It is an important food for brant geese and wigeons, and even (occasionally) caterpillars of the grass moth Dolicharthria punctalis.

The genus as a whole is widespread throughout seashores of much of the Northern Hemisphere as well as Australia, New Zealand, Southeast Asia and southern Africa.

The discovery of Z. chilensis in 2005 adds an isolated population on the Pacific coast of South America to the distribution.

More recently, the plant has been used in its dried form for insulation in eco-friendly houses and as a ground cover in permaculture gardens, once its salt layer washed off (ex: Friland, Danish eco-village).

Some studies show promise for eelgrass meadows to sequester atmospheric carbon to reduce anthropogenic climate change.