What's New Archive
NOAA and Oregon State University researchers have developed an effective method to use an underwater robotic glider to measure sound levels over broad areas of the ocean, published today in the journal PLOS ONE.
“Healthy marine ecosystems need to have noise levels within particular ranges,” said Joe Haxel, lead author of the paper and assistant professor/senior research at Oregon State University and part of NOAA’s Pacific Marine Environmental Lab Acoustics Program. “As an analogy for humans it’s the difference between living in the country or living in the city or somewhere really loud.”
Ocean sound was recently listed as an essential ocean variable by the Global Ocean Observing System, a UNESCO program, due to its importance for marine life and seagoing humans and because it is used to monitor and locate everything from earthquakes to tsunamis to nuclear explosions.
Traditionally, scientists have measured ocean sound by attaching hydrophones, essentially an underwater microphone, to a fixed mooring in the water. The problem with that is scientists only get data from that single location. Ocean sound can also be measured from a research ship, but they are expensive to operate. They also create a lot of noise themselves, which disturbs marine animals and fish that are sensitive to sound.
Attaching a hydrophone to a glider solves those problems because gliders operate autonomously, relatively quietly and can cover hundreds of miles over several weeks.
Gliders equipped with hydrophones can conduct repeated surveys of a region of concern for acoustic habitat degradation and provide real-time measurements of changing noise levels. Gliders have also successfully been used by scientists to measure noise from an underwater volcano and to predict surface wind speeds. An additional benefit of gliders is that they are outfitted with other sensors and instruments that provide important measurements, such as temperature, salinity and depth.
In the research described in the PLOS ONE paper, the research team attached the hydrophone to the glider, which is about 5 feet long and weighs about 120 pounds. The glider traveled for 18 days between Grey’s Harbor, Washington and Brookings, Oregon, a distance of about 285 miles. The glider operated along the North American continental shelf break, which on average is about 30 miles off the coast where the ocean depth begins to drop more steeply. The shelf break is a key migratory path for marine animals.
Once the scientists retrieved the hydrophone data, their main challenge was fine-tuning their algorithms to filter out the noise the glider creates when operating. After that filtering occurred, the researchers were able to cross-reference the data collected during the 18-day glider trip with historical data from hydrophones attached to moorings along that route.
Haxel said it was pretty shocking how closely the data sets aligned. That led the team to conclude that the gliders are an effective and valuable asset for measuring underwater ocean sound.
Read the paper here: https://doi.org/10.1371/journal.pone.0225325
The story was originally published by Oregon State University on November 20, 2019.
Storms, boat traffic, animal noises and more contribute to the underwater sound environment in the ocean, even in areas considered protected, a new study from Oregon State University, Cornelle University, National Park Service, and NOAA PMEL and NOAA Fisheries scientists shows.
Using underwater acoustic monitors, researchers listened in on Stellwagen Bank National Marine Sanctuary off the coast of Boston; Glacier Bay National Park and Preserve in Alaska; National Park of American Samoa; and Buck Island Reef National Monument in the Virgin Islands. They found that the ambient sounds varied widely across the sites and were driven by differences in animal vocalization rates, human activity and weather.
The findings demonstrate that sound monitoring is an effective tool for assessing conditions and monitoring changes, said Samara Haver, a doctoral candidate in the College of Agricultural Sciences at OSU and the study’s lead author. “This is a relatively economical way for us to get a ton of information about the environment,” said Haver, who studies marine acoustics and works out of the Cooperative Institute for Marine Resources Studies, a partnership between OSU and the National Oceanic and Atmospheric Administration at the Hatfield Marine Science Center in Newport. “Documenting current and potentially changing conditions in the ocean soundscape can provide important information for managing the ocean environment.”
Passive acoustic monitoring is seen as a cost-effective and low-impact method for monitoring the marine environment. The researchers’ goal was to test how effective acoustic monitoring would be for long-term assessment of underwater conditions.
“Ocean noise levels have been identified as a potential measure for effectiveness of conservation efforts, but until now comparing sound across different locations has been challenging,” Haver said. “Using equipment that was calibrated across all of the sites, we were able to compare the sound environments of these diverse areas in the ocean.”
The researchers collected low frequency, passive acoustic recordings from each of the locations between 2014 and 2018. They compared ambient sounds as well as sounds of humpback whales, a species commonly found in all four locations. The inclusion of the humpback whale sounds – mostly songs associated with mating in the southern waters, and feeding or social calls in the northern waters – gives researchers a way to compare the sounds of biological resources across all the soundscapes, Haver said.
The researchers found that ambient sound levels varied across all four study sites and sound levels were driven by differences in animal vocalization rates, human activity and weather. The highest sound levels were found in Stellwagen Bank during the winter/spring, driven by higher animal sound rates, vessel activity and high wind speeds. The lowest sound levels were found in Glacier Bay in the summer.
“Generally, the Atlantic areas were louder, especially around Stellwagen, than the Pacific sites,” Haver said. “That makes sense, as there is generally more man-made sound activity in the Atlantic. There also was a lot of vessel noise in the Caribbean.”
The researchers also were able to hear how sound in the ocean changes before, during and after hurricanes and other severe storms; the monitoring equipment captured Hurricanes Maria and Irma in the Virgin Islands and Tropical Cyclone Winston in American Samoa. Ultimately, the study provides a baseline for these four regions and can be used for comparison over time. Documenting current and potentially changing conditions in the ocean soundscape can provide important information for managing the ocean environment, particularly in and around areas that have been designated as protected, Haver said.
This story was originally posted by Oregon State University: https://today.oregonstate.edu/news/underwater-soundscapes-reveal-differences-marine-environments
Learn more about PMEL's work with NOAA and National Park Service's Noise Reference Station here: https://www.pmel.noaa.gov/acoustics/noaanps-ocean-noise-reference-station-network
PMEL is excited to host seven undergraduates this summer from across the United States! They are working across various research groups studying ocean carbon, Madden-Julian oscillation impacts, meteorological data from Station Papa, fisheries-oceanography research in the Bering Sea, acoustic data from the Ross Sea, and analyzing e-DNA samples. The students are supported through NOAA, University of Washington’s Joint Institute for the Study of the Atmosphere and Ocean (JISAO) internship program, and Oregon State University’s Research Experience for Undergraduates.
Harrison Knapp is a NOAA Hollings Scholar working with Dr. Chidong Zhang on assessing the influence of the Madden-Julian Oscillation on snowpack in the Western United States. He is currently a student at the University of Southern California pursuing both a B.S. in GeoDesign and a B.A. in Earth Sciences.
Sam Mogen is a NOAA Hollings Scholar working with Drs. Jessica Cross and Darren Pilcher on exploring oxygen cycling in the Bering Sea using the Bering 10K model. He is a student at the University of Virginia studying environmental science and global studies.
Madeline Talebi is a JISAO intern working with Drs. Meghan Cronin and Nick Bond on finding and interpreting archived meteorological data from Station Papa Ocean Weather Ship between December 1949 and 1981. She is currently studying Chemical Engineering at the University of California, Irvine.
Isabelle Chan is a JISAO intern working on decreasing the degree of uncertainty between water vapor and carbon dioxide measurements with Dr. Sophie Chu. She is currently studying Environmental Science with an emphasis in Conservation at the University of North Carolina, Wilmington.
Leo MacLeod is a undergraduate at the University of Washington working with Dr. Carol Ladd on fisheries-oceanography research in the Bering Sea.
Ellie Lee is a JISAO intern working with Dr. Carol Stepien in the Genetics and Genomics Group.
Miriam Hauer-Jense is working with Drs. Bob Dziak and Joe Haxel on analyzing data from the Ross Sea hydrophones for marine mammals through Oregon State University’ Research Experience for Undergraduates program. She is a sophomore at Scripps College.
Read more about each of them and their projects here.
PMEL staff at the NOAA Cooperative Institute for Marine Research Studies at Oregon State University recently participated on a hydrophone deployment cruise aboard the Spanish R/V Sarmiento de Gamboa in the Bransfield Strait off the western Antarctic Peninsula along with colleagues from the University of Washington, Woods Hole Oceanographic Institute, Queens College and the University of Granada (Spain) from January 4 - 17. PMEL successfully deployed 6 hydrophone moorings, while the University of Washington, Woods Hole and Queens College deployed 30 ocean bottom seismometers, and the University Granada deployed 20 land-based seismic stations.
The Bransfield Strait region is a highly volcanic area, with multiple, recently active, submarine and subaerial volcanoes including the active Deception Island volcano which last erupted in 1970 damaging the Spanish Antarctic base located there. Thus the goal of the project is to assess the volcanic hazard to the collection of international polar bases located in this part of Antarctica, as well as to better understand the ocean soundscape and sea-ice dynamics in the region. Using both active and passive seismo-acoustic data collection techniques, researchers will be able to image shallow pockets of magma in the crust that are likely distributed throughout the entire area. This research is funded by the National Science Foundation Antarctica Program.
Learn more about PMEL's Acoustic Program here: https://www.pmel.noaa.gov/acoustics/
On October 17, 2018, a joint NOAA/PMEL and Oregon State University Marine Mammal Institute (OSU-MMI) team, with the assistance of a U.S. Coast Guard helicopter on patrol providing real time radio reports of cetacean sightings, traveled 27 miles off the Oregon coast (due west of Newport, Oregon) to acquire acoustic recordings and biopsy two North Pacific blue whales. Through MMI contacts, the Coast Guard helicopter out of North Bend spotted blue whales off shore during routine patrol, and alerted the team to their approximate location.
A PMEL drifting hydrophone was used to record the blue whale calls, while OSU-MMI personnel successfully collected a biopsy sample of one of the two blue whales, and documented the encounter with photographs. Genetic results show the biopsied animal was a male, acoustic analysis of call signal strength shows two animals observed during biopsying were likely source of recorded vocalizations. The researchers are currently doing further genetic analysis and photo identification work to confirm blue whale population and gender of animals recorded. These data will be used to correlate the genetic identity and acoustic call type of a North Pacific blue whale.
The goal is to quantify and relate call signal characteristics and genetic identity. Typically, only remote recordings of blue whale calls are used to assess population size and distribution of this endangered species.
All research was conducted under NMFS permit 20465 with the support of the Marine Mammal Institute whale telemetry group.
PMEL's Acoustic and Earth-Ocean Interactions programs have successfully recorded the sound of methane bubbles from the seafloor off the Oregon coast using a hydrophone, opening the door to using acoustics to identify - and perhaps quantify - this important greenhouse gas in the ocean. Methane is found both as an icy hydrate deposit and in a gas phase within the sediments of the continental margins. The methane stored in the Cascadia margin, located offshore Washington, Oregon, and northern California, is of particular interest because the methane is stored within a major subduction zone which can potentially have an environmental impact on the upper water column and possibly the atmosphere.
In recent years, scientists have found hundreds of bubble streams emanating from methane deposits off the Pacific Northwest coast, but they have no way to determine how much methane is stored there. In 2016, researchers used the remotely operated vehicle (ROV) Hercules from the Ocean Exploration Trust's Exploration Vessel (E/V) Nautilus to deploy a hydrophone about 6 miles off Heceta Bank on the Oregon continental margin in 1,228 meters of water (about three-fourths of a mile deep). The acoustic signatures of the bubbles from the seep site are depicted in the hydrophone record as a series of short, high-frequency bursts, lasting 2-3 seconds.
"The bubbles in the streams make sound, and the frequency of the sound is related to the size of the bubble," said Robert Dziak, an acoustics scientist with the National Oceanic and Atmospheric Administration and lead author on the study. "The smaller the bubble, the higher the pitch. And the larger the bubble, the lower the sound pitch, but the more methane it contains.
The researchers then compared the sound record with still images from the ROV and found their estimates of bubble size from the hydrophone record matched the visual evidence. Results of the study have just been published in the journal Deep-Sea Research II.
On the current Nautilus research cruise mapping methane seeps, a hydrophone was deployed and recovered at various depths of Astoria Canyon in order to compare how bubble sizes and rates change with depth.
The next step, researchers say, is to fine-tune their ability to detect the acoustic signature of the bubbles so they can use the sounds to estimate the volume of methane in the offshore reservoirs. The ultimate goal is to be able to use sound to estimate the volume and rate of methane gas exiting the seafloor.
Join PMEL at Marine Science Day THIS SATURDAY, April 14, at the Hatfield Marine Science Center, in Newport, OR. Join tours, meet scientists, and get a behind-the-scenes look at the research, education, and outreach in marine sciences that makes this marine laboratory unique in the Pacific Northwest. Admission is FREE and open to the public. There will be interactive research exhibits that will feature emerging ocean observing technologies, bioacoustics of whales, video of volcanoes and deep ocean vents, and a new video on the emerging issue of ocean acidification. Activities for children and families can be found throughout the event.
PMEL will have two booths highlighting the work done at underwater volcanoes around the world and locally at Axial Seamount and ocean noise. You'll be able to view videos from recent expeditions and listen to various recorded sounds.
More information can be found here: https://hmsc.oregonstate.edu/marinescienceday
The PMEL Acoustics Program is back in the Ross Sea in Antarctica replacing six hydrophones that record icequakes, iceberg tremors and other naturals sounds near the Drygalski and Nansen Ice Shelves. The data collected from these hydrophones over the last four years will allow the Acoustics program to characterize the soundscape of the Terra Nova Bay polynya and to assess ice flow dynamics, as well as marine mammal presence/distribution in the newly formed Antarctic Marine Protected Area.
Ice shelves are permanent floating sheets of ice that connect to a landmass and are mostly found around the coast of Antarctica. They also slow the rate of ice flow from glaciers and ice streams coming into the ocean from the interior of the land. If an ice shelf collapses, then the glaciers flow more quickly out to the ocean and can accelerate sea level rise. Sea shelves can also calve, or split apart, as seen when two iceberg broke away from the Nansen ice shelf in April 2016 due to the largest low pressure storm system in more than a year that ultimately caused the icebergs to break free of the Nansen shelf.
The PMEL Acoustics Program has been collaborating with the Korea Polar Research Institute (KOPRI) for several years on multiple projects in Antarctica.
At the Ocean Sciences Meeting this week, Dr. Joe Haxel with Oregon State University's Cooperative Institute for Marine Resources Studies and PMEL's Acoustic Program presented findings from acoustic recordings from a series of drifting hydrophone deployments off of the Oregon coast from May-October 2016. The hydrophone recorded loud sounds characteristic of snapping shrimp, which are typically found in warm, shallow subtropical waters all over the world, but are undocumented in the colder coastal waters off the coast of the Pacific Northwest, until now. Analysis of the recordings provide estimates of the number of snapping shrimp along the central and southern Oregon coasts and their activity levels.
In addition to discovering the presence of snapping shrimp, the researchers found eastern Pacific gray whales were often foraging near the rocky reefs the shrimp inhabit. Gray whales don't eat snapping shrimp, but they do eat other types of prey usually found near the rocky reefs, in particular mysids. Joe Haxel and his colleagues suspect the loud snaps and crackling din of the snapping shrimp could be an acoustic cue to direct whales to areas of the ocean where their typical food might be plentiful.
The discovery is part of a larger effort by researchers to better understand the acoustic environment of Pacific Northwest coastal waters. By deploying the hydrophones, they hope to characterize the volume and types of sounds animals hear in Pacific Northwest waters. The new research shows snapping shrimp are an important contributor to the coastal soundscape, Haxel said.
Read the press release from AGU here.
More than 50 PMEL scientists, including scientists from NOAA, University of Washington's Joint Institute for the Study of the Ocean and Atmosphere (JISAO), Oregon State University's Cooperative Institute for Marine Resources Studies (CIMRS) and the National Research Council, will present a talk or share a poster on their research at the 2018 Ocean Sciences Meeting in Portland, Oregon February 12-16, 2018. PMEL research groups that will be present at the conference are: Acoustics, Arctic, Earth-Ocean Interactions, EcoFOCI, Engineering, Global Tropical Moored Buoy Array, Innovative Technology for Arctic Exploration, Large Scale Ocean Physics, Ocean Carbon, Ocean Climate Stations, Pacific Western Boundary Currents, Science Data Integration Group, Thermal Modeling and Analysis Project
28 talks will present research on ocean carbon, ocean acidification, ocean observing systems, Arctic research including the Distributed Biological Observatory and Arctic Marine Pulses (AMP), ENSO, MJO, hydrothermal vents, Saildrone research, air-sea interactions, SOCCOM, and ocean mixing. 26 posters will be up during the poster sessions and highlight research in the Arctic, hydrothermal vents, acoustics, methane bubbles and hydrates, Saildrone, Oculus Coastal Glider, ocean carbon, deep ocean temperatures, glider research in the Solomon Sea, and ocean acidification and hyopxia.
PMEL staff will also be chairing sessions and workshops on:
- El Nino-Southern Oscillation (ENSO) Diversity, Predictability, and Impacts
- Western Pacific and Indonesian Sea Circulation and Its Environmental and Climatic Impacts
- New Platform and Sensor Technologies: Advancing Research, Readiness, and Transitioning for Sustained Ocean Observing of Essential Ocean Variables
- Methane from the Subsurface Through the Bio-, Hydro-, and Atmosphere: Advances in Natural Hydrate Systems and Methane Seeps in Marine Ecosystems
- Cascadia Margin methane seep and hydrates to share results and coordinate future work
The 2018 Ocean Sciences Meeting is co-sponsored by the American Geophysical Union (AGU), the Association for the Sciences of Limnology and Oceanography (ASLO), and The Oceanography Society (TOS). The meeting is an important venue for scientific exchange across broad marine science disciplines. Sessions will include all aspects of oceanography, especially multidisciplinary topics, as well as presentations that reflect new and emerging research on the global ocean and society, including science education, outreach, and public policy