increases. Unauthorized activities such as free camping, transit and anchoring of
motor boats; recreational fishing or scuba-diving; and urban solid waste and
untreated sewage from nearby villages (e.g. Nerja) are the main threats. In the
same way, agriculture greenhouses have proliferated in recent years in the western
part of the MPA (e.g. Maro village), generating a high visual impact and a large
amount of solid (plastic) and liquid (pesticides, fertilizers, etc.) waste, which can
negatively affect the long-term stability of habitats that are sensitive to coastal water
quality such as seagrass beds. This together with some illegal bottom trawling was
postulated among the potential drivers that led Z. marina beds to their local extinction (Rueda et al. 2009).
25.4.2 Alboran Island SPAMI and Collateral
Figures of Protection (Spain)
The Alboran Island is a small and flat island, 642 m long and 265 m wide, located in
the centre of the Alboran Sea from which it received its name. It belongs administratively to the Almería province, distance ca. 85 km, and is situated ca. 55 km away
from Morocco.
The island is of volcanic origin and represents the top of the Alboran Ridge, an
elongated submarine seamount that is one of the main structural highs of the Alboran
Basin. This island is flat (not exceeding 15 m in height) with an irregular morphology, as well as the surrounding insular platform, due to the abrasive marine erosion.
It corresponds to an outcrop of volcanic breccias and tuff of the cal-calkaline series
that varies from pyroxene andesites to basalt-andesites, of Upper Tortonian age
(IGME 1983; Aparicio et al. 1991). This outcrop is abraded by several levels of
quaternary marine terraces with detrital limestone deposits, which provide a characteristic tabular relief to the island, and covered by a deposit of Holocene eolic sands
(IGME 1983).
The island is located on a linear NE-SW elongated platform that is ca. 45 km long
and 10 km wide and is disconnected from the nearest continental areas (Bárcenas
et al. 2004). The platform is located in the NE sector of the Alboran Ridge, an
elevation of ca. 200 km in length which controls the physiography of the southern
part of the Alboran Sea. This structure is made up of a series of tight anticlinalsyncline folds generated since the Upper Tortonian to the present and is located over
a main thrust (Vázquez et al. 2015a) according to the convergence of the Nubian
plate towards the northwest (see Vázquez et al. 2021, Chap. 5 of this book). This
elevation is dotted with volcanic outcrops, highlighting the trapezoidal building that
corresponds to the basal Alboran Island edifice (Vázquez et al. 2000).
The insular platform is connected to a high slope flank that extends down to
1000–2000 m (Vázquez et al. 2015a). The morphology and sediments spatial
distribution indicates the existence of two different hydrodynamic areas on the
Alboran Ridge (Bárcenas et al. 2018): (a) the northern area with energetic
25 Marine Protected Areas and Key Biodiversity Areas of the Alboran Sea and. . .
835
motor boats; recreational fishing or scuba-diving; and urban solid waste and
untreated sewage from nearby villages (e.g. Nerja) are the main threats. In the
same way, agriculture greenhouses have proliferated in recent years in the western
part of the MPA (e.g. Maro village), generating a high visual impact and a large
amount of solid (plastic) and liquid (pesticides, fertilizers, etc.) waste, which can
negatively affect the long-term stability of habitats that are sensitive to coastal water
quality such as seagrass beds. This together with some illegal bottom trawling was
postulated among the potential drivers that led Z. marina beds to their local extinction (Rueda et al. 2009).
25.4.2 Alboran Island SPAMI and Collateral
Figures of Protection (Spain)
The Alboran Island is a small and flat island, 642 m long and 265 m wide, located in
the centre of the Alboran Sea from which it received its name. It belongs administratively to the Almería province, distance ca. 85 km, and is situated ca. 55 km away
from Morocco.
The island is of volcanic origin and represents the top of the Alboran Ridge, an
elongated submarine seamount that is one of the main structural highs of the Alboran
Basin. This island is flat (not exceeding 15 m in height) with an irregular morphology, as well as the surrounding insular platform, due to the abrasive marine erosion.
It corresponds to an outcrop of volcanic breccias and tuff of the cal-calkaline series
that varies from pyroxene andesites to basalt-andesites, of Upper Tortonian age
(IGME 1983; Aparicio et al. 1991). This outcrop is abraded by several levels of
quaternary marine terraces with detrital limestone deposits, which provide a characteristic tabular relief to the island, and covered by a deposit of Holocene eolic sands
(IGME 1983).
The island is located on a linear NE-SW elongated platform that is ca. 45 km long
and 10 km wide and is disconnected from the nearest continental areas (Bárcenas
et al. 2004). The platform is located in the NE sector of the Alboran Ridge, an
elevation of ca. 200 km in length which controls the physiography of the southern
part of the Alboran Sea. This structure is made up of a series of tight anticlinalsyncline folds generated since the Upper Tortonian to the present and is located over
a main thrust (Vázquez et al. 2015a) according to the convergence of the Nubian
plate towards the northwest (see Vázquez et al. 2021, Chap. 5 of this book). This
elevation is dotted with volcanic outcrops, highlighting the trapezoidal building that
corresponds to the basal Alboran Island edifice (Vázquez et al. 2000).
The insular platform is connected to a high slope flank that extends down to
1000–2000 m (Vázquez et al. 2015a). The morphology and sediments spatial
distribution indicates the existence of two different hydrodynamic areas on the
Alboran Ridge (Bárcenas et al. 2018): (a) the northern area with energetic
25 Marine Protected Areas and Key Biodiversity Areas of the Alboran Sea and. . .
835