Are the Fish Safe to Eat?

If you’ve cast a line in Florida’s waterways over the years, you’ve probably noticed the change. What were once clear, thriving estuaries now often carry the scars of sewage spills, chemical spraying, industrial waste, and relentless overdevelopment. Nowhere is this more evident than in the Indian River Lagoon, a 156-mile stretch of water that runs along Florida’s east coast, shadowed by the John F. Kennedy Space Center. In 1990, the Environmental Protection Agency recognized it as an Estuary of National Significance. Today, it stands at the center of one of the most pressing environmental questions: are the fish safe to eat?

The lagoon is home to the greatest biodiversity in North America. Yet, over the decades, harmful algae blooms have ravaged its waters, stripping away more than a hundred thousand acres of seagrass. In 2013, the world turned its eyes here when mass die-offs of manatees, dolphins, and pelicans led journalists to dub the lagoon a “killing zone.” Scientists had been warning for years that water quality was slipping, but the alarms often went unheeded until catastrophe struck.

For the people who live along the lagoon, this isn’t just about wildlife. Fishing is a way of life, a source of income, and for many, a source of food. But toxins in the water don’t just stay in the water, they accumulate in the fish, raising real concerns about what ends up on the dinner plate. The list of potential contaminants is long: microcystin, mercury, PFAS, cyanotoxins, microplastics, PCBs, pesticides, saxitoxins. Brevard County has already issued mercury advisories for several lakes and rivers, yet none currently exist for the Indian River Lagoon or the neighboring Banana River.

Mercury is one of the most troubling contaminants. Released into the environment by coal-burning plants, it travels great distances before settling into rivers and estuaries. Once in the water, it builds up in fish, becoming the primary way humans are exposed. Florida has some of the highest recorded levels of methylmercury in the nation. When the Ocean Research & Conservation Association (ORCA) analyzed more than 700 fish across four counties, Martin County’s catches showed the highest concentrations. In the Indian River Lagoon, levels haven’t climbed much over the past two decades, but that doesn’t make them safe.

Florida’s Department of Health, Department of Environmental Protection, and Department of Agriculture oversee fish advisories, but they cannot test every body of water, nor do they consistently look for emerging contaminants like PFAS. These “forever chemicals” have been used for decades in firefighting foams, agriculture, and aerospace industries. Brevard County has been flagged as having some of the highest PFAS levels in the country. Once in the environment, they accumulate in fish and, ultimately, in people.

Fight for Zero, in partnership with the University of Florida and ORCA, is studying these compounds in fish tissue to understand how deeply they’ve penetrated the ecosystem. At the same time, researchers are tracking another silent threat: microplastics. The Indian River Lagoon has some of the highest recorded concentrations in the world. From cigarette butts to plastic bottles, everyday litter breaks down into tiny fragments that fish mistake for food. When ORCA examined 380 fish, more than half had plastic in their stomachs. Researchers are now testing fillets to see what might be passing into human consumers.

Standing on the shore at sunrise, the water may look peaceful, rippling with the movement of mullet or the leap of a tarpon. But beneath the surface lies a chemical story decades in the making, one that links industrial practices, consumer waste, and government oversight to the very fish people hope to catch and eat.

The question of whether the fish are safe is not just scientific, it’s personal, and it’s urgent. Projects like ORCA’s One Health Fish Monitoring program are working to uncover the truth, but they need help. Volunteers and local anglers can play a role by donating fish for study and supporting research that seeks to protect both ecosystems and human health.

The Indian River Lagoon still teems with life, but its future, and the safety of its fish, depends on whether we act now to understand and reduce the toxins coursing through its waters.

Resources and Further Reading

ORCA citizen scientists dissect fish to investigate whether algae-borne toxins are accumulating in their bodies.

Data from the One Health study suggest cadmium is present in the Indian River Lagoon but not building up in fish at levels of concern. Cadmium pollution typically comes from fertilizers, pesticides, herbicides, and industrial processes.

Florida’s fish consumption guide warns that developing fetuses and young children are especially vulnerable to mercury’s harmful effects on the brain.

“Do not eat shark, swordfish, king mackerel, or tilefish, as they contain high levels of mercury,” warns Florida’s fish consumption guide.

All pufferfish in Florida’s marine waters carry a “do not eat” advisory due to saxitoxin from toxic algal blooms. Consuming them can cause poisoning with symptoms like numbness, tingling, drowsiness, and difficulty breathing.