This story describes the Mercury Poisoning in 1989.

An above average amount of mercury was found in fish and other animals from the Everglades, which caused a larger concentration of the toxin in consumers and in turn poisoned the panthers due to biomagnification. Air pollution from metals mining and smelting, coal-fired utilities and industry, and solid-waste incinerators all contributed the the pollution of the water which eventually made its way up the trophic levels.