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Zooplankton community and water quality in the Eastern Harbor of Alexandria, Egypt Remarkably, temperature has an influence on the pH, alkalinity and DO concentratio1 in water (Alprol et al., 2021). Water temperature was at its minimum (16.42°C) in Januar and its maximum (31.4°C) in July as presented in Fig. (2). Zaghloul et al. (2020) reporte that, the temperature of the water in the Eastern Harbor increased over time, recording 7.2°C during the years of 2004/2005 as reported in the study of Abdel Halim and Khairy (2007 While, it reached a degree of 14.4°C during 2009 (Khairy et al., 2014) and 15.6°C during th period of 2011/2012 (Tadros et al., 2016). Changes in air temperature (climatic changes) an the shallowness of the Eastern Harbor water account for all these changes. Tha axvraranan TV) wane wusad hatruanan 2 & mal Anwne Ianaan AO? mall Anwine ANaxvnh

Figure 2 Zooplankton community and water quality in the Eastern Harbor of Alexandria, Egypt Remarkably, temperature has an influence on the pH, alkalinity and DO concentratio1 in water (Alprol et al., 2021). Water temperature was at its minimum (16.42°C) in Januar and its maximum (31.4°C) in July as presented in Fig. (2). Zaghloul et al. (2020) reporte that, the temperature of the water in the Eastern Harbor increased over time, recording 7.2°C during the years of 2004/2005 as reported in the study of Abdel Halim and Khairy (2007 While, it reached a degree of 14.4°C during 2009 (Khairy et al., 2014) and 15.6°C during th period of 2011/2012 (Tadros et al., 2016). Changes in air temperature (climatic changes) an the shallowness of the Eastern Harbor water account for all these changes. Tha axvraranan TV) wane wusad hatruanan 2 & mal Anwne Ianaan AO? mall Anwine ANaxvnh

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Fig. 1. Location map of the Eastern Harbor of Alexandria and sampling site 2.2. Samples collection and processing
Fig. 1. Location map of the Eastern Harbor of Alexandria and sampling site 2.2. Samples collection and processing
Fig. 3. Monthly variations of dissolved oxygen parameter in water during the study
Fig. 3. Monthly variations of dissolved oxygen parameter in water during the study
Fig. 4. Histogram showing monthly variation of salinity (%o) of seawater in the Eastern Harbor. Alexandria Zooplankton community and water quality in the Eastern Harbor of Alexandria, Egypt
Fig. 4. Histogram showing monthly variation of salinity (%o) of seawater in the Eastern Harbor. Alexandria Zooplankton community and water quality in the Eastern Harbor of Alexandria, Egypt
Ammonia (NHg) attained an annual average of 2.30 uM, varying from a minimum of 0.95 uM during September to a maximum of 5 uM during July. Most weeks of May, September and December sustained the lowest values, while other months showed markedly high concentrations (Fig. 5). Ammonium is a major nitrogenous product of bacterial decomposition of nitrogen-containing organic materials, and it is a significant excretory product of invertebrates and vertebrates. Its easiness of absorption and integration into amino acids made NH,"/N the preferred inorganic supply of nitrogen - containing materials (N- assimilation) (Heneash & Alprol, 2020). Khairy et al. (2014) recorded 0.03-23.49 uM with total average of 3.57uM. In addition, Abdelsalam et al. (2015) reported that the average of NH," during summer 2012 was 4.31 uM.
Ammonia (NHg) attained an annual average of 2.30 uM, varying from a minimum of 0.95 uM during September to a maximum of 5 uM during July. Most weeks of May, September and December sustained the lowest values, while other months showed markedly high concentrations (Fig. 5). Ammonium is a major nitrogenous product of bacterial decomposition of nitrogen-containing organic materials, and it is a significant excretory product of invertebrates and vertebrates. Its easiness of absorption and integration into amino acids made NH,"/N the preferred inorganic supply of nitrogen - containing materials (N- assimilation) (Heneash & Alprol, 2020). Khairy et al. (2014) recorded 0.03-23.49 uM with total average of 3.57uM. In addition, Abdelsalam et al. (2015) reported that the average of NH," during summer 2012 was 4.31 uM.
Fig. 6. Histogram showing variations of nitrate parameter in water during the study period Nitrite (NO) concentration fluctuated between 0.35 uM (26 June) and 24 uM (4 December), with annual average 2.02 uM. The highest average concentrations were noticed during December 2012 (Fig. 7). This is mostly owing to the high rate of denitrification processes, which resulted in a high level of NH," concentration during the study period. Nitrate (NO3 ) had a varied weekly distributional pattern, fluctuating between 0.3 uM (29 April) and 32.1 uM (25 September), but it fluctuated dramatically over the year as shown in tig. (6). In oxygenated seawater, the nitrate form is the most stable and abundant inorganic 1itrogen compound. The average of 9.32 uM reported in the study of Nessim et al. (2014) ndicates that the wastewater discharges in the Eastern Harbor seawater are greater than those ecorded in the current study.
Fig. 6. Histogram showing variations of nitrate parameter in water during the study period Nitrite (NO) concentration fluctuated between 0.35 uM (26 June) and 24 uM (4 December), with annual average 2.02 uM. The highest average concentrations were noticed during December 2012 (Fig. 7). This is mostly owing to the high rate of denitrification processes, which resulted in a high level of NH," concentration during the study period. Nitrate (NO3 ) had a varied weekly distributional pattern, fluctuating between 0.3 uM (29 April) and 32.1 uM (25 September), but it fluctuated dramatically over the year as shown in tig. (6). In oxygenated seawater, the nitrate form is the most stable and abundant inorganic 1itrogen compound. The average of 9.32 uM reported in the study of Nessim et al. (2014) ndicates that the wastewater discharges in the Eastern Harbor seawater are greater than those ecorded in the current study.
Fig. 7. Variations of nitrite parameter in water during the study period
Fig. 7. Variations of nitrite parameter in water during the study period
Fig. 8. Variations of phosphorus parameter in water during the study period
Fig. 8. Variations of phosphorus parameter in water during the study period
Fig. 9. Histogram exhibiting variations of silicate in water during the study period content distribution preservation (Verschuren et al., 1998). One of the major constituents of seawater is silicate. It is a good indicator of diatom potential and freshwater dispersal. The concentration of silicate ranged from 7.01 to 56.3 uM, with an annual average of 26.03 uM (Fig. 9). Moreover, the highest value for silicate was recorded in March, while the lowest value was reported on the 25" of October. Silicate in the Eastern Harbor indicates that the source of silicate is not all achthonous from drains, but rather autochthonous from the synthesis of biogenic silicate from diatoms, resulting in silicate content distribution preservation (Verschuren et al., 1998).
Fig. 9. Histogram exhibiting variations of silicate in water during the study period content distribution preservation (Verschuren et al., 1998). One of the major constituents of seawater is silicate. It is a good indicator of diatom potential and freshwater dispersal. The concentration of silicate ranged from 7.01 to 56.3 uM, with an annual average of 26.03 uM (Fig. 9). Moreover, the highest value for silicate was recorded in March, while the lowest value was reported on the 25" of October. Silicate in the Eastern Harbor indicates that the source of silicate is not all achthonous from drains, but rather autochthonous from the synthesis of biogenic silicate from diatoms, resulting in silicate content distribution preservation (Verschuren et al., 1998).
In total, 65 zooplankton species were identified, including the larval stages of ifferent groups. Most of them were protozoans (32 species: 3 species of non- tintinnid iliates, 18 species of tintinnids and 11 species of Foraminifera). Copepods formed 17 species, otifers 6 species and Annelida 2 species. This result coincides with those of Aboul Ezz 1990) and El-Gindy et al. (2007). In addition, both the studies of Dowidar et al. (1983) and Aansour et al. (2020) showed that the dominant groups were those of copepod and rotifer (6 pecies and metamorphosis of rotifer). In terms of the number of species, Tintinnids were ominated by Tintinnopsis (8 species) and Favella (3 species), while Copepoda was ominated by Acartia (3 species). Other zooplankton groups like Rotifera, Cladocera, Yecapoda, Mollusca, Annelida and Cnidaria were represented by a few species. Moreover, ooplankton larvae were represented by the following Ostracoda, Cirripedia and Nematoda. ‘he zooplankton density demonstrated marked weekly fluctuations from 3825 to 306000 1d./m? (Fig. 10). It attained an annual average of 49405 ind./m*. In addition, two xceptionally high counts were recorded on the 12" of October (207650 ind./m*) and the 25" f October (306000 ind./m?).
In total, 65 zooplankton species were identified, including the larval stages of ifferent groups. Most of them were protozoans (32 species: 3 species of non- tintinnid iliates, 18 species of tintinnids and 11 species of Foraminifera). Copepods formed 17 species, otifers 6 species and Annelida 2 species. This result coincides with those of Aboul Ezz 1990) and El-Gindy et al. (2007). In addition, both the studies of Dowidar et al. (1983) and Aansour et al. (2020) showed that the dominant groups were those of copepod and rotifer (6 pecies and metamorphosis of rotifer). In terms of the number of species, Tintinnids were ominated by Tintinnopsis (8 species) and Favella (3 species), while Copepoda was ominated by Acartia (3 species). Other zooplankton groups like Rotifera, Cladocera, Yecapoda, Mollusca, Annelida and Cnidaria were represented by a few species. Moreover, ooplankton larvae were represented by the following Ostracoda, Cirripedia and Nematoda. ‘he zooplankton density demonstrated marked weekly fluctuations from 3825 to 306000 1d./m? (Fig. 10). It attained an annual average of 49405 ind./m*. In addition, two xceptionally high counts were recorded on the 12" of October (207650 ind./m*) and the 25" f October (306000 ind./m?).
Table 1. Number of species and larvae or occurrences recorded in Eastern Harbor from 1967 to 2018 Table 1. Number of species and larvae or occurrences recorded in Eastern Harbor from 1967
Table 1. Number of species and larvae or occurrences recorded in Eastern Harbor from 1967 to 2018 Table 1. Number of species and larvae or occurrences recorded in Eastern Harbor from 1967
3.7. Similarity between weeks Zooplankton community and water quality in the Eastern Harbor of Alexandria, Egypt
3.7. Similarity between weeks Zooplankton community and water quality in the Eastern Harbor of Alexandria, Egypt
physicochemical parameters in the Eastern Harbor during the latest decades.
physicochemical parameters in the Eastern Harbor during the latest decades.
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