With recording technology now more affordable, Rodney Rountree, Francis Juanes and colleagues are exploring the idea that many fish make sounds to communicate with each other, especially those that live in the perpetual dark of the deep ocean.
Though little is known at present about the significance of sounds made by deep-sea fishes, Rountree and Juanes say that if, as their pilot study suggests, these tend to be low-amplitude, then man-made noise in the oceans may turn out to be a particular problem for some important species.
Their paper appears in the new book, "Effects of Noise on Aquatic Life," from Springer Science+Business Media in its "Advances in Experimental Medicine and Biology" series. It compiles papers from an international workshop in Ireland in 2010.
Using hydrophones deployed by fishermen during normal fishing operations, Rountree, Juanes and colleagues obtained a 24-hour recording in Welkers Canyon south of Georges Bank that yielded "a wealth of biological sounds" including sounds of fin, humpback and pilot whales, dolphins and examples of at least 12 other unique and unidentified sounds they attribute to other whales or fish.
Their new paper includes graphics showing the number of these grunts, drumming and duck-like calls recorded per minute by time of day, plus peak volume and frequencies of various noises. Some of the sounds exhibited strong temporal patterns, for example fin whale and dolphin sounds dominated the recording and peaked at night.
Rountree, who makes a collection of fish sounds available on his popular website to engage and educate the public, explains, "We think work to describe underwater sounds is extremely valuable. The importance of sound in the ecology of both freshwater and marine systems is poorly understood. At this point, in fact, most of our work consists of making careful observations, which of course is the first step in the scientific process."
He adds, "If sound is important to these deep sea fishes, it’s a whole area of ecology we need to know about. One reason is that fishermen are exploring deeper and deeper water to make their catch, and we need to know such things as the baseline populations of food fish, their requirements for spawning, their essential habitat and other key aspects of their lives. We believe passive acoustic monitoring is an important tool in this study. And, it doesn’t harm the fish or their habitat."
Unlike active acoustic studies that bounce sound waves out and back, passive acoustic studies involve just listening. Rountree and Juanes have been promoting underwater passive acoustic studies for more than a decade. They hope to create a census of sounds and behavior observed concomitant with sounds from many different aquatic and marine habitats.
Juanes says some fish use special "sonic muscles" to produce some sounds, and different sounds have different meanings or functions. Many are believed to be related to reproductive behavior. Some fish use a "sound map" for orientation in their immediate environment and may even use sound waves returning from distant beaches to help them navigate over longer distances. "There is a fascinating acoustic soundscape out there just waiting to be explored."
Rountree adds, "It’s not only that some fish make sounds, but we think the overall soundscape is interesting and important." This study was supported by MIT Sea Grant.
In addition to their deep-sea recording project, the researchers are conducting pioneering passive acoustic surveys of sound in many different habitats, such as freshwater ponds, rivers and streams and coastal estuaries of New England, as well as on the commercial fishing grounds in the Gulf of Maine.
Rodney Rountree | EurekAlert!
Minimized water consumption in CSP plants - EU project MinWaterCSP is making good progress
05.12.2017 | Steinbeis-Europa-Zentrum
Jena Experiment: Loss of species destroys ecosystems
28.11.2017 | Technische Universität München
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
11.12.2017 | Physics and Astronomy
11.12.2017 | Materials Sciences
11.12.2017 | Earth Sciences