Major fine-scale spatial heterogeneity in accumulation of gelatinous carbon fluxes on the deep seabed

Frontiers in Marine Science

Marine Science

Autun Purser¹  Inken Suck²  Henk-Jan Hoving²  Matthias Haeckel²  Jens Greinert³  Katherine Dunlop⁴  Yann Marcon⁵  Antje Boetius⁶  Tanja Stratmann⁷  Daniel O. B. Jones⁸  Erik Simon-Lledó⁸  Andrew K. Sweetman⁹ 

[1] Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany;GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany;Christian-Albrechts University Kiel, Institute of Geosciences, Kiel, Germany;Institute of Marine Research, Fram Centre, Tromsø, Norway;MARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany;MARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany;Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany;Max Planck Institute for Marine Microbiology, Bremen, Germany;Max Planck Institute for Marine Microbiology, Bremen, Germany;NIOZ − Royal Netherlands Institute for Sea Research, t Horntje (Texel), Netherlands;Utrecht University, Utrecht, Netherlands;National Oceanography Centre, European Way, Southampton, United Kingdom;Scottish Association for Marine Science (SAMS), Oban, United Kingdom;

关键词: abyssal plain;    DISCOL;    food fall;    Pyrosoma;    seafloor disturbance;    bentho-pelagic coupling;   

DOI  :  10.3389/fmars.2023.1192242

 received in 2023-03-23, accepted in 2023-06-12,  发布年份 2023

来源: Frontiers

【 摘 要 】

Abyssal plain communities rely on the overlying water column for a settling flux of organic matter. The origin and rate of this flux as well as the controls on its fine-scale spatial distribution following seafloor settlement are largely unquantified. This is particularly true across regions where anthropogenically-induced seafloor disturbance has occurred. Here, we observed, quantified and mapped a mass deposition event of gelatinous zooplankton carcasses (pyrosomes) in July-September 2015 across one such physically disturbed region in the Peru Basin polymetallic nodule province (4150 m). Seafloor in this area was disturbed with a plough harrow in 1989 (as part of the DISCOL experiment) causing troughs in the sediment. Other parts were disturbed with an epibenthic sled (EBS) during a cruise in 2015 resulting in steep-walled, U-shaped troughs. We investigated two hypotheses: a) gelatinous food falls contribute significantly to the abyssal plain carbon pump and b) physical seafloor disturbance influences abyssal distribution of organic matter. We combined optical and bathymetric seafloor observations, to analyze pyrosome distribution on seabeds with different levels of disturbance. 2954 pyrosome colonies and associated taxa were detected in > 14,000 seafloor images. The mean regional carbon (C) deposition associated with pyrosome carcasses was significant compared to the flux of particulate organic C (182 to 1543%), and the total respired benthic C flux in the DISCOL Experimental Area (39 to 184%). EBS-disturbed seafloor tracks contained 72 times more pyrosome-associated C than an undisturbed reference site, and up to 4 times more than an area disturbed in 1989. Deposited pyrosomes collected had a higher proportion of labile fatty acids compared to the sediment. We document the temporal and spatial extent of an abyssal food fall event with unprecedented detail and show that physical seafloor disturbance results in the accumulation of detrital material. Such accumulation may reduce oxygen availability and alter benthic community structure. Understanding both the relevance of large food falls and the fine scale topography of the seafloor, is necessary for impact assessment of technologies altering seafloor integrity (e.g. as a result of bottom-trawling or deep seabed mining) and may improve their management on a global scale.

【 授权许可】

Unknown   
Copyright © 2023 Hoving, Boetius, Dunlop, Greinert, Haeckel, Jones, Simon-Lledó, Marcon, Stratmann, Suck, Sweetman and Purser