Two Indiana state agencies warned that harmful algal blooms were confirmed on the Ohio River near Cincinnati, Ohio and Louisville, Kentucky. The bloom could potentially affect river-adjacent areas in southern Indiana and the Indiana-Ohio border.

The Indiana Department of Environmental Management and the Indiana State Department of Health said the blooms were also observed on other portions of the river upstream and downstream of those locations.

IDEM told the Indiana Environmental Reporter that the Ohio River Valley Water Sanitation Commission, an interstate commission representing eight states and the federal government, took several water samples from the Indiana side of the Ohio River. Results are expected later this week.

IDEM says ORANSCO staff spoke with people who observed possible blooms. Those sightings have not been confirmed.

Harmful algal blooms were confirmed on the Ohio River near Cincinnati, Ohio and Louisville, Kentucky. Water tests will determine whether the blooms have spread to the Indiana side of the river.

Agencies from Kentucky and Ohio have also issued warnings about the algae and are monitoring conditions in their areas.

The agencies cautioned swimmers and boaters to take precautionary measures when entering recreational waters.

The agencies warned that harmful algal blooms are made up of blue-green algae. Exposure to the algae could lead to rashes, skin or eye irritation, and other effects like nausea, stomach aches and tingling in fingers and toes.

Pets and livestock could also exhibit similar symptoms when exposed to the algae.

People and animals who come into contact with the algae should take a bath or shower with warm, soapy water.

According to IDEM, many factors can affect the growth of blue-green algae, including sunlight, warm weather, low turbulence and nutrient pollution.

In August, IDEM issued a recreational advisory after high levels of toxic blue-green algae were discovered in several Indiana lakes.

Algal blooms happen every year, but climate change could increase the rate at which they happen.

The Purdue University Indiana Climate Change Impacts Assessment found that climate change has led to increased temperature and more frequent and intense precipitation. More rain increases the risk of human-derived nutrients like phosphorus and nitrogen entering Indiana waterways. More nutrients and warmer water temperatures mean more algal blooms.

Algal blooms can greatly impact the health of Indiana’s waterways by depleting oxygen levels and harming the upper and lower levels of the food web.