Environmental controls and distributions of surface foraminifera from the Otter estuary salt marsh, UK: their potential use as sea level indicators

Abstract

Fifty-six surface samples were collected from the Otter estuary salt marsh, Devon, UK. Previous work from temperate salt marshes have shown the vertical distribution of foraminifera is primarily controlled by the duration of tidal flooding, whilst working on the general assumption that the elevation of the intertidal zone controls the variations of any environmental parameters affecting foraminifera distributions. Cluster analysis identifies three foraminifera assemblage zones, and a clear vertical distribution of species within the high and low marsh zones is present. However Canonical Correspondence Analysis (CCA) identifies that within the middle marsh elevation has less of a control over the distribution of the dominant Jadammina macrescens, whilst pH has increased significance. The calculation of a Root Mean Square Error of Prediction (RMSEP) for the data set indicates an approximate vertical error of ±0.30m, which is directly comparable to similar studies in the area. Therefore the foraminifera can be considered suitable indicator proxies for Holocene sea level reconstructions.