The Bottom of the Suez Canal
63
Pollution, chiefly from bunker oil, mayaIso explain the presence of the muchmentioned "gelatinous mud" on the bottom of the shipping channel through the
Bitter Lakes. The frrst record of this, along the eastern coast of the Lake, is to be
found in Tillier (1902) who speaks of a "vase noire remarquablement molle et
collante que nous avons pu parfois comparer a un epais sirop". Fox (1926) speaks
of a "black evil-smelling gelatinous mud". Thorson was very interested in this
gelatinous mud, which he considered to cover the bottom over great distances
[see correspondence between Steinitz and Thorson Israel J. Zoo1. 21 (3-4),
pp. 143-147, 1972]. Beets (1953) found that the foul bottom layer may be due to
"stagnancy and exhaust products of mechanically driven ships". As late as 9 July
1974 the International Herald Tribune reports "a layer saturated with oil and
salt ... fuel which leaked from ships" which was encountered by American naval
divers who worked in the clearing operation ofthe Suez Cana1.
It seems that the mysterious "gelatinous mud", one of the curious features of
the Canal, is a bunker oil, salt and water mixture covering parts of the bottom of
the Bitter Lakes.
2.4 The Bottom of the Suez Canal
The Suez Canal is a habitat for many species-regardless of where they originate or their chan ces of becoming invaders of the opposite sea. F or most of these
animals the types of bottom found in the Suez Canal are of crucial importance.
Conditions are more or less natural and undisturbed in the Bitter Lakes and Lake
Timsah. In the Canal proper, the continuous dredging and the periodical deepening and widening are very important as stability factors. The waves and turbulence caused by the many ships passing the Canal day and night are a further
factor to be considered as deeply influencing the sediments of the Canal sections.
Most of the Canal used to be dredged once every three to four years. The
minimum frequency ofthe dredgings was five-six years, maximum two years. W.
Steinitz (1929) gives an average time span of 2-3 years between dredgings. To that
one has to add the several widening and deepening projects which have been
carried out over the past century. As a rule, the Canal was widened along its east
bank. The enlarging of the Canal did not result in more undisturbed conditions
along the banks and the bottom, since the projects were always carried out as an
answer to the increasing size and draught ofthe throughgoing ships.
Following Gruvel's detailed description (1936) the Canal bottom can be characterized in the following way: in the North to about Km 55 the bottom is sandy,
mixed with black mud of lagoon origin. From Ballah onwards the bottom becomes "cleaner", mixed with gypsum concretions. Crossing the ridge of Guisr
(Km 72) the bottom is marly with some rocky outcrops. Sandy mud predominates
between the two lakes (Lake Timsah and Bitter Lake). South of the Bitter Lakes
the sand is cleaner, with a mixture of gravel and shell. In the stretch crossing the
ridge of Shallufa (Km 140), rocky outcrops are again found on the bottom.
With the exception of the northern stretch, the bottom is clean enough to
allow for a dense population of the lancelet Branchiostoma lanceolatum in the
sediment. This has been a stable and frequent inhabitant ofthe Canal stretches for
63
Pollution, chiefly from bunker oil, mayaIso explain the presence of the muchmentioned "gelatinous mud" on the bottom of the shipping channel through the
Bitter Lakes. The frrst record of this, along the eastern coast of the Lake, is to be
found in Tillier (1902) who speaks of a "vase noire remarquablement molle et
collante que nous avons pu parfois comparer a un epais sirop". Fox (1926) speaks
of a "black evil-smelling gelatinous mud". Thorson was very interested in this
gelatinous mud, which he considered to cover the bottom over great distances
[see correspondence between Steinitz and Thorson Israel J. Zoo1. 21 (3-4),
pp. 143-147, 1972]. Beets (1953) found that the foul bottom layer may be due to
"stagnancy and exhaust products of mechanically driven ships". As late as 9 July
1974 the International Herald Tribune reports "a layer saturated with oil and
salt ... fuel which leaked from ships" which was encountered by American naval
divers who worked in the clearing operation ofthe Suez Cana1.
It seems that the mysterious "gelatinous mud", one of the curious features of
the Canal, is a bunker oil, salt and water mixture covering parts of the bottom of
the Bitter Lakes.
2.4 The Bottom of the Suez Canal
The Suez Canal is a habitat for many species-regardless of where they originate or their chan ces of becoming invaders of the opposite sea. F or most of these
animals the types of bottom found in the Suez Canal are of crucial importance.
Conditions are more or less natural and undisturbed in the Bitter Lakes and Lake
Timsah. In the Canal proper, the continuous dredging and the periodical deepening and widening are very important as stability factors. The waves and turbulence caused by the many ships passing the Canal day and night are a further
factor to be considered as deeply influencing the sediments of the Canal sections.
Most of the Canal used to be dredged once every three to four years. The
minimum frequency ofthe dredgings was five-six years, maximum two years. W.
Steinitz (1929) gives an average time span of 2-3 years between dredgings. To that
one has to add the several widening and deepening projects which have been
carried out over the past century. As a rule, the Canal was widened along its east
bank. The enlarging of the Canal did not result in more undisturbed conditions
along the banks and the bottom, since the projects were always carried out as an
answer to the increasing size and draught ofthe throughgoing ships.
Following Gruvel's detailed description (1936) the Canal bottom can be characterized in the following way: in the North to about Km 55 the bottom is sandy,
mixed with black mud of lagoon origin. From Ballah onwards the bottom becomes "cleaner", mixed with gypsum concretions. Crossing the ridge of Guisr
(Km 72) the bottom is marly with some rocky outcrops. Sandy mud predominates
between the two lakes (Lake Timsah and Bitter Lake). South of the Bitter Lakes
the sand is cleaner, with a mixture of gravel and shell. In the stretch crossing the
ridge of Shallufa (Km 140), rocky outcrops are again found on the bottom.
With the exception of the northern stretch, the bottom is clean enough to
allow for a dense population of the lancelet Branchiostoma lanceolatum in the
sediment. This has been a stable and frequent inhabitant ofthe Canal stretches for