Rotarian Dr. E.J Neafsey, visiting scientist at SCCF, discussed the islands' mangrove ecosystems at Rotary's meeting at the Community House. Rotary photo
Rotarian Dr. E.J Neafsey, visiting scientist at SCCF, discussed the islands' mangrove ecosystems at Rotary's meeting at the Community House. Rotary photo

EDITOR'S NOTE: The following report from the Rotary Club of Sanibel Captiva meeting at the Sanibel Community House on Friday, Oct. 2, was submitted by Shirley Jewell of the Rotary Club.

We are extremely lucky to have numerous opportunities on Sanibel and Captiva to learn about the environment that surrounds us. The Sanibel Captiva Conservation Foundation spearheads a number of research projects that provide information and research findings not only for Island residents but extends these findings to numerous scientific agencies across the globe.

Sanibel-Captiva Rotary recently asked SCCF visiting research scientist and Rotarian, Dr. E.J. Neafsey, a research scientist on the faculty of the University of Virginia’s Department of Environmental Sciences concentrating in Southwest Florida on the inventory and health assessment of local mangrove ecosystems, to speak to us about Island mangroves.

So, let’s start with the basics. There are three types of mangroves on our Islands…red, black, and white. The red mangroves are closest to the shoreline, black centrally located behind and elevated slightly, and the white farthest away from the shoreline. EJ’s research is looking at each individual mangrove species to quantify the health of the species and the contribution it is making to our environment. Believe it or not, that contribution is immense; mangroves protect us from storm surge, floods, and provide screening from wind and waves. They are central to stabilizing our shorelines. Mangroves provide protected nursery locations for many fish species, crustaceans and shellfish. They provide food for our local marine species and nesting/rookery areas for our island bird population.

The studies include observations about the stresses on our mangrove species. EJ stated that there is good news on that front; three-quarters of our Island mangroves are intact. Stress does come from storm surge and travels inward through the old mosquito drenches/canals doing harm. Refuse gets caught in the mangroves along the canals. Vegetation growth and impounding from constructed blockades form a barrier disallowing water flow and nutrients to reach some of the inland mangrove areas. EJ’s example of this was Wildlife Drive at 'Ding' Darling…right side of Wildlife Drive healthy because of great tidal flow…left side impounded by road, deficient of nutrients, less vibrant.

Salinity, water temperature, tidal fluctuation, and soil also affect mangroves. High rain events and submerging for a length of time is definitely harmful to the mangroves.

EJ’s research extends beyond Sanibel and Captiva to Estero, Fort Myers, Fort Myers Beach, Naples, and Marco Island. There was a question regarding the coloration of the water close to the mangroves…EJ told us that if the mangroves are healthy the surrounding water will be clear; unhealthy mangroves present that sulfur smell and brownish in color.

Although just slightly mentioned at the meeting, many of us Islanders remember the mangrove restoration project a few years ago in Clam Bayou…project description…”return Clam Bayou to a healthy estuarine system that supports productive marine fisheries and wildlife habitat by restoring an historic tidal connection between Clam Bayou and Pine Island Sound. The project will prevent the repeated artificial impoundment of freshwater which has caused the die-off of 116 acres of mangrove forest, fish kills, and the death of all oyster bars in Clam Bayou. The anticipated result of the project is the complete restoration of the mangrove forest, oyster bars, tidal mudflats, grass beds and fisheries in the bayou. An important component of community driven project is a volunteer mangrove planting effort and an environmental education outreach program.” The good news here is that project proved to be an absolute success.

The Sanibel-Captiva Rotary meets at 7 a.m. Friday mornings at the Sanibel Community House, Periwinkle Way. Guests are always welcomed.