Carbon and nutrient burial within Peruvian coastal marsh driven by anthropogenic activities.

This research assessed carbon and nutrient burial during the past ~60 years within a Peruvian coastal marsh ecosystem affected by anthropogenic activities, by examining total organic carbon (TOC), total nitrogen (TN) and isotopes (δC and δN) tracers in two dated sediment cores. Significantly higher TOC and TN burial, up to 416.4 ± 65.0 and 0.7 ± 0.1 g m year respectively, were observed after an uncontrolled urban expansion starting in the early 1970's to the 1990's. The TOC and TN burial rates were up to twofold higher than those observed for preserved coastal marshes. Furthermore, the decreased δC values (-16.1 ± 0.6 ‰) and increasing δN values (+10.6 ± 2.6 ‰) indicate higher deposition of algal material and urban sewage during the same period. The higher burial rates during 1970's-1990's and reduced rates thereafter evidenced the role of coastal marsh ecosystems plays in sequestering carbon and nutrients.