Mangrove forests, or mangals, are low energy, tropical-subtropical habitats at the interface of land and sea and can be found all over the world. These habitats are known for being extremely productive communities that have a complex food web that is based on the detritus derived from dead vegetation and associated microorganisms as well as entrained marine and terrestrial material. This food web supports a wide diversity of food to a diversity of infaunal, epifaunal, and juvenile species. Besides supporting a food web of permanent inhabitants, mangroves may also contribute to the food webs of offshore communities, such as seagrass beds, through the migration of predatory and herbivorous fish. Port Everglades has always featured mangroves lining the sides of the intercoastal waterway as well as the individual channels, but it is also an extremely active site for commercial and recreational use and has undergone significant physical changes. Three different mangrove communities in Port Everglades were examined and through field collection, flora and fauna species were taken from each of the three mangrove sites These samples were then analyzed using stable isotope analysis to establish patterns of energy flow from mangrove vegetation to apex predators, identify possible influences from the port activities, and discover transference of energy to other communities.
Individual samples were collected from four mangrove species, four algal families, three terrestrial plant families, four crustacean families, eight gastropod families, and ten osteichthyes families. The stable isotope analysis revealed that gastropod species had a similar average δ13C signature (-22.52) to that of the algae species (-22.93). The stable isotope analysis also revealed that the detrital material had a more enriched carbon signature (-25.64) than the distinguishable live mangrove vegetation (-28.29), revealing that the detrital material provides a useful linkage between the mangrove vegetation and the consumers. The ranges of the δ15N signatures of vertebrate and invertebrate consumers (6.50-11.25) compared to the wide range of signatures of producers (1.5-5.16) shows a strong trophic system. This data has so far revealed that the mangroves provide not only an energy source, but also substrata for growing primary producers and sessile consumers as well as a collection site for decaying material.
Available at: http://works.bepress.com/amy-hirons/23/