36
The Historical Background
ofthe lagoon was 80-95%0. In some remote areas it exceeded even 100%0. With the
reopening ofBoghaz 1 in August 1971 the salinity became "normal" again.
Summer temperatures may exceed 30° C but, owing to the shallowness, O 2
content never decreases below 80% saturation (Roth, 1973). Nitrate and silica
contents seem to be higher than in the open sea (in a yearly average), whereas no
difference is found in phosphate values (Roth, 1973).
The flora and fauna of the Sirbonis are qualitatively poor, showing a drastic
impoverishment from the openings inwards. Knowledge is still at a preliminary
stage and only fishes and benthic copepods were studied in detail (Por, 1972; BenTuvia and Herman, 1973). There is, however, a general knowledge of the main
benthicorganisms (Por, 1971 b, 1973a; Ehrlich, 1975a); and ofthe dominant plankton (Kimor and Berdugo, 1969). Some further organisms were identified: the
sabellid polychaete Augeneriella lagunari by Gitay (1970), some of the plants by
Lipkin (unpublished), molluscs by Barash and Danin (1972) and the chironomid
Cricotopus mediterraneus by Margalit (unpublished).
In the plankton, Kimor and Berdugo (1969) recognize several species of Diatomacea among them Synedra hennedyana, S. gailloni, and S. undulata. The species
Campylostylus striatus is found in high-salinity areas of over 70%0; it has also been
reported from salt springs of the Dead Sea area. There are three species of Ceratium-all of them euryhaline neritic species also known from Suez Canal waters.
There are three species of Tintinnoidea: Tzntinnopsis radix, T. beroidea, and Favella campanula. The first two are of Red Sea origin and Kimor and Berdugo
(1969) write concerning the third: " ... it may subsist though not thrive in the
hypersaline lagoon". The planktonic copepods so far identified are the euryhaline
species Euterpina acutifi"ons, Acartia clausi, and A. latisetosa. The two latter species are known from the Suez Canal. Most interesting is the presence of the
cladoceran Bosmina coregoni maritima-unknown in the Eastern Mediterranean
area except the Sirbonis and the Suez Canal (Kimor, 1972). Artemia salina lives
only in some hypersaline pools isolated from the main body of the lagoon (Por,
1972).
The Diatomacea of the benthos are very diversified, and according to Ehrlich
(1975a) they fall into three categories: (1) the stenohaline marine species are concentrated around the openings and do not live beyond salinities of about 40%0;
(2) euryhaline marine species are distributed to a salinity limit of 60%0; and (3) the
holeuryhaline diatoms, of continental origins, are found all over the lagoon and
become dominant to exclusive at salinities above 60%0. In dead assemblages
collected in 1970, the year ofmaximum salinity due to the closure of the openings,
the euryhalines dominated the lagoon (Ehrlich, 1975a). This author lists 147
species and varieties of diatoms; however, only some 15 species represent the
dominant euryhaline assemblage.
This picture is very similar to that found in the benthic Copepoda (Por,
1973 a), although this study was carried out in 1970 when salinity was high and
some of the salinity limits observed represented possibly sub optimal circumstances. From among the 15 species found, seven species advanced only as far as
salinity values of 45%0. A second group consisting of four species survive to values
of 65-70%0. Two species of marine origin are found up to 85%0, namely the
harpacticoids Robertsonia salsa and Heterolaophonte quinquespinosa. At salinities
The Historical Background
ofthe lagoon was 80-95%0. In some remote areas it exceeded even 100%0. With the
reopening ofBoghaz 1 in August 1971 the salinity became "normal" again.
Summer temperatures may exceed 30° C but, owing to the shallowness, O 2
content never decreases below 80% saturation (Roth, 1973). Nitrate and silica
contents seem to be higher than in the open sea (in a yearly average), whereas no
difference is found in phosphate values (Roth, 1973).
The flora and fauna of the Sirbonis are qualitatively poor, showing a drastic
impoverishment from the openings inwards. Knowledge is still at a preliminary
stage and only fishes and benthic copepods were studied in detail (Por, 1972; BenTuvia and Herman, 1973). There is, however, a general knowledge of the main
benthicorganisms (Por, 1971 b, 1973a; Ehrlich, 1975a); and ofthe dominant plankton (Kimor and Berdugo, 1969). Some further organisms were identified: the
sabellid polychaete Augeneriella lagunari by Gitay (1970), some of the plants by
Lipkin (unpublished), molluscs by Barash and Danin (1972) and the chironomid
Cricotopus mediterraneus by Margalit (unpublished).
In the plankton, Kimor and Berdugo (1969) recognize several species of Diatomacea among them Synedra hennedyana, S. gailloni, and S. undulata. The species
Campylostylus striatus is found in high-salinity areas of over 70%0; it has also been
reported from salt springs of the Dead Sea area. There are three species of Ceratium-all of them euryhaline neritic species also known from Suez Canal waters.
There are three species of Tintinnoidea: Tzntinnopsis radix, T. beroidea, and Favella campanula. The first two are of Red Sea origin and Kimor and Berdugo
(1969) write concerning the third: " ... it may subsist though not thrive in the
hypersaline lagoon". The planktonic copepods so far identified are the euryhaline
species Euterpina acutifi"ons, Acartia clausi, and A. latisetosa. The two latter species are known from the Suez Canal. Most interesting is the presence of the
cladoceran Bosmina coregoni maritima-unknown in the Eastern Mediterranean
area except the Sirbonis and the Suez Canal (Kimor, 1972). Artemia salina lives
only in some hypersaline pools isolated from the main body of the lagoon (Por,
1972).
The Diatomacea of the benthos are very diversified, and according to Ehrlich
(1975a) they fall into three categories: (1) the stenohaline marine species are concentrated around the openings and do not live beyond salinities of about 40%0;
(2) euryhaline marine species are distributed to a salinity limit of 60%0; and (3) the
holeuryhaline diatoms, of continental origins, are found all over the lagoon and
become dominant to exclusive at salinities above 60%0. In dead assemblages
collected in 1970, the year ofmaximum salinity due to the closure of the openings,
the euryhalines dominated the lagoon (Ehrlich, 1975a). This author lists 147
species and varieties of diatoms; however, only some 15 species represent the
dominant euryhaline assemblage.
This picture is very similar to that found in the benthic Copepoda (Por,
1973 a), although this study was carried out in 1970 when salinity was high and
some of the salinity limits observed represented possibly sub optimal circumstances. From among the 15 species found, seven species advanced only as far as
salinity values of 45%0. A second group consisting of four species survive to values
of 65-70%0. Two species of marine origin are found up to 85%0, namely the
harpacticoids Robertsonia salsa and Heterolaophonte quinquespinosa. At salinities