acidification, salination, sedimentation, salinity, nitrification, silting, desertification, anoxia, estuaries, upwelling, freshwater, denitrification, hypoxia, deglaciation, overexploitation, overfishing, soil erosion, phytoplankton, sediment, hydrologic cycle, algae, nitrogen fixation, dinoflagellate, denudation, ecological, alkalinity, shoaling, cyanobacteria, benthic, dieback, waterweed, degradation, urbanization, biota, benthos, pollution, oxygenation, biodiversity, biofouling, el nino southern oscillation, diatoms, plankton, turbidity, intertidal, pollutants, gastropods, amphipods, estuarine, volcanism, eelgrass, anabaena, alkalosis, toxaphene, acidosis, rhizosphere, acid rain, zebra mussel, halophyte, azolla, geosphere, sinkage, desiccation, hydrosphere, gyres, seiche, headwater, atherogenesis, embayment, freshwater mussel, shallowing, phosphorus, deforestation, phosphorous, schistosomiasis, submergence, milfoil, mudflat, biodegradation, ecosystems, tributary, depletion, invertebrates, wetland, daphnia, amur river, metabolic acidosis, deltaic, trematode, decomposition, hypovolemia, winterkill, leaf scorch, endemism, carbonic acid, deoxygenation, planktonic algae, organisms, gobies, orthophosphate, cormorants, natriuresis, zooplankton, erosion, flooding, fracturing, warming, corrosion, subsidence, weathering, abrasion, defoliation, destabilization, buildup, commercialization, mechanization, politicization, attrition