No quick fix for current water quality problem
A reactive message has been sent by the State of Florida and Governor Rick Scott, when they highly recommended to the U.S. Army Corps of Engineers to divert the rising Lake Okeechobee discharges from the usual Caloosahatchee and St. Lucie Rivers, south to the Everglades.
Voices were heard from Southwest Florida after dark waters invaded the normally pristine waters of the Gulf of Mexico, which now has negatively effected the coasts of Sanibel and Fort Myers Beach, as well as the surrounding region up and down the beach lines.
Economic and environmental impacts are already being felt since the arrival of the murky water, which emanated from Lake Okeechobee via the Caloosahatchee River, which also added its own share of runoff within its own watershed.
With some of the discharge now flowing south into the Everglades, it does not mean home sailing for the coastal areas which line down from the Caloosahatchee River’s mouth.
In the Sanibel Captiva Conservation Foundation’s daily updates of the rate of discharge flow as of Feb. 25, 5,070 cfs of Lake O discharge entered the Caloosahatchee. That is down from previous marks of 14,000-plus, with the major decline coming from the switch of flow to the south.
“Then there is another 2,460 cfs added by the Caloosahatchee basin by the time it reaches us (for a total of 7,530 cfs),” said SCCF director of its marine laboratory Dr. Eric Milbrandt. “But that still is more than the (normal) maximum for this time of year, which is 2,800 cfs.”
The amount of cfs released by Lake Okeechobee in normal releases is bracketed from 750-2,800 cfs. Thus far, that mark of 2,800 cfs has been surpassed in years 2005, 2006, 2013 and now in 2016. There also was a long term of a dry period, which sent too little of freshwater to the estuary in 2007.
The bracketed numbers were made in the prime years of 2014 and 2015, though.
Ultimately, what is being affected is the seagrass, oysters and many other aquatic wildlife, which depends on the photosynthesis and food provided by the seagrass.
With that much freshwater channeling in from the Caloosahatchee River, it has had a major affect on the salinity in the surrounding estuary.
“We may see slow growth in the oysters, because when there is low salinity, they close up and don’t feed,” Dr. Milbrandt said. “That leads to slow growth and they might not even spawn at all this season.”
Another concern of the dark water is the ability of sunlight reaching the seagrass beds, which provides habitat for various aquatic wildlife and provides food for manatees.
“With the low light and low salinity, the seagrass is becoming stressed,” Dr. Milbrandt said. “Obviously, clear water is the best conditions for seagrass, but in Iona, it’s being measured at .66 of a meter and in the San Carlos Bay, sunlight is reaching only a meter down.”
April is the peak season for seagrass and oysters to grow and reproduce, since that’s the start of the sun being out longer and being more intense. Growth potentially could be postponed to June or July and may not have a peak growing season like the last two years for quite sometime.
“It may take three to five years to recover,” Dr. Milbrandt said. “In 2013, when we had flood conditions, with low salinity and high discharges from the Lake, it lasted months before seagrass and oysters recovered. Now, with these events happening one after another, they can’t recover.”
In a study researching the growth of seagrass after the 2013 event, the shoots per meter, started off with less the year after, thus showing long term effects.
So is the discharge of more water south to the Everglades a fix to the dark waters surrounding Sanibel and lapping on the beaches of Fort Myers Beach?
“There is no quick fix,” Dr. Milbrandt said. “It is helping, because we are getting about a third less of the discharge, but we are still receiving almost twice as much as what our (2,800 cfs) threshold is.”
The best answer will be supplied by Mother Nature, not humans.
“Right now, Lake Okeechobee is falling,” Dr. Milbrandt said. “As long as we have more dry days ahead and not much more rainfall, we’ll be fine. But we need more water storage around the Caloosahatchee basin. The St. Lucie basin is in the same boat.
“But right now, sending water south is the only thing we can do.”
Water being sent to Everglades is nutrient-laden
The current issue of sending Lake Okeechobee’s discharges east and west down the Caloosahatchee and St. Lucie is directly related to the vicious hurricane which hit Florida in 1928.
During the storm, Lake Okeechobee’s waters pummeled the communities surrounding the lake, killing 2,500 people in the process.
It sparked the government to direct the Corp to build dikes around the lake by 1940 and ultimately stop sending the water south through its natural flow, instead artificially sending it east and west through the two rivers.
One of the major negative effects happening with the discharges is that the water is nutrient laden with nitrogen and phosphorus, said Thomas Van Lent, who is the director of science and policy for The Everglades Foundation in the BIG ARTS “Talking Points” presentation Wednesday, Feb. 24.
“So what does water quality mean?” Van Lent asked the audience. “Three things: One, salinity. Two, nutrients. And three, water clarity.”
Nutrient pollution is a “global problem” and one which affects everything. It exacerbates the growth of harmful algae, which in turn produces toxins which can kill many forms of wildlife.
Much of the nitrogen and phosphates come from the use of fertilizers, which is used by much of the agricultural sector. It is caught in the water runoff, which ultimately ends up in waterways, such as Lake Okeechobee.
“The mouth of the Mississippi River which lines the coast of Louisiana and the Texas coasts, is basically a dead zone because of all the nutrients which is expelled in the Gulf,” Van Lent said.
Locally, 61-percent of the nitrogen which is flowing through the Caloosahatchee River’s veins is from Lake Okeechobee. From the Franklin Lock on, 24-percent is from agricultural runoff and 14-percent from other various sources.
“It has been estimated, that 11,490,281 pounds of nitrogen a year is in the water of the Caloosahatchee,” Van Lent said. “Two thirds of that nitrogen comes from agriculture. In the past, most of it was produced from sewer, but in 1972, the Clean Water Act absolved that source.”
There are different regulations to control urban storm water, which brings it to the current problem of nutrient laden water.
Education of using fertilizer is a starting point, Van Lent said.
“Sanibel is at the forefront of fertilizer use, too,” he added.
Other practices which people can follow is cleaning up litter, which adds to the nitrogen levels in water.
Unfortunately, regulations are not addressing the 61-percent of nitrogen from Lake Okeechobee, but instead are attacking the “other” 14-percent, which is still not being brought down.
The affect of big sugar on the nitrogen levels is mostly from past sins, not current practices. In 1988, most of sugar producers dumped their nitrogen waste into Lake Okeechobee, which raised levels to astronomical numbers.
But today, big sugar is not adding to the problem, but current nitrogen levels are still from the 1988 production.
“We have created a legacy bomb,” Van Lent said. “It takes a long time for nitrogen to be broken down in nature.”
For a longterm solution, Van Lent said going back to what Mother Nature intended to help drain Lake Okeechobee, move it south.
“Restore it the way it used to be,” Van Lent said. “It’s a massive project and it’s complex. From 2000, only two authorized bills for restoration have been approved by Congress. We need to re-plumb our water management plan, which can lead to clean water with the construction of more marshes and removing the dams and adding bridges in the Everglades.
“We need more water storage to replace the lost wetlands south of Lake Okeechobee, which can capture water during the drought times.”
To learn more of the Everglades Foundation’s mission, go to evergladesfoundation.org or call 305-251-0001.