Updated:BREVARD COUNTY, Fla. —
Dozens of manatees are dying in the Indian River Lagoon in Brevard County and no one has figured out what's causing it.
Since July, authorities with the Florida Fish and Wildlife Conservation Commission have counted 55 of the dead mammals.
When the manatees are found, their stomachs are full of macroalgae with little of the sea grass that they typically eat.
That leads some to believe fertilizer runoff could be to blame for an increase in macroalgae that cuts off the growth of sea grass.
"100 percent of the sea grass along this stretch from Melbourne here to Pinellas County is gone," said Dr. Leesa Soto of the Marine Resources Council.
Soto is among those pushing for more communities to adopt fertilizer ordinances.
The ordinance being considered in Rockledge would limit fertilizer use to slow-release formulas used only in the spring, instead of in the summer rainy season.
"If the water quality isn't good enough for manatees, it is not good enough for humans," said Soto.
Proponents said fertilizer ordinances enacted years ago are helping sea grass beds recover in South Florida.