Mangroves

We are extremely lucky to have many 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 provides 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.

Dr E J Neafsey

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 impoundment 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.