Velinsky, D.J.; Paudel, B.; Belton, T.J., and Sommerfield, C.K., 2017. Tidal marsh record of nutrient loadings in Barnegat Bay, New Jersey. In: Buchanan, G.A.; Belton, T.J., and Paudel, B. (eds.), A Comprehensive Assessment of Barnegat Bay-Little Egg Harbor, New Jersey.

Sediment and nutrient burial in tidal marshes of Barnegat Bay was investigated using age-dated sediment cores collected along a north-to-south transect. Measurements of radionuclides (²¹⁰Pb and ¹³⁷Cs) and stable isotopes (¹³C and ¹⁵N) were accompanied by nutrient and organic matter concentrations. Sediment accumulation rates, measured using ²¹⁰Pb and ¹³⁷Cs chronology, ranged from 48 to 81 mg cm² y⁻¹, whereas corresponding accretion rates ranged from 0.16 to 0.30 cm y⁻¹. Sediment nitrogen (N) accumulation rates increased twofold at an upper bay site, starting in the mid-1950s, whereas at other locations, only small to no increases were seen with time. Phosphorus (P) accumulation was minimal with time. N and P accumulation rates were higher between the 1940s to 1950s at stations BB-1 and BB-3, while higher accumulation rate in the down-bay (BB-4) was identified in the early 1990s. Results indicate that bay marshes can sequester approximately 79 ± 11% of N and 54 ± 34% of P entering the Bay from upland sources; thus, these marshes perform an important ecosystem service in the form of nutrient sequestration. Marsh accretion rates at the coring sites fall at, to just below, rates of relative sea-level rise recorded by nearby tide gauges. These relatively low rates of accretion render the marsh vulnerable to inundation should the rate of sea-level rise accelerate in the future.