Using eDNA tools to examine the impact of kelp farming on underlying sediments.

Using environmental DNA (eDNA)-based tools, we examined sediments underlying a ~ 1.25 hectare commercial kelp farm in the Gulf of Maine growing sugar kelp (Saccharina latissima) for two farming seasons, post-harvest. Two eDNA methods were used: a newly designed S.

Kelp forest loss and emergence of turf algae reshapes energy flow to predators in a rapidly warming ecosystem.

Climate change is decimating habitat-forming species in ecosystems around the world. Yet, the impacts of habitat loss on the energetics of the wider food web remain uncertain for many iconic ecosystems, including cold-water kelp forests. Here, we assessed how the loss of kelp forests and the subsequent proliferation of low-lying turf algae in the Gulf of Maine have altered the trophic niches of, and energy acquired by, predatory reef fishes.

Turf algae redefine the chemical landscape of temperate reefs, limiting kelp forest recovery.

In temperate regions experiencing rapid ocean warming, kelp forests are being replaced by chemically rich turf algae. However, the extent to which these turf algae alter the surrounding chemical environment or affect the rebound potential of kelp forests (through chemically mediated interactions) remains unknown. Here, we used underwater visual surveys, comprehensive chemical profiling, and laboratory experiments to reveal that turf algae release bioactive compounds into the water that fundamentally alter the reef "chemical landscape" and directly suppress kelp recruitment.