Tag Archives: Salmon migration

Amusing Monday: Using musical notes to describe salmon migration

Researchers working on innumerable scientific investigations throughout the world continue to present their findings in new and interesting ways, often apart from the usual charts and graphs. Some have turned to animation, others to interactive graphics and some to the medium of sound — a process called sonification.

Jens Hegg of the University of Idaho has collaborated with several musical composers to turn the migration of young chinook salmon into a musical score — although it doesn’t exactly have a beat you want to dance to.

In the first video on this page, you can close your eyes and imagine that you are standing at the mouth of the Snake River facing upstream, Jens advises in an email. To get the full effect, you need to listen with headphones. Fish moving on the Upper Snake River are represented by notes that sound the farthest away, the Clearwater River somewhat closer and the Lower Snake River closer still.

“The ocean is at your back, so as they enter the ocean, the washy sound sounds as if it is either behind you or directly between your ears,” Jens told me.

“Each river has it’s own set of tones that build a chord,” he continued. “The YouTube video uses the same WAV recording every time, but the actual sonification program randomly assigns fish to a new tone each time it is played, so that the music actually changes and is slightly different each time it is played while maintaining the same meaning.”

I have to confess that I’ve listened to this recording more than a dozen times and I’m still trying to visualize the movement in my mind. The map on the video actually helps with the understanding, but that’s not the movement of fish on the river that I’m trying to visualize. Jens said the program was set up so that fish in the Upper Snake are heard in the right ear; fish in the Lower Snake are heard in the left ear; and fish in the Clearwater are heard in the center.

Some sonification efforts result in music that is quite enjoyable to listen to. See Water Ways, Jan. 1, 2016. But if the point is to convey information, then the underlying music can sometimes be a distraction.

Jens told me that his experiments with sound originated in a roundabout way, somewhat out of desperation, as he tried to design his doctoral dissertation to meet the cross-disciplinary requirements for the program in Water Resources Science and Management.

“I had been told that the geology/ecology combination I had used for my master’s in the same program was not quite interdisciplinary enough, so I was in search of other possibilities,” he said.

Jens had read a newspaper profile about Jonathan Middleton of Eastern Washington University, who was creating music from protein data. He was finding that the people could discern variations in complex protein structure more easily with sonic rather than visual clues.

Jens always enjoyed music. He even writes his own songs. (See second video on this page.) Combining music and scientific data provided a fascinating challenge. “Nobody could say this wouldn’t be interdisciplinary,” he noted, “and it incorporates something I enjoy already, so it seemed like something worth pursuing.”

The data needed to create the sonic composition comes from Jens’ extensive study of salmon migration based on the ear bones of fish, called otoliths. Otoliths are composed of chemicals that build up over time as a fish grows. Rivers have their own chemical signatures, which are captured in the otoliths, so the movement of salmon can be determined by the chemical record stored in their ear bones.

Understanding the timing of salmon migration can help researchers figure out why some populations are more successful than others, especially as climate change shifts the timing of streamflows and alters the temperature and dissolved oxygen levels.

Mounds of otolith data were converted to notes with the help of Middleton at Eastern and Ben Luca Robertson at the University of Virginia. Middleton had developed a software program to help researchers turn their data into sound. Courtney Flatt of Northwest Public Broadcasting separated out some of the individual sounds in a piece she produced for Earthfix. Listen below.

      1. Tracking Salmon With Musical Notes

Part of Jens’ research was to see if people could tell when the sound pattern changed, thus discerning the movement of fish from one place to another. The complexity of the sound reduced the ability of listeners to distinguish transitions, according to a new report by Jens and his collaborators in the journal Heliyon. Check out the additional sounds and animations in the “supplementary content” at the end.

It also turned out that people were able to describe the changes more accurately if they were not watching a related animation. One reason could be that the visual clues caused people to divide their attention, focusing less on the sound.

“We have a long way to go before a sonification of a large number of fish can clearly indicate movement,” Jens told me in his email. “Our paper shows that people can accurately distinguish movement of individuals played alone, two at a time, or three at a time. But we haven’t spent as much time optimizing the sonification for a large number of fish.

“Knowing how it is set up helps in interpreting it,” he said. “On repeated listenings, you can hear times where larger numbers of fish are all moving at once from one place to another. These are the kinds of trends we want to highlight in terms of understanding salmon migration timing.”

A deeper look into the Ballard Locks, where antique equipment rules

The Ballard Locks is a great place to visit, especially in the late summer and fall when the salmon are migrating into Lake Washington. I’ve been taking out-of-town friends and family there for years to observe the multitude of boats using the locks and to peer at salmon through windows of the fish ladder.

I never thought much about all the mechanical equipment that keeps the locks functioning. But during a recent visit, I was taken to a darker and more dangerous side of the facility. I walked down a spiral iron staircase some 60 feet deep into an abandoned pumping plant. Rusty iron pipes and pumps were still in place, having been shut down three years ago out of concern that a pipe might burst while someone was down in the well.

Pumps are pipes at the Ballard Locks were shut down after they became too corroded to be safe. Photo: Christopher Dunagan
Pumps and pipes used to empty the Ballard Locks for maintenance were shut down after they became too corroded to be safe.
Photo: Christopher Dunagan

Growing concerns about the safety and maintenance problems inspired me to write a story about the locks for the Encyclopedia of Puget Sound, along with a sidebar about salmon in the Lake Washington watershed that migrate along a treacherous route through the locks.

The locks were completed in 1916, and much of the antique equipment is still in operation — including gears, pulleys and chains. The mechanical works and the big steel doors with their neatly aligned rivets remind me of the art and aesthetic design of steampunk (Wikipedia), a style with its own dedicated page on Pinterest.

A dam-safety study and growing awareness of the outmoded equipment could help bring money for a major renovation, which could cost $50 million or more. President Obama’s budget, recently submitted to Congress, includes funding for replacing the pumping plant I mentioned above but not much more. By the way, while I was at the locks in early January, contractors were beginning to remove the old pumping plant equipment — even though replacement is not yet authorized.

My trip to the locks and my follow-up reporting have given me a new perspective on a place I thought I knew fairly well. In reality, I knew very little about the inner workings of the Ballard Locks, officially known as the Hiram S. Chittenden Locks. I hope you can learn something about the facility by reading my story.

The SS Roosevelt, owned by the Bureau of Fisheries, was the first “official” ship to pass through the Ballard Locks on July 4, 1917, leading a parade of 80 boats. Photo: Army Corps of Engineers
The SS Roosevelt, owned by the Bureau of Fisheries, was the first “official” ship to pass through the Ballard Locks on July 4, 1917, leading a parade of 80 boats.
Photo: Army Corps of Engineers

Meanwhile, officials at the locks are planning a major centennial celebration. Although the first ship went through the “Government Locks” in August of 1916, the opening celebration was delayed until the Fourth of July in 1917. (Check out Friends of the Ballard Locks.) At the time, it was a major event, including fireworks and other festivities. More than 100,000 people attended, according to reports.

I’m told that supporters will roll out various activities throughout next year, in part because July 4 is now associated with many other events. For information, see ballardlocks.org.

I will try to keep up with the various centennial plans and report details of the events as information becomes available.