About
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1,176
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Citations since 2017
Introduction
Additional affiliations
January 2007 - December 2012
Position
- Scientific coordinator of the research programme SIEGMA
Description
- Sedimentological and biological (benthos, fish, stomach contents) monitoring of an experimental extraction site of marine aggregates in Baie de Seine
February 2000 - February 2012
Position
- Private Expert & associated researcher
Description
- Teaching in Master Environnement on environmental impact of marine aggregate extractions (sediments, benthos, fish, trophic relationships, habitats)
January 1991 - December 2016
International Council for the Exploration of the Sea, WGEXT
Position
- Biologist expert
Education
July 1978 - June 1981
Publications
Publications (50)
The Working Group on the Effects of Extraction of Marine Sediments on the Marine Eco-system (WGEXT) met in Norwich, UK, 24–27 April 2017, chaired by Ad Stolk, the Nether-lands. Eighteen participants from ten ICES member countries attended the meeting. Contributions were provided by correspondence from Portugal, Estonia and Lithuania whose represent...
Compare the recovery time of benthos and demersal fish in commercial (10 years of extensive extraction) and experimental sites (2 years of intensive extraction) located in the eastern Channel.
The main objective of the Working Group on the Effects of Extraction of Marine Sediments on the Marine Ecosystem (WGEXT) is to provide a summary of data on marine sediment extraction (ToR A1), marine resource and habitat mapping, changes to the legal regime and policy, and research projects relevant to the assessment of environmental effects (ToR A...
The Working Group on the effects of extraction of marine sediments on the marine ecosystem (WGEXT) met in Reykjavik, 2–5 June 2014. Thirteen participants from eight ICES member countries attended the meeting.
The objective of WGEXT is to provide a summary of data on marine sediment extrac-tion (ToR A1), marine resource and habitat mapping, changes...
This document is a comprehensive survey of the scientific knowledge acquired in late 2012 on the environmental impacts of marine aggregate extraction.
The synthesis completes international knowledge (ICES WGEXT, COST Action 638 "MAGGNET") with local investigation in Normandy on two sites of the eastern English Channel in the framework of the 2003-2...
2 G.I.S SIEGMA Stakeholder consortium on the impact of marine gravel extraction End users (fishermen, mining companies) Scientists Authorities, policymakers Supported by private, regional, national and european fundings Objectives : Complete international knowledge on the impact Test exploitation methods to minimize impact and favour restoration
In coarse sediments of the eastern Channel, an appropriate extraction strategy can minimize the degradation of the biodiversity and function of the marine environment :
- a low extraction intensity (< 1h/ha/year) limits the impact on benthos and fish communities, and accelerates the functional restoration of the disturbed area by promoting the bent...
A low intensity of extraction can : - reduce the impact on the main fish population parameters (species richness, , abundance, biomass) ; - provide feeding areas for sole, cod and black seabream (movement into more suitable habitats) ; - increase habitat diversity favouring resilient species of economical value (sole, red mullet) ; -have potential...
The impacts of marine aggregate dredging and the recovery levels, 1 and 10 years after cessation of dredging, are investigated for a commercial dredging site. The site consists of mixed sandy to pebbly sediments. Dredging intensity is low (generally less than 1h/ha/year) and heterogeneous in space and time, allowing to distinguish adjacent areas of...
Desprez, M., Pearce, B., and Le Bot, S. 2010. The biological impact of overflowing sands around a marine aggregate extraction site: Dieppe (eastern English Channel). – ICES Journal of Marine Science, 67: 270–277.
The study investigates the physical impact of sediment deposition associated with aggregate dredging at a site off Dieppe, and the conseq...
The study investigates the physical impact of sediment deposition associated with aggregate dredging at a site off Dieppe, and the consequences for benthic fauna. Sampling stations were sited across potential zones of impact classified as high, moderate, and low deposition, depending on their proximity to dredging activities and their position rela...
Review of knowledge for the period 1998 – 2004
Conservation managers need to be able to assess and prioritize issues that may affect their target habitats and species. In the Baie de Somme, France, conservation issues affecting overwintering shorebirds include hunting pressure, cockle fishing, recreational disturbance, Spartina encroachment, and changing sediment levels. We used an individual-b...
The overall aim of this project was to provide for policy-makers and their scientific advisors a
suite of field-tested predictive population models with which they can devise local and
Europe-wide management plans for maintaining the biodiversity of migratory (wintering/on
passage) coastal birds (waders and wildfowl) that feed on inter-tidal and, o...
Waders consume only 7% of the total biomass of the Somme estuary
The Bay of the Somme: an underused site waterfowls. The biomass and the productivity of benthic invertebrates were studied in the Bay of Somme in 1993, an internationally significant site for Eurasian Shelduck. These data were used to produce an estimate of invertebrate consumption by the eight most numerous species of waterfowl. They consume an av...
Sediment and associated macrofauna of an industrial extraction site off Dieppe have been monitored during a 10-year period.
The original heterogeneous substrate of the shingle bank, characterized by gravels and coarse sands, was progressively dominated
by fine sands deposited in dredging tracks. The maximum impact on benthic macrofauna was a reduct...
Prey depletion and consequenses on a wintering population of Oystercatchers.
The analysis of data relating to Eurasian Oystercatcher Haematopus ostralegus (counts, number of day birds each winter in the Somme bay, density in feeding areas) highlights an increase in numbers, bird days and density of birds on cockle Cerastoderma edule fields. During the study period (1983-1998) Cockle fields have drastically reduced in area....
The hypothesis was tested that towards a species limit of distribution its performance, such as growth or fitness, decreases. To this end, latitudinal changes in growth, maximum attainable length and genetic constitution were assessed for the Baltic clam, Macoma balthica (L.), at stations ranging from the most southern distribution limit (France) t...
The stress sensitivity, determined in copper exposureexperiments and in survival in air tests, and thegenetic structure, measured by means of isoenzymeelectrophoresis, were assessed in populations of theBaltic clam Macoma balthica (L.) from itssouthern to its northern distribution limit, in orderto test the hypotheses that near the distributionlimi...
The relation between condition and copper concentration was assessed in three bivalve species (the Baltic clam Macoma balthica, the cockle Cerastoderma edule and the mussel Mytilus edulis) from several Dutch and French estuaries. In general, the copper concentration in the bivalves was negatively related to condition. The slope of this relation was...
The use of free amino acids (FAA) as a stress indicator was assessed during a copper exposure experiment for specimens of the estuarine bivalve M. balthica from a geographical gradient extending from the Netherlands to its most southern limit of distribution in the Gironde, France. Changes in FAA were significant. A higher alanine content at the st...
Variation in the sensitivity to stress of Macoma balthica was measured in several French and Dutch estuaries. For adult and juvenile Macoma balthica exposed to copper under conditions of starvation, differences in mortality rate, condition, glycogen, burrowing rate and copper content were assessed. No significant differences were observed between a...
Consistent patterns of genetic variation in the marine bivalve Macoma balthica (L.) were found after exposure to low levels of copper, starvation, and along geographic clines. The geographic clines were related to temperature and salinity. Genetic differences were primarily found in the LAP (Leucine aminopeptidase) locus; under stress the frequency...
The areas occupied by seven biosedimentary facies (or communities) have been measured across the entire area, stretching from the inner estuary of the Somme out to sand flats which extend into the Channel. The fauna of the area is dominated by the cockle (Cerastoderma edule) facies in terms of biomass and in terms of abundance by upstream facies, w...
The intertidal macrofauna of the inner part of the Baie de Somme, constituting the estuary of the Somme has been investigated. The conditions in the area range from tidal freshwater into virtually marine conditions over a short distance of 4 km. The fauna comprised a compressed estuarine sequence. In such a situation salinity is the controlling eco...
A stratified methodology for water sampling on tidal flats was adopted in 1988 and 1989 in the Bay of Somme.
Analyses of nutrients, particulate matter and faecal germs showed the poor mixing of fresh and marine water and the weakness of stratification of the water column. Freshwater is pushed by marine water to the inner reaches of the bay and ther...
The first effects of eutrophication in the Bay of Somme became apparent in the years 1982–1985, when the cockle population collapsed. Areas of high mortality were mapped. Following exceptionally high summer temperatures, other effects were seen in 1982, 1983 and 1989, notably a mass mortality of the benthos. It appeared that the mortality of the be...
L'effet inhibiteur des adultes du bivalve suspensivore Cerastoderma edule (L.) sur leur propre recrutement a été étudié par échantillonnage de populations naturelles et testé par des expériences faisant varier la densité des adultes in situ. Un échantillonnage quantitatif réalisé en plusieurs stations intertidales réparties sur les côtes françaises...
Events in the reproduction of Cerastoderma edule were studied simultaneously during 1937, in eight intertidal zones, with relatively homogeneous edaphic conditions and distributed along the French Channel and Atlantic coasts. This approach was intended at identify the variability of spawning which may induce fluctuations in the recruitement from si...
Two indices of estuarine equality have been developed in Ireland to facilitate comparison of estuarine ecosystems: 1) the Biological Quality Index is based on the proportions of the estuarine intertidal zone classified abiotic, opportunistic or stable; 2) the Pollution Load Index is obtained from analysis of the intertidal sediments for pollutants...
In this paper, the results collected since 1978 on the cockle (Cerastoderma edule) in the Bay of Somme have been recapitulated. A synthesis is brought up about causes of the bivalve population collapse which was portended as early as 1982 from the animal cinetics study. In order to back up the discussion, the main results dealing with the biology a...
Seasonal patterns of changes in length and weight during their second year of life were studied in two intertidal populations of the tellinid bivalve Macoma balthica (L.), viz. in The Netherlands (Wadden Sea) and in France (Seine estuary). The Wadden Sea population showed a single and short annual period of growth in spring (March through June), fo...
The study of the intertidal benthic population dynamics in three estuaries of the English Channel (Baie des Veys, Seine estuary, Baie de Somme:France) brings to light two types of species:u
key-species which directly respond to the local disturbance of the environmental conditions in their densities (Spionidae, Capitellidae) and in their growth ra...
This paper investigates the influence of physical structures such as seawalls on the substratum and the associated Macoma communities. The breaching of a seawall in the Seine estuary induced a rapid change in sediment and macrozoobenthos. The drop in fine particles was followed by a reduction in both species diversity and numbers.
In contrast, the...
Many harbour installations have reduced the intertidal zone and involved estuary choking by marine sediments. In 1980, weirs were built in dikes of navigation channels. This study strikes the balance of their impact on estuarine biofacies and points out indicator species for the study of biological impact of environmental design.
The recent collapse in the landings of cockles (Cerastoderma edule) from the Bay of Somme (France) required to investigate if a change in the environmental factors was liable for the drop of the bivalve populations. This project has led to a preliminary assessment of the situation and has been drawn up from the data collected by the Groupe d'Etude...
Projects
Projects (2)
Improve the international knowledge :
- on the impacts of marine aggregate extraction on benthos, fish and habitats in different environmental conditions and under different extraction strategies (ICES Rec 11)
- on trophic consequences of benthic depletion (ICES Rec 1)
- on direct (physical disturbance) and indirect (through the food-web) impacts of m.a.e. on demersal fish communities (ICES Rec 9)
- on the restoration process (ICES Rec 9)
