Kent, OH A research project funded by Ohio Sea Grant and carried out by Dr. Joseph Ortiz of Kent State University will develop a new method to monitor Lake Erie algal blooms using satellite imagery. Once validated, the technology could be used to monitor water quality and algal blooms in the entire Great Lakes system.
Ortiz, Professor in the Department of Geology, is focusing on the level of chlorophyll, a green plant pigment also present in certain types of algae, and how surface readings of chlorophyll relate to algal growth within the entire water column. Because satellite readings only detect characteristics of the surface water, computer programs that convert those readings into chlorophyll levels throughout the lake have to be developed.
"Part of what we’re doing with this project is trying to figure out how representative the surface samples are of what’s happening at depth," says Ortiz. "We use information from water samples to better calibrate the remote sensing tools so we can get much more accurate and much better coverage of what is happening in the lake." Those water samples were collected in the summer and fall from vessels operated by OSU’s Stone Laboratory on Gibraltar Island in western Lake Erie.
In addition to generally favorable conditions for algal blooms in this area, recent monitoring data has shown that nutrient levels in the lake have been rising, probably due to a number of influences such as agricultural practices and an increase in the lakeshore population. As an increase in nutrients, especially phosphorus, can be linked to an increase in harmful algal blooms, being able to monitor water quality as efficiently as possible is becoming increasingly more important.
Current methods of detecting chlorophyll levels are rather time-consuming, as they require sample collection by boat in various locations on a body of water. "For us to go out and collect about 20 samples takes a whole day," Ortiz explains. "So one better way is to take your sensor and put it up in space or fly it from an aircraft, where you can use remote sensing techniques to measure pigment."
Results so far show that the remote satellite surface measurements are fairly representative of what is happening in the water column. This is allowing Ortiz and his colleagues to consider practical applications of the technology in the near future.
Ortiz is also starting to work with the Ohio Environmental Protection Agency to monitor conditions in the reservoirs that are being used for drinking water in various municipalities. As community resources are often limited, taking measurements on a full number of samples by employing remote sensing techniques gives a more accurate picture of the quality of drinking water drawn from the lake while reducing the cost to local water managers.
To learn more about this Ohio Sea Grant-funded research, visit ohioseagrant.osu.edu/_documents/twineline/v33i4.pdf#page=8
Ohio State University’s Ohio Sea Grant program is part of NOAA Sea Grant, a network of 32 Sea Grant programs dedicated to the protection and sustainable use of marine and Great Lakes resources. For information on Ohio Sea Grant and Stone Lab, visit ohioseagrant.osu.edu .
Dr. Joe Ortiz, Professor of Geology, Kent State University, 330.672.2225, firstname.lastname@example.org