The device, which contains water pumps, electronic sensors and meteorological instruments, is being used to evaluate the quality of the St. Johns River in Florida by the Florida Marine Research Institute, mainly to detect harmful algal blooms and fish diseases, before they can destroy river life, as has occurred in this river. The platform contains more than 30 different remote sensors allowing specific variables to be measured at short intervals for an extended period.
Until now, it has been difficult to obtain representative samples, as few data points are used to represent long time periods or a large geographic area, missing most of the high-frequency variability in aquatic ecosystems and being limited by time, personnel and logistics. The floating platform, which has been developed by local company AMJ Equipment Corporation, avoids these problems with its continuously recording instrumentation aboard a small pontoon boat deck, which permits safe and convenient maintenance and portability among sites.
A control module operates the sampling intervals of the sensors and stores the data, while a volumetric sampler can collect whole water samples for analysis in the laboratory. Various sensors are connected to a flow-through sample system that can draw water from 3 depths. The sensors measure relative fluorescence, nitrate, phosphate, water temperature, dissolved oxygen, pH, salinity and turbidity. The platform also has a meteorological package, light sensors (ambient and underwater), and a current meter/tide gauge, while data transmission to a home base can be accomplished via a cell phone, and eventually over the internet.
“If this is successful and we can continuously monitor the health of the river, we’ll have our finger on the health of the estuary because we can detect small changes,” commented Brian Bendis of the Florida Marine Research Institute on the $150,000 project.