Hurricane Ian barreled into the west coast of Florida on September 28 as a powerful Category 4 hurricane. As relief efforts remain rightly focused on the heartbreaking human toll of the storm, the environmental fallout has yet to come front and center. Satellite images are helping to piece together the beginnings of a story that has only just begun to play out.

In the NASA satellite image above, swirls of sediment stirred up in Florida’s coastal water, “lifted from the seafloor as Ian neared the coast,” starkly contrast with dark plumes of stormwater runoff exiting the land. Though this tannin-colored runoff is not altogether unusual, the sheer volume of water coming off the landscape is out of the ordinary, and likely carried nutrients like nitrogen and phosphorus out of the local basin with it — a threat that could forecast harmful algal blooms in the months ahead.

Even after average rainfall, local basin runoff will impact downstream water, depressing salinity and dissolved oxygen, and dark plumes of water can block light necessary for photosynthesis to maintain healthy seagrass beds. During Hurricane Ian, this water also intermingled with untold gallons of raw and poorly treated sewage that flowed into the streets and river as infrastructure was overwhelmed.

For now, water is not flowing from Lake Okeechobee into the Gulf of Mexico. With the lake at 14.62 feet, the Army Corps of Engineers has remained firm that discharges to either coast are not yet necessary and the locks leading to the Caloosahatchee and St. Lucie rivers remain closed. The end of the rainy season is approaching, but with the Kissimmee chain of lakes still inundated by water from Hurricane Ian, the possibility of toxic discharges in the days ahead will depend on how wet or dry we remain over the next several weeks. Even without Lake O discharges, environmental challenges are likely to linger in the aftermath of Ian — one of the storm’s many costly tolls.