The upshot was, as in Kuliński & Pempkowiak (2011), that the net CO2 emissions to the atmosphere were calculated at 1.36 ± 1.71 Tg C yr− 1. The mean CO2 emission was –3.5 g C m− 2 yr− 1 (–12.9 g CO2 m− 2 yr− 1). Thus, the Baltic Sea’s status as a source of CO2 to the atmosphere was confirmed. Moreover, when the SGD carbon loads are added to the Baltic carbon budget, the status of the sea defined to date as ‘marginally heterotrophic’ becomes minimally, yet definitely heterotrophic. The projected estimates of dissolved carbon input into the Baltic Sea via SGD should draw attention to the significance of SGD in hydrological carbon cycles. The projections demonstrate

that SGD sites may transport substantial loads of carbon to coastal areas. One immediate consequence of this is a change Epigenetic inhibitor concentration in the biodiversity in seepage-affected areas (Liu et al., 2012 and Kotwicki et al., 2013). The global carbon cycle involves processes among the major global reservoirs of this element: the atmosphere, ocean and land. The fundamental carrier in carbon cycling is CO2. Ocean carbonate chemistry

has a great impact on CO2 partial pressure in the atmosphere. So far, no carbon fluxes via SGD to the World Ocean have been considered in the global carbon cycle. As indicated, however, the SGD-derived carbon load constitutes a significant portion of the carbon budget in entire coastal basins (Table 2). Moreover, it has been estimated that the total flux of SGD to the Atlantic Ocean is comparable in volume to the riverine flux (Moore 2010). Hence,

in U0126 order to establish the order of magnitude of the SGD derived carbon load, we attempted to Amino acid calculate carbon fluxes via SGD to the World Ocean. Global SGD rates and dissolved carbon concentrations are required for this purpose. There are few reports on carbon concentrations in groundwater impacted areas (Cai et al., 2003, Moore et al., 2006 and Liu et al., 2012) (Table 2) and few on global groundwater discharges (Zektser and Loaiciga, 1993, Zekster et al., 2007 and Moore, 2010) (Table 3). Since the carbon concentrations obtained in this study are comparable to those in other study areas (Table 2), we decided to use the DIC and DOC concentrations measured in this study and literature derived SGDs to the World Ocean to establish the load of carbon that might enter the marine environment with SGD (Table 3). The calculated carbon fluxes are in the following ranges: (142–838) × 103 kt C yr− 1 (DIC) and (13–75) × 103 kt C yr− 1 (DOC). Reports define the carbon load delivered to the sea with river run-off with much better precision – see Table 3 (Ludwig 1996, Hen et al. 2003, Emerson & Hedges 2008). It follows from the data in Table 3 that the SGD-derived carbon load and the carbon load delivered with riverine discharge are comparable.