Red tide remains in Northwest Florida, with "low to medium" concentrations reported this week in Santa Rosa and Okaloosa counties.

K. brevis, the bacteria that causes the red tide, appeared to decrease Friday, according to reports from the Florida Fish and Wildlife Conservation Commission (FWC).

In the FWC's Wednesday report, levels were observed as "medium." Fish kills were also reported in Okaloosa and Walton counties Wednesday.

The FWC said Friday that only Okaloosa had reports of respiratory irritation.