Water Quality and Associated Aquatic Fungi in Selected Wetland Ecosystems in Southern Nigeria: Potential Implications for Food Safety and Public Health
Objective: Seasons, physical, and chemical properties of water bodies influence the diversity and distri bution of aquatic mycoflora in wetlands. The study was conducted in March during the dry season of 2022. This study aimed to evaluate the effect of water quality on aquatic fungi in selected wetland ecosystems in southern Nigeria.
Materials and Methods: Physical parameters (temperature, turbidity, pH, and Electrical conductivity (EC)), chemical properties (salinity, hardness, dissolved oxygen (DO), total suspended solid (TSS), chemical oxygen demand (COD), and biochemical oxygen demand (BOD))., heavy metals, and trace elements (Ca, Na, K, Mg, V, Pb, Zn, Cd, Cr, and Ni) constituents were measured. The fungal loads on water and sediment specimens from the wetlands were also assessed using standard analytical and scientific procedures.
Results: The results showed that the temperature, pH, turbidity and EC of the test specimens ranged 27.27±0.35-29.21±0.003 °C, 5.17±0.03-7.30±0.17, 0.59±0.002-2.51±0.08 NTU, and 4.88±0.05-209.40±0.23 µs/cm, respectively. Salinity (7.10±0.06-710±5.77 gCl-/L), hardness (4.80±0.11-18.59±0.35 mg/L), TDS (2.44±0.01-104.70±0.03 mg/L) were below the WHO recommended limits. However, certain heavy metals including Cu (0.021±0.02-0.22±0.01 mg/L), Fe (0.22±0.001-0.33±0.02 mg/L), Pb (0.28±0.01-0.09±0.001 mg/L), Cd (0.05±0.001-0.36±0.16 mg/L), Cr (0.01±0.001-0.03±0.02 mg/L) and Mn (0.21±0.001 mg/L) exceeded WHO recommendations. The remaining elements were within acceptable limits. Most chemical qualities were highest at Ibeno and lowest at Nsit Ibom. Candida tropicalis, Penicillium citrinum, P. rolfsii, Trametes polyzona, and Aspergillus species were isolated from the wetlands.
Conclusion: The concentrations of heavy metals (Cu, Fe, Pb, Cd, Cr and Mn) above regulatory limits, along with the array of potentially pathogenic aquatic fungi, constitute concerns regarding the safety of sea foods from these wetlands. Thus, a regular assessment of the health of wetlands in the State is warranted.