Why Measure TSM?
Total Suspended Material (TSM; aka total suspended solids, suspended particulate
matter) can include a wide variety of material such as silt, decaying plant and animal
matter, and industrial waste. TSM is often used to examine water column turbidity and
water quality. As the amount of suspended material increases, the appearance of the
water becomes cloudier as more light is scattered by particles within the water column.
Changes in TSM concentration can have long ranging effects on the biogeochemistry of an area. As TSM levels increase, light penetration decreases adversely affecting photosynthesis by primary producers. Suspended solids can clog fish gills, either killing them or reducing their growth rate.
TSM as a Biogeochemical Proxy
TSM measurements are labor intensive and require discrete sample collection. The relationship between TSM concentration and light attenuation or scattering can be exploited and optical parameters might be used as a proxy for TSM.
Protocols for Measuring TSM