Dynamics of nutrients, total organic carbon, prokaryotes and viruses in onboard incubations of cold-water corals

• Published in: Biogeosciences
• Main Authors: Maier, C., de Kluijver, A., Agis, M., Brussaard, C., van Duyl, F., Weinbauer, Markus
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), The publication of this article is financed by CNRS-INSU
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDU]Sciences of the Universe [physics]; Lophelia pertusa
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03324794; https://hal-insu.archives-ouvertes.fr/insu-03324794/document; https://hal-insu.archives-ouvertes.fr/insu-03324794/file/bg-8-2609-2011.pdf; https://doi.org/10.5194/bg-8-2609-2011

International audience Abstract. The potential influence of the cold-water corals (CWCs) Lophelia pertusa and Madrepora oculata on the dynamics of inorganic nutrient and total organic carbon (TOC) concentrations and the abundances of prokaryotes and viruses in bottom water was assessed in onboard incubation experiments. Ammonium, nitrite, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) and TOC concentrations and N:P ratios were typically higher in incubation water with corals than in controls, whereas nitrate concentrations did not reveal a clear trend. Mucus release (normalized to coral surface) was estimated by the net increase rate of TOC concentrations and averaged 23 ± 6 mg C m−2 h−1 for L. pertusa and 21 ± 8 mg C m−2 h−1 for M. oculata. Prokaryotic and viral abundance and turnover rates were typically stimulated in incubation water with corals. This estimated prokaryotic stimulation averaged 6.0 ± 3.0 × 109 cells m−2 h−1 for L. pertusa and 8.4 ± 2.9 × 109 cells m−2 h−1 for M. oculata, whereas the estimated viral stimulation averaged 15.6 ± 12.7 × 109 particles m−2 h−1 for L. pertusa and 4.3 ± 0.4 × 109 particles m−2 h−1 M. oculata. Our data suggest that prokaryotes and viruses are released from corals and that nutrient and mucus release enhanced prokaryotic and viral production. The result of this stimulation could be a fuelling of bottom water in CWC reefs with nutrients and organic matter and consequently an enhancement of microbe-mediated processes.