Fall 2010 Nikki Byrd What is turbidity? Measure of water clarity Degree to which water is scattered and absorbed Causes Heavy rainfall, storms Algal blooms Flocculation in estuaries Waste discharge Run-off Land changes Native vegetation and agriculture POM/CDOM What is turbidity? Why does turbidity matter? High turbidity effects Drinking water Correlation with high levels of pathogens Reduced light penetration Increased K d Photosynthesis Dissolved oxygen Water temperature Dissolved oxygen Measuring turbidity Secchi disk Accuracy Nephelometers Common Measures scattering 90 from an incident beam of light Scattering is proportional to turbidity Relative units: NTU More scattering = higher turbidity Measuring Turbidity Measuring turbidity Measuring Turbidity Cruise 1 Turbidity Cruise 2 Turbidity Cruise 1 v LCFRP Cruise 2 v LCFRP Cruise 1 v. Class Averages Cruise 2 v. Class Averages Turbidity v. Surface Salinity- Cruise 1 H B M18 Turbidity v. Deep Salinity-Cruise 1 Turbidity v. Surface Salinity- Cruise 2 Turbidity v. Deep Salinity-Cruise 2 Turbidity v. K d -Cruise 1 Turbidity v. K d -Cruise 2 Conclusions Cruise 1 Higher than LCFRP No correlation with class average Cruise 2 Higher than LCFRP Close to class average Turbidity maximum around M 35, M42 for 1 st cruise, M54 for 2 nd cruise Decrease with salinity Dilution Direct relationship with K d for both cruises, surface and deep