The impact of discharging treated effluent from a garment assembly factory into a forested, mangrove wetland in Belize, Central America was examined by comparing selected physical, chemical, and biological characteristics of vegetation, soil, and water of this wetland (the treatment wetland) with that of a nearby wetland not receiving effluent (the reference wetland). Characteristics examined were soil redox, pH, total Kjeldahl nitrogen (TKN), and extractable nitrogen (EXN), interstitial porewater, dissolved oxygen (DO), salinity, pH, ammonia (NH4+), and nitrate (NO3-). Botanical structure and character was also surveyed for species density, diameter at breast height (dbh), basal area, biomass and species importance.
Four of the fourteen parameters examined: 1) porewater salinity, 2) porewater NO3-, 3) the dbh of the stem of mean basal area, and 4) species importance, differed (p= 0.5) in the treatment wetland. These differences indicate an increase in freshwater hydrology and biogeochemical processing of plant available forms of inorganic nutrients, particularly nitrate, in the treatment wetland. As a result of these changes plant growth in the treatment wetland has been enhanced and a shift in plant species has occurred. Conclusions indicate that the mangrove system under study has the capacity to assimilate wastewater with concentrations of total organic nitrogen (TIN) up to 20-40 mg/l and suggests that mangrove species have a role in wetland treatment technology.