In-Situ Sondes collect the horizontal movement in specified directions (North,
South, East, West) and vertical In-Situ Sondes collect the upwelling and settling of water column particulate motion.
These specially designed Sondes produce movement of fluid mud and dense particle
movements in a maximum of 6 directions. The resulting data are reported in terms of the mass movement or motion (mass/unit
area/time - kg/meter2/day) of the dense nephelometry layer at or near the water bottom in aquatic habitats.
Horizontal motion measurements in Indian River Lagoon areas suggest the equivalent
of a 10 lb bag of flour of fluid mud horizontally moving per meter2 in a day - or well over a ton of fluid
mud moving per year per meter2.
Obviously, this fluid mud blocks light
from reaching the bottom of the water column where aquatic vegetation and other organisms use the light for growth and to
support living functions such as "seeing their food".