Harmful Algae Blooms

ORSANCO operates four datasondes with telemetry systems.  The systems are located at Pike Island Locks and Dam,  Meldahl Locks and Dam, Markland Locks and Dam, and Newburgh Locks and Dam. Sensors on these datasondes collect pH, Conductivity, Turbidity, Dissolved Oxygen, Temperature, and Chlorophyll a data every 30 minutes.  Data is collected during the primary HAB season.

2015 Ohio River Harmful Algae Bloom

On August 19, 2015, ORSANCO received a report of a “green sheen” on the Ohio River at Pike Island Locks and Dam (mile 84.2) which covered 100 by 200 feet.  This green sheen was quickly identified as a bloom of the blue-green algae Microcystis aeruginosa.

Over the next month, this bloom expanded to cover the Ohio River from Pike Island L&D to Cannelton L&D (river mile 84.2 to 720.7).  Below Cannelton L&D there were intermittent patches of the bloom but not a continuous coverage.  The bloom reached its peak around September 23, 2015 after which point it began to decay.  The bloom was determined to be over by the last week of October.

Ohio, West Virginia, Kentucky and Indiana issued recreation advisories for the Ohio River as the bloom extended into their areas.  Illinois issued a precautionary statement concerning recreation in the river due to concern that the bloom would reach their border.  After the bloom ended these recreation advisories were lifted.

During the event ORSANCO collected 150 samples from the Ohio River, which were analyzed for the toxin microcystin.  Finished drinking water was sampled by either the water utilities or State personnel.  Analysis of the samples was conducted either by ELISA or LC/MS.  No toxins were detected in finished drinking water.  Of the samples collected by ORSANCO, 15 (or 10%) were greater than 6 ug/L.  The highest toxin concentration was 1900 ug/L at river mile 468.8 (Cincinnati, OH). View the 2015 sampling results.