiological indicators, such as stress hormone levels, the team will quantify a response while correlating any behavioral observations when different acoustic stimuli are presented to the animals. Specifically, Triton will study the effects on species with cultural and commercial significance, beginning with salmon and Dungeness crabs.

This year, Triton published “Triton Explains: Acoustic Particle Motion and Marine Energy” which explains how fishes and invertebrates hear using this component of sound, implications for the marine energy industry, and Triton’s contributions to particle motion research.

Developing Flow Shields 

Hydrophones donning different flow shields prior to performance tests in Sequim Bay, Washington. The flow shields include an oil-filled enclosure (left) and nylon fabric shield (right). (Photo by Michael Richlen | Pacific Northwest National Laboratory). 

As part of Triton’s underwater noise research, Emma Cotter and Joe Haxel led a project testing and developing various flow shields to reduce the effects of flow noise. Flow noise is the acoustic pressure fluctuation from turbulence, caused by the flow of water past an acoustic sensor. Triton developed several flow shields intended to reduce the effects of flow noise during underwater noise monitoring and improve the quality of measurements taken. 

This year, the team published a paper in the Journal of the Acoustical Society of America Express Letters, titled “Performance of Three Hydrophone Flow Shields in a Tidal Channel.” The paper presents results from a study that evaluated the performance of three hydrophone flow shields in the Sequim Bay tidal channel at PNNL-Sequim. Due to the flow shields’ ability to effectively reduce flow noise, these monitoring tools were successfully deployed during underwater noise monitoring in Igiugig, Alaska for the PNNL Environmental Monitoring Campaign. 

Cotter also gave a talk titled “Evaluating the Performance of Three Flow Shields in a Channel,” at the 2024 Ocean Sciences Meeting where she presented Triton’s work to develop and test flow shields that enable more effective monitoring of underwater sounds at tidal energy sites. The Triton team is now working with an industry partner to commercialize the flow shield technology and make it available to researchers using hydrophones in high energy areas worldwide.

Exploring Collision Risk Mitigation Strategies 

An Integrated Collision Detection and Mitigation researcher places a marine mammal surrogate into the flume to see how the surrogate behaves around a tidal turbine prototype in the simulated current. (Photo by the University of Washington).

The risk of collision between marine fauna and tidal turbines is a primary regulatory and societal concern around the development of tidal energy. While significant efforts are improving monitoring and modeling collision risk, mitigation solutions are an important piece of the puzzle when it comes to improving the safety of animals around marine energy devices. The Integrated Collision Detection and Mitigation (ICDM) project is evaluating if strain gauge sensors integrated into turbine blades can be used to slow or stop blade movement when a marine mammal is detected in its vicinity. 

In April, Emma Cotter traveled to the 2024 Environmental Interactions of Marine Renewables Conference (EIMR) in Kirkwall, Scotland to present Triton’s ICDM research and co-lead a workshop on environmental monitoring at the array scale. Next year, the ICDM project team will conduct additional tank tests to continue exploring strain gauges for possible collision mitigation. 

Triton’s Research Soared in California 

The sun sets beyond the horizon as the team prepares the tethered balloon system for nighttime operations. (Photo by Cailene Gunn | Pacific Northwest National Laboratory).

In partnership with Sandia National Laboratories, the Marine Wildlife Detection and Tracking Project team, led by Alicia Amerson, deployed and tested the utility of a tethered balloon system (TBS) to advance tracking and detecting marine animals at sea. 

To test the TBS as a potential long-term monitoring technology for observing marine wildlife occurrence and behavior at marine energy sites, the team traveled to the central California coast in February to deploy a TBS and sensor package to monitor gray whale and other coastal wildlife. The fieldwork took place at the National Oceanic and Atmospheric Administration Southwest Fisheries Science Center Granite Canyon field site near Carmel, California. The sensor package included thermal and optical cameras deployed at different altitudes and times of day. Amerson traveled to the 2024 Society for Marine Mammalogy Conference in Perth, Australia to present findings from this research and will be publishing a paper on this research soon—stay tuned. 

Improving Triton’s Probability of Encounter Model 

Triton researchers and partners at the University of New Hampshire-led Atlantic Marine Energy Center spent a week at the Chase Ocean Engineering Laboratory. (Photos by Makena Lee | University of New Hampshire).

Triton quantitative ecologist Kate Buenau and fish biologist Garrett Staines lead the Probability of Encounter Model. The goal of the PoEM project is to develop a model that estimates the probability of fish encountering turbines during movement or migration periods. The model is developed using data collected from side looking sonar, an active acoustic method for estimating the biomass of salmon smolt approaching a deployed riverine turbine. 

Last winter, the PoEM team convened sonar subject matter experts at the Jere A. Chase Ocean Engineering Laboratory at the University of New Hampshire to conduct tests that address data gaps in active acoustics research and theory, ultimately aiming to improve data collection for monitoring fish in rivers and shallow channels. These improvements will directly strengthen and refine PoEM’s ability to estimate potential fish encounters. 

Recently, Buenau also traveled to the 2024 American Fisheries Society Meeting in Honolulu, Hawaii. Buenau’s talk, “Modeling Salmon Smolt Turbine Encounter Risk in the Kvichak River, Igiugig, Alaska,” was part of a symposium on Partnering for Innovation and Fish Protection in the Clean Energy Transition. Buenau discussed PoEM’s capabilities and the project’s collaboration with local communities, developers, and academic partners.  

The PoEM team looks forward to another year of active acoustics research and model development in 2025!

Highlighting Science Communication at the Ocean Sciences Meeting

Triton researchers smiling big after an energizing week of networking and sharing Triton’s work at the 2024 Ocean Sciences Meeting! (Photo by Pacific Northwest National Laboratory)

Triton’s communications team also had a busy year, which included co-chairing a session entitled “Exploring Storytelling: Creating Waves of Change in Communication, Outreach, Social Media, and the Arts for Ocean Sciences” at the 2024 Ocean Sciences Meeting. This session invited participants to engage in a series of presentations where science communication professionals, researchers, and industry stakeholders discussed strategies and needs related to communication and outreach for ocean science research. Triton communications lead Cailene Gunn gave a talk titled, “Communication Strategies for Amplifying Marine Energy Research” which highlighted impactful outcomes, challenges, and lessons learned related to Triton’s communication, outreach, and engagement efforts. 

Looking to 2025, the team will expand its scope to include stakeholder engagement and science communication research. We look forward to sharing more as the research develops! 

Happy Holidays from the Triton Initiative!

As 2024 comes to a close, the Triton team wishes you a joyful holiday season and a happy, healthy start to the new year! We’ve accomplished so much in 2024, due in large part to our partners and support from our sponsor. We extend gratitude to our collaborators—and to our readers—for following along and supporting Triton’s research. We look forward to sharing updates from new research efforts launching in 2025! 

If you would like to receive additional information or want to reach out to the Triton team, please ask our team or e-mail tritonmre@pnnl.gov. If you know someone who might enjoy Triton updates, please forward this newsletter along!

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Triton is designed to support the development and testing of more precise and cost-effective environmental monitoring technologies for marine energy. Pacific Northwest National Laboratory leads Triton on behalf of the Department of Energy’s Water Power Technologies Office.

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