Sedimentation Rates on Tidal Salt Marshes in Connecticut

Abstract

ABSTRACT Rates of sediment accretion from 1963-1973 on five high marsh sites on the Connecticut coast of Long Island Sound ranged from 2.0 mm/yr to 6.6 mm/yr. The rates are correlated with tidal range; the highest sedimentation rates are on marshes with the greatest tidal range. The greater the tidal range, the larger are the deviations of high-tide level. Thus, greater net flooding occurs on high marshes with greater tide ranges and may cause the observed high accretion rates. Over ten years no measurable compaction has taken place within the near-surface sediment. Years with fewer than average storms show less sediment accretion. A sedimentation rate of 17.1 mm/yr from 1963-1973 was measured where Spartina patens salt marsh is giving way to Phragmites communis.