Influence of benthic regeneration on the biogeochemical cycle of CO2 in littoral ecosystems

Jm Forja,Ta Del-Valls,A Gómez-Parra,T Ortega

doi:10.7773/cm.v27i3.494

Abstract

The benthic fluxes of inorganic carbon were measured in the Bay of Cádiz, located in the SW of the Iberian Peninsula (Southern Europe). The values measured ranged between 74 and 224 mmol m–2 d–1, which are higher than most reported fluxes. They were linearly correlated with the organic carbon content in surface sediments. For the Bay of Cádiz, a carbon budget is proposed. It was determined that 53% of the benthic inorganic carbon production is used by the phytoplankton of the area, and 43% is exported by tides to other littoral areas. The rest of the benthic production, together with direct emission of CO2 from intertidal sediments to the atmosphere, yielded a maximum net flux of 5.6 · 108 mol C y–1. If extrapolated to coastal areas globally, these values are particularly significant. Taking 44 mmol m–2 d–1 as an average value for benthic fluxes of dissolved inorganic carbon, it is estimated that the benthic CO2 production by coastal ecosystems is about 4.2 · 1014 mol y–1, similar to the estimated annual CO2 emissions to the atmosphere from the burning of fossil fuels.

Highlights

INTRODUCCIÓNIn terms of mass transfer between continents, the oceans and the atmosphere, the carbon cycle constitutes one of the most active sets of processes that control the behavior of other systems on the planetary scale
Tomando un flujo bentónico medio de carbono inorgánico disuelto de 44 mmol m–2 d–1, se ha estimado que la producción bentónica de CO2 para los sistemas costeros es del orden de 4.2 · 1014 mol año–1 y, por tanto, similares a las emisiones anuales de CO2 a la atmósfera provocadas por la utilización de combustibles fósiles
Spatial and seasonal variations of benthic fluxes of inorganic carbon and nutrients are available from previous studies (Gómez-Parra and Forja, 1993; Forja et al, 1994; Forja and Gómez-Parra, 1998)

Summary

Introduction

INTRODUCCIÓNIn terms of mass transfer between continents, the oceans and the atmosphere, the carbon cycle constitutes one of the most active sets of processes that control the behavior of other systems on the planetary scale. Tomando un flujo bentónico medio de carbono inorgánico disuelto de 44 mmol m–2 d–1, se ha estimado que la producción bentónica de CO2 para los sistemas costeros es del orden de 4.2 · 1014 mol año–1 y, por tanto, similares a las emisiones anuales de CO2 a la atmósfera provocadas por la utilización de combustibles fósiles.

Results

Conclusion