Philippe Soudant

Philippe Soudant
French National Centre for Scientific Research | CNRS · Institut universitaire européen de la mer (IUEM)

Ph D

About

268
Publications
83,092
Reads
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11,953
Citations
Additional affiliations
October 2011 - present
October 2000 - October 2011
French National Centre for Scientific Research
Position
  • Research Associate
Description
  • Bivalve physiology, bivalve nutrition, lipid biochemistry, flow cytometry, protozoan parasite perkinsus, harmful algae, innate immunity, microplastics
March 1998 - March 2000
Virginia Institute of Marine Science
Position
  • PostDoc Position

Publications

Publications (268)
Article
Full-text available
Few estuaries remain unaffected by water management and altered freshwater deliveries. The Caloosahatchee River Estuary is a perfect case study for assessing the impact of altered hydrology on natural oyster reef (Crassostrea virginica) populations. The watershed has been highly modified and greatly enlarged by an artificial connection to Lake Okee...
Article
Full-text available
The last century has witnessed an increasing rate of new disease emergence across the world leading to permanent loss of biodiversity. Perkinsea is a microeukaryotic parasitic phylum composed of four main lineages of parasitic protists with broad host ranges. Some of them represent major ecological and economical threats because of their geographic...
Article
Food characteristics are amongst the most influential factors determining the fish life history traits as quantitative and qualitative changes in individuals' diet can lead to a decline in the energy allocated to their growth, and hence influence natural populations' characteristics. The size-at-age and weight of European sardines (Sardina pilchard...
Article
Full-text available
The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a 13C-enriched isotopic marker, 13CO2, for 24 h during the exponential growth of the algae. The 13C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsa...
Article
Full-text available
The benefits of physiological biomarkers, knowledge and concepts are well-established in fish and wildlife management as they confer the ability to understand mechanistic processes, identify cause-and-effect relationships, and develop predictive models. Although this approach is gaining momentum in the context of species conservation, the use of ph...
Article
Long-chain polyunsaturated fatty acids (LC-PUFA) are molecules produced at the basis of marine food webs and essential for ecosystem functioning. This study reports detailed fatty acid (FA) composition including the two LC-PUFA 20:5n-3 and 22:6n-3, in suspended organic matter (SPOM) from the upper 300 m collected in the Kerguelen Island region in t...
Article
Full-text available
Pacific oysters (Crassostrea gigas) may bio-accumulate high levels of paralytic shellfish toxins (PST) during harmful algal blooms of the genus Alexandrium. These blooms regularly occur in coastal waters, affecting oyster health and marketability. The aim of our study was to analyse the PST-sensitivity of nerves of Pacific oysters in relation with...
Article
Full-text available
Omega-3 long-chain polyunsaturated fatty acids (hereafter, omega-3), including eicosapentaenoic-acid (EPA) and docosahexaenoic-acid (DHA), are essential nutritional compounds for humans, providing several benefits related to cardiovascular and neural health. Human intake of omega-3 occurs mostly via seafood, particularly fish. The primary source of...
Article
Dinoflagellates from the globally distributed genus Alexandrium are known to produce both paralytic shellfish toxins (PST) and uncharacterized bioactive extracellular compounds (BEC) with allelopathic, ichthyotoxic, hemolytic and cytotoxic activities. In France, blooms of Alexandrium minutum appear generally during the spawning period of most bival...
Article
The aetiological agent Perkinsus olseni is globally recognised as a major threat for shellfish production considering its wide geographical distribution across Asia, Europe, Australia and South America. Another species, Perkinsus chesapeaki, which has never been known to be associated with significant mortality events, was recently detected along F...
Article
Carbon isotopic fractionation was studied during the development of the diatom Chaetoceros muelleri grown in batch culture with ¹³C-depleted CO2 addition. Cellular and growth parameters and isotopic composition of dissolved inorganic carbon and particulate organic carbon were monitored every two days, while the content and isotopic composition of i...
Article
Long-chain omega-3 fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) are health beneficial lipids found in high concentration in pelagic fishes, including Atlantic mackerel. While EPA and DHA are sensitive to oxidation during fish storage and processing, post-mortem degradation in the first hours following fish death is poo...
Article
Full-text available
Cultivation of salt-tolerant crops help to face to irreversible global salinization of freshwater and soils. In New-Caledonia, three halophytes are candidates for saline crops, Salsola australis R.Br., Suaeda maritima (L.) Dumort and Enchylaena tomentosa R.Br. Their success and quality depend yet on availabilities of salinity and essential nutrient...
Article
Early life stages (ELS) of numerous marine invertebrates mustcope with man-made contaminants, including plastic debris, during their pelagic phase. Among the diversity of plastic particles, nano-sized debris, known as nanoplastics, can induce effects with severe outcomes in ELS of various biological models, including the Pacific oyster Crassostrea...
Article
An important, but underappreciated, consequence of climate change is the reduction in crucial nutrient production at the base of the marine food chain: the long-chain omega-3 highly unsaturated fatty acids (n-3 HUFA). This can have dramatic consequences on consumers, such as fish as they have limited capacity to synthesise n-3 HUFA de novo. The n-3...
Article
Full-text available
The synthetic pathways responsible for the production of the polyunsaturated fatty acids 22:6n-3 and 20:5n-3 were studied in the Dinophyte Alexandrium minutum. The purpose of this work was to follow the progressive incorporation of an isotopic label (13 CO 2) into 11 fatty acids to better understand the fatty acid synthesis pathways in A. minutum....
Preprint
Full-text available
The synthetic pathways responsible for the production of the polyunsaturated fatty acids 22:6n-3 and 20:5n-3 were studied in the Dinophyte Alexandrium minutum. The purpose of this work was to follow the progressive incorporation of an isotopic label (13 CO2) into 11 fatty acids to better understand the fatty acid synthesis pathways in A. minutum. T...
Article
Full-text available
Determining the lipid content and fatty acid (FA) composition of aquatic organisms has been of major interest in trophic ecology, aquaculture, and nutrition for over half a century. Although protocols for lipid analysis are well-described, their application to aquatic sciences often requires modifications to adapt to field conditions and to sample...
Article
Oysters are keystone species that use external fertilization as a sexual mode. The gametes are planktonic and face a wide range of stressors, including plastic litter. Nanoplastics are of increasing concern because their size allows pronounced interactions with biological membranes, making them a potential hazard to marine life. In the present stud...
Article
Plastic pollution is a source of chemical to the environment and wildlife. Despite the ubiquity of plastic pollution and thus plastic additive in the environment, plastic additives have been studied to a limited extend. As a prerequisite to a study aiming to evaluate the leaching of a common additive used as an antioxidant (Irgafos® 168) from polye...
Article
Full-text available
: The present study sought to characterize the synthesis pathways producing the essential polyunsaturated fatty acid (PUFA) 20:5n-3 (EPA). For this, the incorporation of 13C was experimentally monitored into 10 fatty acids (FA) during the growth of the diatom Chaetoceros muelleri for 24 h. Chaetoceros muelleri preferentially and quickly incorporate...
Article
The dinoflagellate genus Alexandrium comprises species that produce highly potent neurotoxins known as paralytic shellfish toxins (PST), and bioactive extracellular compounds (BEC) of unknown structure and ecological significance. The toxic bloom-forming species, Alexandrium minutum, is distributed worldwide and adversely affects many bivalves incl...
Technical Report
Full-text available
Case study for Western (Brazil) and Eastern (Cape Verde, Senegal) tropical Atlantic countries, information on marine and coastal natural resources and their use and exploitation status
Article
FREE ARTICLE LINK UNTIL JULY 1st, 2019: https://authors.elsevier.com/a/1Z2BpzLNSRqpN Due to the growing concern about the presence of microplastics (MP) in the environment, the number of studies evaluating the toxicity of these small persistent particles on different marine species has increased in recent years. Few studies have addressed their im...
Poster
Full-text available
Poster highlighting my PhD objective and first results. Presented in 2019 at the University of North Carolina Wilmington (UNCW) in the Center for Marine Sciences (CMS) for the Graduate Student Day. Final results for the C. neogracile and A. minutum experiments have been published in Biomolecules in 2020.
Preprint
Full-text available
Hydrogen isotope ratios of biomarkers have been shown to reflect water isotope ratios, and in some cases correlate significantly with salinity. The δ²H-salinity relationship is best studied for long-chain alkenones, biomarkers for haptophyte algae, and is known to be influenced by a number of different environmental parameters. It is not fully know...
Article
Nowadays, environmental pollution by microplastics (<5 mm; MP)is a major issue. MP are contaminating marine organisms consumed by humans. This work studied MP contamination in two bivalve species of commercial interest: blue mussel (Mytilus edulis)and common cockle (Cerastoderma edule)sampled on the Channel coastlines (France). In parallel, 13 plas...
Article
The potential presence of nanoplastics (NP) in aquatic environments represents a growing concern regarding their possible effects on aquatic organisms. The objective of this study was to assess the impact of polystyrene (PS) amino-modified particles (50 nm PSeNH2) on the cellular and metabolic responses of the diatom Chaetoceros neogracile cultures...
Article
The dinoflagellate Alexandrium minutum produces toxic compounds, including paralytic shellfish toxins, but also some unknown extracellular toxins. Although copper (Cu) is an essential element, it can impair microalgal physiology and increase their toxic potency. This study investigated the effect of different concentrations of dissolved Cu (7 nM, 7...
Chapter
The explosion of the Deepwater Horizon (DWH) drilling unit in April 2010 led to the largest marine oil spill in US history. For 87 days, unprecedented amounts of crude oil and dispersant were released into the Gulf of Mexico (GoM), coincident with the spawning and recruitment season of the oyster, Crassostrea virginica. Effects of acute exposures t...
Article
The Deepwater Horizon (DWH) disaster released crude oil in the Gulf of Mexico for 87 days, overlapping with the reproductive season and recruitment of the oyster Crassostrea virginica. The pelagic larval life stages of C. virginica are particularly vulnerable to contaminants such as polycyclic aromatic hydrocarbons (PAHs) and oil droplets. Based on...
Research Proposal
Lipids in the Ocean: Structure, function, ecological role and applications This interdisciplinary and international conference will strengthen the position of worldwide research on marine lipids toward more global scientific questions, ranging from cellular-level to marine ecosystem functioning in the context of global changes. The conference will...
Article
Disseminated neoplasia (DN) is a disease that affects bivalves worldwide and can lead to mass mortalities. In the present study, a pathological survey conducted from December 2011 to August 2012 in Crassostrea gasar, an oyster of commercial interest in northeast Brazil, revealed the occurrence of DN in oysters reared in the Mamanguape estuary, Para...
Article
Harmful algal blooms are a threat to aquatic organisms and coastal ecosystems. Among harmful species, the widespread distributed genus Alexandrium is of global importance. This genus is well-known for the synthesis of paralytic shellfish toxins which are toxic for humans through the consumption of contaminated shellfish. While the effects of Alexan...
Article
Allelochemical interactions are likely to be a contributing factor explaining the success of large blooms of the harmful marine dinoflagellate Alexandrium, however, the physiological mechanisms of allelochemical interactions remain poorly described. Here we investigated the sub-lethal effects (on an hourly scale) of a filtrate containing allelochem...
Article
As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dinoflagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditio...
Article
In the marine environment, most bivalve species base their reproduction on external fertilization. Hence, gametes and young stages face many threats, including exposure to plastic wastes which represent more than 80% of the debris in the oceans. Recently, evidence has been produced on the presence of nanoplastics in oceans, thus motivating new stud...
Article
Full-text available
Plastics are found to be major debris composing the marine litter, microplastics (MP, <5 mm) being found in all marine compartments. Microplastics number tends to increase with decreasing size leading to a potential misidentification when only visual identification is performed. These last years, pyrolysis coupled with gas chromatography/mass spect...
Poster
There is increasing evidence that climate change critically depletes crucial nutrients in food web. In particular, a reduction in the production of Omega 3 fatty acids in microalgae as a result of climate change can alter the fatty acid composition of biological membranes of consumers. This is particularly true for marine fish as they are unable to...
Article
The Gulf of Mexico, including the southwest Florida coast, USA, experience recurrent blooms of the brevetoxin (PbTx)-producing dinoflagellate, Karenia brevis. Northern quahogs (hard clams) Mercenaria mercenaria, are an important commercial species in this region. This study examined the effects of field and laboratory exposure of adult clams to K....
Article
Full-text available
Marine plastic pollution is a major environmental issue. Given their ubiquitous nature and small dimensions, ingestion of microplastic (MP) and nanoplastic (NP) particles and their subsequent impact on marine life are a growing concern worldwide. Transfers along the trophic chain, including possible translocation, for which the hazards are less und...
Article
Abstract Harmful microalgal blooms are a threat to aquatic organisms, ecosystems and human health. Toxic dinoflagellates of the genus Alexandrium are known to produce paralytic shellfish toxins and to release bioactive extracellular compounds (BECs) with potent cytotoxic, hemolytic, ichtyotoxic and allelopathic activity. Negative allelochemical int...
Article
Full-text available
The lipid class and the fatty acid compositions of microalgae highly influence bivalve larval and post-larval development. Light is an essential environmental factor for microalgal culture, and quantity and quality of light may induce changes in the biochemical composition of the algae. The objective of this study was to investigate the effect of l...
Article
While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, th...
Article
Full-text available
We combined the use of pigments, fatty acids and sterols as biomarkers of the seasonal variation in food sources of the great scallop Pecten maximus. From March to October 2011, on a biweekly to twice-weekly basis, scallops and seawater from the water column and the water- sediment interface were collected in the Bay of Brest (Brittany, France). Pi...
Article
Harmful Algal Blooms are worldwide occurrences that can cause poisoning in human seafood consumers as well as mortality and sublethal effets in wildlife, propagating economic losses. One of the most widespread toxigenic microalgal taxa is the dinoflagellate Genus Alexandrium, that includes species producing neurotoxins referred to as PST (Paralytic...
Article
Blooms of the dinoflagellate Alexandrium spp., known as producers of paralytic shellfish toxins (PSTs), are regularly detected on the French coastline. PSTs accumulate into harvested shellfish species, such as the Pacific oyster Crassostrea gigas, and can cause strong disorders to consumers at high doses. The impacts of Alexandrium minutum on C. gi...
Article
Full-text available
The 2010 explosion of the Deepwater Horizon (DWH) oil rig generated the largest marine oil spill in US history with millions of barrels of crude oil released in the Gulf of Mexico (GoM). The eastern oyster, Crassostrea virginica, is an ecologically and economically important species in the northern GoM. Due to its biological characteristics (sessil...
Article
Full-text available
Stable isotope composition of the eastern oyster Crassostrea virginica was characterized from three estuaries in the Ten Thousand Islands (Florida). Freshwater in flow from watershed management is affecting this region and has deeply modified the salinity gradient. Stable carbon and nitrogen isotopes were used to trace specific sources of organic m...
Article
Abstract Standard and mutant Tisochrysis lutea strains were grown in batch culture for 10days under nitrogen (N)-replete and N-reduced conditions to determine the effects of N supply in culture medium and growth phase on microalgal physiology and biochemistry. These two T. lutea strains were compared in terms of growth, morphology, associated free-...
Presentation
Full-text available
International Conference on Microplastic Pollution in the Mediterranean Sea (μMED)