Seagrass Posidonia is impaired by human-generated noise

Marta Solé,Marc Lenoir,José-Manuel FortuñO,Steffen De Vreese,Michel André,Mercè Durfort,Mike Van Der Schaar

doi:10.1038/s42003-021-02165-3

Abstract

The last hundred years have seen the introduction of many sources of artificial noise in the sea environment which have shown to negatively affect marine organisms. Little attention has been devoted to how much this noise could affect sessile organisms. Here, we report morphological and ultrastructural changes in seagrass, after exposure to sounds in a controlled environment. These results are new to aquatic plants pathology. Low-frequency sounds produced alterations in Posidonia oceanica root and rhizome statocysts, which sense gravity and process sound vibration. Nutritional processes of the plant were affected as well: we observed a decrease in the number of rhizome starch grains, which have a vital role in energy storage, as well as a degradation in the specific fungal symbionts of P. oceanica roots. This sensitivity to artificial sounds revealed how sound can potentially affect the health status of P. oceanica. Moreover, these findings address the question of how much the increase of ocean noise pollution may contribute in the future to the depletion of seagrass populations and to biodiversity loss.

Highlights

The last hundred years have seen the introduction of many sources of artificial noise in the sea environment which have shown to negatively affect marine organisms
The extent to which noise in the sea affects marine ecosystems has become a topic of concern to the scientific community as well as to society at large[1,2] A critical question is whether human-generated noise and other forms of energy may interfere with the normal behavior of marine organisms or cause them physical harm
Recent studies have shown that artificial sounds affect cephalopods, cnidarians, and crustaceans even though they lack proper auditory receptors[8,11,12,13]

Summary

Introduction

The last hundred years have seen the introduction of many sources of artificial noise in the sea environment which have shown to negatively affect marine organisms. Nutritional processes of the plant were affected as well: we observed a decrease in the number of rhizome starch grains, which have a vital role in energy storage, as well as a degradation in the specific fungal symbionts of P. oceanica roots This sensitivity to artificial sounds revealed how sound can potentially affect the health status of P. oceanica. No study has addressed the sensitivity to noise and other forms of energy of sessile marine organisms, such as plants or coral reefs, whose immobility makes them highly susceptible to chronic effects. These marine organisms have sensory organs that are specialized in gravity perception, essential for detecting their natural substrate and with which inner structures could be affected by sound exposure. The worldwide rate of seagrass decline has been estimated to be 110 km[2] per year since 198022

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Conclusion