Rising CO2 levels in oceans 'will muffle sounds crucial to marine life and could affect fish populations'

Snapping shrimps are the loudest invertebrate in the sea but risk being silenced by the end of the century

The snapping noise made by shrimps is used by many marine creatures to find food and shelter (PA)

Rising levels of CO2 in the oceans will muffle sounds that are crucial to marine life such as the snapping noise made by shrimps, which could hit fish populations hard, new research warns.

Snapping shrimps are the loudest invertebrate in the sea but risk being silenced by the end of the century as ocean acidification interferes with the acoustics of the water, according to a new study by the University of Adelaide.

A wide variety of marine life use the sounds made by the shrimp to orient themselves, gleaning information from them about the location and quality of crucial resources such as food, shelter, predators and potential partners.

Fish eggs – or larvae - are among the most at risk from the loss of the snapping sound, which helps guide them through the open ocean to the reefs where they settle and develop. The loss of this crucial navigation system could reduce the number of fish born, the research suggests.

“Fish and invertebrate larvae may become lost at sea or take longer to pick up these cues as they drift with ocean currents,” said Ivan Nagelkerken, of the University of Adelaide in Australia.

“This may reduce the number of larvae that safely arrive at coastal reefs, with consequences for the replenishment and sustainability of their populations,” he added.

The research also found that the rising level of CO2 is likely to reduce the frequency of the shrimp snapping as well as the volume – although the researchers were not sure why.

The research is published in the journal Proceedings of the Royal Society B.