Suspended in the waters of rivers, estuaries, coastal seas and the open oceans are tiny particles of sediment (mud, silt and sands), small animals (zooplankton) and tiny plants (phytoplankton) as well as a range of dead and decaying detritus. Characterizing what these particles are and quantifying variations in abundance, size, shape and composition aids understanding of such processes as aggregation/dis-aggregation, particle transport and sedimentation, pollutant and carbon sequestration, opto-acoustic scattering and absorption, primary production and zooplankton feeding and reproduction.
Suspended particles range in length from a few microns to many millimeters. Electrical molecular forces and sticky biological glues bind small particles together into bigger, loosely bound aggregates which are relatively fragile and can be broken apart by strong turbulence or invasive sampling. Simple measurements such as size, shape, composition and settling speed are not easily obtained from suspended particles since these characteristics are constantly changing as particles aggregate and dis-aggregate.
Plymouth University has a strong history of instrument development for particle imaging and research work centered around particle characterization across a range of environments.