Thoughts on critters sought, plus landscape musings
Groundwater packed with nitrogen that oozes into the Gulf of Mexico through deepwater springs from Central Florida could be contributing to red tide outbreaks in Southwest Florida waters.
And the spark that fed the red tide flame could be the boys and girls of the summer of 2004: Hurricanes Charley, Frances and Jeanne.
That hypothesis has been proffered by scientists with the University of South Florida and the U.S. Geological Survey. They've said that heavy rains from the four storms that hit Florida two years ago caused the underground network of waterways to become loaded with excess nitrogen that could have helped feed the 14-month-long algae bloom off the state's coast.
Before the biological explanation, though, there needs to be a geological history lesson.
Florida's underground composition has been likened to a big sponge. There is dirt and clay on top of the sponge, but porous limestone pretty much underlies the state. Rivers, streams and creeks carry a lot of surface water from ponds and lakes to the Gulf and the Atlantic Ocean, but the vast amount of freshwater that feeds the waters off the state comes from springs deep beneath the surface.
The springs have outfalls in the Gulf, outfalls that in some instances well up from thousands of feet deep beneath the surface. Divers have found some of these springs to be almost pure freshwater in the midst of saltwater, with flow rates of hundreds of thousands of gallons per minute.
The big underwater sponge allows water from the surface to slowly seep down to these underground springs. Whatever was contained in that groundwater - nitrogen-based fertilizers, pesticides, toxic chemicals - is somewhat filtered during the natural cycle of Florida's regular weather patterns. It's a slow process that can take decades.
But when you add huge storms to the pattern, the water flow is faster and the filtration is lessened. Seepage turns into surge.
The USF and USGS researchers, in looking into water flow from the land into the Gulf in conjuction with the 2004-05 red tide outbreak, sampled rivers and streams. The assumption was that the surface water runoff had carried nitrogen to the red tide and fed it, prompting the long-lasting bloom.
Red tide, by the way, is a naturally occurring algae that suddenly blooms. The blooms can kill fish, manatees and dolphins, and cause respiratory problems for humans who breathe the aerosol toxin the bloom produces.
The river samples didn't carry very much nitrogen, which, although fertilizer for land-based plants, also serves as a good munch for red tide algae. In fact, the stormwater runoff wasn't that big a deal environmentally - at least in the long-term geological perspective.
But the lag time between the summer hurricanes and the eventual long-lasting red tide outbreak hinted that there was something else going on, and checks on the underwater springs provided the clue.
Now, not all this food for the red tide was manmade, the researchers were quick to point out. The St. Petersburg Times reported that Florida's underground strata is rich in nitrogen. Remember Bone Valley in the center of the state, the source of a huge amount of fertilizer for the world? All that phosphorous is naturally occurring in the ground.
Add three major hurricanes, and the chemicals' seepage rate as transported by the water flow is radically enhanced. Give it all a few months to filter through the limestone to the springs, and voila! It's in the Gulf and serving up lunch for red tide.
Since the red tide was already there - it always is, by the way, in background levels - and nobody knows just what triggers a bloom, but something does and did two years ago -suddenly the red tide had a new form of free lunch.
The theory is one of those things that makes perfect sense when you think it through, and begs the question of why nobody had thought of it before.
Got a nice note from Pat Gentry regarding last week's column and mention of the ancillary uses of WD-40. He too had received the Internet comments about its myriad uses and pointed out that, "These uses have been heralded for years and I have even heard that the elderly use the stuff to spray on their skin to relieve the pain of arthritis. I keep hearing how safe the stuff is, but the fact is the ‘mystery ingredients' are petroleum products and should not be used directly on the skin. The health issues of petroleum products can be researched on the Internet.
"Also, the use of this product inside the home without adequate ventilation is dangerous. There is also the problem with residual contamination. All petroleum products have toxic byproducts and contaminate our air, water and soil. I realize that we cannot get away from them completely, but we should all know by now that IF we have the choice to use a natural product that does not contain petroleum, we are doing ourselves, our children and the future of our planet a favor."
There was also this comment:
"A totally different slant on the subject would contain the question of dependency on oil (foreign or in our own Gulf). The gasoline we put in our cars is just one way oil is used. The multiple products that are manufactured using petroleum make up a huge portion of the crude oil we consume."
Thanks for the thoughts, Pat.
According to the USF/USGS researchers, underwater springs from the Tampa Bay area carry 35 percent as much nitrogen into the Gulf as all the north and central Florida rivers combined.
And don't every underestimate the importance and interconnectiveness of what's under the earth's surface. The tsunami that hit the southern Pacific Ocean a couple years ago caused the Floridan Aquifer in Florida to rise 12 inches one hour after the seismic event took place halfway around the world. The shock that caused that bubble of water to rise - and it was a heckuva big bubble - traveled at better than 600 mph to cause the belch here.
Oh, and the measurements made in our Floridan Aquifer were made more than 1,000 feet beneath the surface.