On the other hand, some of the species traditionally considered of interest for
fisheries and included in Annex III (species whose exploitation is regulated) of the
Barcelona Convention should be moved to Annex II and be considered as threatened. This should apply especially for large exploited crustaceans that are increasingly scarce in the Alboran Sea, such as Palinurus elephas and Homarus gammarus,
or those that have practically disappeared from this Mediterranean area, such as
Scyllarides latus and Scyllarus arctus.
10.6 Species Originally Described from the Alboran Sea
The overview on the Mediterranean Sea biodiversity compiled by Coll et al. (2010)
pointed out that the Alboran Sea displays the highest values of species richness of the
basin. This was also suggested by Templado et al. (2006), García Raso et al. (2010)
or Aguilar et al. (2011a) and makes this area a biodiversity hotspot, within the wider
hotspot that the Mediterranean Sea represents globally. The Alboran Sea represents a
transition zone between the Atlantic Ocean and the Mediterranean Sea where
co-exist warm-water (from Atlantic North Africa), cold- and temperate-water
(from the northeast Atlantic) and Mediterranean species, plus some endemic species
restricted to this zone. Only the insular shelf of Alborán Island hosts more than a
quarter (26.87%, 1636 species) of the total Mediterranean species richness of
11 benthic groups (Gofas et al. 2014). As another example, the megadiverse
Mollusca, a good proxy indicator for total marine species richness, comprises in
Spanish waters of the Alboran Sea and Gibraltar Strait 1245 species, about 52.5% of
the total diversity of this phylum in the entire Spanish waters, including the Canary
Islands (Gofas et al. 2017).
All said above is reflected in the sustained description of new species from the
Alboran Sea during the past four decades. According to the non-exhaustive review
listed in Table 10.2, no less than 154 new species have been described since 1980 in
the Alboran Sea and the Strait of Gibraltar (18 Porifera, 6 Cnidaria,
5 Platyhelminthes, 1 Kinorhyncha, 2 Entoprocta, 8 Polychaeta, 1 Nemertea,
1 Tardigrada, 25 Crustacea, 1 Pycnogonida, 75 Mollusca, and
11 Bryozoa) (Fig. 10.18). The highest number of new species were described from
the Strait of Gibraltar (89) on both African and European sides, followed by the
Alboran Island (28) and other localities within the Alboran Sea (28) and the
Chafarinas Islands (9).
10.7 Mass Mortality Events
Events of mass mortality related to climatic anomalies (storms, high water temperature or oxygen deficiency episodes) and mainly affecting filter-feeding benthic
invertebrates (sponges, corals, gorgonians, bivalves, ascidians, etc.) have become
406
J. Templado et al.
fisheries and included in Annex III (species whose exploitation is regulated) of the
Barcelona Convention should be moved to Annex II and be considered as threatened. This should apply especially for large exploited crustaceans that are increasingly scarce in the Alboran Sea, such as Palinurus elephas and Homarus gammarus,
or those that have practically disappeared from this Mediterranean area, such as
Scyllarides latus and Scyllarus arctus.
10.6 Species Originally Described from the Alboran Sea
The overview on the Mediterranean Sea biodiversity compiled by Coll et al. (2010)
pointed out that the Alboran Sea displays the highest values of species richness of the
basin. This was also suggested by Templado et al. (2006), García Raso et al. (2010)
or Aguilar et al. (2011a) and makes this area a biodiversity hotspot, within the wider
hotspot that the Mediterranean Sea represents globally. The Alboran Sea represents a
transition zone between the Atlantic Ocean and the Mediterranean Sea where
co-exist warm-water (from Atlantic North Africa), cold- and temperate-water
(from the northeast Atlantic) and Mediterranean species, plus some endemic species
restricted to this zone. Only the insular shelf of Alborán Island hosts more than a
quarter (26.87%, 1636 species) of the total Mediterranean species richness of
11 benthic groups (Gofas et al. 2014). As another example, the megadiverse
Mollusca, a good proxy indicator for total marine species richness, comprises in
Spanish waters of the Alboran Sea and Gibraltar Strait 1245 species, about 52.5% of
the total diversity of this phylum in the entire Spanish waters, including the Canary
Islands (Gofas et al. 2017).
All said above is reflected in the sustained description of new species from the
Alboran Sea during the past four decades. According to the non-exhaustive review
listed in Table 10.2, no less than 154 new species have been described since 1980 in
the Alboran Sea and the Strait of Gibraltar (18 Porifera, 6 Cnidaria,
5 Platyhelminthes, 1 Kinorhyncha, 2 Entoprocta, 8 Polychaeta, 1 Nemertea,
1 Tardigrada, 25 Crustacea, 1 Pycnogonida, 75 Mollusca, and
11 Bryozoa) (Fig. 10.18). The highest number of new species were described from
the Strait of Gibraltar (89) on both African and European sides, followed by the
Alboran Island (28) and other localities within the Alboran Sea (28) and the
Chafarinas Islands (9).
10.7 Mass Mortality Events
Events of mass mortality related to climatic anomalies (storms, high water temperature or oxygen deficiency episodes) and mainly affecting filter-feeding benthic
invertebrates (sponges, corals, gorgonians, bivalves, ascidians, etc.) have become
406
J. Templado et al.