Marine Life on Seafloor Stressed Out by Human Noise Pollution

Scientists have shown that human noise can travel to the seafloor and have an impact on the marine life that dwells there.

New research indicates that human-made sounds, such as low-frequency noises, are resonating throughout the oceans, and that some invertebrates that thrive on and on the seafloor are affected by these sounds in ways that may have an impact on the crucial services they do for their ecosystems.

The Alfred Wegener Institute (AWI), citing a study carried out by its experts, said as much in a statement.

Authored by AWI experts Sheng V. Wang, Nelly Tremblay, Alexa Wrede, and Jan Beermann, the study will be released in the October issue of the peer-reviewed academic journal Environmental Pollution.

According to the study, even low-frequency noise can cause stress in marine animals living on the seafloor and alter their behavior.

Disturbed Animal Behavior

Invertebrates like worms, mussels, and crustaceans are ecosystem engineers, according to the AWI. Through their burrowing, feeding, aeration, and fertilization with their excrement, they continuously alter the sediment they live in. These processes are essential to the recycling of nutrients and the storage of more carbon from decomposing organic matter on the seafloor.

Ocean acidification, warming temperatures, and pollution are all stressing out marine ecosystem organisms. The problem has been exacerbated in recent decades by human noises and activities, which have an impact on the foraging, behavior, or communication of marine animals.

The AWI also blamed other human activities like mining for natural resources from the seafloor and sound produced by underwater explosions. International shipping ships and tourist boats make noises that are stressful for the animals living on the ocean's seafloor.

According to the AWI, loud drones from cargo ships and pleasure boats travel through the oceans alongside sounds from explosives and resource extraction.

These sounds strain marine mammals and invertebrates, according to experts.

Low-Frequency Human Noise

According to Wang from the Department of Biosciences at AWI, their team looked into how crustaceans, mussels, and worms that live on the seafloor react to low-frequency human noise and how frequently and vigorously they can change and decompose sediment when exposed to the noise.

According to the claim and the study, low-frequency noise has frequencies between 10 and 500 Hertz (Hz), and in water, these sounds can travel great distances.

The AWI said that It is unknown how noise impacts invertebrates on the seafloor, although noise pollution brought on by human activity is constantly increasing. AWI researchers used so-called "noise eggs" to investigate in the lab how amphipods, lugworms, and Baltic clams are impacted by sound waves having frequencies that range between 100 and 200 Hz to close this knowledge gap.

Read also: Study Shows How a Noisy Ocean Hurts its Inhabitants 

The Chain Reaction

The three species reacted to the noise after six days, according to AWI ecologist Beermann, although they are all members of very distinct types of animals that have little or no hearing organs.

For instance, the amphipods dug considerably fewer and shallower holes in the sediment, according to the AWI statement. For the lugworms, no distinct response was seen, but they appeared to act more erratically. The Baltic clams may have shown stress reactions, which require more research. However, the researchers emphasize the urgent necessity for field research because laboratory-based experimental setups do not account for all of nature's complexity.

This additional man-made noise may prevent seafloor invertebrates from growing and reorganizing sediments, which may have an impact on crucial ecological processes like nutrient supply and fish food availability.

According to Beermann, because of human activity, the seafloor may become even more "noisy."

He continued by saying that the group is just starting to comprehend exactly how noise processes function in this field. But for the oceans to be used sustainably, this needs to be understood.

While tests at other AWI sites are expected to yield more comprehensive results, the team intends to conduct additional research in this area, Newsweek reports.

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