The effect of tidal forcing on biogeochemical processes in intertidal salt marsh sediments

Abstract

Background: Early diagenetic processes involved in natural organic matter (NOM) oxidation in marine sediments have been for the most part characterized after collecting sediment cores and extracting porewaters. These techniques have proven useful for deep-sea sediments where biogeochemical processes are limited to aerobic respiration, denitrification, and manganese reduction and span over several centimeters. In coastal marine sediments, however, the concentration of NOM is so high that the spatial resolution needed to characterize these processes cannot be achieved with conventional sampling techniques. In addition, coastal sediments are influenced by tidal forcing that likely affects the processes involved in carbon oxidation.

Changes in ultrastructural features of the foraminifera Ammonia spp. in response to anoxic conditions: Field and laboratory observations

“…2), micro-oxic conditions, or microenvironments with free oxygen, may at least periodically exist in deeper sediment units. Intertidal sediments can be very heterogeneous and tidal activity and bioturbation are known to significantly influence oxygen and nitrogen dynamics in these settings (e.g., Aller and Aller, 1998;Taillefert et al, 2007;Bonaglia et al, 2014). The intertidal mudflat of Mokbaai is also known to be heavily bioturbated (Hongguang et al, 1995), and during core processing large polychaete worms (several cm in size) were seen especially deep in the sediment, occurring generally from a depth of 5 cm but burrowing well below 10-cm depths in sediment.…”

“…Dormancy or reduced metabolism could be a widespread response in benthic foraminifera to survive unfavorable conditions (e.g., anoxia) (Ross and Hallock, 2016). This coping mechanism could be especially common for shallow-water foraminifera living in dynamic environments, like subtidal and intertidal settings, which experience frequent changes in pore water chemistry associated with tidal action (e.g., Taillefert et al, 2007). In addition, these environments are commonly heavily bioturbated due to the relatively high abundance of macrofauna, leading to the potential development of oxygenated micro-niches deeper in the sediment (e.g., Aller and Aller, 1992;Wenzhöfer and Glud, 2004).…”

Solid‐State Au/Hg Microelectrode for the Investigation of Fe and Mn Cycling in a Freshwater Wetland: Implications for Methane Production

“…The solid-state Au/Hg microelectrode has been used to measure the distribution of these redox components in the water column of lakes, estuaries, inland bays, the Chesapeake Bay, the Black Sea as well as hydrothermal vents [3 -11] and in the porewaters of marine and freshwater sediments at (sub)millimeter vertical resolution [4,12,13]. Voltammetry is a powerful technique because it provides chemical speciation data (e.g.…”

The Role of Sediments in Coastal Monitoring

“…Taillefert et al ., 2007), and the marine sediments form such a complicated, rich organic matrix (Mille et al ., 2006;Mazur-Marzec et al ., 2007;Szymczak-Zyła and Kowalewska, 2007;Stephens et al ., 2007;Unlu and Alpar, 2006) that neither laboratory experiments nor mathematical models can give as full and reliable information as the results of case studies on contaminants in the natural environment. Such study should not include solely the chemical analyses (Falandysz et al ., 2006), but also investigate the relations of the contaminants studied with the environmental conditions, including biological (Nakata et al ., 2006;Carafa et al ., 2006), geological (Lee et al ., 2006), hydrodynamic (Bone et al ., 2006 and other factors (e.g.…”