Floating robots “go with the flow” to monitor water quality

A UC Berkeley research team has built a fleet of floating robots that will be deployed in a freshwater, tidal wetland of the San Francisco Estuary, as part of a new Delta Science Fellowship project.

The data collected by the high-tech swarm of smart drifters will help build a picture of how packets of water move through the Liberty Island wetland and the degree to which these flows export algae, important food for fishes and other animals, to the estuary’s open waters.

“We would like to know more about algae and the processes that transport algae,” said Qingfang Wu, an environmental engineer and post-doctoral researcher at UC Berkeley, who was recently awarded a 2013 Delta Science Fellowship. “The drifters help us because they can go anywhere we need them to go.”

The drifters, officially called the Floating Sensor Network, are each equipped with sensors that measure time, position (GPS), water turbidity (cloudiness), chlorophyll, salinity, and water temperature. Measurements are taken about every 5 seconds. Inside each waterproof canister is ballast, a battery and the brains of a smart phone, hence the nickname “smart drifters.” The researchers plan to launch the drifters one or two times each season for three days to a week, depending on the weather conditions.

“Qingfang’s research will help elucidate how tidal shallow water habitats support pelagic foodwebs in the delta with a particular emphasis on developing quantitative models of these effects,” explained Brian Bergamaschi, a research chemist with the USGS California Water Science Center in Sacramento and one of Wu’s mentors on the project.

Understanding how tidal flows affect mixing and dispersion of water properties and phytoplankton is also a major focus of the project.

“This is important because future plans call for large scale tidal wetland restoration,” he said. “Understanding and being able to model the effects of tidal restorations will allow these restorations to be most beneficially implemented,” particularly within the context of future river discharges and sea level rise.

Contact: Qingfang Wu, University of California, Berkeley, qingfangwu@berkeley.edu, 510.387.0078

Written by Christina S. Johnson