Page 6 - UNEP_MAP2015

Abstract

This Sicilian Channel has complex bottom morphology. Two sill systems are separated by
deep basins or grabens, the Eastern Sill system (Malta plateau and Medina Bank)
connects the Sicilian Channel with the Ionian Basin. The Western Sill (Skerki bank,
Adventure Bank, Empedocle seamount and the Nameless Bank) is the major obstacle to
the Modified Mediterranean Water (MAW). Three major depressions, the Pantelleria
graben (1317-m depth), Linosa graben (1529-m depth), and Malta graben (1731-m depth)
are located on the middle of the channel. A large shallow shelf characterizes the area on
the south close to the Tunisia and Libya. The Sicilian Channel is a high-energy site with a
dynamic and highly variable current system that exchanges the waters between western
and eastern basins. Three water masses characterize the circulation in the Sicilian
Channel, the upper layer (about 200m thick) of MAW) flows eastward, the Levantine
Intermediate Water (LIW) and the deeper layer of the Eastern Mediterranean Deep Water,
which flow from the east toward the Tyrrhenian Sea and then to the Western
Mediterranean. After entered onto the Sicily channel the MAW splits into two main
branches Atlantic Ionian Stream (AIS) and Atlantic Tunisia Current (ATC). The complex
circulation patterns together with bottom structures such as seamounts, banks, volcanoes,
pockmarks and steep walled basins are the main responsible of the biodiversity richness
of the Sicily Channel, where healthy deep coral communities find favourable habitat and
several pelagic species such as anchovies, bluefin tuna and fin whales have spawning
and feeding areas.

As subject of other reviews, here the physical effects on benthic commercial target
species and pelagic such as sharks, swordfish and other cetacean species have not taken
into account.

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