Mangroves

Driving along the coast of northern Florida, one can expect to see patches and pockets of salt marsh grasses jetting from the shallow waters, but as temperatures begin to climb, a new plant species is settling in and making home. Mangroves, a common site in southern Florida, are starting to adapt and expand their territory. Similar to spartina, mangroves also help prevent erosion and provide habitat to countless fish, crabs, snails and other marine life. 

There are 3 different kinds of mangroves in the United States, black, red and white.

Black mangroves are probably the hardiest, they can be recognized by their pneumatophores, which are finger-like woody growths that emerge from the water and help exchange oxygen and gases.

They reproduce in a very unique way, the seeds (propagules) germinate while on the plant and drop into the water. The seed will float along until it finds an ideal location to establish itself.

Out in the waters of St. Joseph Bay Aquatic Preserve, a study is being done by Ray Bradbury, of University of Florida’s Institute of Food and Agricultural Sciences.

Ray is studying the decomposition of mangrove leaf litter versus salt marsh wrack.  A tall white survey post marks the location of one of the substations. There are three substations in total, marking the various ecotones where the study is being conducted. The first substation is located in a salt marsh; the second one is located in population of mangroves and the third is in a transition zone between the two. The substation consists of a white survey post, a mesh bag and inside of it, smaller fabric bags stuffed with leaf litter from either salt marshes or mangroves. Using the bags, Ray is able to analyze how the left litter breaks down without the interference of marine herbivores, such as crabs and snails.    

Every 2 weeks, Ray visits his test sites and extracts a sample from each eco-tone. The sample is left to dry and then weighed. So far, it appears that the mangrove litter takes longer to break down than the salt marsh litter. It also appears that the salt marsh litter traps more sediment than the mangrove litter, it is likely this is because the mangrove leaves have a cuticle that allows sediment to easily drift through. 

This is just part 2 of a 3 part studying being conducted by the University of Florida/Institute of Food and Agricultural Sciences, we are looking forward to hearing the results and learning how this will impact our ever-changing bay. 

St. Joseph Bay State Buffer Preserve attracts researchers from all across the United States. Researchers can book lodging at the Buffer Preserve by contacting Caitlin McCauley at Caitlin.McCauley@floridadep.gov