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Water quality monitoring program off to good start

By Staff | Jan 23, 2009

During the January meeting of the Captiva Community Panel, Mark Thompson and Dr. Loren Coen of the Sanibel-Captiva Conservation Foundation presented an overview of the SCCF marine laboratory’s Captiva Water Quality Monitoring and Assessment Program.

“There are perceived problems right now with the declining quality of habitat, declining water quality, declining fisheries, algae washing up on the beach, algal blooms in our water decreasing water clarity and all of these can affect our quality of life here. They can affect our health, affect our tourism and the reason people come here and they can affect fisheries, our food supplies,” said Thompson, citing loss of vegetation as one of the major sources of water quality problems.

According to Thompson, the water monitoring project, which officially began in November, is designed to: identify local water quality monitoring efforts and collect and evaluate existing data; identify pollutants of concern and potential local pollutant sources; develop monitoring programs for nearshore waters and fill in data gaps; coordinate monitoring design with the reopening of Blind Pass and track and identify problem areas and specific sources of pollution.

“Our focus of effort is mostly Captiva and hopefully we’ll get up to North Captiva and also the very northern part of Sanibel because there are a lot of potential pollution sources there on Sanibel Island that could be affecting Captiva water quality,” added Thompson.

The project will take into account seasonal variations in island population and rainfall that will affect the design of the monitoring program.

“When there are more people on the island, they use more water, they irrigate their lawns more, they probably fertilize their lawns more, there is more flow to the septic tanks and more flow to wastewater treatment plants,” Thompson noted, all of which are possible sources of pollution.

The differences between wet season and dry season are also important to take into account because during rainy season, there is more sediment, nutrients and bacteria washing into coastal waters from terrestrial sources.

In addition, water color can be considered a pollutant because it can cause low-clarity in the water and starve seagrasses of the sunlight they need to survive.

The project seeks to determine which pollutants are affecting water quality and clarity, including nutrient loads (nitrogen and phosphorus), salinity, dissolved oxygen, temperature, pH levels, turbidity, colored dissolved organic matter (CDOM) and high amounts of fecal indicator bacteria (FIB), and where these pollutants are coming from.

“We picked eight sites around Captiva that we’re going to sample three times during the wet season and three times during the dry season, regardless of whether it’s raining or not. We always take our samples at outgoing low tide,” Thompson added.

He also noted that they will also do storm water runoff monitoring at 22 sites, during both wet and dry seasons, in addition to a focused FIB study at four sites to determine the cause of frequent beach closures.

The project is currently funded by the Tourist Development Council’s beach and shoreline funding throughout the rest of the year, but due to potential changes and allotments in the TDC’s beach and shoreline funding, whether or not the second year of this project will be funded is still in question.

To learn more about the SCCF marine laboratory, visit www.sccf.org.