Lipid compounds from seven sedimentary stations were used to assess sources of organic matter in two mangrove ecosystems located on Santa Catarina Island, southern Brazil. Ratones Mangrove forms part of a national preservation area and has suffered only minimal human influence. Itacorubi Mangrove has been seriously impacted by anthropogenic activities due to its proximity to the city of Florianopolis. Higher levels of total organic carbon (2.13 mmol g-1) and total phosphorus (14.9 µmol g-1) were found in Ratones Mangrove sediments. However, sediments from Itacorubi showed a greater percentage of inorganic phosphorus (84%) than those from Ratones (58%), which can be related to urban contamination. The importance of sewage outfalls into the tidal creeks crossing Itacorubi Mangrove was clearly seen as the concentration of coprostanol averaging 7.7 ng g-1 in Ratones sediments was found to be as high as 1.42 µg g-1 in Itacorubi, which is comparable to other sewage contaminated hydrosystems.
sediments; mangrove; Ratones; Itacorubi; phosphorus; coprostanol
