Oceans are crucial to human survival, providing natural resources and most of the global oxygen supply, and are responsible for a large portion of worldwide economic development. Although it is widely considered a silent world, the sea is flled with natural sounds generated by marine life and geological processes. Man-made underwater sounds, such as active sonars, maritime trafc, and ofshore oil and mineral exploration, have signifcantly afected underwater soundscapes and species. In this work, we report on a joint optical fber-based communication and sensing technology aiming to reduce noise pollution in the sea while providing connectivity simultaneously with a variety of underwater applications. The designed multifunctional fber-based system enables two-way data transfer, monitoring marine life and ship movement near the deployed fber at the sea bottom and sensing temperature. The deployed fber is equally harnessed to transfer energy that the internet of underwater things (IoUTs) devices can harvest. The reported approach signifcantly reduces the costs and efects of monitoring marine ecosystems while ensuring data transfer and ocean monitoring applications and providing continuous power for submerged IoUT devices.