Nicolas Duprey

Nicolas Duprey
Max Planck Institute for Chemistry | mpic · Department of Biogeochemistry

PhD

About

31
Publications
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383
Citations
Introduction
I am a multi-disciplinary ecologist conducting research on the alteration of the global cycles by humans (C,N, heavy metals...). I am particularly interested on how the human activities affect the biosphere and the global climate. I am using the skeleton of hard-corals as an archive to track human-induced changes and to understand their influence on the Earth system.

Publications

Publications (31)
Preprint
Full-text available
Nitrogen isotopes are widely used to study the trophic position of animals in modern food webs, however, their application in the fossil record is severely limited by degradation of organic material during fossilization. In this study, we show that the nitrogen isotopic composition of organic matter preserved in mammalian tooth enamel (δ15Nenamel)...
Article
Full-text available
The ability of corals to modulate their nutrition strategy in response to variable nutrient supply remains poorly understood, limiting our understanding of energy flow in coral reef ecosystems and thus our comprehension of their resilience to global changes. We used a naturally occurring nutrient gradient along the reef flat of two seabird-inhabite...
Article
Full-text available
Recently, we published a novel method used to assess the trophic niches of different coral species and demonstrated that their nutrition varied considerably, with some species highly dependent on their photosynthetic algal symbionts and others able to feed on plankton to meet energetic requirements. Adjustments to the use of this tool are necessary...
Article
Symbiotic corals receive energy not only by ingesting food (e.g. plankton, inorganic/organic matter, i.e. heterotrophy), but also by endosymbiosis, which supplies photosynthates (dissolved inorganic carbon, i.e. autotrophy). These two sources of energy have distinct fatty acid (FA) profiles, which can be used to differentiate corals by their primar...
Article
Nitrogen isotope ratios (δ¹⁵N) are a well-established tool for investigating the dietary and trophic behavior of animals in terrestrial and marine food webs. To date, δ¹⁵N values in fossils have primarily been measured in collagen extracted from bone or dentin, which is susceptible to degradation and rarely preserved in deep time (>100,000 years)....
Article
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Observations of coral reef losses to climate change far exceed our understanding of historical degradation before anthropogenic warming. This is a critical gap to fill as conservation efforts simultaneously work to reverse climate change while restoring coral reef diversity and function. Here, we focused on southern China’s Greater Bay Area, where...
Article
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Ocean warming increases the incidence of coral bleaching, which reduces or eliminates the nutrition corals receive from their algal symbionts, often resulting in widespread mortality. In contrast to extensive knowledge on the thermal tolerance of coral-associated symbionts, the role of the coral host in bleaching patterns across species is poorly u...
Article
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Large quantities of anthropogenic nitrogen (N) in the marine environment are detrimental for coastal ecosystems and understanding the magnitude and distribution of this N opens paths to remediation. One area of concern is Cocos Lagoon, in the south of Guam, Northern Mariana Islands, which hosts a diversity of corals including Acropora species liste...
Data
This dataframe presents the d15N signature of 348 long-lived benthic bivalves from 12 species. Individuals were trapped at 27 sites in 2012 around the Peninsula of Nouméa, New Caledonia. For each bivalve specimen, muscle tissues were dissected and stored frozen. Muscles were freeze-dried, ground into powder, and weighed in tin cups for isotopic ana...
Article
Full-text available
Historical coral skeleton (CS) δ18O and δ15N records were produced from samples recovered from sedimentary deposits, held in natural history museum collections and cored into modern coral heads. These records were used to assess the influence of global warming and regional eutrophication, respectively, on the decline of coastal coral communities fo...
Article
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Pulau Redang and Pulau Tioman have experienced huge tourism growth over the last two decades, but minimal sewage treatment may threaten the resilience of their coral reefs. This study uses stable isotope techniques to identify suitable bioindicators of sewage nutrients (δ 15 N) at these islands by measuring macroalgae (Lobophora spp.), gastropods (...
Article
Full-text available
Economic development and environmental conservation are often seen as opposing forces in the arena of government policy-making. With more than 7 million people and a rich diversity of marine species and habitats, Hong Kong is an excellent case study to explore this dynamic. Despite anthropogenic impacts, Hong Kong still hosts more than 90 species o...
Article
We investigated the potential of coral skeleton δ¹⁵N (CS-δ¹⁵N) records for tracking anthropogenic-N sources in coral reef ecosystems. We produced a 56 yr-long CS-δ¹⁵N record (1958–2014) from a reef flat in Guam that has been exposed to varying 1) levels of sewage treatment 2) population density, and 3) land use. Increasing population density (from...
Article
Marine ecosystem health is threatened by excessive inputs of dissolved inorganic nitrogen (DIN) from various anthropogenic sources and effective mitigation can result from source identification. Here, we use stable isotope analysis of endosymbiotic Symbiodinium hosted by hard corals Porites spp. ( δ <sup>15</sup>N<sub> sym </sub>) as recorder of DI...
Article
Full-text available
Although the impacts of nutrient pollution on coral reefs are well known, surprisingly, no statistical relationships have ever been established between water quality parameters, coral biodiversity and coral cover. Hong Kong provides a unique opportunity to assess this relationship. Here, coastal waters have been monitored monthly since 1986, at 76...
Article
Full-text available
The giant clam Tridacna maxima presents a strong potential for paleoclimatic reconstructions but its use remains limited by the fact that the relationship between the shell stable oxygen isotopes ratio (δ 18Oshell), the sea surface temperature (SST), and the stable oxygen isotopes ratio of seawater (δ 18Osw) has not been calibrated yet. In this stu...
Article
Full-text available
Nonlethal effects of predators on prey behaviour are still poorly understood, although they may have cascading effects through food webs. Underwater observations and experiments were conducted on a shallow fringing coral reef in Malaysia to examine whether predation risks affect diel activity, habitat use, and survival of the rhynchocinetid shrimp...
Article
Full-text available
The Lapita colonization, which occurred in the late Holocene, is one of the most remarkable prehistorical human colonizations. To explore the possible influence of El Niño – Southern Oscillation (ENSO) on this event, bulk oxygen (δ18Oshell) and carbon (δ13Cshell) stable isotope records were obtained from eight fossil Tridacna sp. and Hippopus hippo...
Article
Full-text available
We present early mid-Holocene records of Sr/Ca, δ18O and δ18Osw from marine archives collected in Vanuatu: two Porites sp. corals (6.7–6.5 ka BP) and a Tridacna maxima giant clam (6.2–6.0 ka BP). Sr/Ca, δ18O, and δ18Osw were used as proxies for sea surface temperature (SST) and sea surface salinity (SSS). The fossil geochemical records were compare...
Article
The recent increase in sea surface temperature and ocean acidification raises major concerns about the evolution of the coral calcification rate. Digitized X-radiographs have been used for coral skeleton density measurements since the 1980s. The main limitation of coral densitometry from digitized X-radiographs is the X-ray intensity heterogeneity...

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Projects

Projects (2)
Project
: In recent years total anthropogenically fixed nitrogen sources (210 Tg N yr-1) have surpassed natural sources (203 Tg N yr-1), globally. A large fraction of this fixed nitrogen is transferred from land to the ocean through fresh waters (50-70 Tg N yr-1) or can enter through atmospheric deposition (30 Tg N yr-1). These dramatic inputs of excess N are fundamentally shifting many ecosystems away from their natural background. However, due to the scarcity of long-term monitoring datasets, in many environmental settings it is challenging to compare current changes to truly natural states or environmental baselines. Here we present high resolution, multi-proxy data (C- N-, O-isotopes) from two Siderastrea siderea coral cores taken at two distinct locations on the Caribbean coast of Costa Rica reaching as far back as ~1920 CE and ~1870 CE. We use these records to evaluate the potential impact of past changes in coastal N inputs related to substantial land-use change in Costa Rica. While oxygen isotopes record a long-term sea surface temperature trend of +1°C and carbon isotopes reflect anthropogenic CO2 emissions known as the Suess effect, nitrogen isotopes convey a more nuanced picture with location specific dynamics. With a 16-fold increase of nitrogenous fertilizer use and well recorded land use change at the Caribbean coast of Costa Rica, we expected a substantial shift in nitrogen isotope values with respect to their pre-industrial baseline. Surprisingly, we neither detect long-term trends nor large inter-annual variations that can be linked to anthropogenic N inputs, which raises the question of the fate and retention time of nitrogenous fertilizer at Caribbean coastal interfaces.
Archived project
The study's purpose is to show how the coral communities have changed in a relatively short period of time after human settlement. The main hypothesis is that after the colonization of Hong Kong the reclamation activities have negatively affected the species rich communities in the coastal waters of Hong Kong. The study will also glance at the effects of the lime industry and the need of slacked-lime that was mainly produced by burning corals in lime kilns, and how the demand may have decreased the abundance of coral communities.