Farm Runoff

Satellite view of toxic algal bloom on Lake Erie
NASA Earth Observatory

Algal blooms are once again causing problems for lakes and streams in Ohio this summer. But farmers are combating the situation, and so far, they’re getting some help from the weather.

When rain falls on farm fields that have been treated with fertilizers containing nitrogen and phosphorus, whatever chemicals haven't soaked deep enough into the soil, or made their way into the crops, can end up in nearby streams and lakes. That runoff is feeding nutrients to harmful algal blooms.