#manatees

#manatees

Visitors can stroll the park's boardwalk-a one-third-mile stretch from the St. Johns River to the headspring-and watch from above as manatees float peacefully below, socializing or nursing their calves in the clear, warm water. It is not only a rare chance to observe these gentle giants without disturbing them, but also a conservation success story: When research began in the 1970s, around 36 manatees visited the park. Now, there are well over 700.

It is home to 4,300 species, including many of the state's remaining manatees, whose large, paddle-tailed bodies graze slowly through the shallows. For decades, the lagoon has also been a destination for Florida's municipal sewage. State law long ago aimed to stop much of the flow from wastewater plants, but in practice continued to allow dumping during heavy rains. Residential septic tanks have kept leaching into the water, too. Over time, that pollution fed algae blooms that choked out the area's seagrass-manatees' main food source.

National Geographic's 'Underdogs' focuses on animal misfits, showcasing their unique traits and giving recognition to often overlooked species, narrated by Ryan Reynolds.