Several hundred manatees have died off the coast of Florida this year, and scientists think human waste is crippling their food sources.
Manatees, also known as sea cows, are large aquatic mammals often found in shallow, slow moving rivers and coastal waters. In the U.S., they are mostly concentrated in Florida.
So far this year, 738 manatee deaths had been recorded as of late last week, according to figures from the Florida Fish and Wildlife Conservation Commission, already surpassing 2020's year-long figure of 637.
Martine de Wit, a veterinarian in the state's marine mammal pathology lab, told the Tampa Bay Times there are cases of manatees suffering from the effects of starvation, and pointed to the loss of huge amounts of seagrass—a key part of the manatee's diet.
Patrick Rose, executive director of the Save the Manatee Club, told Newsweek his organization is working to step up efforts to monitor the manatees' health in association with local authorities—but fears the situation could worsen come next winter.
Rose said: "The rescues of sick and injured manatees is the first priority while we work to clean-up and restore the manatees' essential aquatic habitat.
"Sadly, since the situation was allowed to deteriorate so dramatically, we could be facing an even more deadly scenario going into next winter and there truly is no time to waste in preventing such a recurrence."
According to Rose, populations of seagrass have experienced "devastating losses" in the Indian River Lagoon, where up to 90 percent have been killed off by repeated algal blooms.
These blooms, he said, are being driven by human waste and pollutants entering the environment through sources such as poorly treated wastewater, septic drain fields, and stormwater runoff containing fertilizers and other pollutants.
Steve Murawski, a fisheries biologist and marine ecologist at the University of South Florida's College of Marine Science, told Newsweek why increases in algal blooms can be a problem for sea grasses.
"The increase in algal blooms are related to coastal degradation and the increase in nutrients," he said. "As algal blooms increase in frequency and duration, they tend to result in less sunlight reaching the bottom in shallow waters.
"Severe declines in submerged aquatic vegetation (SAVs) have been documented in numerous coastal estuaries including Chesapeake Bay, and are likely associated with light attenuation due to greater concentrations of algae in the water.
"Interestingly, starting about 30 years ago, a program to reduce nitrogen runoff in Tampa Bay by limiting fertilizer use in summer months and upgrading wastewater treatment was successful and resulted in large increases in SAVs in the Bay, which are food for manatees and habitat for many other species including fishes."
Rose said that Floridians can help by contacting their local state and federal leaders and putting pressure on them to stop human pollution from driving further algae blooms and to remove excess nutrients that are already in the water.
He noted there is also an opportunity to call for water quality improvements in future infrastructure funding. President Joe Biden is due to announce his budget proposal May 28.
Rose added: "What is more basic than keeping human waste products from spoiling our aquatic ecosystems?"
