Assessment of Biodiversity, Physicochemical water parameters, Length-weight Relationship and Condition factor of fish species in Tiga Lake, Kano State, Nigeria

Abstract

Timely assessment of fisheries resources provides updated information crucial for the formulation of management strategies that ensures its sustainability. The study investigated
the physicochemical water parameters, biodiversity, length-weight relationships (LWRs), and condition factors of fish species in Tiga Lake, Kano State, Nigeria, with a focus on seasonal variations. Physicochemical parameters such as temperature, dissolved oxygen (DO), pH, total dissolved solids (TDS), and electrical conductivity (EC) of surface water were evaluated during both dry and wet seasons. Fish and water sampling were conducted at Tiga and Rurum sections of the lake utilizing catches from local fishers. Total length and body weight were measured in centimeters and grams respectively to assess Length-Weight Relationships (LWRs) and condition factor of fish species. The assessment of the physicochemical water parameters indicated consistent seasonal trends in DO, pH, EC, and TDS values. Biodiversity indices, estimated using Margalef, Shannon, and Simpson indices, indicated higher values in wet season, suggesting increased abundance and distribution during this period. The fisheries were dominated by Cichlids, comprising 49.1% of the total fish composition. Temporal patterns in fish biodiversity, analyzed through Non-metric Multidimensional Scaling (NMDS) and Analysis of Similarities (ANOSIM), indicated no significant difference ((R=-0.0129, p=0.05) between dry and wet seasons. LWRs analysis revealed significant differences (p≤0.05) among species, indicating variability in size-weight associations. The estimated condition factor indicated temporal  variations, with certain species demonstrating higher values during the dry-season. The water quality parameters of Tiga Lake support fish survival, and contributing to the high abundance and diversity.