High dissolved organic carbon release by benthic cyanobacterial mats in a Caribbean reef ecosystem
Hannah J. Brocke
Frank Wenzhoefer
Dirk de Beer
Benjamin Mueller
Fleur C. van Duyl
Maggy M. Nugues
Abstract
Benthic cyanobacterial mats (BCMs) are increasing in abundance on coral reefs worldwide. However, their impacts on biogeochemical cycling in the surrounding water and sediment are virtually unknown. By measuring chemical fluxes in benthic chambers placed over sediment covered by BCMs and sediment with BCMs removed on coral reefs in Curaçao, Southern Caribbean, we found that sediment covered by BCMs released 1.4 and 3.5 mmol C m−2 h−1 of dissolved organic carbon (DOC) during day and night, respectively. Conversely, sediment with BCMs removed took up DOC, with day and night uptake rates of 0.9 and 0.6 mmol C m−2 h−1. DOC release by BCMs was higher than reported rates for benthic algae (turf and macroalgae) and was estimated to represent 79% of the total DOC released over a 24 h diel cycle at our study site. The high nocturnal release of DOC by BCMs is most likely the result of anaerobic metabolism and degradation processes, as shown by high respiration rates at the mat surface during nighttime. We conclude that BCMs are significant sources of DOC. Their increased abundance on coral reefs will lead to increased DOC release into the water column, which is likely to have negative implications for reef health.
Brocke H.J., Wenzhoefer F., de Beer D., Mueller B., van Duyl F.C. and Nugues M.M. (2015) High dissolved organic carbon release by benthic cyanobacterial mats in a Caribbean reef ecosystem. Scientific Reports 5(1). 10.1038/srep08852
@article{Brocke2015,
Title = {High dissolved organic carbon release by benthic cyanobacterial mats in a Caribbean reef ecosystem},
Author = {Brocke, Hannah J. and Wenzhoefer, Frank and de Beer, Dirk and Mueller, Benjamin and van Duyl, Fleur C. and Nugues, Maggy M.},
Editor = {},
Journal = {Scientific Reports},
Year = {2015},
Volume = {5},
Doi = {10.1038/srep08852},
Abstract = {Benthic cyanobacterial mats (BCMs) are increasing in abundance on coral reefs worldwide. However, their impacts on biogeochemical cycling in the surrounding water and sediment are virtually unknown. By measuring chemical fluxes in benthic chambers placed over sediment covered by BCMs and sediment with BCMs removed on coral reefs in Curaçao, Southern Caribbean, we found that sediment covered by BCMs released 1.4 and 3.5 mmol C m−2 h−1 of dissolved organic carbon (DOC) during day and night, respectively. Conversely, sediment with BCMs removed took up DOC, with day and night uptake rates of 0.9 and 0.6 mmol C m−2 h−1. DOC release by BCMs was higher than reported rates for benthic algae (turf and macroalgae) and was estimated to represent 79% of the total DOC released over a 24 h diel cycle at our study site. The high nocturnal release of DOC by BCMs is most likely the result of anaerobic metabolism and degradation processes, as shown by high respiration rates at the mat surface during nighttime. We conclude that BCMs are significant sources of DOC. Their increased abundance on coral reefs will lead to increased DOC release into the water column, which is likely to have negative implications for reef health.},
}
TY - JOUR
AU - Brocke, Hannah J.
AU - Wenzhoefer, Frank
AU - de Beer, Dirk
AU - Mueller, Benjamin
AU - van Duyl, Fleur C.
AU - Nugues, Maggy M.
TI - High dissolved organic carbon release by benthic cyanobacterial mats in a Caribbean reef ecosystem
T2 - Scientific Reports
PY - 2015
VL - 5
DO - 10.1038/srep08852
AB - Benthic cyanobacterial mats (BCMs) are increasing in abundance on coral reefs worldwide. However, their impacts on biogeochemical cycling in the surrounding water and sediment are virtually unknown. By measuring chemical fluxes in benthic chambers placed over sediment covered by BCMs and sediment with BCMs removed on coral reefs in Curaçao, Southern Caribbean, we found that sediment covered by BCMs released 1.4 and 3.5 mmol C m−2 h−1 of dissolved organic carbon (DOC) during day and night, respectively. Conversely, sediment with BCMs removed took up DOC, with day and night uptake rates of 0.9 and 0.6 mmol C m−2 h−1. DOC release by BCMs was higher than reported rates for benthic algae (turf and macroalgae) and was estimated to represent 79% of the total DOC released over a 24 h diel cycle at our study site. The high nocturnal release of DOC by BCMs is most likely the result of anaerobic metabolism and degradation processes, as shown by high respiration rates at the mat surface during nighttime. We conclude that BCMs are significant sources of DOC. Their increased abundance on coral reefs will lead to increased DOC release into the water column, which is likely to have negative implications for reef health.
ER -
