.png)
1 hour ago
1
Fewer than 100
Rice’s whales
remain on Earth. Here’s what they sound like when they communicate.
Sound recording from Dec. 20, 2013
They live only in the Gulf of Mexico, where
air guns
firing sonic blasts are used to survey the ocean floor for oil and gas.
Sound recording from Aug.12, 2020
The low frequency of the
blasts
overlaps with the frequency of the
calls of the whales
.
The Gulf of Mexico, which the Trump administration calls the Gulf of America, is one of the noisiest bodies of water in the United States. Air gun blasts are the loudest element there, according to research by scientists who monitor underwater acoustics. Shipping traffic is another major contributor.
The noise could affect the ability of Rice’s whales to find food and mates, scientists say. The chronic stress of living in a loud environment could be detrimental to their health.
Seismic air guns are used to survey for oil and gas deposits by blasting large pockets of air into the water. By measuring the sound that bounces back, companies can determine the location and size of deposits.
Historical records suggest the whales once lived throughout a broader area in the Gulf of Mexico. Now, they mostly cluster off the coast of Florida.
Scientists think the shallower waters there might be protecting them from the noise. Sound travels farther in deep water, especially at lower frequencies.
Here is a recording of an air gun fired in 2021. Its sound waves traveled more than 620 miles.
Sound traveling at depths of 65 to 3,280 feet
For each seismic survey, air guns are fired roughly every 10 seconds for days, weeks or even months. And several companies are permitted to survey in the Gulf at any given time.
Here are some of the loudest seismic surveys that took place continuously from May to September 2023.
Sound traveling at depths of 490 to 820 feet
Last year, a federal analysis found that oil and gas activities in the Gulf were “likely to jeopardize the continued existence of the Rice’s whale” and offered some actions the industry could take to help prevent that. Noise, vessel strikes and oil spills are all threats.
Still, in March, the Trump administration waived Endangered Species Act restrictions for oil and gas drilling in the Gulf, part of an effort to boost fossil fuel production in the name of national security.
The oil and gas industry says it takes steps to ensure the safety of marine life.
Surveys begin with softer blasts, intended to give animals a chance to leave the area. And teams use visual and acoustic monitoring to scan for marine mammals, suspending surveys if they detect any.
In quieter regions of the Gulf, the calls of Rice’s whales can travel up to 47 miles, according to a 2022 study.
But in louder areas, a similar call could only be detected up to 12 miles away.
Oil and gas groups point out that just because sound travels far, it is not necessarily harmful at long distances. Sound energy weakens as it travels.
Scientists are trying to learn more about how seismic surveys affect Rice’s whales.
For conservationists, the uncertainty is reason enough to curtail the surveys. For those who want to expand oil and gas production, it means exploration should continue.
Methodology
Sound recordings are from Kaitlin Frasier and Vanessa ZoBell with the Scripps Machine Listening Lab at the University of California, San Diego, in partnership with the National Oceanic and Atmospheric Administration’s Southeast Fisheries Science Center as part of the LISTEN project; data on seismic surveys is from NOAA, the Bureau of Ocean Energy Management and the Scripps Machine Listening Lab; the distribution of Rice’s whales comes from NOAA; seismic survey areas from 2010-25 were provided by the Scripps Machine Listening Lab; and the Rice’s whale’s long moan call was recorded by Melissa Soldevilla of NOAA SEFSC in 2013.
All audio recordings were sped up by 1.25x in order for humans to better hear the low-frequency sounds.
To visualize the overlapping frequencies of the Rice’s whales’ calls and the air guns, The New York Times used audio spectrum analysis to distinguish the sounds at low frequencies.
Visualizations of how sound spreads from seismic surveys is based on modeling from a federally funded study by Sean M. Wiggins, Vanessa ZoBell, Lynne Hodge, Melissa Soldevilla and Kaitlin Frasier. The visualizations do not reflect the movement of the ships during the survey. Each second in the visualization represents six days in the actual survey, and each circle represents about 7,200 air guns fired over the course of a day.
Diagrams of air guns are based on explanations by the Bureau of Ocean Energy Management.
