Faunal Movements from the Meditterranean into the Red Sea
157
while to investigate the relation between normal animal feeding and symbiotic
feeding in this medusa under different and extreme environmental conditions.
Until a tropical symbiotrophic species settles in the Levant Sea, there is no
reason for speaking of an expanded trophic frame. At the same time, unless such
organisms-corals and tropical plankton-settle the Mediterranean, there is no
reason to assume that parts of that sea will become a province of the Indo-Pacific
realm. As shown above, there is no indication that such a profound qualitative
change in the species diversity array ofthe Lessepsian migration may occur in the
near future.
Oren (1970) assumes the possibility of a gradual increase in the total salinity of
the Levant Basin following the cessation of the Nile influx. There are as yet no
data to indicate if this actually happens, or how considerable this salinity increase
might be. lt is evident that in the event of a certain increase in the salinity of the
Mediterranean, Lessepsian species already present will have further competitive
advantage. However, there will probably be little enrichment of species. Perhaps
only a few species which are presently in the Mediterranean confined to coastal
lagoons and the Sirbonic Lagoon, for example, Acetabularia calyculus, M etapenaeus stebbingi, Mactra olorina, and Crenidens erenidens may expand their area in
the Levant Sea.
lt is necessary to elose the remarks concerning the future of the Lessepsian
migration with a few words on pollution. The Gulf of Suez is increasingly polluted
by the nearshore and submarine oilfields such as EI Morgan, and Abu Rudeis, etc.
Soon the refineries at Suez will work again and the SUMED (Suez-Mediterranean) pipeline will be built. In the navigation of the recently reopened Suez
Canal the tankers will occupy an even more preponderant role than before. On
the Mediterranean coast are the Ashkelon and Tripoli oil terminals, the existing
refmeries and oil slicks coming from the Libyan oil fields. Oil pollution which
chiefly hits the nearshore organisms, may deeply interfere with the natural evolution of the Lessepsian migration and expansion. Domestic sewage and chemical
emuents will also undoubtedly contribute their share. Will the thermal pollution
perhaps create optimal environments for the Lessepsian migrants? Until such a
beneficial exception is proven, marine pollution in the Eastern Mediterranean
should be seen as an indiscriminate menace for all marine life-Iocal or invading.
3.9 Fauna} Movements from the Mediterranean into the Red Sea -
Anti-Lessepsian Migration
In 1865 Leon Vaillant expected "un melange des faunes" following the
opening of the Suez Canal. In 1902 Tillier was the first to discern the one~
sidedness of the migrational phenomena. In later years this became more and
more evident. De Lattin (1967, p.46) writes: "lt is rather remarkable that for the
time being there are scarcely any facts pleading for an opposite migrational
direction i.e. from the Mediterranean to the Red Sea" (my translation).
Ben-Tuvia (1966) saw this one-sidedness as a result of the contact between a
rich and diverse fish fauna such as that of the Red Sea with an impoverished one
157
while to investigate the relation between normal animal feeding and symbiotic
feeding in this medusa under different and extreme environmental conditions.
Until a tropical symbiotrophic species settles in the Levant Sea, there is no
reason for speaking of an expanded trophic frame. At the same time, unless such
organisms-corals and tropical plankton-settle the Mediterranean, there is no
reason to assume that parts of that sea will become a province of the Indo-Pacific
realm. As shown above, there is no indication that such a profound qualitative
change in the species diversity array ofthe Lessepsian migration may occur in the
near future.
Oren (1970) assumes the possibility of a gradual increase in the total salinity of
the Levant Basin following the cessation of the Nile influx. There are as yet no
data to indicate if this actually happens, or how considerable this salinity increase
might be. lt is evident that in the event of a certain increase in the salinity of the
Mediterranean, Lessepsian species already present will have further competitive
advantage. However, there will probably be little enrichment of species. Perhaps
only a few species which are presently in the Mediterranean confined to coastal
lagoons and the Sirbonic Lagoon, for example, Acetabularia calyculus, M etapenaeus stebbingi, Mactra olorina, and Crenidens erenidens may expand their area in
the Levant Sea.
lt is necessary to elose the remarks concerning the future of the Lessepsian
migration with a few words on pollution. The Gulf of Suez is increasingly polluted
by the nearshore and submarine oilfields such as EI Morgan, and Abu Rudeis, etc.
Soon the refineries at Suez will work again and the SUMED (Suez-Mediterranean) pipeline will be built. In the navigation of the recently reopened Suez
Canal the tankers will occupy an even more preponderant role than before. On
the Mediterranean coast are the Ashkelon and Tripoli oil terminals, the existing
refmeries and oil slicks coming from the Libyan oil fields. Oil pollution which
chiefly hits the nearshore organisms, may deeply interfere with the natural evolution of the Lessepsian migration and expansion. Domestic sewage and chemical
emuents will also undoubtedly contribute their share. Will the thermal pollution
perhaps create optimal environments for the Lessepsian migrants? Until such a
beneficial exception is proven, marine pollution in the Eastern Mediterranean
should be seen as an indiscriminate menace for all marine life-Iocal or invading.
3.9 Fauna} Movements from the Mediterranean into the Red Sea -
Anti-Lessepsian Migration
In 1865 Leon Vaillant expected "un melange des faunes" following the
opening of the Suez Canal. In 1902 Tillier was the first to discern the one~
sidedness of the migrational phenomena. In later years this became more and
more evident. De Lattin (1967, p.46) writes: "lt is rather remarkable that for the
time being there are scarcely any facts pleading for an opposite migrational
direction i.e. from the Mediterranean to the Red Sea" (my translation).
Ben-Tuvia (1966) saw this one-sidedness as a result of the contact between a
rich and diverse fish fauna such as that of the Red Sea with an impoverished one