By Carrie Schuman, Ph.D., SCCF Coastal Resilience Manager

The following is part of “Coastal Reslience Connections,” a regularly occurring series that explores how building coastal resilience is interwoven with various local issues and topics.

Florida ecosystems harbor particularly rich soundscapes, with choral members representing a vast diversity of living things. Bernie Krause, a seminal figure in soundscape ecology, calls this sonorous living part of the natural audio tapestry, the “biophony.”

Our local biophony — the blanket of sound radiating from every corner and crevice of our beaches, marshes, and mangrove forests — already competes with human-created noises for airplay, a component Krause labels as the “anthropophony” of a soundscape. For example, the calls of local wildlife are often punctuated by the audio footprint of cars, landscapers, and excited travelers.

One recent focus of soundscape ecology, a field focused on how humans and natural systems interact to create patterns of sound over space and time, is how climate change may be altering the melodies of our environment. While we don’t know exactly what shifts to expect on Sanibel and Captiva, we can look to research on sound in other places to suggest what we could see (or hear) in our future.

First, we can consider changes to the environment and the mediums that host all of those bustling natural acoustics. At its most fundamental, sound is a series of vibrations that propagate as a wave through some kind of medium. Sound travels faster through denser materials and so, for example, will move more rapidly in water than air.

In the ocean, water properties like salinity, pressure, and temperature all interact to influence how sound behaves underneath its surface. In research released this year, the authors modeled the effects of future climate conditions on ocean soundscapes, and found warmer waters may lead to increased sound transmission, especially within two hotspots — the Greenland Sea and the Northwestern Atlantic Ocean. While not as drastic, the Gulf of Mexico was also identified as a site where underwater noise will get speedier. This change in the physics of ocean sound travel could cause confusion for marine organisms, who use sound for a suite of different purposes. Those savvy animals who adapt to use these changes to their advantage could still be in fierce competition with anthropogenic noise pollution.

Second, we can consider how impacts on the choral members themselves may change the nature of their compositions. For instance, this year’s State of the World’s Birds report lists climate change as an important emerging driver for the expansion, shift, and contractions of many species’ ranges, and as a factor in the steady global decline of many bird populations. In a 2021 study, researchers examined the changing nature of birdsong across North America and Europe by reconstructing soundscapes from historic and current bird counts. The study found that the audio fingerprint of bird song has become quieter and less diverse over the last 25 years.

Lastly, for some creatures, warming might not just affect where they are and when, but also how metabolically active they are. One particularly interesting example involves snapping shrimp, a noisy neighbor in ocean suburbs. Each shrimp bears one comically oversized claw. They can snap these claws shut with such lightning speed that they create little vapor bubbles, which produce a crackling sound upon bursting.

Sound clip of snapping shrimp (genera Alpheus and Synalpheus) in Matlacha Pass recorded by Rick Bartleson of the SCCF Marine Lab. Bartleson and his team have been collaborating with students and faculty at Florida Gulf Coast University and other researchers to study sound as an indicator of ecosystem health in the Caloosahatchee watershed — both in response to stressors like low oxygen conditions and before and after restoration and management efforts.

According to 2020 research results from Woods Hole Oceanographic, the small crustaceans snap louder and faster as water conditions warm. An increase in snapping shrimp-produced sound could crowd out the messages of other animals and interfere with human-used sonar systems. However, the increased snapping might assist some organisms like fish and larval oysters that likely use the sound as a sort of homing beacon to find their desired habitat.

Research and findings like these are important, but often less considered, compared to other lines of evidence about the impacts of a rapidly changing climate on natural systems. Our own health and wellbeing have also been linked to the quality of sounds around us. For instance, urban environments can be a source of unwanted sounds that translate into health problems like increased cardiovascular risks, while the sounds of nature can make us more relaxed by reducing our fight or flight response. This represents another way we have a personal stake in responding to climate impacts. We can hear the winds of change, but will we speak up?

Learn More about Soundscape Ecology and the Connections Between Climate and Sound:

• Everything Is Wrong: Bernie Krause’s Concept of ‘Biophony’ | The MIT Press Reader – Read about Bernie Krause, who coined the term “biophony” and is a seminal figure in the field of “soundscape ecology.”
• The Last Sound | NPR’s Invisibilia Podcast – Listen to this podcast episode that describes the story of Bernie Krause and explains some of the ideas around the concept of soundscape ecology.
• This Is What Climate Change Sounds Like | The New York Times – Read about the ClimateMusic Project, a group that creates music pieces based on climate data.
• Climate change is robbing us of this one amazing part of nature | Inverse.com – Read more about how researchers Simon Butler and Catriona Morrison collaborated with a team to study changing bird song across North America and Europe.
• How climate change is altering the underwater soundscape | Kate Stafford | TEDxCERN – Watch oceanographer Stafford talk about the important role of sound in the ocean environment.
• Podcast: Capturing the Songs of a Changing Climate | Undark.org – Listen to “Undark” podcast hosts speak with researchers using acoustics to explore how climate change could be altering soundscapes in locations like Joshua Tree National Park.
• Climate Change May Make the Snapping Shrimp Louder | NPR – Listen to this short piece summing up research about temperature and the sounds of snapping shrimp.