Carbon dioxide dynamics driven by groundwater discharge in a coastal floodplain creek

Carbon dioxide and methane fluxes across the sediment-water interface in different grass carp Ctenopharyngodon idella polyculture models

“…Because carbon provides the substrate necessary for microbial CO 2 and CH 4 formation (Adams 2005, Beaulieu et al 2009, Atkins et al 2013, high positive correlations were observed between DIC, POC, and DOC and CO 2 and CH 4 fluxes (Table 3). Several studies revealed that the continuous enrichment of OM and TC increases DIC, POC, and DOC in aquatic systems (Li 2004, Yokoyama et al 2006, Valdemarsen et al 2009).…”

“…the sediment−water interface, shows significant variations in its physical, chemical, and biological characteristics (Schindler 1981, Nixon 1986, and plays a vital role in the circulation, transfer, and storage of materials in aquatic ecosystems (Santschi et al 1990). Sediment is a source of LLGHGs such as CH 4 and CO 2 (Adams 2005, Beaulieu et al 2009, Atkins et al 2013, which are dissolved in the overlying water, or are emitted to the atmosphere through molecular diffusion, plant transport, or gas bubbles (Belger et al 2011). Both CH 4 and CO 2 might originate from the organic carbon accumulated in freshwater pond substrates due to uneaten feed, organic fertilizers, dead plankton, and cultured species excreta (Bachoon & Jones 1992, Liikanen et al 2002, Algesten et al 2005, Shalini et al 2006, Laverman et al 2010, Adhikari et al 2012.…”

Dissolved iron exports from an estuary surrounded by coastal wetlands: Can small estuaries be a significant source of Fe to the ocean?

“…Coastal creeks are stretches of funnel shaped inlets with tidally driven flushing, and are often incised into coastal wetland systems such as mangroves, saltmarshes, or freshwater floodplain wetlands (Atkins et al, 2013;Muller and Muller, 2014). In contrast, rivers typically contain pronounced estuarine systems, forming basins that transform dissolved and colloidal metal loads through physical, biological and geochemical processes, such as flocculation, primary production and respiration, and redox and ion exchange processes before reaching the ocean (Boyd and Ellwood, 2010;Carroll and Moore, 1993;de Baar and de Jong, 2001;Rahaman et al, 2010).…”

Estuarine canal estate waters: Hotspots of CO2 outgassing driven by enhanced groundwater discharge?

“…However, recent studies suggest that inputs of high pCO 2 groundwater may also contribute to the water-to-air flux of CO 2 (Atkins et al, 2013;Cai, 2011;Cai et al, 2003). As groundwater is often highly enriched in CO 2 compared to surface waters, groundwater discharge can influence CO 2 evasion from surface waters even when seepage rates are relatively low (Santos et al, 2012).…”