Scientists consider the Indian River Lagoon, which stretches for 156 miles along Florida’s East Coast, one of the most biodiverse waterways in North America. But agricultural runoff and leakage from septic tanks send high levels of nitrogen and phosphorus into the lagoon, causing harmful algal blooms. The blooms block sunlight and starve the water of oxygen, which over the past five years has destroyed more than half the seagrass in the lagoon, killed millions of fish, and suffocated manatees. As Brian Lapointe, scientist at Florida Atlantic University’s Harbor Branch Oceanographic Institute puts it, “It really is like the perfect storm coming together creating a big, big problem in this area.” And with one in five American households using septic tanks, which are unable to adequately filter waste in densely populated areas, waterways from Cape Cod, Massachusetts, to Long Island, New York, are also seeing increased algae blooms.
LISA DESAI: In March of this year, they caused one of the biggest fish kills in the estuary’s history.
LISA DESAI: Those nutrients in the water come from sewage and fertilizers and can spur algal blooms — when algae grows out of control, blocking sunlight, and starving the water of oxygen. The blooms destroyed over half the seagrass in the lagoon during the past five years.
BRIAN LAPOINTE: It killed millions of fish, but also caused die off of a lot of the biological diversity that we have in the lagoon.
LISA DESAI: In May, the St. Lucie River, which is part of the Indian River Lagoon, became so polluted that the Florida Department of Health warned residents not to touch the water. This toxic blue green algae smothered parts of the river, suffocating endangered manatees. Pictures and videos of the contamination are all over social media. In this one a manatee swims through the thick sludge — desperate for relief— as good Samaritans hose it down with fresh water.
Blooms in the Indian River Lagoon have killed millions of fish, suffocated manatees, and destroyed seagrass.