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vol-17PHYSICO-CHEMICAL CHARACTERISTICS OF DIFFERENT WATER TYPES
OF BL-MEX BAY, ALEXANDRIA, EGYPI’.
M.A. SAID, M.S. EL-DEEK, TH.H. MAHMOUD AND M.M.A. SHRIADAH
National Institute of Oceanography and Fisheries,
Alexandria, Egypt.
ABSTRACT
Surface and bottom water samples were collected during
the period from January 1988 to January 1989 to measure
temperature, salinity, pH, dissolved oxygen, oxidizable
organic matter, hydrogen sulphide, nitrogen cClqlOUnds
(ammonia, nitrite &nitrate), phosphate and chlorophyll-a.
lased on the salinity values, the water types were
classified into four different categories, namely;
Mediterranean Sea water (S X : > 38.50>, diluted sea water o (S Xo : 30 – 38.5); mixed water (S Xo : 10 – 30> and mixed
land drainage (S X < 10). o The percentage distribution of th~ different
physlco·chemlcal parameters in the different water types
indicated that water type ilL" exhibited the lowest
percentage of dissolved oxygen and highest of hydrogen
sUlphide, oxidizable organic matter. ammonia and
chlorophyll-a. In contrast, water type "S" exhibited the
highest percentage of dissolved oxygen and lowest of
oxidizable organic matter, hydrogen sulphide, ammonia,
chlorophyll-a. Water types M and 0 represent the
intermediate stage between water type "L" and water type
IISII.
The calculated amount of dissolved oxygen that presents
after complete oxidation of organic matter was on the order
of water type "L" < water type "M" < water type "0".
The mean annual ratio of NIP suggests that phosphorus is
the most limiting factor for the growth of algae in water
types "L" and "M". In water type "0" the ratio are near the
optimal assimilative proportion.
