An ecosystem of shadows and natural shelters.
The progressive growth of encrusting algae encourages the formation of small crevices in the rocks, creating a suitable habitat for numerous fish and marine invertebrates.
Furthermore, the erosion caused by water gives rise to underwater tunnels and galleries, known as underwater caves, which form a unique landscape with a low density of organisms.
An environment with extreme conditions
In underwater caves, the scarcity of light prevents the development of plant life. As one moves deeper inside, the fauna covering the walls progressively decreases until it almost vanishes entirely.
Other environmental factors, such as oxygen, temperature and nutrients, are also more limited inside these cavities, which restricts the presence of marine life.
Tunnels and currents: more life underwater
In underwater tunnels, the presence of marine currents facilitates the renewal of the water. As a result, the walls host a richer fauna, made up mainly of filter-feeding invertebrates.
A similar phenomenon occurs in crevices, where, despite not being fully enclosed, light is scarce. These spaces become ideal shelters for numerous species.
Species associated with underwater caves
Some species use caves and crevices as shelter, such as the European moray eel; others make them their preferred habitat, such as spiny lobsters.
