124
The Migrant Biota
remains so along the entire Lebanese coast and southern part of the Syrian coast,
broadening somewhat in the Bay of Mersin (Alexandretta, Iskenderun).
The bottom of the shelfis formed from Nile sediments, which predominate in
the northeast till near Jaffa; from there, the width of the sheIf decreases and the
amount of Nile sediments decreases too. The rocky basement layer is covered by
the sediment, for most of the shelf to Netanya. Off the Sirbonic Lagoon there is
one area of shell bottom with some rocky outcrops between 10 and 50 m depth
(Gorgy, 1966). Farther to the north the bottoms again become uniformly sedimentary. Gilat (1964), working north of Ashdod, did not encounter rocky bottoms. Around Netanya coralligenous bottoms start to appear regulady at depths
of about 20 m. Gilat (1964) suggests that some "islands" of coralligenous bottom
might occur even south of Netanya, at depths of 80-90 m. The isobaths as well as
the shore line are remarkably straight along the coast of Israel. Only the Bay of
Haifa, protected by the Carmel ridge and its calcareous prornontory has a more
complicated bottom structure with an alternance of coralligenous reefs between
10-20 m, partly formed by the coral Dendrophyllia cornigera, and of level bottoms
covered with meadows of Caulerpa scalpellijormis. The shallow 4-5 m deep bottoms in the old port of Acre are covered by pearl oyster beds (Pinctada radiata).
North of Haifa Bay the shelfbecomes steep and predominantly rocky.
According to Gilat (1964), the sequence of the sedimentary bottoms north of
Ashdod is as follows: the bottom is sandy to approximately 20 m; the sediment is
sand mixed with equal amounts of silt and clay around 35 m; at 46 m the bottom
is predominantly silt and clay. The organic content, plant detritus deposited by
the Nile, is relatively high on the southern shores of Israel i.e., up to 0.86% of the
sediment (Gilat, 1964). Shell bottoms start to occur off Netanya.
The shore is almost uniformly sandy till Mikhmoret, a point nortQ of Netanya
(Safriel and Lipkin, 1975). Only one rocky outcrop is found along this long 400-km
stretch from Port Said to Mikhmoret: the rocky prornontory of Yavne Yam
(Pairnahim) south of Tel Aviv. From the area of Ashkelon northwards slabs of
beachrock appear, obliquely covering the bottom immediately below the sea
level.
The beachrocks, wave-battered and permanently corroded by sand, can harbor only a limited number of animals. Typically rocky littoral environments
appear only from Mikhmoret northward. However, as soon as rocky ridges of
sandstone appear, the ridges are accompanied by organogenic rock platforms of
the vermetid molluscs, Vermetus triqueter and Dendropoma petraeum (Safriel,
1975).
The Levant shore is practically tideless, differences between high and low tides
usually not exceeding an amplitude of 30 cm. At high air pressure and eastern
winds the level of the sea is exceptionally lowered by several tens of centimeters.
The current is generally directed eounterclockwise and is relatively weak. In
the Port Said-EI Arish area, Gorgy (1966) indicates for Oetober 1959 and 1960 a
veloeity of 4.5 knots near Port Said, whieh slows down through aseries of antieydonic branches near the Sirbonis to only 0.8-1.0 knots along the shore at EI Arish
(Fig.34). This eurrent is further slowed down along the Israel eoast: Liebman
(1935) gives a maximum value 0.6 knots. Oren and Komarovsky (1961) mention a
veloeity of 0.20 knots (0.1 rn/sec) as most frequent along the Israel shores. The
The Migrant Biota
remains so along the entire Lebanese coast and southern part of the Syrian coast,
broadening somewhat in the Bay of Mersin (Alexandretta, Iskenderun).
The bottom of the shelfis formed from Nile sediments, which predominate in
the northeast till near Jaffa; from there, the width of the sheIf decreases and the
amount of Nile sediments decreases too. The rocky basement layer is covered by
the sediment, for most of the shelf to Netanya. Off the Sirbonic Lagoon there is
one area of shell bottom with some rocky outcrops between 10 and 50 m depth
(Gorgy, 1966). Farther to the north the bottoms again become uniformly sedimentary. Gilat (1964), working north of Ashdod, did not encounter rocky bottoms. Around Netanya coralligenous bottoms start to appear regulady at depths
of about 20 m. Gilat (1964) suggests that some "islands" of coralligenous bottom
might occur even south of Netanya, at depths of 80-90 m. The isobaths as well as
the shore line are remarkably straight along the coast of Israel. Only the Bay of
Haifa, protected by the Carmel ridge and its calcareous prornontory has a more
complicated bottom structure with an alternance of coralligenous reefs between
10-20 m, partly formed by the coral Dendrophyllia cornigera, and of level bottoms
covered with meadows of Caulerpa scalpellijormis. The shallow 4-5 m deep bottoms in the old port of Acre are covered by pearl oyster beds (Pinctada radiata).
North of Haifa Bay the shelfbecomes steep and predominantly rocky.
According to Gilat (1964), the sequence of the sedimentary bottoms north of
Ashdod is as follows: the bottom is sandy to approximately 20 m; the sediment is
sand mixed with equal amounts of silt and clay around 35 m; at 46 m the bottom
is predominantly silt and clay. The organic content, plant detritus deposited by
the Nile, is relatively high on the southern shores of Israel i.e., up to 0.86% of the
sediment (Gilat, 1964). Shell bottoms start to occur off Netanya.
The shore is almost uniformly sandy till Mikhmoret, a point nortQ of Netanya
(Safriel and Lipkin, 1975). Only one rocky outcrop is found along this long 400-km
stretch from Port Said to Mikhmoret: the rocky prornontory of Yavne Yam
(Pairnahim) south of Tel Aviv. From the area of Ashkelon northwards slabs of
beachrock appear, obliquely covering the bottom immediately below the sea
level.
The beachrocks, wave-battered and permanently corroded by sand, can harbor only a limited number of animals. Typically rocky littoral environments
appear only from Mikhmoret northward. However, as soon as rocky ridges of
sandstone appear, the ridges are accompanied by organogenic rock platforms of
the vermetid molluscs, Vermetus triqueter and Dendropoma petraeum (Safriel,
1975).
The Levant shore is practically tideless, differences between high and low tides
usually not exceeding an amplitude of 30 cm. At high air pressure and eastern
winds the level of the sea is exceptionally lowered by several tens of centimeters.
The current is generally directed eounterclockwise and is relatively weak. In
the Port Said-EI Arish area, Gorgy (1966) indicates for Oetober 1959 and 1960 a
veloeity of 4.5 knots near Port Said, whieh slows down through aseries of antieydonic branches near the Sirbonis to only 0.8-1.0 knots along the shore at EI Arish
(Fig.34). This eurrent is further slowed down along the Israel eoast: Liebman
(1935) gives a maximum value 0.6 knots. Oren and Komarovsky (1961) mention a
veloeity of 0.20 knots (0.1 rn/sec) as most frequent along the Israel shores. The