Words cannot describe the immense loss of life unfolding along a 50-mile stretch of Florida's Indian River Lagoon.

More than 30 species of fish, estimated in the hundreds of thousands, have started floating to the surface and washing up along shores. In some places, the normally idyllic waterways are being replaced with thousands of rotting fish.

“We’re seeing stingrays, horseshoe crabs, sheepshead, the mullet, the flounder — everything is being impacted by what’s going on here in the lagoon,” Michelle Spahn, a waterway tour operator, told WFTV9.

Why the sudden die-off? Thanks to El Nino, parts of Florida received triple the amount of water that's normal for January, leading to massive torrents coursing through urban environments and picking up synthetic fertilizers and other pollutants. This potent mix helped feed a toxic algae bloom, resulting in a "brown tide" that robbed oxygen from the water and effectively suffocated marine life.

"With all these dead fish in the water, so many people are looking at this saying, 'Who's to blame for this?,'" Dr. Robert Weaver, director of the Indian River Lagoon Research Institute, told Derrol Nail at Fox 10. "This is a tough question to answer, because we all have to look in the mirror. This problem started years ago with unfettered development over the past 50 years is what's to blame for this."

While fish kills are not uncommon in Florida, they're generally more prevalent during the warmer months. Both the timing and magnitude of the Indian River Lagoon kill is raising alarms all over the state. The news is particularly troubling to conservationists working to prop up manatee populations. A dramatic drop-off in water oxygen levels doesn't just kill fish, but also vital food sources such as sea grass.

"That's manatee food. Manatee eat sea grass," added Weaver. "So we can expect that it's likely the manatees will start being stressed."

With the lagoon's dire state no longer hidden beneath its surface, residents are now faced with changing their own habits to help restore the waters and give marine life a chance to rebound.

"I'll give up my green lawn," Tony Sasso, director of the nonprofit Keep Brevard Beautiful, told Florida Today. "When I was growing up, nobody fertilized their yards."