1. Impact of Meteorological Events and Sand Excavation on Turbidity and Total Suspended Solids Levels of Imo River by Dr. Chinedu E. Ihejirika Department of Environmental Technology, Federal University of Technology, Owerri, Nigeria at ICCEB 2015: XIII International Conference on Climate, Environment and Biosciences in Miami, USA March, 9-10, 2015

2. INTRODUCTION Challenges faced by fresh water bodies in developing countries include the following: (a) Anthropogenic impacts: + Industrial effluent and domestic sewage discharges + Dumping of solid wastes + Sand mining/ excavation + Dredging, etc. (b) Natural impacts: + Climate change (rainy and dry seasonal effects) + Flooding + Wind-induced currents

3. Fig. 1. Percentage Monthly Rainfall in Nigeria

4. Fig. 2. Sand Excavation in a Nigerian River

5. Fig. 3. Flooding in a Nigerian City

6. Fig. 4. Dumping of Solid Waste on Drainage Paths

7. Fig. 1. Map of Study Area

8. MATERIALS AND METHODS + Sample Collection: Water samples were collected at 7 major points of sand excavation activities at the peaks of the seasons; the dry season,-between November and March, while the rainy season was between May and September, for two consecutive years. + Chemical analysis: Turbidity (NTU) and Total Suspended Solids (TSS) (mg/L) levels of the water samples were determined as described in the Standard Methods for the Examination of Water and Wastewater (1998).

9. SEASONAL VARIATION IN TURBIDITY AND TSS
RESULTS AND DISCUSSION
TABLE I
SEASONAL VARIATION IN TURBIDITY AND TSS
Locations Season Turbidity TSS
Ekenobizi Dry ±1.00A ±1.00A
Rainy ±1.00A ±1.00A
Udo Dry ±1.00A ±1.00A
Rainy ±1.00A ±1.00A
Owerrinta Dry ±1.00A ±1.00A
Rainy ±1.00A ±1.00A
Alulu Dry ±1.00A ±1.00A
Rainy ±1.00A ±1.00A
Owaza Dry ±1.00A ±1.00A
Rainy ±0.58A ±1.00A
Obigbo Dry ±1.00A ±0.00A
Rainy ±1.00A ±1.00A
Akwette Dry ±1.00A ±1.00A
Rainy ±1.00A ±1.00A
At P =0.05, values with A - letter are significantly different while values with B – letter are not significantly different from each other

10. Fig. 2: Relationship Between Turbidity and TSS

11. There were notable variations in values of turbidity and TSS between seasons.
Values were higher during the rainy season than the dry season.
Sand excavation might have influenced increased values of parameters at the sampling points.

12. Consequences of Increasing Turbidity and TDS Levels on River Quality (a) Wind-induced currents re-suspend sediments in shallow waters (b) Reduced penetration of light, temperature changes, and sedimentation (c) Physical alteration: undesirable aesthetic effects higher costs of water treatment reduced navigability of channels decreased longevity of dams and reservoirs

13. Consequences of Increasing Turbidity and TDS Levels on River Quality (Contd.)
(d) Chemical alterations:
- release of contaminants, such as heavy metals and pesticides, and nutrients such as phosphorus, into the water body from adsorption sites on the sediment
- add high organic content, depleting levels of dissolved oxygen in the water, producing a critical oxygen shortage which can lead to fish death during low-flow conditions.

14. Consequences of Increasing Turbidity and TDS Levels on River Quality (Contd.) (e) Biological effects: - fine sediment deposited on the streambed can fill gravel spaces, eliminating spawning habitat for some fish species and many invertebrate species - reduce light penetration, decreasing algal growth, and low algal productivity, reducing the productivity of aquatic invertebrates, a food source of many fishes

15. Consequences of Increasing Turbidity and TDS Levels on River Quality (Contd.) - Gill function in some fish may also be impaired after 5 to 10 days of exposure to a turbidity level of 25 NTU - Large bed loads can also reduce or eliminate pool habitat essential to low-flow and dry season survival of fish - Increased turbidity, TSS and acidity and the depletion of oxygen tension of the water might cause 91% and 72% reduction in zooplankton population and taxa respectively following dredging

16. CONCLUSION
This study confirmed the impact of meteorological events like seasonal (rainy and dry seasons) variations and sand excavation on the turbidity and TSS values of Imo River and that the subsequent increase in TSS and turbidity levels may lead to adverse consequences on the river quality and aquatic biota in the habitat.

17. THANK YOU