Peter Barile, Marine Biologist: All these homes along the Lagoon that are on 4septic tanks are slowly leaking literally tons of nitrogen and phosphorus into the system. 

CNN Correspondent:  Marine biologist Peter Barile has studied manatees for decades. He says those 5pollutants are being 6released by septic tanks and water treatment facilities along the Lagoon and are fueling 7algae growth in the water, which is causing the manatee's main food source, 8seagrass, to die. 

Peter Barile: So this algae is reducing light down to the seagrasses, 9essentially 10smothering them and killing them. 

CNN Correspondent: He says manatees need to eat nearly 100 pounds of 11vegetation a day. Between December 2020 and April 2022, more than 1,200 manatees died of 12starvation. Most of them here in the northern part of the Indian River Lagoon. 

"Just a couple of decades ago, the water in this Indian River Lagoon was 13crystal clear. You could easily see down to the bottom. Now it's dark and 14murky and polluted with chemicals and algae. With their seagrass gone, the manatees had little choice but to eat the algae that killed it, which is toxic for them. Their normally round bodies became flat as they became more and more 15emaciated. Katrina Shadix is the Executive Director of Bear Warriors United, which sued Florida's Department of Environmental Protection in 2022 to help protect the manatees. 

Katrina Shadix, Exec. Director Bear Warriors United: They suffered immensely and for a very long time. When a manatee 16starves to death, it's an extremely painful process. 

CNN Correspondent: These photos from Bear Warriors United show how desperate some of the manatees were, 17attempting to pull themselves out of the water to eat leaves off dry land or grass along the water's edge. On this beach in the Lagoon, Katrina says she found many manatee 18carcasses. She showed us some of their bones that still remain and shared this picture with us of a manatee skull. Earlier this month, a federal judge ruled in favor of Bear Warriors United and against the state, finding Florida's Department of Environmental Protection was, quote, in violation of the 19Endangered Species Act. 

Peter Barile: There was 20lax leadership from the state of Florida. The state of Florida has admitted that it will be 12 to 15 years before seagrasses start to recover. 

CNN Correspondent: We reached out to both the Florida Department of Environmental Protection and Florida Governor Ron DeSantis, but neither provided a response to our questions.