Physico-chemical characteristics and abundance of aquatic macroinvertebrates in River Galma, Zaria, Kaduna State, Nigeria

Abstract

River Galma serves a multitude of purposes for the Zaria populace. It is a source of drinking water, also for irrigation and fishing. A section of the River was surveyed for the physicochemical characteristics of the water and macroinvertebrate abundance for 12 months from May 2013 to April 2014, using standard methods. Among the four sampling stations surveyed, Surface water temperature, dissolved oxygen, biochemical oxygen demand, alkalinity, conductivity and pH did not show any significant difference within the stations (P>0.05), whereas phosphate, nitrate and depth varied significantly among the stations (P<0.05). Macroinvertebrates abundance shows that, out of the total number of species identified, 14 were arthropods, distributed among 3 classes; 10 species were of class Insecta, 2 species from class Arachnida and 2 species from the class Crustacean. Phylum Mollusca and phylum Annelida had 2 and 1 species, respectively. Among all the species collected, Argyroneta aquatica from class Arachnida of the phylum Arthropoda recorded the highest number of 303 individuals, while Hirudo medicinalis belonging to the phylum Annelida recorded the least number of 13 individuals. The distribution of macroinvertebrates among the sampling stations indicated no significant difference.

Keywords: Water quality, benthic fauna, health condition, River Galma, Zaria