Biogeochemical consequences of infaunal activities

Abstract

The public reporting burden for this collection of Information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, Activities of sedimentary infauna have significant consequences on overall sedimentary diagenesis. Infauna directly participate in sedimentary processes by organic matter metabolization coupled to aerobic respiration and metabolite excretion. In addition, they indirectly influence the diagenetic pathways by changing the transport regimes of dissolved and particulate species as well as by modifying microbial habitats. The couplings between infaunal activities and their biogeochemical consequences have been studied in recent years, but many of the results and conclusions remain site-and species-specific due to the diverse and highly interrelated ways in which sedimentary infauna interact with the transport. reaction, and microbial regimes. A generalized understanding of infauna-influenced sedimentary systems will require (It a systematic classification of the infauna-sediment interaction mechanisms Activities of sedimentary infauna have significant consequences on overall sedimentary diagenesis. Infauna directly participate in sedimentary processes by organic matter metabolization coupled to aerobic respiration and metabolite excretion. In addition, they indirectly influence the diagenetic pathways by changing the transport regimes of dissolved and particulate species as well as by modifying microbial habitats. The couplings between infaunal activities and their biogeochemical consequences have been studied in recent years, but many of the results and conclusions remain site-and species-specific due to the diverse and highly interrelated ways in which sedimentary infauna interact with the transport, reaction, and microbial regimes. A generalized understanding of infauna-influenced sedimentary systems will require (1) a systematic classification of the infauna-sediment interaction mechanisms and (2) a comprehensive model framework that incorporates all known effects of infauna-sediment interactions associated with transport, reaction, and microbial regimes.

The microbial landscape in bioturbated mangrove sediment: A resource for promoting nature‐based solutions for mangroves

“…In intertidal sediments, at low tide, burrows enhance the downward vertical transfer of gases and act to increase the surface area for gaseous exchange and redox reactions (Kristensen, 2008 ), whereas at high tide, they provide sites with steep geochemical gradients since they form boundaries between anoxic sediment (rich in reduced chemical species and metabolites) and water (enriched in oxygen) (Furukawa, 2005 ). Uptake of dissolved oxygen by sediments via diffusion occurs at these oxic/anoxic interfaces (Furukawa, 2005 ), and burrows influence the rates and extent of organic matter mineralization in addition to fluxes in nutrient cycling (Aller, 2001 ). They allow carbon substrates and oxygen to be transported deeper into the sediment, while toxic metabolites (e.g.…”

A Surrogate Approach to Studying the Chemical Reactivity of Burrow Mucous Linings in Marine Sediments

“…A large fraction-estimates range between one-third to one-half-of shallow-marine sediments are affected by burrowing activity (e.g., Aller and Aller, 1986;Kostka et al, 2002;Furukawa, 2005). At any given time the density of burrows present may range from less than a few hundred per m 2 made by such large animals as lobsters, crabs, and shrimp (e.g., Webb and Eyre, 2004), to as high as several thousand individuals per m 22 in sediments inhabited by such smaller animals as marine annelids (e.g., Bell et al, 1993) and arthropods (e.g., amphipods; Pearson and Gingras, 2006).…”