Organic matter burial capacity and characterization of coastal lakes in the Gösku Delta salt marsh

Abstract

Coastal vegetated environments are among the most productive ecosystems of planet earth, despite covering a fairly small global area. Their high capacity to capture and store Carbon in their sediments has recently been the object of much research. The aim of this research is to investigate the burial capacity and the Carbon sources of several saline lakes in the Gösku Delta salt marsh. Sediment cores were collected in three different lakes along a salinity gradient connected by a small channels, with outlets ending in the Mediterranean Sea. Sedimentary organic matter was quantified over time and space in all three lakes. Stable isotope analysis of Carbon and Nitrogen was performed on samples to identify biomass sources. Results indicate that organic matter burial in the sediments is strongly variable along the salt marsh, and not related to the salinity gradient. Peaks of sedimentary organic matter concentration were associated with increases in macrophyte biomass within the lakes. Moreover, the results highlight how anthropogenic-driven changes, such as the building of agricultural runoff drainage channels pumping water and nutrients into Lake Akgöl, likely affected the specie composition of the system. The Carbon burial rates are extremely variable within the different sampling locations, highlighting the importance of heterogeneity in salt marsh systems like the Gösku Delta.