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Collection, analysis, and age-dating of sediment cores from natural and restored salt marshes on Cape Cod, Massachusetts, 2015-16

June 30, 2021

Nineteen sediment cores were collected from five salt marshes on the northern shore of Cape Cod where previously restricted tidal exchange was restored to part of the marshes. Cores were collected in duplicate from two locations within each marsh complex: one upstream and one downstream from the former tidal restriction (typically caused by an undersized culvert or a berm). The unaltered, natural downstream sites provide a comparison against the historically restricted upstream sites. The sampled cores represent a chronosequence of restoration occurring between 2001-10. Collected cores were up to 168 cm in length with dry bulk density ranging from 0.04 to 2.62 grams per cubic centimeter and carbon content 0.12 % to 48.91 %. Land surface elevation was measured at each site (ranging from 0.484 meters to 1.51 meters relative to NAVD88) to determine the boundaries of each site within current tidal conditions. Gamma counting results for excess lead-210 were used to construct Constant Rate of Supply age models to date individual depth intervals in the core. Additionally, gamma counting results for other radionuclides, particularly cesium-137, gave further insight to evaluate how vertical accretion and carbon burial rates have changed during the past century. Carbon isotopes were measured to evaluate organic matter source.

Citation Information

Publication Year 2021
Title Collection, analysis, and age-dating of sediment cores from natural and restored salt marshes on Cape Cod, Massachusetts, 2015-16
DOI 10.5066/P9R154DY
Authors Jennifer A O'keefe Suttles, Meagan J Eagle, Adrian C Mann, Amanda Spivak, Kelly Sanks, Roberts Daniel, Kevin D Kroeger
Product Type Data Release
Record Source USGS Digital Object Identifier Catalog
USGS Organization Woods Hole Coastal and Marine Science Center