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Our green lawns not worth loss of sea grass beds in gulf

The Weeki Wachee River, with that spectacularly clear water and white-sand bed, is the star, the glamor-puss.

Then there's the subtle beauty of the Withlacoochee River, darker and, in every sense of the word, deeper — at least after a decent rain.

The appeal of the Gulf of Mexico is on the surface, up in the sunshine, blue water and fast boats.

Underneath? The water is shallow off the coast, the bottom flat and drab. Diving there is about as interesting as hiking across a parking lot.

That's the standard knock against the gulf, and, basically, it's all wrong, said Keith Kolasa of the Southwest Florida Water Management District, leader of a team that recently mapped sea grass beds in the gulf from the mouth of the Anclote River, in northern Pinellas County, to the Withlacoochee, on the Citrus-Levy county line.

Kolasa found 380,000 acres of beds, all but about 100,000 acres of that classified as "dense.'' It is a natural plain, an underwater savanna, the second-largest expanse of sea grass in the country after the one that stretches in the gulf from the Florida Keys to Naples. Though documentation is spottier outside the United States, the sea grass field off our coast may be the fourth-largest in the world.

It's full of life — manatees, mullet and sea turtles. And if estuaries are the incubators of marine life, sea grass beds are its K-12s, refuges for juvenile grouper and other game fish before they grow and move on to deeper water.

All in all, it's an overlooked treasure on par with any other natural feature in Hernando, Pasco or Citrus counties — and generally well preserved.

These beds have been measured twice before, in 1985 and 1999. Though improved mapping techniques make comparisons inconclusive, the best guess is that the beds are smaller and sparser than the first time they were surveyed, but bigger and healthier than a decade ago.

That may be, Kolasa said, because 1999 was the year after the floods of the last major El Niño event.

See, what is good for rivers — heavy rain — can be bad for sea grass beds. Runoff carries nutrients such as phosphorous and nitrogen into the gulf. These feed algae, which clouds water and blocks the sunlight grass needs to grow.

Yes, much of this runoff is contained in retention ponds, but that is no guarantee nutrients will all be filtered away. One reason nitrogen levels have recently flattened in the Weeki Wachee and some other major spring-fed rivers is the drought, Swiftmud scientists say.

When the rains come again, maybe during this winter's El Niño, not only will more water be washed into the gulf, but maybe more water with a higher concentration of nitrogen.

So, we should think whether we really need to dump more chemicals on our lawns, whether green grass that feeds the envy of our neighbors is as important as the grass that feeds fish, manatees and sea turtles — that feeds, really, our commercial fishery and tourism industry.

Also, the timing of Kolasa's report is perfect for environmentalists fighting the well-funded plan to allow oil drilling within a few miles of the state's shoreline — prime sea grass territory, in other words.

The beaches, statewide, are the star attractions. They will be protected, according to the lawyers hired to promote the drilling plan. The sea grass beds will be overlooked, unfairly, just like always.

Our green lawns not worth loss of sea grass beds in gulf 12/01/09 [Last modified: Tuesday, December 1, 2009 8:28pm]

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