Waterways commission hears manatee, salinity and algae update; deaths remain at nine

Dr. Jerry Pinto, a Jacksonville University researcher, told the Jacksonville Waterways Commission on June 12 that local manatee counts remain lower than recent years and that staff have detected algal blooms containing microcystin at several sites.

Pinto said salinity readings were near normal for the river system — citing roughly 33 at Mayport and 12–15 at Dames Point — and that temperatures were “running around 80 degrees.” He reported rain totals “probably a couple of inches above normal for this time of year.”

Pinto described multiple algal observations: “There do seem to be a lot of algae blooms around, that have microcystin,” and noted that at some sites, such as Shands Bridge and Mandarin Point, species associated with microcystin were present though he said “there was no toxin detected” in some samples. By contrast, two sampling sites in Doctors Lake recorded microcystin concentrations of about 4 to 5 micrograms per liter, which Pinto called “concerning.” He also said a cyanobacterial genus identified at New Kings Road-area Rose Creek was detected but without measurable toxin.

On manatee mortality, Pinto said the commission’s count of deaths in the county remains at nine, including one watercraft-related death, and he gave the results of a May 23 aerial survey that counted about 42 manatees (compared with about 46 in April). He noted statewide watercraft-related manatee deaths rose to 47 this month and placed that figure in the context of the state total referenced in his report.

Commissioners asked no substantive follow-up beyond thanks. Pinto concluded by saying he would take questions from the commission.

The commission received the report as an informational update; no formal action was taken.