Wild bottlenose dolphins in the Indian River Lagoon experience more health issues than those living in aquariums, according to a study by the Public Library of Science.

The report, published Wednesday, compared immune systems of wild dolphins to those living in aquatic facilities. It found that wild dolphins’ immune systems are more at risk due to a rise in ocean pollution.

SeaWorld Parks & Entertainment posted the report Thursday on its blog with the headline, “This Recent Dolphin Study is Changing the Game.”

Since 2003, field researchers from the Health and Environmental Risk Assessment for Atlantic Bottlenose Dolphins have been following 360 dolphins in the Indian River Lagoon (IRL) and off the coast of Charleston, S.C. The IRL stretches 156 miles from Ponce Inlet to Jupiter Inlet.

Scientists found dolphins have been developing tumors, skin diseases and infectious illnesses caused by high levels of mercury and industrial pollution off the coasts of Florida and South Carolina. This pollution is shocking their immune systems, making it harder for them to fight off bacteria, fungus, parasites and other illnesses in the wild, according to the study.

Dolphins along the Indian Lagoon River in Florida were mainly suffering from a high mercury concentration. In the past, dolphins in the river have also been developing fungal skin diseases due to their affected immune systems. The South Carolina dolphins suffered from industrial poisoning from small fish eating human-produced organic chemicals that are then consumed by dolphins.

“This information is incredibly troubling given that these toxins become increasingly concentrated and potent as they travel along the food chain making it virtually impossible for dolphins to eliminate this from their bodies,” according to a statement from the SeaWorld blog. “This isn’t just a concern for the dolphins, this high mercury content as well as some of these infectious illnesses are also a risk to human health.”

The PLOS report is being compared to a dolphin study at the Georgia Aquarium and the Space and Naval Warfare Systems Center in San Diego. The captive dolphins were found to have significantly less stress and illnesses. Researchers believe this is due to better water quality and constant monitoring by aquariam veterinarians.