Macroalgae, plants and animals like corals and sponges create complex habitats that provide resources, shelter and nursery grounds for many marine organisms.
Forests of macroalgae are mainly formed by large brown algae such as kelp or fucoids, but also by red and green algae (© Douglas Klug).
Seagrasses are plants that evolved and adapted to live in the sea. They have roots, leafs and produce flowers and fruits (© Manu Sanfelix).
Marine animal forests are mostly formed by invertebrates that live attached to rock, such as coral reefs and gorgonian gardens (© NOAA).