Institut for Biologi

Aarhus Universitets segl

Niels Peter Revsbech

What supports the deep chlorophyll maximum in acidic lakes? The role of the bacterial CO2 production in the hypolimnion

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review


  • lno.11391

    Forlagets udgivne version, 2,22 MB, PDF-dokument


  • Sara Soria-Píriz, University of Cádiz
  • ,
  • Miguel Lara, University of Cádiz
  • ,
  • Juan Luis Jiménez-Arias, University of Cádiz
  • ,
  • Sokratis Papaspyrou, University of Cádiz
  • ,
  • Bárbara Úbeda, University of Cádiz
  • ,
  • Emilio García-Robledo, University of Cádiz
  • ,
  • Julio Bohórquez, University of Cádiz
  • ,
  • José Ángel Gálvez, University of Cádiz
  • ,
  • Niels Peter Revsbech
  • Alfonso Corzo, University of Cádiz

The interactions between phytoplankton, bacteria and resources, irradiance, and nutrients, leading to the formation of deep chlorophyll maxima (DCMs), are little understood in acid lakes. In “El Sancho” reservoir (Iberian Pyritic belt, Huelva, Spain), an acid mine drainage impacted waterbody (pH 3.5–4.0), a strong DCM forms in the metalimnion during the stratification period. The DCM was located always below the 1% irradiance level, where the decreasing irradiance profile overlapped with a dissolved inorganic carbon concentration (CO2) gradient decreasing upward from the hypolimnion. The DCM was dominated by the chlorophyte Carteria sp. and showed the highest volumetric photosynthetic and dark respiration rates. The DCM, however, only contributed around 20% of water column integrated gross primary production, while it accounted for 54–66% of water column chlorophyll. The total bacterial abundance correlated significantly with the CO2 concentration (r = 0.74). To test the hypothesis of a possible dependence of the formation of the DCM in acid lakes on the production of CO2 by heterotrophic bacteria, a one-dimensional reactive transport model (DCM-CO2) was developed and tested. The DCM-CO2 model simulated the vertical distribution of chlorophyll (R2 > 0.63) and the vertical profile of CO2 rather accurately (R2 > 0.79), the position of DCM depending on both light penetration and an upward flux of CO2 produced by hypolimnetic heterotrophic bacteria. Overall, the results support the hypothesis of microbial degradation of organic matter being a source of CO2 for acid lake primary producers at the DCM.

TidsskriftLimnology and Oceanography
Sider (fra-til)1318-1335
Antal sider18
StatusUdgivet - jun. 2020

Se relationer på Aarhus Universitet Citationsformater


Ingen data tilgængelig

ID: 190871742