Carbon and nitrogen cycling in intertidal sediments near Doel, Scheldt Estuary

As a red tide algal toxin with intense neurotoxicity distributed worldwide, domoic acid (DA) has attracted increasing concerns. In this work, the integrative analysis of metagenome and metabolome are applied to investigate the impact of DA on nitrogen cycling in coastal sediments. Here we show that DA can act as a stressor to induce the variation of nitrogen (N) cycling by altering the abundance of functional genes and electron supply. Moreover, microecology theory revealed that DA can increase the role of deterministic assembly in microbial dynamic succession, resulting in the shift of niches and, ultimately, the alteration in N cycling. Notably, denitrification and Anammox, the important process for sediment N removal, are markedly limited by DA. Also, variation of N cycling implies the modification in cycles of other associated elements. Overall, DA is capable of ecosystem-level effects, which require further evaluation of its potential cascading effects.

Carbon and nitrogen cycling in intertidal sediments near Doel, Scheldt Estuary

Introduction. Major biological processes in European tidal estuaries C. Heip, P. Herman. Primary production. Nutrients, light and primary production by phytoplankton and microphytobenthos in the eutrophic, turbid Westerschelde estuary (the Netherlands) J. Kromkamp, et al. Dynamics of microphytobenthic chlorophyll-a in the Scheldt estuary (SW Netherlands) D.J. de Jong, V.N. de Jonge. Bacterial processes. Comparison of heterotrophic bacterial production in early spring in the turbid estuaries of the Scheldt and the Elbe N.K. Goosen, et al. Nitrous oxide emissions from estuarine intertidal sediments J.J. Middelburg, et al. Carbon and nitrogen cycling in intertidel sediments near Doel, Scheldt estuary J.J. Middelburg, et al. Zooplankton. Copepod feeding in the Westerschelde and the Gironde M. Tackx, et al. Long-term changes in eurytemora affinis population (copopoda, calanoids) in the Gironde estuary (1978-1992) J. Castel, et al. Contribution of the zooplankton copepod communities to the carbon fluxes in the brackish part of the Westerschelde estuary (the Netherlands) V. Escaravage, K. Soetaert. Feeding rates and productivity of the copepod Acartia bifilosa in a highly turbid estuary the Gironde (SW France) X. Irigoien, J. Caste. Production rates of Eurytemora affinis in the Elbe Estuary, comparison of field and enclosure production estimates A. Peitsch. Comparative spring distribution of zooplankton in three macrotidal European estuaries B. Sautour, J. Castel. Hyperbenthos. Comparative study of the hyperbenthos of three European estuaries J. Mees, et al. Meiobenthos. Effects of experimental food supply on estuarine meiobenthos M.C. Austen, R.M. Warwick. Meiobenthic distributionand nematode community structure of five European estuaries K. Soetaert, et al. Macrobenthos. The response of two estuarine benthic communities to the quantity and quality of food M.A. Kendall, et al. Modelling. Estimating estuarine residence times in the Westerschelde (the Netherlands) using a simple box model K. Soetaert, P.M.J. Herman. Nitrogen dynamics in the Westerschelde estuary (SW Netherlands) estimated by means of a global ecosystem model (MOSES) K. Soetaert, P.M.J. Herman. Carbon flows in the Westerschelde estuary (the Netherlands) evaluated by means of a global ecosystem model (MOSES) K. Soetaert, P.M.J. Herman.

In sandy sediments, the burrow ventilation activity of benthic macrofauna can generate substantial advective flows within the sediment surrounding their burrows. Here we investigated the effects of such advective bio-irrigation on carbon and nitrogen cycling in sandy sediments. To this end, we combined a range of complementary experimental and modelling approaches in a microcosm study of the lugworm Arenicola marina (Polychaeta: Annelida). Bio-irrigation rates were determined using uranine as a tracer, while benthic fluxes of oxygen (O-2), total carbon dioxide (TCO2), dissolved inorganic nitrogen (NH4+, Sigma NO2-+NO3-) and dinitrogen (N-2) were measured in closed-core incubations containing lugworms acclimatized for a relatively short (2 d) and long (3 wk) duration. The fluxes induced by A. marina were compared to those induced by mechanical mimics that simulate the flow pattern induced by the lugworm. These mechanical mimics proved a useful tool to simulate the effect of l! ugworm irrigation on sediment biogeochemistry. Subsequently, reactive transport model simulations were performed to check the consistency of the measured fluxes and rates, and to construct closed mass balances for sedimentary nitrogen. This reactive transport model Successfully captured the essential features of the nitrogen cycling within the sediment. Advective irrigation by both lugworm and mechanical mimics significantly stimulated the sediments O-2 consumption, organic matter mineralization rate (TCO2 release), and denitrification rate (N-2 production). While sedimentary O-2 consumption was directly correlated to advective input of O-2, increasing irrigation rates increased the importance of coupled nitrification-denitrification over the external input of nitrate from the overlying water.

The effects of semi-lunar spring and neap tidal change on nitrification, denitrification and N 2O vertical distribution in the intertidal sediments of the Yangtze estuary, China

Synergetic effects of chlorinated paraffins and microplastics on microbial communities and nitrogen cycling in deep-sea cold seep sediments

Microbial interaction patterns and nitrogen cycling regularities in lake sediments under different trophic conditions

Herbivory is a common process in salt marshes. However, the direct impact of marsh herbivory on nutrient cycling in this ecosystem is poorly understood. Using a 15N enrichment mesocosm study, we quantified nitrogen (N) cycling in sediment and plants of black needlerush (Juncus roemerianus) salt marshes, facilitated by litter decomposition and litter plus grasshopper feces decomposition. We found 15 times more 15N recovery in sediment with grasshopper herbivory compared to sediment with no grasshopper herbivory. In plants, even though we found three times and a half larger 15N recovery with grasshopper herbivory, we did not find significant differences. Thus, herbivory can enhance N cycling in black needlerush salt marshes sediments and elevate the role of these salt marshes as nutrient sinks.

In this study the impact of hydrocarbons on nitrogen cycling in intertidal sediments from a barrier island in the north central Gulf of Mexico was investigated. Initial total petroleum hydrocarbon (TPH) concentrations of the sediments averaged 49 ± 27 mg kg−1 in June and 75 ± 48 mg kg−1 in November. Following the addition of crude oil, TPH concentrations increased to 340 ± 73 and 296 ± 50 mg kg−1 in June and November, respectively. Sediment oxygen demand (SOD), inorganic nitrogen and phosphorus fluxes, and denitrification capacity, measured with the isotope pairing technique (IPT) within a week of oiling, were consistently higher in June compared to rates in November when temperatures were 10°C lower. Despite significantly higher TPH concentrations in the oiled treatments, SOD, nutrient fluxes, nitrogen fixation, denitrification, and anammox, did not differ between the treatments. Potential denitrification rates, measured in the presence of excess nitrate (100 μM), were similar between the control and oil treatments, but significantly higher than rates measured with the IPT. The elevated rates of potential denitrification suggest the presence of an active extant microbial community capable of significant attenuation of porewater nitrate concentrations. The insignificant changes in nitrogen cycling in response to petroleum hydrocarbon additions at a site with hydrocarbons present, albeit at low concentrations, suggests resiliency in nitrogen cycling in response to additional hydrocarbon inputs in ranges investigated in this study.

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 199:1-11 (2000) - doi:10.3354/meps199001 Nitrogen cycling in sediments of the Lagoon of Venice, Italy Jonas Martin Svensson1,*, Giovanni Marco Carrer2, Martina Bocci2 1Department of Ecology/Limnology, Ecology Building, University of Lund, 223 62 Lund, Sweden 2Dipartimento di Processi Chimici dell¹ingegneria, Universitá di Padova, Via Marzolo 9, 35 131 Padova, Italy *E-mail: jonas.svensson@limnol.lu.se ABSTRACT: In order to identify the importance of different areas for nitrogen retention in the Lagoon of Venice, Italy, undisturbed sediment cores of different origin were collected in late April 1998. The cores were transferred to the laboratory and incubated for denitrification activity using the method of Œnitrogen isotope pairingŒ. The sampled sediments were collected in a freshwater stream (Stn A), an intertidal area (Stn B), in an area characterised by Ulva sp. (Stn C) and in an area vegetated by Zostera sp. (Stn D). Stn D was close to the lagoon outlet (mouth) and highly affected by tidal actions. The ambient concentrations of water column nitrate ranged from 132 to 4.4 µM. The highest denitrification rate was found in the area with the highest concentration of water nitrate, i.e. at Stns A and B, 292 ± 75 and 204 ± 52 µmol m-2 h-1, respectively. Sediment denitrification in the areas closer the lagoon outlet was significantly lower, 16 ± 2 µmol m-2 h-1 at Stn C and 11 ± 2 µmol m-2 h-1 at Stn D. Oxygen and nitrate consumption, release of ammonium and denitrification in the sediment at Stn B was correlated to the biomass of benthic infauna. About 30% of the denitrification in the B sediment was explained by the presence of benthic infauna. More than 50% of the denitrification in the sediment at Stn D was due to denitrification of nitrate produced by nitrification. KEY WORDS: Denitrification · Sediment · Bioturbation · Lagoon of Venice Full text in pdf format NextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 199. Publication date: June 26, 2000 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 2000 Inter-Research.

Unveiling microplastic's role in nitrogen cycling: Metagenomic insights from estuarine sediment microcosms

Ammonium oxidation coupled to dissimilatory reduction of iron under anaerobic conditions in wetland soils

BackgroundThe ecosystems of marine ranching have enhanced marine biodiversity and ecological balance and have promoted the natural recovery and enhancement of fishery resources. The microbial communities of these ecosystems, including bacteria, fungi, protists, and viruses, are the drivers of biogeochemical cycles. Although seasonal changes in microbial communities are critical for ecosystem functioning, the current understanding of microbial-driven metabolic properties and their viral communities in marine sediments remains limited. Here, we employed amplicon (16S and 18S) and metagenomic approaches aiming to reveal the seasonal patterns of microbial communities, bacterial-eukaryotic interactions, whole metabolic potential, and their coupling mechanisms with carbon (C), nitrogen (N), and sulfur (S) cycling in marine ranching sediments. Additionally, the characterization and diversity of viral communities in different seasons were explored in marine ranching sediments.ResultsThe current study demonstrated that seasonal variations dramatically affected the diversity of microbial communities in marine ranching sediments and the bacterial-eukaryotic interkingdom co-occurrence networks. Metabolic reconstruction of the 113 medium to high-quality metagenome-assembled genomes (MAGs) was conducted, and a total of 8 MAGs involved in key metabolic genes and pathways (methane oxidation - denitrification - S oxidation), suggesting a possible coupling effect between the C, N, and S cycles. In total, 338 viral operational taxonomic units (vOTUs) were identified, all possessing specific ecological characteristics in different seasons and primarily belonging to Caudoviricetes, revealing their widespread distribution and variety in marine sediment ecosystems. In addition, predicted virus-host linkages showed that high host specificity was observed, with few viruses associated with specific hosts.ConclusionsThis finding deepens our knowledge of element cycling and viral diversity in fisheries enrichment ecosystems, providing insights into microbial-virus interactions in marine sediments and their effects on biogeochemical cycling. These findings have potential applications in marine ranching management and ecological conservation.DRyDF7ykR-XALqAtu34uZtVideo

Sensitivity analysis of nitrogen and carbon cycling in marine sediments

Restoration of submerged macrophytes is one of the important measures for ecological treatment of eutrophic lakes. The changes in physical and chemical conditions caused by submerged macrophytes also affect the process of benthic nitrogen cycling. The growth period of Potamogeton crispus is mainly in winter. In order to understand the effect of submerged macrophytes growing in winter on nitrification rate and denitrification rate in the process of nitrogen cycling, experiments were carried out from winter to summer with vegetated and non-vegetated treatments. The results showed that the effect of submerged macrophytes on water temperature was not significant in winter. The nitrogen cycling was mainly affected by variables, which were inorganic nitrogen and dissolved oxygen. Submerged macrophytes had little effect on nitrification rate, but had a certain inhibition on denitrification rate by providing oxygen from photosynthesis. In total, submerged macrophytes growing in winter have little effect on nitrogen cycling in sediment. However, submerged macrophytes growing in winter can increase the attachment surface of microbes and inhibit resuspension of sediment, which play a complementary role to submerged macrophytes growing in summer for maintaining stability of eutrophic lakes.