other algae with soft and small thalli such as Phyllophora crispa, Flabellia petiolata,
Codium spp., Valonia macrophysa, Zonaria tournefortii, Halopteris filicina,
Dictyopteris polypodioides, Arthocladia villosa, and Sporochnus pedunculatus,
among many others. As previously mentioned, they can also include Phyllariopsis
purpurascens and P. brevipes.
At this level, as well as on infralittoral bottoms, the community of maerl is
developed. This community consists of red calcareous algae forming rhodoliths
(also known as rhodolithic bottoms), whose thalli grow three-dimensionally into
spheroids that facilitate both their movement along the bottom and the maximum use
of the scant incident light. These communities are restricted to certain areas close to
capes, usually with intense currents. Smaller rhodoliths are found on shallower
bottoms, whereas the larger ones tend to occur at greater depths. In Alboran Sea,
the smaller rhodoliths appear from 20 m depth, whereas those of average size and
larger are found at 30–40 m (Gofas et al. 2014). The typical maerl-forming species
are Lithothamnion coralloides and Phymatolithon calcareum, which are accompanied by Peyssonnelia spp (Fig. 8.8c). Other characteristic species of these maerl
bottoms are Zanardinia prototypus, Bonnemaisonia asparagoides, Fauchea repens,
Phyllophora crispa, Botryocladia botryoides, Kallymenia spp., Sebdenia spp.,
Scinaia spp., Flabellia petiolata, and Codium spp. The composition of the community associated with maerl beds of Alboran Island presents remarkable variations
depending on the depth. In the shallowest part, macroalgae such as Ulva rigida or the
kelp Laminaria ochroleuca are often fixed to rhodoliths. Here the specific composition of the calcareous algae can vary, and the coverage of non-calcified algae
decreases (Gofas et al. 2014). The growth of the rhodoliths requires very particular
environmental conditions, which is why these bottoms are relatively rare and
confined to small areas in the Alboran Sea (Ramos Esplá and Luque 2004). These
communities are very structured, harboring a great diversity in both species and
functional richness.
Semi-dark caves and the entrances of caves and tunnels can occur at any
bathymetric level of the infralittoral zone. In these permanently submerged environments, the light conditions are very similar to those described for the circalittoral
horizon, so the species that develop are the same as in the coralligenous community.
The intensity of hydrodynamism determines the presence or absence of certain
species. Among those that can be observed are encrusting red algae such as
Lithophyllum stictaeforme or Mesophyllum lichenoides and others such as
Hildenbrandia spp. or various species of Peyssonnelia (Fig. 8.8d).
In the infralittoral and circalittoral on detritic sedimentary bottoms, on which
materials of terrigenous and biogenic origin are mixed, a community is developed in
which the algal cover consists small species whose attachment systems allow them
to develop on the limited surfaces offered by this type of substrate. Many of these
algae are also present in the maerl bottoms, and some of them can be found together
with corallinaceans already mentioned before such as Scinaia furcellata,
Peyssonnelia rosa-marina, P. rubra, Phyllophora crispa, Halopteris filicina,
Zanardinia prototypus, Arthrocladia villosa, Sporochnus pedunculatus,
Phyllariopsis brevipes, Flabellia petiolata, Valonia utricularis, and Codium spp.
among others.
8 Seaweeds and Seagrasses: The Marine Forests from the Alboran Sea
265
Codium spp., Valonia macrophysa, Zonaria tournefortii, Halopteris filicina,
Dictyopteris polypodioides, Arthocladia villosa, and Sporochnus pedunculatus,
among many others. As previously mentioned, they can also include Phyllariopsis
purpurascens and P. brevipes.
At this level, as well as on infralittoral bottoms, the community of maerl is
developed. This community consists of red calcareous algae forming rhodoliths
(also known as rhodolithic bottoms), whose thalli grow three-dimensionally into
spheroids that facilitate both their movement along the bottom and the maximum use
of the scant incident light. These communities are restricted to certain areas close to
capes, usually with intense currents. Smaller rhodoliths are found on shallower
bottoms, whereas the larger ones tend to occur at greater depths. In Alboran Sea,
the smaller rhodoliths appear from 20 m depth, whereas those of average size and
larger are found at 30–40 m (Gofas et al. 2014). The typical maerl-forming species
are Lithothamnion coralloides and Phymatolithon calcareum, which are accompanied by Peyssonnelia spp (Fig. 8.8c). Other characteristic species of these maerl
bottoms are Zanardinia prototypus, Bonnemaisonia asparagoides, Fauchea repens,
Phyllophora crispa, Botryocladia botryoides, Kallymenia spp., Sebdenia spp.,
Scinaia spp., Flabellia petiolata, and Codium spp. The composition of the community associated with maerl beds of Alboran Island presents remarkable variations
depending on the depth. In the shallowest part, macroalgae such as Ulva rigida or the
kelp Laminaria ochroleuca are often fixed to rhodoliths. Here the specific composition of the calcareous algae can vary, and the coverage of non-calcified algae
decreases (Gofas et al. 2014). The growth of the rhodoliths requires very particular
environmental conditions, which is why these bottoms are relatively rare and
confined to small areas in the Alboran Sea (Ramos Esplá and Luque 2004). These
communities are very structured, harboring a great diversity in both species and
functional richness.
Semi-dark caves and the entrances of caves and tunnels can occur at any
bathymetric level of the infralittoral zone. In these permanently submerged environments, the light conditions are very similar to those described for the circalittoral
horizon, so the species that develop are the same as in the coralligenous community.
The intensity of hydrodynamism determines the presence or absence of certain
species. Among those that can be observed are encrusting red algae such as
Lithophyllum stictaeforme or Mesophyllum lichenoides and others such as
Hildenbrandia spp. or various species of Peyssonnelia (Fig. 8.8d).
In the infralittoral and circalittoral on detritic sedimentary bottoms, on which
materials of terrigenous and biogenic origin are mixed, a community is developed in
which the algal cover consists small species whose attachment systems allow them
to develop on the limited surfaces offered by this type of substrate. Many of these
algae are also present in the maerl bottoms, and some of them can be found together
with corallinaceans already mentioned before such as Scinaia furcellata,
Peyssonnelia rosa-marina, P. rubra, Phyllophora crispa, Halopteris filicina,
Zanardinia prototypus, Arthrocladia villosa, Sporochnus pedunculatus,
Phyllariopsis brevipes, Flabellia petiolata, Valonia utricularis, and Codium spp.
among others.
8 Seaweeds and Seagrasses: The Marine Forests from the Alboran Sea
265