Stéphane Le FLOCH

Centre de documentation, de recherche et d'expérimentations sur les pollutions accidentelles des eaux | Cedre · Research

There is increasing evidence that sunscreen, more specifically the organic ultra-violet filters (O-UVFs), are toxic for aquatic organisms. In the present study, we simulated an environmental sunscreen exposure on the teleost fish, Chelon auratus. The first objective was to assess their spatial avoidance of environmental concentrations of sunscreen...

Biomarkers involved in detoxification process (GST), oxidative stress (SOD and MDA), immune response (Laccase) and neurotoxic disorders (AChE) were analysed in Pacific oysters and blue mussels collected from 4 locations within the Pertuis sea (France). Seasonal variations of total pesticide mean concentrations were found in seawater with metolachlo...

This study aimed to develop a multidisciplinary approach to assess the ecological status of six moderate-sized French estuaries. For each estuary, we gathered geographical information, hydrobiological data, chemistry of pollutants and fish biology, including integration of proteomics and transcriptomics data. This integrative study covered the enti...

Port areas are socio-ecosystems impacted by chronic mixture pollution. Some marine species benefit from living there and may be studied to define the ecological state of such environments. In this study, the risks of chronic chemical contamination and its consequences on three marine molluscs were evaluated in North Corsica (France) port areas. Med...

Pollution particularly affects coastal ecosystems due to their proximity to anthropic sources. Among those environments, harbours are subjected to marine traffic but also to accidental and chronic pollution. These areas are thus exposed to complex mixtures of contaminants such as trace elements and organic contaminants which can impact marine speci...

Aims: To investigate fungal diversity and biosurfactant-producing fungi in four oil-contaminated sites. Methods and results: Water and sediment samples were collected from four sites in Brittany (France), over two periods, in winter/spring and summer. Fungal diversity was investigated using a metagenetic approach targeting the ITS2 region. Surfa...

FAIR and open data is not a simple, static and achievable one-step process. Challenges emerge when structuring, sharing and opening up research data, multidisciplinary in particular. An iterative approach is necessary, above all, to achieve sufficient formalism for the data to be readable also by machines and to comply with the requirements of the...

The main objective of this study was to improve our knowledge on the responses of fish populations to multistress (diffuse pollution and warming waters) in estuaries. Adult flounders were caught in two estuaries in the Eastern English Channel: the heavily polluted Seine estuary vs the moderately contaminated Canche estuary. Fish samplings were cond...

Acute exposure to oil and oil dispersants can cause a wide range of physiological dysfunctions in marine fish species and evidences for consequences on behaviour are also increasing. In response to the presence of predators or to food availability, the modulation of locomotor activity and schools' behaviour enable fish to maximize their survival ra...

Biosurfactants are amphiphilic molecules with surface tension reducing activities. Among biosurfactant producers, fungi have been identified as promising organisms. While many studies have investigated biosurfactant production in fungal species from the Ascomycota and Basidiomycota phyla, less is known concerning species from the Mucoromycota phylu...

Issu de : Loss Prevention 2022 - 17th EFCE International Symposium on Loss Prevention and Safety Promotion in Process Industries, Prague, République Tchèque, June 5-8 2022

The present pilot study aimed to provide an overview of organic contaminant concentration levels in the littoral ecosystems of the Pertuis seas. The study determined the concentrations of twenty-nine pesticides, six nonylphenols and seven polybrominated diphenyl ethers (PBDEs) in sediments, seawater, Pacific oysters and blue mussels. Oysters accumu...

Dans les zones portuaires, les divers polluants retrouvés dans le milieu constituent une menace sérieuse pour le milieu marin et les espèces qui y résident [1]. Les activités récréatives, le trafic maritime, le carénage, etc. provoquent une contamination qui s'ajoute à celle déjà observée en zone côtière. Ces pressions anthropiques chroniques peuve...

Human activities, whether at sea, on land or along the human‐made coastline may cause chronic and diffuse pollution in the marine environment that represents 75% of the global marine pollution. The use of bioindicators is particularly relevant from a biological point of view if the directly measured concentrations reflect the bioavailable fractions...

Nowadays, pesticides and microplastics (MPs) are commonly found in coastal waters worldwide. Due to their widespread use, their persistence and toxicity, they may induce adverse effects on physiology and behaviour of marine organisms such as the Pacific oyster (Crassostrea gigas). This study explored the growth and valve activity of juvenile oyster...

On 16 March 1978, the oil tanker the Amoco Cadiz, transporting 223,000 tons of crude oil and 4,000 tons of bunker fuel oil, suffered a failure of her steering mechanism and ran aground on Portsall Rocks, on the Breton coast. The entire cargo spilled out as the breakers split the vessel in two, progressively polluting 360 km of French shoreline from...

In situ burning (ISB) is an OSR (Oil Spill Response) technique generally not accepted as a “standard” response by most regulators. Main reluctance generally comes from the occurrence of large and dark smokes plumes as well as possible heavy burn residues likely to sink and reach the seafloor. However, ISB has been widely used during the Macondo oil...

In the early 1970s, studies of marine litter first appeared in the scientific literature. Fifty years later, knowledge of several coastal areas of the Atlantic, the driving forces of oyster farmers and aquaculture, is lacking. This work documents a pilot study on an Atlantic coastal area (France). This study aims to (i) characterize the abundance o...

In cases of maritime pollution by Hazardous and Noxious Substances (HNS), specific methods of identification and characterization are needed. The project POLLUPROOF (which started in January 2014 and ended in mid‐2017) aims to test and validate the use of optical sensing methods, including hyperspectral and radar sensors, in order to detect, locate...

With an increase in the overseas maritime transport of hazardous and noxious substances (HNSs), HNS-related spill accidents are on the rise. Thus, there is a need to completely understand the physical and chemical properties of HNSs. This can be achieved through establishing a library of spectral characteristics with respect to wavelengths from vis...

Accidental spills are pervasive pollution in aquatic ecosystems. Resorting to chemical dispersant is one of the most implemented strategies in response to oil spills, but it results in an increase in the bio-availability of oil compounds known to disturb fish neurosensory capacities and hence fish habitat use. While it has become well established t...

The objective of this study was to develop an integrative approach in ecotoxicology (from biomarkers to population genetics) to assess the ecological status of fish populations. Flounders (Platichthys flesus) collected after the spawning season in the heavily polluted Seine estuary were compared with the moderately polluted Bay of Douarnenez. The m...

Coastal areas are the interface between terrestrial and marine ecosystems and are a habitat for 90% of the marine biodiversity. However, these waters are the first impacted by anthropic activities, especially in port areas, due to the maritime traffic or accidental pollution. Following the recommendations of the Marine Strategy Framework Directive,...

Hypoxia and petrogenic hydrocarbon contamination are two anthropogenic stressors that coexist in coastal environments. Although studies have estimated the impact of each stressor separately, few investigations have assessed the effects of these stressors in interaction. We therefore investigated the impact of these combined stressors on sea bass, (...

The use of online remote control for 24/7 behavioural monitoring can play a key role in estimating the environmental status of aquatic ecosystems. Recording the valve activity of bivalve molluscs is a relevant approach in this context. However, a clear understanding of the underlying disturbances associated with behaviour is a key step. In this wor...

In the context of new oil exploration/production areas, knowledge of the biological impact of dispersed oil in the deep-sea environment is essential. Hence, the aim of this study was to perform a comparison, at atmospheric pressure (0.1 MPa) and at a high hydrostatic pressure corresponding to 1000 m depth (10.1 MPa), of lethal concentrations (LC) o...

Since the DeepWater Horizon oil spill and the use at 1450 m depth of dispersant as a technical response, the need of relevant ecotoxicological data on deep-sea ecosystems becomes crucial. In this context, this study focused on the effect of high hydrostatic pressure (10.1 MPa) on turbot hepatocytes isolated from fish exposed either to chemically di...

The depletion of traditional oil fields is driving the oil & gas industry to explore new exploitation sites previously considered as unprofitable. Deep-sea oil fields represent one of these new areas of exploitation. Well drilling during exploration and production operations generate large quantities of drilling waste whose biological impact on the...

Aquatic ecosystems are subject to many anthropogenic disturbances, and understanding their possible impacts is a real challenge. Developing approaches based on the behaviour of bivalve mollusks, an integrating marker of the state of the organisms, and therefore of their environment, is relevant, whether within a natural ecosystem or an ecosystem su...

We studied how exposure to oil spill response technologies affect marine microorganisms during Arctic winter and spring. Microorganisms were exposed to chemically dispersed oil (DISP), in situ burnt oil (ISB), and natural attenuated oil (NATT) in mesocosms from February to May. We subsampled the mesocosms and studied the effects of oil in laborator...

Aquatic ecosystems are now chronically polluted by a cocktail of many chemical substances. There is now clear evidence of associations between exposure to pollutants and greater susceptibility to pathogens. The aim of the present study was to characterize the defense capacities of rainbow trout (Oncorhynchus mykiss), chronically exposed to pendimet...

Le projet AQUAECOs (Amélioration de la QUAlité Environnemental en zones COnchylicoles) porté par le CRC (Comité Régional Conchylicole Charente-Maritime) est mené en partenariat avec l’AFB (Agence Française pour la Biodiversité), la Région Nouvelle-Aquitaine, le Comité Départemental de la Charente Maritime ; il vise à étudier les effets de stress na...

Hydrocarbons contamination and hypoxia are two stressors that can coexist in coastal ecosystems. At present, few studies evaluated the combined impact of these stressors on fish physiology and behavior. Here, we tested the effect of the combination of hypoxia and petrogenic hydrocarbons on the anti-predator locomotor performance of fish. Specifical...

Coral reefs around the world are under threat due to anthropogenic impacts on the environment. It is therefore important to develop methods to monitor the status of the reefs and detect changes in the health condition of the corals at an early stage before severe damage occur. In this work, we evaluate underwater hyperspectral imaging as a method t...

Measured 2-methylnaphthalene concentration in exposure beakers. S2 Table shows the concentration of 2-methylnaphthalene for the exposure beakers. The exposure was performed with 3 corals in each exposure beaker, across 4 replicates for each of the 5 treatment groups. Regarding the analyses performed on the 2-methylnaphthalene water samples, the lim...

Experimental setup for UHI image acquisition. S5 Fig shows the experimental set-up for hyperspectral imaging. The photo corresponds to schematic sketch given in Fig 3. Experimental setup for UHI image acquisition. The upper image shows coral samples placed on grids at the bottom of a water filled tank. The UHI with lamps were attached to a scanning...

Example spectra from hyperspectral images of the two color morphs of Lophelia pertusa, exposed and unexposed to 2-methylnaphthalene. Reflectance spectra of white unexposed corals (top left), orange unexposed corals (top right), white high exposure corals (bottom left), and orange high exposure corals (bottom right). For each subfigure, all three sp...

PLS X scores for corals with mortality coloring. PLS X scores colored with the mortality variable are given for orange (A) and white (B) corals are given in S3 Fig. The results correspond exactly to those presented in Fig 8 and S2 Fig, except for the coloring of the dots. (TIF)

Measured 2-methylnaphthalene concentration in stock bottles. S1 Table shows the concentration of 2-methylnaphthalene measured in water samples collected from stock solutions every 24 h during the 96 h exposure period. The average (avg) value and corresponding standard deviation (std dev) are also given. Nominal concentrations, Cnom, are listed for...

PLS X scores for orange corals. PLS X scores for orange corals are given in S2 Fig. The results correspond exactly to those presented in Fig 8, except that S2 Fig presents results for the orange color morph. (TIF)

Equipment used for sampling of corals. The ROV was maneuvered towards the rocky wall growing L. pertusa colonies, and the fish net was carefully poked towards the corals from below. This resulted in pieces of the coral colony breaking off and landing in the fish net. Precaution was taken to avoid any accidental damage of adjacent colonies. (TIF)

Periods of food deprivation of several months are common events for fishes and in such conditions, fitness will be determined by their capacity to maximize food encounters while minimizing predation risk. In this context, the propensity to take risks and the willingness to associate with conspecifics are particularly important as they contribute to...

The present paper focuses on experimental tests performed in an experimental outdoor basin with three gases (air, CO2 and methane) in order to characterize the consequences of underwater gas release. Water elevation (fountain effect) and surface velocity where measured for various mass flow. Results for maximum water elevation clearly show a strong...

This study evaluated the toxicity of dispersant application which is, in nearshore area, a controversial response technique to oil spill. Through an experimental approach with juveniles of Liza aurata, the toxicity of five exposure conditions was evaluated: (i) a chemically dispersed oil simulating dispersant application; (ii) a single dispersant a...

Consequences of exposure to polyaromatic hydrocarbons (PAH), toxic components of crude oil, on fish has been widely documented due to their ecological and economical importance. However, although forming a valuable and consistent body of knowledge, use of these data in spill response is limited. Objective of the present study was thus to facilitate...

Pendimethalin is a herbicide active substance commonly used in terrestrial agricultural systems and is thus detected at high concentrations in the surface water of several European countries. Previous studies reported several histopathological changes, enzymatic antioxidant modulation and immunity disturbance in fish exposed to this pesticide. The...

In the Transchem project, rainbow trout genitors were exposed to environmental concentrations of pendimethalin over a period of 18 months and two new first generations of offspring, F1_2013 and F1_2014, were obtained. We investigated the impact of direct chemical exposure on juveniles as well as the potential cumulative transgenerational and direct...

Increasing activity along the French Atlantic coast has led to chronic pollution with, in particular, mixtures of con- taminants such as hydrocarbons, phytosanitary products, PCBs and heavy metals. Based on previous research, pollution biomarkers were used in this study as they can indicate health status when monitoring the impact of pollutants on...

Coral reefs around the world are under threat due to anthropogenic impacts on the environment. It is therefore important to develop methods to monitor the status of the reefs and detect changes in the health condition of the corals at an early stage before severe damage occur. In this work, we evaluate underwater hyperspectral imaging as a method t...

Impacted marine environments lead to metal accumulation in edible marine fish, ultimately impairing human health. Nevertheless, metal accumulation is highly variable among marine fish species. In addition to ecological features, differences in bioaccumulation can be attributed to species-related physiological processes, which were investigated in t...

A test program was conducted at laboratory and pilot scale to assess the ability of clays used in drilling mud (calcite, bentonite and barite) to create oil-mineral aggregates and disperse crude oil under arctic conditions. Laboratory tests were performed in order to determine the most efficient conditions (type of clay, MOR (Mineral/Oil Ratio), mi...

When oil spills occur, behavior is the first line of defense for a fish to avoid being contaminated. Here, we determined the avoidance threshold of the European seabass (Dicentrarchus labrax) to the water-soluble fraction (WSF) of oil using a dual flow choice box. Our experiment revealed that a plume of 20%-diluted WSF (total PAH concentration: 8.5...

In case of an oil spill, dispersant application represents a response option, which enhances the natural dispersion of oil and thus reduces coating of seabirds and coastal areas. However, as oil is transferred to the water phase, a trade-off of potential harmful effects shifted to other compartments must be performed. This paper summarizes the resu...

Oil spill response in ice-prone regions requires access to all response tools because of the multiple challenges that ice produces. Oil spilled in ice can become rapidly encapsulated into the ice during the ice-growth season. This encapsulation minimizes marine organisms contactwith oil, but also restricts / eliminates access to the oil for respons...

Oil spills pose a threat to aquatic organisms. However, the physiological effects of crude oil on cardiac function and on thermal tolerance of juvenile fish are still poorly understood. Consequently, in this paper, we will present results of two separate experiments where we exposed juvenile rainbow trout and European sea bass to crude oil and made...

This study explored the impact of petroleum hydrocarbons exposure upon habitat exploring behaviour of juvenile European sea bass. Objectives of the study also aimed to looked if behavioural traits are affected in a dose-response manner and if individuals recover after the exposure. Results showed effect at the highest dose (10 times the realistic d...

(ID 2017-381) Knowledge of the behavior of HNS (Hazardous and Noxious Substances) spilled into the aquatic environment is essential to define appropriate response actions; e.g. deployment of efficient equipment and activation of appropriate procedures. As a first approach, the Standard European Behaviour Classification (SEBC) may be used to acquire...

Data on the biological impact of oil dispersion in deep-sea environment are scarce. Hence, the aim of this study was to evaluate the potential interest of a pressure challenge as a new experimental approach for the assessment of consequences of chemically dispersed oil, followed by a high hydrostatic pressure challenge. This work was conducted on a...

Objectives: • Determine the LC50s of three petroleum hydrocarbons to the Sablefish based on the static renewal test. • Assess if sablefish exhibit sensitivity within the observed range for pelagic species

Kinetics of accumulation and elimination in liver and muscle of two marine fish species, Dicentrarchus labrax, and Solea senegalensis, dietary exposed to 3.5 ppm dw of Cd are investigated. During 60 days, fish were fed with a prepared diet containing Cd, after which a 30 day depuration period was carried out. No significant impact of Cd on growth...

The presented study aimed to looked at the effect of food deprivation on four aspect of fish behaviour, neophobia, curiosity, sociability and risk-taking. The results revealed that sociability is affected by feeding status in juvenile European sea bass. However, neophobia, curiosity and risk-taking were not affected by feeding status. This results...

Approximately 9.5 billion tonnes of goods is transported over the world oceans annually with dry bulk representing the largest cargo group. This paper aims to analyse whether the transport and associated inputs of dry bulks into the sea create a risk for the marine environment. For this purpose, we analyse the international regulatory background co...

In order to evaluate the potential toxicity of dispersant application in an oil slick in near-shore areas, this study presents an experimental system designed to perform toxicity tests on fish. Three possible oil spill scenario issues during an oil spill were tested on juvenile sea bass (Dicentrarchus labrax); the Water Soluble Fraction of oil; the...