It has been discovered that bottlenose dolphins in the Florida Coastal Everglades have higher concentrations of mercury than any other populations in the world. Florida International University (FIU) scientists examined dolphins from the lower Florida Keys, Everglades National Park and Florida Bay and found the highest levels of mercury concentration ever recorded was from the Everglades. Potential sources of mercury are both natural and from man-made sources but mangroves are thought to be the primary source of the mercury in this case as when leaves are dropped into brackish swamp waters, the mercury from the mangroves interacts with bacteria and is converted to highly toxic methylmercury.
FIU marine scientist Jeremy Kiszka, who co-authored the study (published in Environmental Pollution) said that although results obtained on bottlenose dolphins from the Everglades were surprising, it’s now vital to assess the effect of mercury on the health of this particular population. The findings raise concerns about potential impacts on their health as mercury can disrupt the immune system and reproduction of dolphins, making the animals more vulnerable to infection and disease.