Florida Bay

There are lots of bad things happening in the Florida environment right now. Many problems have their beginning in Lake Okeechobee. The papers are full of stories of algae invading beaches and of damage to the Indian River.

But if I had to choose the worst environmental issue right now linked to Lake Okeechobee it would be Florida Bay.

Map of Florida Bay

Florida bay is the large expanse of water off the southern tip of the Florida Peninsula. It's bounded on the north by the Everglades and on the East and South by the Florida Keys. Fresh water from the Everglades mixes with salty water from the Gulf of Mexico to create a shallow brackish water environment. As Florida Sea Grant puts it:

Its nearly 1,000 square miles of interconnected basins, grassy mud banks, and mangrove islands are nesting, nursery, and/or feeding grounds for a host of marine animals: the American crocodile, the West Indian manatee, the loggerhead turtle, bottlenose dolphins, a variety of bird species and many gamefish.

The problem is that Florida Bay earlier this year suffered from increased salinity. It may may still be suffering. But first some background. Most of Florida Bay is considered brackish water. That means it has more salt than fresh water but less than the sea water.

Here's the breakdown:

Salinity of Water

In the Florida Bay there's always a lot of variation in salinity. Rain brings freshwater into the system. Gulf currents can bring saltwater. But the variation usually stays within a narrow range.

But things can go bad quickly if the salinity increases too much. In 1987 the salinity increased and the seagrass died on about 15 square miles of Florida Bay. In an effort to get fresh water into the bay the water managers released lots of nutrient rich runoff from agriculture fields. The ensuing algae bloom expanded the seagrass devastation to 94 square miles. It took the next 20 years for the bay to recover all the seagrass lost.

Seagrass is the basis of life in Florida Bay. Manatees eat it. Fish hide and raise young in it. With no seagrass the amount of life supported by Florida Bay collapses.

The current problem is the lack of water coming from the everglades. With less fresh water the bay water gets progressively saltier. With the hot and dry summers of 2014 and 2015 evaporation increased the salinity of the shallow water even more. From the Miami Herald:

Last July, when rainfall at Garfield Bight was about 10 inches below average, salinity jumped to more than double the levels typically found in bay water, according to monitoring by Everglades National Park. Water temperatures hovered over 93 degrees in the bight for more than 77 days.

Seagrass Die Off, 2015

Recall that in the die off of 1987 only about 15 sq miles were due to the salinity. The rest of the 94 sq miles was because of the algae bloom from nutrients released from Okeechobee. At least they didn't do that again.

But the weather may have rescued the bay for now. From late summer on in 2015 the rains returned. The water kept coming in 2016 so the salinity has stayed relatively low and the seagrass die off has reversed. But it will take years for the grass to fully recover. That's assuming the salinity doesn't spike again.

One of the reasons I write these pieces is that it gives me a chance to understand what's happening in the environment. My initial thought was that the water managers could solve 2 problems at once. They have too much fresh water in Lake Okeechobee and too little in the Florida Bay. There's a canal connecting, so what's the problem? But releasing the nutrient rich water into Florida Bay would have turned a disaster into an even bigger disaster. The algae growth could have greatly magnified the problem of seagrass dying as it did in 1987.

But the luck of a rainy year won't last. They have to find a way to get relatively clean fresh water into the Florida Bay. The basis for successful water management has never been hoping for a wet year. The answer is probably some water treatment facilities south of Lake Okeechobee to try to remove nutrient load before it goes to the bay. The answers also include a better effort to flush freshwater to the lake during cool weather when there's less likelihood of algae forming.

But none of the answers will be cheap or easy. I'll continue the series on the Lake Okeechobee issues as time permits. But the more I get into it the more I can see just how complex the situation is.