In the Indian River Lagoon, manatees are dying prematurely. Maybe because they are not getting enough sea grass to eat. Maybe sea grass acreage is down because brown algae is blocking sunlight. Maybe the brown algae can be blamed on us. Let me explain. From last July until April 1, some 80 manatees were found dead of shock in the lagoon, mostly in Brevard County. Manatees on the Treasure Coast may also be at risk. Up to four or five thousand manatees spend time each year on Florida’s two coasts. About three or four hundred stay along the Treasure Coast all year long. The big, gentle mammals depend on sea grass for their diet. When they don’t get enough, they become weak and susceptible to disease. Some 31,000 acres of sea grass have disappeared in the lagoon over the past two years, apparently for lack of sunlight. Researchers think the algae that block the sunlight are the result of discharges from Lake Okeechobee and storm-water runoff. The runoff contains fertilizer, and the fertilizer nourishes the algae. Where does the fertilizer come from? From us, of course. From our farms, our golf courses and our handsome lawns. That’s something to think about when we bemoan the loss of our beloved manatees. For 88.9 FM, this is Paul Janensch.