It is a saline soft-sediment submerged plant native to marine environments on the coastlines of northern latitudes from subtropical to subpolar regions of North America and Eurasia.

[4] It anchors via rhizomes in sandy or muddy substrates and its leaves catch particulate debris in the water which then collects around the bases of the plants, building up the top layer of the seabed.

[5] The plant disperses large distances when its stems break away and carry the fertile seeds to new areas, eventually dropping to the seabed.

[7] This plant is an important member of the coastal ecosystem in many areas because it helps to physically form the habitat and it plays a crucial role for many other species.

[11] A great many animals use the plant for food, including the isopod Idotea chelipes and the purple sea urchin Paracentrotus lividus.

[10] When the eelgrass dies, detaches, and washes up on the beach, a whole new ecosystem is founded; many species of insects and other invertebrates begin to inhabit the dead plant, including the amphipod Talitrus saltator, the fly Fucellia tergina, and the beetles Stenus biguttatus, Paederus littoralis, and Coccinella septempunctata.

[5] Pollution from many sources, including riverside farms, sewage lines,[14] fish processing plants, and oil spills, damage eelgrass meadows.

[10] Remaining geese ate less-preferred food plants and algae, and hunters subsequently noticed that brant meat began to taste different.

The researchers revealed key adaptations at the molecular biological level that have occurred during evolution of Z. marina, an angiosperm that has adopted a marine lifestyle.

Also macro-algae like cell wall components (low-methylated polyanionic pectins and sulfated galactans) have been described, unique for Z. marina compared to other angiosperms.

Ángel León, a Spanish chef, has planted meadows of Z. marina (described as "sea rice") in the Bay of Cádiz in order to harvest the grains.