Marine fungi: Can water mushrooms save us from antibiotic resistance and pollution?

TAKE a walk along a seashore almost anywhere in the world and you will probably see colourful patches of life growing on rocks, sea walls and driftwood. These are lichens, mutualistic partnerships between fungi and algae. In Britain, that might include the brightly coloured orange sea lichen and the yellowish maritime sunburst lichen, plus many other drabber species.

Lichens are usually seen as land-living organisms and, indeed, the vast majority are, growing ponderously on inland rocks, tree trunks, leaves and soil. But coastal ones aren’t accidental vagrants from the land: they are marine-adapted species found only on or very near the shore. Until recently, they were thought to be outliers in the almost completely landlubbing kingdom of the fungi. Not any more. “In every marine ecosystem we look at, we find fungi,” says Michael Cunliffe at the University of Plymouth, UK.

The study of marine fungi is now mushrooming, though their exact role and importance in marine ecosystems remain something of a mystery. Nevertheless, there are high hopes that they could help to rescue us from two of the great scourges of the 21st century: antibiotic resistance and plastic pollution.

What are marine fungi?

The existence of marine fungi has been known for many years. The earliest descriptions were published in the mid-19th and early 20th centuries, but these were largely ignored by mainstream mycologists. The species discovered were mostly near-shore inhabitants of seaweed roots and…