There were more bottom samples with low oxygen at levels that would be stressful to marine life.
October 12th: The salinity in the surface waters of lower Sarasota Bay started to return to pre-storm levels, but the oxygen problem was getting slightly worse. In the months leading up to Hurricane Ian, surface salinities at these locations generally ranged from 33-35 ppt. Portions of Lemon Bay exhibited similar stratification as Sarasota Bay, with surface salinities ranging from 11-15 ppt, and bottom salinities ranging from 29-33 ppt.
October 4th (six days after Ian made landfall): sampling in Little Sarasota Bay and southern Roberts Bay showed the salinity on the surface was about 8 to 10 parts per thousand (ppt), while the salinity on the bottom was about 25 ppt.