Community receives education about water quality issues
The community was invited to an environmental education event at the Captiva Island Yacht Club last week to hear about water quality issues, which attracted a large crowd of interested residents.
City of Sanibel Natural Resource Director James Evans said the water quality issues that Sanibel and Captiva face are not unique to Florida.
“In fact the water quality issues we face are really a global problem,” he said.
Nutrient issues, or nutrient enrichment, occurs when systems get to a point where they are over saturated with nutrients such as nitrogen and phosphorous. When this takes place it can affect the oxygen in the water, or hypoxia. Hypoxia, Evans explained, occurs when oxygen gets to the point of becoming harmful to fish and wildlife.
Sanibel Captiva Conservation Foundation Marine Laboratory Director Dr. Eric Milbrandt said fish need oxygen and plants generate oxygen. He said it is a really important part of the ecology.
“After the storm (Hurricane Irma), a week or two after, we had a very large spread hypoxia event, low oxygen event. Everything that could swim away, probably swam away, but a lot of things did not make it,” he said. “The endangered small tooth sawfish, they are now near the Sanibel Causeway and they are normally up near Cape Coral because there is no oxygen there.”
Milbrandt shared information about RECON, River Estuary Coastal Observing Network, which collects data on an hourly basis during his presentation.
“We have a very large geographic area that we are trying to cover, over 100 miles. When we have large scale flows, or lack of flows, it affects a huge geographic area, so we can’t just focus on Sanibel and Captiva. We are actually working all the way up to the Caloosahatchee River and all the way up to the Gulf of Mexico in trying to understand what is going on,” Milbrandt said.
RECON was used for emergency operations during Hurricane Irma. He said much of the sediment in the water was suspended during the high wind.
“We had a lot of mud that was on the bottom that stirred up and went down again,” Evans said.
With Hurricane Irma, Milbrandt said they experienced an extremely low tide, which had impacts on the ecology of the area.
“We were expecting a storm surge, which we fortunately only got about a three foot storm surge. We were able to measure in real time. The emergency operations crews were looking at the data and saying OK, how many trucks do we have to mobilize to this neighborhood. Is it going to be totally under water, or are we going to have just a little bit of flooding,” he said. “That was an unrealized benefit of having a real time system available to everyone to use.”
Evans said there are a number of bodies of water throughout the country that are impaired for nutrients, which means the high levels of nitrogen and phosphorous are above the levels in which a healthy population is maintained for fish and wildlife.
“Once the body of water becomes impaired it goes on a list, a state, or federal list,” Evans explained. “We come up with an action plan to improve and reduce those nutrients in the water bodies.”
He said the issues Sanibel and Captiva face are a little unique compared to the rest of the country who are essentially polluting the water bodies in their own backyards.
In the late 1800s the first connections were made to the Kissimmee River, Lake Okeechobee and the Caloosahatchee. Evans said the watershed expanded roughly 865,000 acres that encompasses all the land south of Orlando.
“This historic Everglades, the watershed used to start south of Orlando and move very slowly into Lake Okeechobee and into the Everglades. It took a matter of weeks to months for the water to move into the Everglades and out into the Florida Bay,” Evans said. “When the Central and Southern Florida Flood Control Project was implemented throughout the beginning of the 1900s and into the ’60s, the Army Corps of Engineers took over. They ditched and drained all the water bodies from the Kissimmee all the way down to Lake Okeechobee and the Caloosahatchee.”
Connections were made to the Caloosahatchee and St. Lucie to the east and west and then to the south.
Evans said that changed the delivery of water to the coast, which made the system very flashy.
“When we get rainfall, the water goes to the coast very quickly. It’s a matter of days instead of weeks and months,” he said. “The water that we do get comes very polluted, meaning that it has high nitrogen and phosphorous.”
The color of the water is also dark. Evans said the water leaches and comes from the wetlands and off the rich organic soils that are located throughout the watershed in the Everglades agricultural area.
“It comes from the plants and leaches from the soils and that’s what gives it the dark color,” Evans said.
The Caloosahatchee Watershed, Evans said encompasses about 865,000 acres.
“It’s not just what comes from Lake Okeechobee that impacts us. It’s also what comes from the watershed. In fact following Hurricane Irma we were receiving flows averaging about 12,000 cubic feet per second,” Evans said.
The high flow harm threshold is when the water flow reaches a point where it begins to impact the estuary resources.
“That high flow harm threshold is set at about 2,800 cubic feet per second,” Evans said. “At the peak of the discharges from the watershed, not what was coming from Lake Okeechobee, our water flow was at 27,000 cubic feet per second at the Franklin Lock Dam.”
The Franklin Lock separates the fresh water from the salt water.
“That’s a tremendous amount of water just from the watershed. When you add from Lake Okeechobee, since the 11th of September, when we saw Hurricane Irma pass through, we saw flows that were averaging 12,000 cubic feet per second. That was up until the first week of October. That was several weeks that we saw flows four, five, six times of high harm flow threshold of freshwater. That has a big impact on the estuary. It has a big impact on the color of water, quality of water and quality of life here on Sanibel and Captiva,” Evans said.
There are two problems Sanibel and Captiva face – too much water, and not enough water.
“When there is not enough flow that goes to the estuary and the salt content goes really high, we tend to get algae blooms because the water stagnates and becomes stratified,” Evans said.
He provided pictures of the outcome of what the sea grass and tape grass beds looked like when the salinity became too high.
“Salinity got so high it actually killed off the tape grass beds. That has an impact on our endangered manatees that depend on those sea grass beds during the winter to forage,” Evans said.
Evans also spoke about the economic impacts in Lee County when talking about water quality problems. On an annual basis tourism generates $3 billion and supports about 57,000 jobs. The real estate values in Lee County generate about $87 billion in 2015. In the same year, water quality impacted home values by $541 million.