"Pearl took some eel-grass"
Eel-grass
Public DomainEel-grass - Credit: C. A. M. Lindman
Eel-grass and egg cases
Creative Commons AttributionEel-grass and egg cases - Credit: Luke McGuff

Technically known as zostera marina, eel-grass is a flowering sea-plant with vivid, ribbon-like leaves. Growing up to four feet long, it likes shallow water around bays and estuaries and reproduces so prolifically that it often forms dense sea meadows. These provide invaluable shelter for a host of marine life, including starfish, anemones, sea urchins, crabs, numerous fish and birds, and even mammals such as seals.