Sebastian Naeher

Sebastian Naeher
GNS Science

Dr. sc. ETH (PhD), Dipl.-Geol (MSc)

About

50
Publications
8,323
Reads
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906
Citations
Citations since 2016
24 Research Items
756 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Introduction
Organic and stable isotope geochemist/biogeochemist at GNS Science, Lead Scientist and Manager of GNS/VUW Organic Geochemistry Laboratory, Adjunct Teaching Fellow and Honorary Research Associate at Victoria University of Wellington, Associate Editor of Biogeosciences, New Zealand Journal of Geology and Geophysics and New Zealand Journal of Marine and Freshwater Research, Convener of Geochemistry Special Interest Group of Geoscience Society of New Zealand and National Committee member.
Additional affiliations
November 2016 - present
GNS Science
Position
  • Manager
November 2016 - December 2020
Victoria University of Wellington
Position
  • Research Associate
March 2016 - August 2016
MARUM Center for Marine Environmental Sciences
Position
  • DFG Postdoctoral Fellow
Education
August 2009 - October 2012
Eawag / ETH Zurich, Switzerland
Field of study
  • PhD student
October 2007 - May 2009
Johannes Gutenberg-Universität Mainz
Field of study
  • Undergraduate in geology
October 2006 - October 2007
ETH Zurich
Field of study
  • Undergraduate in geology (Erasmus)

Publications

Publications (50)
Article
Full-text available
In this paper we synthesize the new knowledge on oxygen and oxygen-related phenomena in aquatic systems, resulting from the EU-FP7 project HYPOX (“In situ monitoring of oxygen depletion in hypoxic ecosystems of coastal and open seas, and land-locked water bodies”, www.hypox.net). In view of the anticipated oxygen loss in aquatic systems due to eutr...
Article
Full-text available
We analysed the distributions of glycerol dialkyl glycerol tetraethers (GDGTs) and other lipid biomarkers [glycerol dialkyl diethers (DGDs), fatty acids (FAs), sterols, hopanoids and phytol] in the water column and sediments of Lake Rotsee (Switzerland) to understand the processes and organisms involved in CH4 cycling. In the sediment we found subs...
Article
Redox dynamics of manganese (Mn) were studied in the sediment of Lake Zurich using precise sediment core age models, monthly long-term oxygen (O-2) monitoring data of the water column (1936-2010) and high-resolution XRF core scanning. The age models were based on bi-annual lamination and calcite precipitation cycles. If present, Mn exhibits distinc...
Article
We examined the distributions of tetrapyrrole pigments (i.e. intact chlorophylls and bacteriochlorophylls, pheopigments) as well as their compound-specific carbon and nitrogen isotopic compositions in the sediments of three Swiss lakes (Lakes Rotsee, Cadagno and Zurich) and the Black Sea to investigate the biogeochemical cycling of carbon and nitro...
Article
The Paleocene Waipawa Formation is a widespread, ∼2–80 m-thick marine mudstone that occurs in several New Zealand basins. It is relatively enriched in organic matter (OM) and is the inferred source of a sub-commercial oil discovery and several correlated oil seeps. To determine the organofacies and depositional influences on the petroleum potential...
Article
Full-text available
Late Paleocene deposition of an organic-rich sedimentary facies on the continental shelf and slope of New Zealand and eastern Australia has been linked to short-lived climatic cooling and terrestrial denudation following sea level fall. Recent studies confirm that the organic matter in this facies, termed “Waipawa organofacies”, is primarily of ter...
Article
Life on Earth produces innumerable structurally diverse biomolecules. Biomarkers, a subset of these compounds, are sufficiently specific in the structure that they serve as tracers of organisms present in the environment or preserved in the geological record. Biomarkers can be used as proxies for organisms and the biogeochemical processes they medi...
Article
Full-text available
This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles in the American Geophysical Union Biogeosciences section, and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: (a) Global collaboration, technology tra...
Article
Full-text available
Plain Language Summary Paleoceanography and Paleoclimatology seeks to reveal past changes in the oceans and the climate, to help us better understand how Earth systems work. Traditionally, it has a strong focus on international networks and cooperation and we have accomplished many international projects. However, we are still facing some major cha...
Article
This article is composed of three independent commentaries about the state of ICON principles (Goldman et al. 2021) in the AGU Biogeosciences section and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: Global collaboration, technology transfer and application (Section 2), Community enga...
Article
Lakes and their catchments have been subjected to centuries to millennia of exploitation by humans. Efficient monitoring methods are required to promote proactive protection and management. Traditional monitoring is time consuming and expensive, which limits the number of lakes monitored. Lake surface sediments provide a temporally integrated repre...
Preprint
Full-text available
Late Paleocene deposition of an organic-rich sedimentary facies on the continental shelf and slope of New Zealand and eastern Australia has been linked to short-lived climatic cooling and terrestrial denudation following sea-level fall. Recent studies have confirmed that the organic matter in this facies, termed Waipawa organofacies, is primarily o...
Article
The factors controlling Re-Os systematics and potential for geochronology in organic-rich sedimentary rocks deposited in fully terrestrial to paralic environments are not well understood. Here we present Re-Os, bulk pyrolysis and sulfur data for coals and coaly mudstones from the Late Cretaceous Rakopi and North Cape, Paleocene Farewell and Eocene...
Article
In the middle–late Paleocene, a marine, organic-rich sedimentary unit (Waipawa Formation [Fm]) in which the organic matter was derived mainly from terrestrial plants was deposited in many of New Zealand's sedimentary basins. The unique organofacies of this formation has not been identified in any other time interval within the geological history of...
Article
The Orui-1A stratigraphic drillhole near Riversdale, coastal Wairarapa, was drilled in 2011 by East Coast Energy Ventures to assess the prospectivity of the Paleocene Waipawa Formation, a widespread marine source rock. The drillhole was cored from 30.35 m to 117.3 m TD (total depth drilled), and acoustic image logs were run. The cored interval span...
Article
Full-text available
Sedimentary hydrocarbon remnants of eukaryotic C 26 –C 30 sterols can be used to reconstruct early algal evolution. Enhanced C 29 sterol abundances provide algal cell membranes a density advantage in large temperature fluctuations. Here, we combined a literature review with new analyses to generate a comprehensive inventory of unambiguously syngene...
Article
Pigmente aus Algen und Bakterien, zum Beispiel Chlorophyll, tragen dazu bei, den Sauerstoffgehalt sowie den Kohlenstoff- und den Stickstoffkreislauf in Seen und Ozeanen besser zu verstehen.
Article
To reconstruct the impact of eutrophication on phototrophic communities and the biogeochemical cycling of carbon and nitrogen in the surface water, we investigated the distributions and carbon and nitrogen isotopic compositions (δ¹³C and δ¹⁵N values) of chlorins in the sediments of Lake Zurich. The chlorin distributions were dominated by chlorophyl...
Article
Full-text available
To expand the limited knowledge about the ecological significance of anaerobic ammonium oxidation (anammox) in continental aquatic and terrestrial ecosystems, we studied community structure, abundance, and activity of anammox bacteria in soils and sediments in the wetland of Trou Deshayes, a riparian zone in the Seine Estuary, France. Combining (i)...
Article
Full-text available
To expand the limited knowledge about the ecological significance of anaerobic ammonium oxidation (anammox) in continental aquatic and terrestrial ecosystems, we studied community structure, abundance, and activity of anammox bacteria in soils and sediments in the wetland of Trou Deshayes, a riparian zone in the Seine Estuary, France. Combining i)...
Article
Ein Indikator für den Sauerstoffgehalt im Tiefenwasser von Seen ist das Verhältnis von Mangan zu Eisen in Sedimenten. Die Elementzusammensetzung der Sedimente ist mit Röntgenfluoreszenz messbar und zeigt auch die Umweltveränderungen der Vergangenheit.
Article
Full-text available
Ergothioneine and ovothiol A are sulfur-containing histidine derivatives produced by microorganisms including Mycobacterium tuberculosis, Trypanosoma cruzi or Erwinia amylovora and may also play important roles in human physiology. Based on our recent identification of thiohistidine biosynthetic enzymes from Mycobacterium smegmatis and Erwinia tasm...
Article
Full-text available
a Joint first authorship (these authors have contributed equally to the manuscript). b present address: Abstract. In this paper we provide an overview of new knowledge on oxygen depletion (hypoxia) and related phe-nomena in aquatic systems resulting from the EU-FP7 project HYPOX ("In situ monitoring of oxygen depletion in hypoxic ecosystems of coas...
Article
We analysed glycerol dialkyl glycerol tetraether (GDGT) distributions in the water column, sediment and catchment soils of the Swiss Lake Rotsee to determine the sources of GDGTs in the lake sediment and to determine the implications for GDGT-based palaeoclimate proxies. The branched GDGT (brGDGT) distribution in the soils surrounding the lake show...
Article
Maleimides (transformation products of chlorophylls and bacteriochlorophylls) were studied in recent sediments from the Swiss lake Rotsee and the Romanian Black Sea Shelf to investigate chlorophyll degradation, the role of oxygen in maleimide formation, and to identify their sources. Naturally occurring maleimides (i.e. "free" maleimides) and malei...
Conference Paper
Full-text available
Sediments of lakes of high trophic level are often supersaturated with methane, a strong greenhouse gas which significantly contributes to global warming. Lake Rotsee and Lake Lungern are Swiss prealpine lakes known for their methane emission. Relevant transport mechanisms for methane emission are mainly equilibrium-controlled degassing and diffusi...
Article
The Black Sea, containing the world's largest natural anoxic basin since ca 7500 years (Jones & Gagnon 1994), suffers from combined effects of anthropogenic eutrophication, overfishing and climate variability (Oguz & Gilbert 2007). We discuss causes for hypoxia in western shelf waters. Freshwater runoff by the large rivers Danube, Dniester and Dnie...
Article
Full-text available
The evolution of environmental changes during the last decades and the impact on the living biomass in the western part of Amvrakikos Gulf was investigated using abundances of benthic foraminifera and lipid biomarker concentrations. These proxies indicated that the gulf has dramatically changed due to eutrophication. Eutrophication has led to a hig...
Article
The effects of eutrophication on short term changes in the microbial community were investigated using high resolution lipid biomarker and trace metal data for sediments from the eutrophic Lake Rotsee (Switzerland). The lake has been strongly influenced by sewage input since the 1850s and is an ideal site for studying an anthropogenically altered e...
Article
Full-text available
Chlorophylls and bacteriochlorophylls are the most abundant photosynthetic pigments on Earth. These compounds and their transformation products (chlorins, porphyrins, maleimides) can be preserved in limnic and marine sedimentary deposits and crude oils and serve as valuable proxies for palaeoenvironmental reconstructions. Among these degradation pr...
Article
Trace metals, such as iron (Fe) and manganese (Mn), have received much attention in the last decades due to their redox-sensitive behaviour in the environment. In lakes, seasonal redox changes in the water column lead to biogeochemical cycling of Fe and Mn throughout the year. Under reducing conditions during stratification, they are (re)dissolved...
Data
The effects of eutrophication on short term changes in the microbial community were investigated using high resolution lipid biomarker and trace metal data for sediments from the eutrophic Lake Rotsee (Switzerland). The lake has been strongly influenced by sewage input since the 1850s and is an ideal site for studying an anthropogenically altered e...
Data
The evolution of environmental changes during the last decades and the impact on the living biomass in the western part of Amvrakikos Gulf was investigated using abundances and species distributions of benthic foraminifera and lipid biomarker concentrations. These proxies indicated that the gulf has markedly changed due to eutrophication. Eutrophic...

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Project (1)
Project
Whilst the Re-Os isotopic system shows excellent promise in dating and tracing oil generation, questions remain. The mechanism that leads to osmium homogenisation in petroleum basins is not clear – are the isochrons dating source rock age, oil generation, expulsion or migration? Most published work has focussed on sediments and oils with marine affinities. How applicable is this chronometer and tracer to younger, coaly sourced systems such as typify most New Zealand’s petroleum basins? Through Re-Os and Os isotopic analysis of targeted New Zealand source rocks and oils, we aim to evaluate the behaviour of the Re-Os isotopic system in New Zealand petroleum systems, and its potential as both a geochronometer and source tracer. Utilising the extensive existing collections and databases, we will target source rocks of known age, maturity, and depositional facies, to track the effects of these fundamental attributes on the Re-Os signatures of the source rocks. Links between oils and sources will be evaluated using the existing genetic oil families of Sykes et al. (2012). The technique will be applied to Taranaki oils, for which the source rock ages and timing of oil expulsion are relatively well constrained, and then to East Cape seep oils for which the source rock age is less certain.