مختصر البحث:
The study aimed to assess the impact of water quality standards on
bird density in the Bahr al-Najaf depression over a period of seven months,
from October 2023 to April 2024. We selected three sites for the study. We
measured various physical an…
The study aimed to assess the impact of water quality standards on
bird density in the Bahr al-Najaf depression over a period of seven months,
from October 2023 to April 2024. We selected three sites for the study. We
measured various physical and chemical aspects of the water, including its
temperature, air temperature, electrical conductivity, total dissolved solids,
salinity, pH, dissolved oxygen, biological oxygen demand, total hardness,
calcium, magnesium hardness, and chloride. We determined the density of
birds and the number of species in the study area. The air temperature ranged
between (20.6 - 31) °C, the water temperature ranged (20 - 28) °C, the
electrical conductivity ranged between (19.8 - 168.25) ms/cm, and the total
dissolved solids ranged from (11,200 - 83,750) mg. /l, salinity between (13.85
- 117.777) ppt, pH between (7.9 - 8.2), dissolved oxygen between (0.73 - 5.6)
mg/l, and biological oxygen demand between (0). 73 - 3 5 .5) mg/L, total
hardness between (2200 - 21066.66) mg/L, and calcium hardness between
(961.9 - 4382.08) mg/L, magnesium between (216.4 - 4625.7) mg/L, chloride
between (1799 - 17061) mg/L The study identified 29 families and 82 species.
Bird species diversity was greatest in the family Scolopacidae. The family
Scolopacidae had the highest diversity with 14 species, followed by Laridae
with 10 species, Charadriidae, Columbidae, and Ardeidae with five species
each, Motacillidae and Anatidae with four species, and Corvidae and
Passeridae with three species each. The three locations had different species
diversity and abundance. With the exception of one month, the density of
birds at the third site exhibited a higher species abundance and diversity
compared to the other sites. Bird density showed a significant positive
correlation with TDS, salinity, and electrical conductivity, while Mg ions
showed a significant negative correlation. We observed a significant positive
correlation between the number of species and pH, and a significant negative
correlation between the number of species and chloride.
