Audrey Limoges

Audrey Limoges
University of New Brunswick · Department of Earth Sciences

Ph.D.

About

37
Publications
12,802
Reads
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937
Citations
Additional affiliations
October 2015 - December 2016
Geological Survey of Denmark and Greenland
Position
  • PostDoc Position
January 2015 - present
Université du Québec à Montréal
Position
  • Lecturer

Publications

Publications (37)
Article
Full-text available
Radiocarbon dating of Arctic marine sediment is often challenging due to the low availability of calcareous fossils. Consequently, bulk organic matter dating has at times been used to establish sediment core chronologies. Yet, radiocarbon dates based on bulk organic matter often appear to deviate vastly from dates based on fossils, mainly caused by...
Article
Full-text available
The accelerating sea-ice, ice sheet and glacial melt associated with climate warming have resulted in important changes in the Arctic region over the past decades. In northern Baffin Bay, the formation of the North Open Water (NOW) polynya, which is intrinsically linked to regional sea-ice conditions and ocean circulation, has become more variable...
Article
Full-text available
High Arctic ecosystems and Indigenous livelihoods are tightly linked and exposed to climate change, yet assessing their sensitivity requires a long-term perspective. Here, we assess the vulnerability of the North Water polynya, a unique sea ice ecosystem that sustains the world’s northernmost Inuit communities and several keystone Arctic species. W...
Article
Full-text available
Baffin Bay hosts the largest and most productive of the Arctic polynyas: the North Water (NOW). Despite its significance and active role in water mass formation, the history of the NOW beyond the observational era remains poorly known. We reconcile the previously unassessed relationship between long-term NOW dynamics and ocean conditions by applyin...
Article
Full-text available
Climate warming is rapidly reshaping the Arctic cryosphere and ocean conditions, with consequences for sea ice and pelagic productivity patterns affecting the entire marine food web. To predict how ongoing changes will impact Arctic marine ecosystems, concerted effort from various disciplines is required. Here, we contribute multi-decadal reconstru...
Article
Full-text available
Four marine sediment cores from two sites in the Independence Fjord system near the Wandel Sea in eastern North Greenland were analyzed for their dinoflagellate cyst (dinocyst) and foraminiferal fossil content to gain insight into the water mass properties and evolution of the outer fjord system over the Holocene and Last Glacial Period. While rega...
Article
Nares Strait is one of three channels that connect the Arctic Ocean to Baffin Bay. Unique sea-ice conditions in the strait lead to the formation of landfast ice arches at its northern and southern ends. These ice arches regulate Arctic sea-ice and freshwater export through the strait and promote the opening of the North Water polynya. The present s...
Article
Full-text available
A long-term perspective is essential for understanding environmental change. To be able to access the past, environmental archives such as marine and lake sediments that store information in the form of diverse proxy records are used. Whilst many analytical techniques exist to extract the information stored in these proxy records, the critical asse...
Article
Organic-walled resting cysts of planktonic dinoflagellates occur commonly in modern marine sediment where they represent, with rare exceptions, the only geologically preservable part of the life cycle. Although many species do not produce fossilizable resting cysts, upper Quaternary sediments contain a diverse cyst record that is used frequently fo...
Article
We present a new version of the standardized Northern Hemisphere “modern” dinoflagellate cyst (“dinocyst”) database, which includes abundances of 71 taxa at 1968 sites across the Northern Hemisphere, cross-referenced with 17 environmental parameters extracted mostly from the 2013 World Ocean Atlas. Several taxa with tropical to warm temperate affin...
Article
Dinoflagellate resting cysts with rare exception produce the only discrete link between the biology of extant dinoflagellate species and their fossil record. The geological preservability of such cysts allows them to be used for quantitative paleoecological reconstructions, especially in the Quaternary, and for biostratigraphy and the calibration o...
Article
Full-text available
The use of dinoflagellate cyst assemblages as a tool for palaeo-environmental reconstructions strongly relies on the robustness of cyst identification and existing information on the distribution of the different species. To this purpose, we propose a functional key for the identification of Pliocene and Quaternary Spiniferites bearing intergonal p...
Article
In marine sediments of late Cenozoic age, Spiniferites is a very common genus of dinoflagellate cysts (dinocysts). Despite some taxonomical ambiguities due to large range of morphological variations within given species and convergent morphologies between different species, the establishment of an operational taxonomy permitted to develop a standar...
Article
Full-text available
We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly desc...
Article
Full-text available
The biomarker IP 25 and fossil diatom assemblages preserved in seafloor sediments are commonly used as proxies for paleo Arctic sea-ice reconstructions, but how their production varies over the seasons and is exported to the sediment remains unclear. We analyzed IP 25 concentrations and diatom assemblages from a 5-week consecutive series of sea-ice...
Article
Full-text available
The biomarker IP25 and fossil diatom assemblages preserved in seafloor sediments are commonly used as proxies for paleo Arctic sea-ice reconstructions, but how their production varies over the seasons and is exported to the sediment remains unclear. We analyzed IP25 concentrations and diatom assemblages from a 5-week consecutive series of sea-ice c...
Article
Full-text available
The eastern North coast of Greenland is considered to be highly sensitive to the ongoing Arctic warming, but there is a general lack of data on modern conditions and in particular on the modern distribution of climate and environmental proxies to provide a baseline and context for studies on past variability. Here, we present a detailed investigati...
Article
To evaluate the relationship of changes in organic-walled dinoflagellate cyst (dinocyst) fluxes to sediments with environmental variables (air and sea surface temperatures, El Niño conditions, rainfall, and terrigenous index), cyst assemblages were analyzed in a 210Pb-dated sediment core (~100years) from the pristine San José Lagoon (San José Islan...
Article
Full-text available
In order to establish a baseline for proxy-based reconstructions for the Young Sound–Tyrolerfjord system (Northeast Greenland), we analysed the spatial distribution of primary production and sea ice proxies in surface sediments from the fjord, against monitoring data from the Greenland Ecosystem Monitoring Programme. Clear spatial gradients in orga...
Article
Full-text available
The marine record of the Independence–Danmark fjord system extending out to the Wandel Hav in eastern North Greenland (Fig. 1A) is little known due to the almost perennial sea-ice cover, which makes the region inaccessible for research vessels (Nørgaard-Pedersen et al. 2008), and only a few depth measurements have been conducted in the area. In 201...
Article
Full-text available
Palynological and geochemical analyses were carried out on a sediment core collected in the shallow Alvarado lagoon (Veracruz, Southwestern Gulf of Mexico) in order to evaluate the impact of the significant decline in the surrounding native coastal vegetation on phytoplankton assemblages. The sedimentary sequence encompasses the last millennium and...
Article
Full-text available
Coastal lagoons are very sensitive to anthropogenic impacts and sedimentary records may provide valuable temporal reconstructions of the environmental changes in the lagoon, the coastal zone, and the catchment area. The Alvarado Lagoon (Veracruz, southwestern gulf of Mexico) belongs to an extensive complex of wetlands recognized as a Ramsar site. H...
Article
Corrigendum Corrigendum to ''Taxonomic re-examination of the toxic armoured dinoflagellate Pyrodinium bahamense Plate 1906: Can morphology or LSU sequencing separate P. bahamense var. compressum from var.
Article
Full-text available
Palynological analyses are used in conjunction with oxygen isotopes and Mg/Ca ratios in foraminifers in order to document the response of dinoflagellate cysts (dinocysts) assemblages to changing climate conditions in the northeastern Gulf of Mexico over the Holocene and late Pleistocene. During MIS 6, but also during the cooler phases of MIS 5, Imp...
Article
Full-text available
Cysts belonging to the benthic dinoflagellate Bysmatrum subsalsum were recovered from palynologically treated sediments collected in the Alvarado Lagoon (southwestern Gulf of Mexico). The cysts are proximate, reflecting the features of the parent thecal stage, and their autofluorescence implies a dinosporin composition similar to the cyst walls of...
Article
Full-text available
Pyrodinium bahamense Plate 1906 is a tropical to subtropical dinoflagellate that can cause paralytic shellfish poisoning (PSP). Based on differences in the morphology of the motile stage, as well as geographic distribution, this species was separated into two varieties, the toxic var. compressum and the non-toxic var. bahamense by Steidinger et al....
Article
Full-text available
In order to document the distribution of organic-walled dinoflagellate cysts (dinocysts) and their relationship with sea-surface parameters (temperature, salinity, primary productivity), palynological analyses were performed on 44 surface sediment samples from the Gulf of Mexico (17°N to 29°N). Samples display low to moderate concentrations with va...
Article
Full-text available
Dinoflagellate cysts are useful for reconstructing upper water conditions. For adequate reconstructions detailed information is required about the relationship between modern day environmental conditions and the geographic distribution of cysts in sediments. This Atlas summarises the modern global distribution of 71 organic-walled dinoflagellate cy...
Conference Paper
Surface sediment samples (0-1 cm) from 44 sites of the Gulf of Mexico and adjacent lagoonal bodies were analyzed for their palynological content in order to document the relationship between organic-walled dinoflagellates cysts (dinocysts) and sea-surface conditions (temperature, salinity, productivity). The analyses also aimed at identifying trace...
Data
Dinoflagellate cysts are useful for reconstructing upper water conditions. For adequate reconstructions detailed information is required about the relationship between modern day environmental conditions and the geographic distribution of cysts in sediments. This Atlas summarises the modern global distribution of 71 organicwalled dinoflagellate cys...
Poster
Full-text available
Recent warming in the Laurentian Channel bottom water has been observed in the St. Lawrence Estuary [1] and Gulf [2]. This warming might be linked to an enhanced proportion of warm Atlantic water entering the Laurentian Channel and could be the main cause of the year-round hypoxia observed during the last 30 years in bottom waters of the lower Estu...
Article
Dinoflagellate cysts are useful for reconstructing upper water conditions. For adequate reconstructions detailed information is required about the relationship between modern day environmental conditions and the geographic distribution of cysts in sediments. This Atlas summarises the modern global distribution of 71 organicwalled dinoflagellate cys...
Conference Paper
Full-text available
Export Date: 6 February 2013, Source: Scopus, Article in Press
Article
L'analyse palynologique de 47 échantillons de sédiment de surface provenant de la marge mexicaine (15°95 N à 23°11 N) a été réalisée afin de caractériser la relation existant entre les kystes de dinoflagellés (dinokystes) et les paramètres environnementaux du milieu (température, salinité, productivité primaire, distance par rapport à la côte). Les...

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Projects

Projects (2)
Project
The observed decline of Arctic sea ice during the past decades is one of the most striking consequences of global change. Sea ice is an important component of global climate, and its dynamics have a large impact on the primary productivity of Arctic marine ecosystems, with repercussions to the entire food web, carbon cycling (including CO2 uptake by the ocean), and human activities (e.g. fisheries and navigation). However, our understanding of Arctic sea ice variability is severely limited by the fact that reliable datasets are only available for the past ca. 30 years satellite data). The main goal of the project is to reconstruct past sea ice variability and its impact on primary productivity, with implications for the biogeochemical cycle and ecosystem functioning. This will be achieved by analyzing marine sediment records retrieved from fjord and shelf areas in Northeast Greenland using a novel network of biogeochemical proxies. The proxy records will be calibrated and refined by studying surface sediment samples, modern sea ice and plankton assemblages, and by DNA analyses of indicator species. The new data will be incorporated into sea ice and ecosystem models to better predict future scenarios for the Arctic.
Project
ICE-ARC (Ice, Climate, Economics – Arctic Research on Change) will look into the current and future changes in Arctic sea ice – both from changing atmospheric and oceanic conditions. The project will also investigate the consequences of these changes both on the economics of the area and globally, and social aspects such as on indigenous peoples. The four year project brings together physicists, chemists, biologists, economists, and sociologists from 21 institutes from 11 countries across Europe. With a budget of €11.5M we aim to understand and quantify the multiple stresses involved in the change in the Arctic marine environment. Particular focus is on the rapid retreat and collapse of Arctic sea-ice cover. The most spectacular retreat is occurring in summer, and the complete loss of summer sea ice may occur in a very short period of time – years to decades. There is also a significant reduction in sea ice extent in all seasons, which, if continued, will result seasonal ice cover and a widening annual window of the ice-free season. The outcome of the project will be a better understanding of, and ability to predict, Arctic marine change. This will provide an improvement in the scientific baseline for guiding EU and international policies on the protection of the Arctic marine environment, at a time of increased socio-economic pressure, especially in the field of resource exploitation.