The 'groans' that lobsters give in the ocean reach up to 3 kilometers away



Both lobsters and lobsters are 'big shrimp that live in the sea,' but lobsters are crayfishes of the lesser order Prawns, and lobsters are the lesser species of lobsters. Palinurus elephas (European spiny lobster), which lives in the French sea where lobsters are often eaten, emits sounds up to 3 kilometers away in the sea.

Spiny lobster sounds can be detectable over kilometres underwater | Scientific Reports
https://www.nature.com/articles/s41598-020-64830-7


Spiny lobster noises may be heard up to 3 kilometers away
https://phys.org/news/2020-05-spiny-lobster-noises-heard-kilometers.html


In recent years, a research method called ' passive acoustic monitoring (PAM) ' that catches the sound emitted by a living thing and identifies the position of a living thing and the size of an individual has attracted attention. Especially in the sea, which is very difficult to see unlike on the ground, it is also possible to understand the spatial distribution of living things by examining the frequency and detection range of sound with PAM.

The European spiny lobster has a file-like tissue under the antenna, and by rubbing this tissue together, it is possible to generate a humming noise. The loudness is said to record up to 170 decibels in the sea 20 cm away from the European lobster. In addition, according to the guideline for noise caused by the Ministry of the Environment (PDF file) with a jet engine, the noise level in a pachinko parlor is 90 decibels.

Youenn Jézéquel , a researcher at the Institut Universitaire Européen de la Mer (European University of Marine Studies, IUEM), recorded 1560 noises from 24 European lobsters in the Bay of Sainte Anne du Porzic in western France.



The noise was recorded by an underwater microphone installed between 0.5 and 100 meters from the European lobster. Of the 24 European spiny lobsters, the noise emitted by large individuals could be recorded 100 meters away, but the limit was 50 meters for medium-sized individuals and 10-20 meters for small individuals.

According to Jézéquel, the noise generated by a large European lobster can be detected up to 400 m. It was also estimated that the noise emitted by the largest individual with a body length of 13.5 cm could reach up to 3 kilometers due to its frequency and volume. According to Jézéquel, it is possible to predict the rough distribution and size of European spiny lobsters, which are difficult to confirm visually by picking up and analyzing noise in the sea.



Due to overfishing, the European spiny lobster has greatly reduced its population in recent years. Jézéquel said, ``Development of PAM that can detect acoustically non-invasively and non-destructively underwater organisms is necessary to manage species that are depleting due to overfishing such as European lobsters'' ..

in Creature, Posted by log1i_yk