Biology Reference
In-Depth Information
7°W
1°W
37°N
Almería
Málaga
Alboran
Island
Upwelling
areas
nearshore
Strait of Gibraltar
West
Gyre
East
Gyre
Al-Hoceima
Melilla
35°N
Fig. 15.2
Main surface currents and upwelling zones in the Strait of Gibraltar and the Alboran Sea
cited species are available in Guiry and Guiry
2011
). The perennial thalli have a
holdfast with branched haptera, a stipe (in the longest individuals reaching 3 m
length) and a blade (up to 3-4 m length) divided into laciniae.
S. polyschides
(Fig.
15.1b
) is a North Atlantic species (from the Norwegian
shores at the North to Mauritania at the South) that can also be found in the Canary
Islands and in deep waters from the Alboran Sea and the Strait of Messina. It has a
holdfast with a large bulb and small unbranched haptera, a stipe with lateral frills,
and a blade divided into laciniae. Thalli are smaller than those of
L. ochroleuca
, but
they can reach 3-4 m length. This species is annual or biennial.
Both species of
Phyllariopsis
are annuals and inhabit the NW and W Iberian
Peninsula, NWMorocco, the western Mediterranean Sea, and the Strait of Messina,
but
P. purpurascens
has also been found in the Canary Islands.
P. brevipes
(Fig.
15.1c
) has an entire, cordate blade of
0.5 m length and a short stipe; the
holdfasts have unbranched haptera.
P. purpurascens
(Fig.
15.1d
) has a single blade
that, in the longest individuals, reaches 2 m in length. It holds to the substratum by a
disc of around 1 cm diameter, and it has a stipe 10-12 cm in length. The Mediter-
ranean endemic
Laminaria rodriguezii
Bornet inhabits very deep waters (50-120 m
depths) in the Western Mediterranean Sea and in the Adriatic Sea (Feldmann
1934
;
Giaccone
1969
), but this species has not been found in the Alboran Sea (P´rez-
Ruzafa et al.
2003
).
The presence of kelp forests and beds in the Alboran Sea and the Strait of
Gibraltar is linked to the particular oceanographic conditions (Fig.
15.2
). The
negative water balance in the Mediterranean Sea (i.e., the loss of water by evapora-
tion is higher than the inputs by precipitation and rivers) is compensated by a
permanent current flowing from the Atlantic Ocean into the Mediterranean Sea
across the Strait of Gibraltar. Thus, the salinity in the Mediterranean Sea is higher
than that at the same latitude in the neighbor Atlantic Ocean, but it does not increase
further because high-salinity deep water current flows from the Mediterranean to
<
