compiled by Luque and Templado (2004). A synthesis of the dynamics and structure
of deep-water kelp and kelp-like populations was provided by Flores-Moya (2012).
8.4 Seaweed and Seagrass Communities in the Alboran Sea
The peculiar biogeographical location of the Alboran Sea results in the confluence of
three biogeographic regions: Atlantic-boreal, Mediterranean, and Macaronesian
(Lüning 1990). In addition, the physical nature of its coasts presents a great variety
of substrata and habitats, allowing the development of a great diversity of marine
communities, some of which are of great importance and constitute areas of exceptional biodiversity. Moreover, the mixture of Atlantic and Mediterranean waters
together with the outcrops in deep waters is probably a determining factor for the
particular biota inhabiting the sea bottoms from the Alboran Sea (Cebrián and
Ballesteros 2004).
Plant communities are characterized by the presence of one or more dominant
species with narrow ecological niches, which possess a greater “ecological value,”
together with others (subordinate species) with broader niches. Some species present
a wide margin of tolerance to certain environmental conditions, so they present a
wider bathymetric amplitude and can be observed as common species in different
communities. In certain areas, these communities can be marked by the presence of
particular elements such as the presence of pantropical species in the eastern Alboran
Sea (Halimeda tuna, Acetabularia acetabulum; Fig. 8.1) or Atlantic species in the
westernmost part (Lichina pygmaea, Fucus guiryi).
8.4.1 Supralittoral Zone
The supralittoral zone is located above the wave-swept area of the water, so plant
development depends exclusively on hydration provided by the water splashed from
waves. The upper limit is wet only occasionally, during days of heavy weather,
whereas the lower horizon is subjected to continuous splash. This dependence on the
waves causes the vertical extension of this level to vary with the degree of exposure
and inclination of the substrate and the frequency and strength of the waves. The
adverse conditions imposed by the limited exposure to water and the high temperatures and salinity make plant life very difficult in this zone, where only lichens and
cyanobacteria (both endo- and epilithic) can develop. The supralittoral biocenis is
generally uniform on a global scale, with low abundance and diversity of species
(Pérès 1982). Among the lichens are species of Verrucaria (V. amphibia and
V. maura) that form scattered very dark, almost black, spots. At certain sites in the
western area of the Alboran Sea and in contact with the next lower zone, Lichina
pygmaea, a dark-colored lichen with the appearance of a minute tree, is frequent.
The cyanobacteria (epilithic microphytobenthos) develop black crusts, well attached
8 Seaweeds and Seagrasses: The Marine Forests from the Alboran Sea
253
of deep-water kelp and kelp-like populations was provided by Flores-Moya (2012).
8.4 Seaweed and Seagrass Communities in the Alboran Sea
The peculiar biogeographical location of the Alboran Sea results in the confluence of
three biogeographic regions: Atlantic-boreal, Mediterranean, and Macaronesian
(Lüning 1990). In addition, the physical nature of its coasts presents a great variety
of substrata and habitats, allowing the development of a great diversity of marine
communities, some of which are of great importance and constitute areas of exceptional biodiversity. Moreover, the mixture of Atlantic and Mediterranean waters
together with the outcrops in deep waters is probably a determining factor for the
particular biota inhabiting the sea bottoms from the Alboran Sea (Cebrián and
Ballesteros 2004).
Plant communities are characterized by the presence of one or more dominant
species with narrow ecological niches, which possess a greater “ecological value,”
together with others (subordinate species) with broader niches. Some species present
a wide margin of tolerance to certain environmental conditions, so they present a
wider bathymetric amplitude and can be observed as common species in different
communities. In certain areas, these communities can be marked by the presence of
particular elements such as the presence of pantropical species in the eastern Alboran
Sea (Halimeda tuna, Acetabularia acetabulum; Fig. 8.1) or Atlantic species in the
westernmost part (Lichina pygmaea, Fucus guiryi).
8.4.1 Supralittoral Zone
The supralittoral zone is located above the wave-swept area of the water, so plant
development depends exclusively on hydration provided by the water splashed from
waves. The upper limit is wet only occasionally, during days of heavy weather,
whereas the lower horizon is subjected to continuous splash. This dependence on the
waves causes the vertical extension of this level to vary with the degree of exposure
and inclination of the substrate and the frequency and strength of the waves. The
adverse conditions imposed by the limited exposure to water and the high temperatures and salinity make plant life very difficult in this zone, where only lichens and
cyanobacteria (both endo- and epilithic) can develop. The supralittoral biocenis is
generally uniform on a global scale, with low abundance and diversity of species
(Pérès 1982). Among the lichens are species of Verrucaria (V. amphibia and
V. maura) that form scattered very dark, almost black, spots. At certain sites in the
western area of the Alboran Sea and in contact with the next lower zone, Lichina
pygmaea, a dark-colored lichen with the appearance of a minute tree, is frequent.
The cyanobacteria (epilithic microphytobenthos) develop black crusts, well attached
8 Seaweeds and Seagrasses: The Marine Forests from the Alboran Sea
253