76
The Suez Canal
salinity metahaline conditions. This successional history is graphically represen ted in Figure 28.
Is the colonization of the Canal from the Gulf of Suez still going on? There are
no data to indicate it. In fact the preadaptation to high salinities and the permanent tidal current reaching the Little Bitter Lake probably gave the chance for all
potential invaders to reach the Canal. On the other hand, oil pollution has badly
damaged the environment off Suez and also in the whole Gulf.
Gruvel (1936) more than forty years ago found that " ... fish as weIl as invertebrates are repelled by the presence of oll from all the area near the Port Taufiq
refineries and consequently from the entrance of the Canal". Gruvel states that
the diversity offishes has decreased in the Bay of Suez. As for the southern section
of the Canal he writes "the number of fish and molluscs has diminished in this
part of the Canal and in the lake from year to year". The decrease in the number
of pearl oysters in the southern Canal is also due to the crude oil and refmery
products, carried into the Canal by the tidal current: "they chase away the animals which can escape and destroy the sedentaries".
In the last decades the oll fields of EI Morgan and Abu Rudeis have been
increasingly operated on the Sinai coast of the Gulf. Most of these fields are
submarine and big spills around the platforms are frequent. I had the occasion in
1974 to witness the heavy oil pollution caused by an accident on one of these
platforms. More oil fields are operated on the African side of the Gulf.
It is, therefore, hard to conceive that new, i.e. more sensitive and stenotopic
species, slower migrators, should have had better opportunities to colonize the
Canal in the last years. Quite on the contrary, it is conceivable that some species
which succeeded in gaining a foot-hold in the Southern Canal but could not reach
the open expanses of the Bitter Lakes, were wiped out by the oil-Iaden tidal
currents flushing past the refmeries and oll terminals at Suez.
2.7 Species Diversity in the Suez Canal
This chapter considers the climax conditions presumably reached by the Suez
Canal biota. Thorson (1971) calculated that the collections ofthe 1924 Cambridge
Expedition containafaunaof318 species in the Canal. Lipkin (1972a) gives a list of
96 species of algae and sea grasses [if one disregards further three dubious findings by Muschler (1908)]. Por and Marcus (1972) give a total of 83 species of
Copepoda Harpacticoida collected till now in the Suez Canal. Schellenberg's
(1928) and Ruffo's (personal communication) lists brings the number of Amphipoda to 46 species. From different sources one may estimate that there are some
150 species ofmolluscs in the Canal. The report by Eitan (1972) brings the known
species ofthe Bryozoa from the Canal, to 35 species. Ben-Eliahu (1972d) enumerates 78 species of Polychaeta Errantia. In Tillier's time (1902) there were 78 species
offish in the Canal; to this even the small coll_ection reported by Steinitz and BenTuvia (1972) adds another seven species.
One can thus assume that the total number of species in the Canal is in the
magnitude of 1000-2000 species. Therefore, there is no reason to compare the
The Suez Canal
salinity metahaline conditions. This successional history is graphically represen ted in Figure 28.
Is the colonization of the Canal from the Gulf of Suez still going on? There are
no data to indicate it. In fact the preadaptation to high salinities and the permanent tidal current reaching the Little Bitter Lake probably gave the chance for all
potential invaders to reach the Canal. On the other hand, oil pollution has badly
damaged the environment off Suez and also in the whole Gulf.
Gruvel (1936) more than forty years ago found that " ... fish as weIl as invertebrates are repelled by the presence of oll from all the area near the Port Taufiq
refineries and consequently from the entrance of the Canal". Gruvel states that
the diversity offishes has decreased in the Bay of Suez. As for the southern section
of the Canal he writes "the number of fish and molluscs has diminished in this
part of the Canal and in the lake from year to year". The decrease in the number
of pearl oysters in the southern Canal is also due to the crude oil and refmery
products, carried into the Canal by the tidal current: "they chase away the animals which can escape and destroy the sedentaries".
In the last decades the oll fields of EI Morgan and Abu Rudeis have been
increasingly operated on the Sinai coast of the Gulf. Most of these fields are
submarine and big spills around the platforms are frequent. I had the occasion in
1974 to witness the heavy oil pollution caused by an accident on one of these
platforms. More oil fields are operated on the African side of the Gulf.
It is, therefore, hard to conceive that new, i.e. more sensitive and stenotopic
species, slower migrators, should have had better opportunities to colonize the
Canal in the last years. Quite on the contrary, it is conceivable that some species
which succeeded in gaining a foot-hold in the Southern Canal but could not reach
the open expanses of the Bitter Lakes, were wiped out by the oil-Iaden tidal
currents flushing past the refmeries and oll terminals at Suez.
2.7 Species Diversity in the Suez Canal
This chapter considers the climax conditions presumably reached by the Suez
Canal biota. Thorson (1971) calculated that the collections ofthe 1924 Cambridge
Expedition containafaunaof318 species in the Canal. Lipkin (1972a) gives a list of
96 species of algae and sea grasses [if one disregards further three dubious findings by Muschler (1908)]. Por and Marcus (1972) give a total of 83 species of
Copepoda Harpacticoida collected till now in the Suez Canal. Schellenberg's
(1928) and Ruffo's (personal communication) lists brings the number of Amphipoda to 46 species. From different sources one may estimate that there are some
150 species ofmolluscs in the Canal. The report by Eitan (1972) brings the known
species ofthe Bryozoa from the Canal, to 35 species. Ben-Eliahu (1972d) enumerates 78 species of Polychaeta Errantia. In Tillier's time (1902) there were 78 species
offish in the Canal; to this even the small coll_ection reported by Steinitz and BenTuvia (1972) adds another seven species.
One can thus assume that the total number of species in the Canal is in the
magnitude of 1000-2000 species. Therefore, there is no reason to compare the