Anthropogenic sources and distribution of phosphorus in sediments from the Jaguaribe River estuary, NE, Brazil

this paper estimates annual p emission to the jaguaribe river estuary, ne brazil, responsible for approximately 30% of the country's farmed shrimp production. emissions increased three times between 2001 and 2006 and reached 43.9 t.year-1. these emissions make aquaculture the third main source of p for this estuary and are much smaller than emissions from agricultural sources and slightly lower than emissions from wastewater. their relative contribution also increased from 10.5% to 20.5%. temporal variability of p concentrations in estuarine bottom sediments also suggest an increase, but not as evident as the emissions. the spatial distribution and speciation of p (total p and inorganic p) in sampling stations located upstream and downstream from the main aquaculture area confirmed the importance of this source. inorganic p was the dominant form present in sediments downstream and showed an increase from 67% to 75% of the total p present in the sediment.