Major constituents’ distribution as an indicator of Water Exchange between Lake Burullus and the Mediterranean Sea

Ramzy B. Nessim, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt
Hermine R. Z. Tadros, National Institute of Oceanography and Fisheries, NIOF, Cairo, EgyptFollow
Madelyn N. Moawad, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt
Abeer A.M. El-Sayed, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt
Esam El-din M. Deghady, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt
Amaal E.A. Abou Taleb, National Institute of Oceanography and Fisheries, NIOF, Cairo, Egypt

Article Type

Research Article

Subject Area

Marine Chemistry

Corresponding Author

Hermine R. Z. Tadros

Corresponding Author ORCID

https://orcid.org/0000-0002-2230-764X

Abstract

Aim/Objectives: The main objective of the present study is to assess the status of Lake Burullus water quality via salinity, major ions, and chlorinity rate besides side total and specific alkalinity and evaluate the levels and the distribution pattern of different major ions and their chlorinity ratios. Produced data can help decision-makers benefit from the three different water masses with different salinities in farming different types of fish in this important Lake to meet the population's growing need for fish protein.

Background: Lake Burullus is a shallow brackish basin. It is the second largest natural Lake of the five coastal Lakes along the Mediterranean coast in Egypt. It is connected to the sea through a Canal 250 m long (El-Boughaz), which is shallow and saline, and connected to the western branch of the Nile by a small Canal (Brimbal Canal). The Lake is bordered by agricultural land from the south. The average volume of Lake Water (at zero mean sea level) is estimated at 328 million m³, and the annual volume of about 3.9 billion m³ is discharged into the Lake through the agricultural drainage system. The water level in the lake is mostly higher than that of the sea. Saline water enters the Lake from the sea through El-Boughaz during most minor irrigation requirements in the winter. The agricultural drainage waters that discharge into the Lake contain fewer salinity loads than seawater, and massive amounts of fertilizers lead to creating hypertrophic levels. After the political leadership program “Rehabilitation of Egyptian Lakes,” the purification operations and development of the Egyptian lakes started in February 2010. This led to the development and increase of water exchange between the Burullus Lake and the Mediterranean Sea through the El-Boughaz. So, many investigators began to study the effect of these changes on Burullus Lake, considering the water characteristics, climate change, and their effect on fish quality and production.

Methods: Sixty-two subsurface water samples were collected in 1L polyethylene bottles from 31 locations during two cruises (winter and autumn 2020) covering the different sectors of the Lake and its Drains. Salinity was measured using an inductive Salinometer Beckman model (RS-10). Chlorinity was calculated from salinity. Sodium and lithium were determined using a flame photometer (PFP JENWAY 7), and Ca⁺²and Mg⁺² were analyzed titrimetrically against an EDTA solution. Sulphate was measured turbidimetrically. Total alkalinity was measured titrimetrically. Statistical analysis: the correlation coefficient at a confidence limit of 95% (P≤ 0.05) was estimated for all data (N=62) using the Microsoft Office Excel program.

Results and conclusion: Based on salinity and specific alkalinity levels, three different water masses have been identified in Lake Burullus. The eastern sector represents a Lake-Sea connection with relatively high salinity and low specific alkalinity, the middle zone with intermediate levels, and the western part, far from the sea connection, with low salinity and high specific alkalinity. Concerning the analyzed major ions for the two studied seasons where n=62, the average concentration of the studied ions (mg/L) and their corresponding chlorinity ratios are as follows: Na⁺ (788) 0.2740, Mg⁺² (179) 0.0905, Ca⁺² (74) 0.0587, SO₄^-2 (677) 0.3461, alkalinity (336) 0.332, Li⁺ (0.135) 0.1401×10^-3. Salinity average concentrations were 3.783 and 2.096 for CI‰. The major cations or anions concentration in either the eastern or middle zones of the Lake follow the same order: Na⁺˃Mg⁺²˃Ca⁺²˃Cl^-˃SO₄^-2. For the western part, the order of concentration is Na⁺˃Ca⁺²˃Mg⁺²˃Cl^-˃HCO₃^-˃SO₄^-2. Fortunately, the water quality of Burullus Lake tends to be better for fish production as a positive impact was observed after the cleansing and development operations in the lake on all economic variables under study.

Full Text of Submission

wf_yes

Recommended Citation

Nessim, Ramzy B.; Tadros, Hermine R. Z.; Moawad, Madelyn N.; El-Sayed, Abeer A.M.; Deghady, Esam El-din M.; and Taleb, Amaal E.A. Abou (2024) "Major constituents’ distribution as an indicator of Water Exchange between Lake Burullus and the Mediterranean Sea," Blue Economy: Vol. 2 : Iss. 1 , Article 3.
Available at: https://doi.org/10.57241/2805-2994.1017