The vast majority of marine animals rely on a wide array of noises for echolocation, movement, or communication, which results in the formation of diverse soundscapes throughout the oceans of the world. In recent times, however, sounds originating from an increasing number of human activities have been heard permeating the waterways. According to the findings of a new study that was led by the Alfred Wegener Institute for Polar and Marine Research (AWI), such sounds have an effect on certain invertebrates that reside on the seafloor in such a manner that it may have an effect on the important functions that these invertebrates provide for their respective ecosystems.
Marine invertebrates like mussels, crabs, or worms are key ecosystem engineers. Such invertebrates are constantly altering the sediment they dwell in by digging into it, feeding upon that, aerating & fertilizing it, and releasing waste into it. These kinds of activities provide a contribution to the cycle of nutrients in the ocean and make it possible for additional carbon to be stored in the bottom from dead organic matter.
In recent years, marine species have been subjected to an elevated level of stress as a result of human activities such as pollution, warming of the oceans, and acidification of the oceans. It has now been demonstrated by specialists from the AWI that these noises, whether they originate from resource extraction activities, cargo ships, or leisure boats, are stressful to marine invertebrates as well as marine animals.
There was no discernible response shown in the case of lugworms, despite the fact that they appeared to behave more erratically than the amphipods did after being exposed to such sounds, which caused the amphipods to burrow less and not as deep in the silt. Clams from the Baltic Sea have also been shown to exhibit potential stress responses that require further exploration. Since experimental sets under laboratory conditions may not represent the entire complexity of real environments, scientists believe that more field studies should be done in order to make up for this potential shortcoming.
The experts came to the conclusion that noises made by humans could prevent invertebrates from living on the seafloor from cultivating and reshaping sediments. This would have a negative impact on the necessary roles of marine ecosystems, such as the accessibility of nutrients as well as food for living things closer to the top on the trophic chain, like fish.