Do schooling fish make sounds, voluntarily or involuntarily? A general internet search for "schooling fish sounds" doesn't provide many answers, but I found a paper from 1960 describing sounds from some fish in Bermuda. The description of the sound wasn't clear to me.
I'm wondering if there has been recent evidence that predators might clue into the presence of schooling fish as prey by the sounds that they make? And might ocean noise interfere with these interactions?
Yes, fish make sounds that predators can use:
Like us, fish produce sound both unintentionally and intentionally. Unintentional sounds from fish come all the time, resulting from hydrodynamic patterns during swimming and feeding. These sounds can provide information to other fishes. In fact, the fishing industry has recognized predatory fishes’ ability to take advantage of unintentional sounds to find prey and have designed fishing lures that emit low frequency sounds that mimic those produced by injured prey fish.
The opposite is also true:
Many fish take advantage of the noises other species make. We know that some sharks use sound to help them locate prey, while some smaller fish can detect the sounds larger predators make in their hunting. Furthermore, it is believed that a few fish species, including herrings and American shads, can detect the ultrasonic echolocation sound produced by hunting dolphins from a distance of up to 200m.
Interesting tidbit:
The oyster toadfish doesn’t need good looks to attract a mate – just a nice voice. To generate the foghorn sound, the toadfish contracts its sonic muscle against its swim bladder thousands of times a minute. At nearly three times the average wing beat of a hummingbird, toadfish have the fastest known muscle of any vertebrate.
Piranha's bark as a warning to each other for frenzies.
Most fish have a lateral line, which detects water pressure, so it acts like an ear.
Predators use it to orient themselves towards prey, and to follow the vortices generated by fleeing prey.
Prey use sound to detect water displacement from incoming predators and for schooling, territorial defence and mating.
The lateral line system and the inner ear of fish are often grouped together as the octavolateralis system (OLS). The former hears bass and the latter hears high frequencies.
Seasonally, many adult fishes produce sound to synchronise gamete release in spawning aggregations or in courtship interactions for mate selection, with many of these calls forming sustained choruses lasting from weeks to months (Amorim et al., 2015).
Teleosts have the capacity for complex acoustic interactions (Mensinger, 2014).
When a threat or possibility of a threat exists, fishes produces sounds as spontaneous outbursts. They also use sound to control shoal grouping.
Fishes may also generate sounds in stressful situations including when they are attacked by predators or handled by fishermen.
About 20% of fish are thought to produce sound.
About 2/3rds of fish sense electricity, teleost species.
https://onlinelibrary.wiley.com/doi/10.1111/jfb.13867
https://en.wikipedia.org/wiki/Lateral_line
https://blog.nature.org/science/2018/04/18/what-does-the-fish-say/
Keywords: Bioacoustics, hydrophone
Schooling fish do produce sounds voluntarily and there is a cool library of recordings from various species available via Discovery of Sound in the Sea: https://dosits.org/galleries/audio-gallery/fishes/ Each species page includes information regarding the role of the sounds produced and their properties alongside recordings that you can listen to! Regarding schooling fish specifically, an example includes herring that produces series of click-like sounds (here [enter link description here][1] is a paper describing these pulses).
Underwater noise can impact the way fish (and other animals) use sound in various ways: it can limit the acoustic space of individuals trying to communicate via sound, which means that finding mates can be harder (particularly for individual animals rather than schooling fish) and predators might not be able to hear vocalising animals until they are relatively close to them.
Predators can also listen to the ambient sound to find fish and sperm whales, killer whales and other marine mammals have even learned to associate the sounds from fishing gear and salmon farming acoustic deterrents with an easy source of food.
I hope this helps and I am happy to share more references to academic papers if this topic is of interest to you. :)
Reference: Wilson Ben, Batty Robert S. and Dill Lawrence M. 2004. Pacific and Atlantic herring produce burst pulse sounds. Proc. R. Soc. Lond. B. 271S95–S97. [1]: https://doi.org/10.1098/rsbl.2003.0107
You might find this paper by Torres (2017) interesting. It reviews the different type and scales of sensory cues used by cetaceans to sense their environment and find their preys, including acoustics:
The author lists a few studies that found evidence of passive listening from dolphins, locating their preys using the fish calls, beyond the echolocation detection range.
Similar mechanisms have been hypothesized in baleen whales, who could use the sound produced by schooling anchovies, herrings and krill as cues to locate food patches, but it remains theoretical.
From there, it is highly likely that increased noise pollution could have masking effect with repercussion on the ability of predators to rely on sound for foraging.
