Water Quality & Sediment Monitoring
VE has extensive experience in the design and implementation of sediment monitoring programs often running concurrently with macrobenthic infauna assessments. VE vessels have been adapted to accommodate a davit and several different sizes of Ponar grabs for safe work practices in sediment grab sampling. Sediments can be NATA tested for a range of project specific analytes. VE is proficient in the use of a range of univariate and multivariate statistical applications, which increase the power of the hypotheses being tested and allow direct comparisons with sediment characteristics and macrobenthic community assemblages.
Although traditional instruments such as sediment traps measure the downward flux of sediment particles over any given time, it is more important to measure the net flux or bed level change (i.e. whether there is overall deposition or erosion of sediments over a given time). Continuous Autonomous Bed Elevation Monitors (Altimeters) have the ability to measure the fine levels of the sea bed by measuring altitude data from a known position over specified time intervals using an acoustic eco-sounder, similar to a side scan sonar. There are two forms of information provided by the altimeters: instantaneous bed level change indicating the amount of sediment flux occurring at a set point in time, and net cumulative change in bed level over a given period. Modelling of wind direction with sediment deposition data from altimeters in sediment transport models could provide invaluable information for predictive plume modelling.