Technology M Solutions Marine monitoring in near real time
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“What we’d really like to do is get to the point where we could use satellites to predict where there will be a harmful algal bloom,” deploying the buoy in the middle of the bloom to really get a handle on all of the parameters associated with such events, Steinmaus says. “It would save so much time and money in terms of shellfish operations along the coasts and public access to beaches.”
PACIFIC NORTHWEST NATIONAL LABORATORY
A new aquatic monitoring buoy, working in tandem with satellites, could someday be used to help predict the occurrence of harmful algal blooms, say researchers at Pacific Northwest National Laboratory (PNNL) who developed the device. The aquatic bio-optical and environmental assessment monitoring buoy, which can be moored or tethered in coastal waters, is equipped with cell phone technology, a Global Positioning System unit for tracking, and a multisensor platform. The different sensors, located above and below the water, measure wind speed and direction, current, incoming light, turbidity, sea surface temperature, chlorophyll, dissolved oxygen, salinity, and conductivity. The water sampling instruments can be programmed to hold and store water at different intervals, so it can be chemically analyzed later. The data collected by the buoy can be used to validate information about toxic phytoplankton blooms that is currently collected by satellite, says Karen Steinmaus, a PNNL remote sensing program manager. These toxic phytoplankton blooms, which deplete the oxygen in shallower, coastal waters, are emerging more frequently worldwide, according to the U.S. EPA. Possible causes range from species dispersal to nutrient enrichment, climate change, and the transport of algal species in ship ballast water. “Satellites are out there collecting a lot of information, but there’s atmosphere between the sea and the satellites, so what you get from the satellite is not a perfect measurement,” Steinmaus says. So, when a satellite passes over and measures color pertaining to chlorophyll concentrations, for example, the buoy can collect “data at the same time, and that data is compared,” adds Parks Gribble, a PNNL engineer.
quality data, but an advantage to this buoy is its portability and unmanned platform, which is more cost-effective than labor-intensive shipboard platforms, Steinmaus says. “If you were to go and collect the same suite of measurements [using conventional methods], you’d have to send a ship out with people manning the ship and the different instruments.” Other potential applications include emergency response in extreme events such as floods and dam removals to monitor changes over time, Steinmaus says. Additionally, the
A new ,portable,lightw eightbuoyprovidesquick-response data on w aterqualityconditionsin coastal,estuarine,and inland w aters.
The buoy “collects and samples data at periodic intervals,” Gribble says. “That information is stored in a memory, and we can interrogate that through cell phone connections and download the data.” Researchers can also change the parameters being measured, as well as sampling rates, remotely. Deeper water buoys are already quite common for collecting water
ENVIRONMENTAL SCIENCE & TECHNOLOGY / AUGUST 1, 2001
buoy could be used to characterize estuaries and river areas, which are hard to map because of their dynamic environments. With the first testing phase complete, the researchers are now looking at ways to exploit advances in battery technology to miniaturize the vessel, Steinmaus says. In its current configuration, the buoy weighs close to 1200 lbs. KRIS CHRISTEN © 2001 American Chemical Society
