Kelp forest collapse alters reef microbial communities

A study published in the Proceedings of the National Academy of Sciences reveals that the collapse of kelp forests significantly alters the microbial communities and chemical processes within reef ecosystems. Researchers compared reefs off the coast of Maine that are still dominated by kelp to those where the kelp has been replaced by low-growing turf algae, a transition driven by warming oceans in temperate regions.

Using metagenomics and non-targeted metabolomics, the study found that kelp-dominated reefs and turf-dominated reefs host different microbiomes and maintain distinct chemical repertoires. This shift impacts the microscopic machinery responsible for transforming and utilizing essential elements such as carbon and nitrogen. Because kelp forests provide structural refuge, food, and support for carbon storage, their disappearance fundamentally changes how the entire coastal environment functions at both a visible and microscopic level.