Activities

The availability of a stable substrate to which organisms can attach is a determining factor. The rocky surface is covered with algae, colonies of sessile animals (sponges, bryozoans, anemones, mollusks, etc.) that are capable of resisting the action of the waves and also attract other organisms, this time mobile, that live swimming in their vicinity. crawling on the bottom or taking advantage of the shelter offered by the plant or animal cover that covers the rocky substrate. The environment in which these biological communities live is very harsh. The waves can tear away the fixed shapes of the substrate, the solar lighting, which is highly variable depending on the orientation or the presence of cracks or small caves, determines the possibilities of survival of the algae that need light for photosynthesis. At the most superficial levels, depending on the waves or the action of the tides, there are communities adapted to the alternation of emersion/immersion, to solar radiation and to evaporation and desiccation.

In these places we will find plants especially adapted to living in these habitats. In areas where there is a sandy substrate, the sand is arranged forming ridges of dunes oriented parallel to the coastline and with different heights depending on the degree of protection against the sea wind. In the first dune, the one closest to the sea, there are conditions of mobility of the sand grains that allow their colonization by plants highly adapted to the impacts of the sand grains on their stems and leaves. The second dune range has a slightly higher height and the plants are more densely present and also the species that are located in them are different compared to the first dune, and are also different depending on whether they are located to the windward (where the sea wind affects). or leeward (the area most sheltered from the wind). The pioneer vegetation of the dunes will gradually be enriched by the presence of woody species from the coastal scrub in the places most protected by the wind. Behind these dunes, at a greater distance from the sea, there is another different ecosystem, it is the so-called “post-country” or “back shore”, which is very common along the entire Mediterranean coast, where marshes, lagoons, or small lagoons; and the plants present there are different from those located in the dunes. Furthermore, depending on its annual dynamism (presence of water in summer, chemical nature of the water, presence of salinity, etc.), the species best adapted to such conditions will be established in each case.

...functioning of the oceans as an ecosystem. Its study is fundamental, not only because of its scientific interest but also because of the importance of the human activities that take place in its space. The composition of the coastal rocks, their origin and geological history represents a witness to the evolution of the oceans, providing evidence of the rise and fall of sea level in past times and its impact on past organisms and ecosystems.

...of the Red Sea. The first two mentioned are widespread along the entire coastline from surface level to 20-30 m and even 100 m. deep in areas of very transparent water. Posidonia oceanica forms meadows or "forests" while Cymodocea and Zostera form "lawns", covering the seabed. Posidonia oceanica is considered an “engineering species”, that is, with its structures, leaves, rhizomes (stems) and roots, they form compact banks and reefs that determine not only the species and biological communities that live in them, but also They play a very important role in controlling erosion on beaches due to their action to dissipate wave energy and retain sediment at surface levels.