Nutrient pollution may accelerate ocean acidification

Human activities on land cause nutrient pollution which may accelerate the negative impacts of global ocean acidification on coral reefs.

Coral reefs provide critical ecosystem services including food security and shoreline protection to coastal communities. These services largely depend on the highly complex three-dimensional structure of coral reefs.

A study conducted by a team of researchers from the University of Hawaii stated that stressors associated with human-derived carbon dioxide (CO2) emissions, such as ocean acidification, are shifting coral reefs towards net loss, which would lead to the loss of the three-dimensional framework in the future.

"In nutrient-polluted seawater, calcifiers are less able to capitalize on the dissolved compounds that make up the building blocks of coral reefs. Nutrient pollution reduced calcification rates a measure of how quickly reef builders are creating the skeletal framework, nearly tenfold in waters that would otherwise promote reef growth, and enhanced both skeletal dissolution and the growth of seaweed competitors," said the lead author of the study, Nyssa Silbiger.

The study also reinforced that nutrients from fertilizers are often thought to impact reefs indirectly, for example by giving an advantage to weedy seaweeds that can overtake reefs.

The findings are published in the Journal of Proceedings of the Royal Society B.