With the recreational season getting underway at Ohio’s state park lakes, the Ohio Environmental Protection Agency has launched a new web-based map application that features real-time data of algal blooms at park beaches and public notices for drinking water.
The online tool enables users to view current advisories or sampling data of harmful algal blooms. The map shows a color-coded “snapshot” of the entire state, with additional information about any active advisories available by clicking the computer’s mouse.
The application uses two advisories:
- A recreational public health advisory (orange) would be posted if toxin levels exceed the recommended threshold. The pubic would be advised that swimming and wading aren’t recommended and the water shouldn’t be swallowed. Surface scum should also be avoided.
- A no contact advisory (red) would advise the public to avoid all contact with the water at that location. A no contact advisory would be posted if sampling results showed toxin levels above the recommended threshold and there has been a reported probable human illness or pet death.
Once an advisory is posted, the state will periodically sample until the bloom is gone and toxin levels are below the threshold.
If microcystin, anatoxin-a, cylindrospermopsin, or saxitoxin are found above thresholds in treated water of a public drinking water system, the system will issue a public notice to let customers know there is a drinking water advisory.
Depending on the level detected, the water system will issue either a do not drink or do not use warning. The system will remove a public notice when algal toxin levels are below the drinking water thresholds in two consecutive samples collected at least 24 hours apart.
Changing agricultural practices and weather conditions are cited in a study as the likely causes of what is considered the largest harmful algae bloom in Lake Erie’s recorded history.
The study by researchers at the University of Michigan and eight other institutions describes the 2011 algae bloom as a harbinger of things to come rather than an isolated occurrence.
The researchers found that intense spring rainstorms and the resulting runoffs from farm fields resulted in record-breaking levels of phosphorus, a nutrient in agricultural fertilizer that contributes to algae growth, washing into western Lake Erie.
The study says those conditions set the stage for an algae bloom that covered about 2,000 square miles at its peak in early October 2011 – about three times larger than other blooms to occur in the lake, including those that occurred in the 1960s and 1970s.
The paper was published online in April in the journal, Proceedings, of the National Academy of Sciences.
That spring was particularly heavy in precipitation: 2 inches of rain fell over Ohio’s Maumee River Basin on May 26 and almost 7 inches fell during the month – more than 20 percent above the average.
The EPA worked with the Ohio Geographic Information Systems (GIS) Office to develop the application. Ohio EPA GIS maps can be found online at http://epa.ohio.gov/gis.aspx. All HAB advisories also will be listed at ohioalgaeinfo.com.