@misc{neumann_macrofauna_as_2021, 
author={Neumann, A.,Beusekom, J.,Eisele, A.,Emeis, K.,Friedrich, J.,Kröncke, I.,Logemann, E.,Meyer, J.,Naderipour, C.,Schückel, U.,Wrede, A.,Zettler, M.},
title={Macrofauna as a major driver of bentho-pelagic exchange in the southern North Sea},
year={2021},
howpublished = {journal article},
doi = {https://doi.org/10.1002/lno.11748},
abstract = {The contribution of sediments to nutrient cycling of the coastal North Sea is strongly controlled by the intensity of fluxes across the sediment water interface. Pore‐water advection is one major exchange mechanism that is well described by models, as it is determined by physical parameters. In contrast, biotransport (i.e., bioirrigation, bioturbation) as the other major transport mechanism is much more complex. Observational data reflecting biotransport, from the German Bight for example, is scarce. We sampled the major sediment provinces of the German Bight repeatedly over the years from 2013 to 2019. By employing ex situ whole core incubations, we established the seasonal and spatial variability of macrofauna‐sustained benthic fluxes of oxygen and nutrients. A multivariate, partial least squares analysis identified faunal activity, in specifically bioturbation and bioirrigation, alongside temperature, as the most important drivers of oxygen and nutrient fluxes. Their combined effect explained 63% of the observed variability in oxygen fluxes, and 36–48% of variability in nutrient fluxes. Additional 10% of the observed variability of fluxes were explained by sediment type and the availability of plankton biomass. Based on our extrapolation by sediment provinces, we conclude that pore‐water advection and macrofaunal activity contributed equally to the total benthic oxygen uptake in the German Bight.},
note = {Online available at: \url{https://doi.org/10.1002/lno.11748} (DOI). Neumann, A.; Beusekom, J.; Eisele, A.; Emeis, K.; Friedrich, J.; Kröncke, I.; Logemann, E.; Meyer, J.; Naderipour, C.; Schückel, U.; Wrede, A.; Zettler, M.: Macrofauna as a major driver of bentho-pelagic exchange in the southern North Sea. Limnology and Oceanography. 2021. vol. 66, no. 6, 2203-2217. DOI: 10.1002/lno.11748}}
@misc{pein_seasonal_stratification_2021, 
author={Pein, J.,Eisele, A.,Sanders, T.,Daewel, U.,Stanev, E.,Beusekom, J.,Staneva, J.,Schrum, C.},
title={Seasonal Stratification and Biogeochemical Turnover in the Freshwater Reach of a Partially Mixed Dredged Estuary},
year={2021},
howpublished = {journal article},
doi = {https://doi.org/10.3389/fmars.2021.623714},
abstract = {The Elbe estuary is a substantially engineered tidal water body that receives high loads of organic matter from the eutrophied Elbe river. The organic matter entering the estuary at the tidal weir is dominated by diatom populations that collapse in the deepened freshwater reach. Although the estuary’s freshwater reach is considered to manifest vertically homogenous density distribution (i.e., to be well-mixed), several indicators like trapping of particulate organic matter, near-bottom oxygen depletion and ammonium accumulation suggest that the vertical exchange of organic particles and dissolved oxygen is weakened at least temporarily. To better understand the causal links between the hydrodynamics and the oxygen and nutrient cycling in the deepened freshwater reach of the Elbe estuary, we establish a three-dimensional coupled hydrodynamical-biogeochemical model. The model demonstrates good skill in simulating the variability of the physical and biogeochemical parameters in the focal area. Coupled simulations reveal that this region is a hotspot of the degradation of diatoms and organic matter transported from the shallow productive upper estuary and the tidal weir. In summer, the water column weakly stratifies when at the bathymetric jump warmer water from the shallow upper estuary spreads over the colder water of the deepened mid reaches. Enhanced thermal stratification also occurs also in the narrow port basins and channels. Model results show intensification of the particle trapping due to the thermal gradients. The stratification also reduces the oxygenation of the near-bottom region and sedimentary layer inducing oxygen depletion and accumulation of ammonium. The study highlights that the vertical resolution is important for the understanding and simulation of estuarine ecological processes, because even weak stratification impacts the cycling of nutrients via modulation of the vertical mixing of oxygen, particularly in deepened navigation channels and port areas.},
note = {Online available at: \url{https://doi.org/10.3389/fmars.2021.623714} (DOI). Pein, J.; Eisele, A.; Sanders, T.; Daewel, U.; Stanev, E.; Beusekom, J.; Staneva, J.; Schrum, C.: Seasonal Stratification and Biogeochemical Turnover in the Freshwater Reach of a Partially Mixed Dredged Estuary. Frontiers in Marine Science. 2021. vol. 8, 623714. DOI: 10.3389/fmars.2021.623714}}
@misc{zhang_quantifying_importance_2021, 
author={Zhang, W.,Neumann, A.,Daewel, U.,Wirtz, K.,van Beusekom, J.,Eisele, A.,Ma, M.,Schrum, C.},
title={Quantifying Importance of Macrobenthos for Benthic-Pelagic Coupling in a Temperate Coastal Shelf Sea},
year={2021},
howpublished = {journal article},
doi = {https://doi.org/10.1029/2020JC016995},
abstract = {Benthic oxygen fluxes consist mostly of advective and diffusive terms. Both terms in the German Bight exhibit a prominent annual cycle but with opposite variation patterns. To understand the driving mechanisms quantitatively, a novel 3-D benthic-pelagic coupled model resolving interactions among macrobenthos, bioturbation, oxygen consumption, and carbon early diagenesis was applied to reconstruct the benthic states. Simulation results show a satisfactory agreement with field data and reveal that the benthic oxygen flux is determined by not only pelagic drivers but also by internal dynamics associated with the interaction between organic carbon and macrobenthos, and bedform morphodynamics. Variation of advective flux, characterized by summer-low and winter-high, is mainly driven by hydrodynamics and bedform morphodynamics, while variation of diffusive flux, featured by summer-high and winter-low, is a compound effect of pelagic and benthic drivers with a dominant control by macrobenthos through bioturbation. The role of bioturbation in benthic oxygen consumption is twofold: (a) on the one hand, it alters the particulate organic carbon (POC) distribution in surface sediments, thereby changing the availability of POC to oxygen consumption; (b) on the other hand, it mixes oxygen down into sediments, thereby facilitating oxygen consumption. Our results indicate that the first role prevails in sandy seafloor characterized by energetic hydrodynamics, while the second role becomes increasingly important along with a weakening of bottom currents. We found that bioturbation contributes up to 87% urn:x-wiley:21699275:media:jgrc24733:jgrc24733-math-0001 4% and 55% urn:x-wiley:21699275:media:jgrc24733:jgrc24733-math-0002 8% of the total benthic oxygen fluxes in muddy seabed and at a regional scale (the German Bight), respectively.},
note = {Online available at: \url{https://doi.org/10.1029/2020JC016995} (DOI). Zhang, W.; Neumann, A.; Daewel, U.; Wirtz, K.; van Beusekom, J.; Eisele, A.; Ma, M.; Schrum, C.: Quantifying Importance of Macrobenthos for Benthic-Pelagic Coupling in a Temperate Coastal Shelf Sea. Journal of Geophysical Research : Oceans. 2021. vol. 126, no. 10, e2020JC016995. DOI: 10.1029/2020JC016995}}