Maurice Héral - Academia.edu (original) (raw)
Papers by Maurice Héral
HAL (Le Centre pour la Communication Scientifique Directe), 1996
Aquatic Living Resources, 2001
Journal of the Knowledge Economy
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1988
The total lipid contents of four bivalve molluscs (Crassostrea gigas, Mytilus edulis, Ruditapes p... more The total lipid contents of four bivalve molluscs (Crassostrea gigas, Mytilus edulis, Ruditapes philippinarum, Cerastoderma edule) were estimated by two methods, one colorimetric the other gravimetric. 2. No significant differences were evident between the two methods. 3. The energy value of the total lipids, estimated by microcalorimetry varied throughout the year (minimum 29.05, maximum 40.88joules/mg), with an annual mean of 34.83 + 2.29joules/mg.
Oceanologica Acta, 1998
Crepidula fornicata L. (Mollusca, Gastropoda) in the Marennes-OlCron Bay: side-scan sonar mapping... more Crepidula fornicata L. (Mollusca, Gastropoda) in the Marennes-OlCron Bay: side-scan sonar mapping of subtidal beds and stock assessment. Extensive and detailed subtidal ground mapping of the Marennes-Oltron Bay and Fouras-Aix areas was performed with a side-scan sonar. Side-scan sonographs gave a comprehensive view of sedimentological bottom environments and also allowed us to outline locations of grounds colonised by the gastropod mollusc Crepidulafornicata L. with a precise estimate of their surface. A sedimentological map of the centre of the Marennes-O&on Bay is given, descrilbing spatial organisation of the following four types of sediment: pure mud, fine sand, coarse sand and rocks. Crepidula beds were also recognised on sonographs and were estimated to cover 181 hectares in the Fouras-Aix area and 615 hectares within the Marennes-O&on Bay. Standard sampling methods were then combined with the side-scan sonar mapping results, allowing an estimate to be made of the stocks of Crepidula fornicata (live specimens and dead shells). A stratified sampling procedure was performed in April-May 1995, including 80 stations sampled with a Smith McIntyre grab (two grabs per station). The live stock of Crepidula was estimated to be 2 494 & 3 344 tons at Fouras-Aix and 2 644 ct 1 137 tons within the bay of Marennes-OlCron. This latter estimate is similar to the previous one performed in this bay in spring 1984, i.e. I 800 + 900 tons, due to the overlap of 95 % confidence intervals. These comparable estimates within the Marennes-016ron Bay give no evidence to suggest that dredging operations (1000-l 500 tonsyr-') performed in the bay for 15 years are not efficient. However, annual landing operations of slipper limpet cannot prevent further spread of the species, as pointed out by the large development of a new Crepidula ground in the northwestern centre of the bay (north Lamouroux sand bank). Both natural processes (current action and bed load transport) and bottom-trawl activities can facilitate spread of the species in the bay, as revealed by side-scan sonar image analysis. 0 Elsevier, Paris Crepidula fornicata I mapping I stock assessment I side-scan sonar I Marennes-OlCron Bay
Filtration of oyster population (100 animals) have been followed during 16 days in raceway system... more Filtration of oyster population (100 animals) have been followed during 16 days in raceway systems with continuous recorder of the input and output of the raceway for in situ turbidity and fluorescence. Experimental conditions were fluctuated with particulate matter which varied during a tidal cycle from 40 mg.l-1 to 300 mg.l-1. During the same period the phytoplanktonic biomass presented synchronous variations forro 7 ta 20 /Lg.l-1 bound with sediment resuspension of phytobenthos and oyster biodeposit created by alternating currents. Filtration of oyster population during a neap tide cycle, variated between 1.2 and 2.8I.h-1 by animal for a calculated retention based on turbidity and between 2.4 and 4.8 l.h-1 by animal for a retention calculated with phytoplanktonic biomasses. During a spring tide cycle, oysters fùtration varied respectively from 0.7 ta 2.4l.h-1 animal and 0.5 to 4.31.h-1 by animal. Filtration of the oyster population fluctuated during the tidal cycle with the load ...
Aquatic Living Resources, 1996
Evuluution of the energetic budget of the Japunese oyster, Crassostrea gigas, in Marennes-Oléron ... more Evuluution of the energetic budget of the Japunese oyster, Crassostrea gigas, in Marennes-Oléron Huy (fiance).
This publication may be reproduced in whole or in part and in any form of educational and non-pro... more This publication may be reproduced in whole or in part and in any form of educational and non-profit purposes without special permission from the copyright holder, provided acknowledgement of the source is made. PAP would appreciate receiving a copy of any publication that uses this material as a source. No use of this publication may be made for resale or for any other commercial purposes whatsoever without prior permission in writing from PAP. For bibliographic purposes this document may be cited as: PAP/RAC: Approaches for zoning of coastal
une étude bibliographique L'analyse des données historiques des productions annuelles d'huîtres C... more une étude bibliographique L'analyse des données historiques des productions annuelles d'huîtres Crassostrea virginica a été réalisée pour la partie marylandaise de la Baie de Chesapeake. Les différentes tendances sont analysées parallèlement aux principaux évènements et aux stratégies d'aménagements qui ont été appliquées dans la baie. Trois périodes principales sont identifiées: (1) la période de forte production (1840 à 1890) avec des débarquements qui ont dépassé 600 000 tonnes. Elle est caractérisée par une forte surpêche entraînant la destruction de l'habitat des gisements d'huîtres provoquée par une utilisation abusive d'engins de récolte; (2) la période de décroissance et d'apports stables (1900 à 1980) due à l'échec du plan de repeuplement et au fort taux de sédimentation et les conditions estivales anoxiques n'a pas permis de dépasser une production de 80 000 tonnes; (3) la période de forte décroissance de la production (1981-1988) avec des apports annuels inférieurs à 15 000 tonnes est caractérisée par les fortes mortalités liées aux parasites (MSX et Perkinsus marinus), à la prédation et aux pratiques d'aménagement. Des stratégies alternatives pour la restauration de la production d 'huîtres en Baie de Chesapeake sont discutées.
Journal du Conseil: ICES Journal of …, 1991
The Japanese oyster (Crassostrea gigas) has been introduced in France on a large scale to replace... more The Japanese oyster (Crassostrea gigas) has been introduced in France on a large scale to replace cultivation of the Portuguese oyster (Crassostrea angulata), affected by a viral disease. The importation took place from 1971 to 1975, with broodstock coming from ...
Aquatic Living Resources, May 1, 2001
The production of biodeposits followed with physiological experiments. Function of the quantity a... more The production of biodeposits followed with physiological experiments. Function of the quantity and quality of the available food the production laws been designed to simulate the quantity of biodeposits produced estuarine conditions. impact of biodeposits on the vertical flux of organic have been measured as well for nitrogen, and phosphorus.
The historical landings of Eastern oyster Crassostrea virginica are described for the Maryland pa... more The historical landings of Eastern oyster Crassostrea virginica are described for the Maryland part of the Chesapeake Bay. The different trends are analyzed concurrently with the main events and management strategies whieh occurred. Three main periods are identified : (1) the great fishery when annual oyster landings from 1840 to 1890 reached 600,000 metric tons. This period was characterized by
Journal of Experimental Marine Biology and Ecology, 1994
A genetic and metabolic basis for faster growth among triploids induced by blocking meiosis I but... more A genetic and metabolic basis for faster growth among triploids induced by blocking meiosis I but not meiosis II in the larviparous European flat oyster, Ostrea edulis L.
HAL (Le Centre pour la Communication Scientifique Directe), 1996
Aquatic Living Resources, 2001
Journal of the Knowledge Economy
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1988
The total lipid contents of four bivalve molluscs (Crassostrea gigas, Mytilus edulis, Ruditapes p... more The total lipid contents of four bivalve molluscs (Crassostrea gigas, Mytilus edulis, Ruditapes philippinarum, Cerastoderma edule) were estimated by two methods, one colorimetric the other gravimetric. 2. No significant differences were evident between the two methods. 3. The energy value of the total lipids, estimated by microcalorimetry varied throughout the year (minimum 29.05, maximum 40.88joules/mg), with an annual mean of 34.83 + 2.29joules/mg.
Oceanologica Acta, 1998
Crepidula fornicata L. (Mollusca, Gastropoda) in the Marennes-OlCron Bay: side-scan sonar mapping... more Crepidula fornicata L. (Mollusca, Gastropoda) in the Marennes-OlCron Bay: side-scan sonar mapping of subtidal beds and stock assessment. Extensive and detailed subtidal ground mapping of the Marennes-Oltron Bay and Fouras-Aix areas was performed with a side-scan sonar. Side-scan sonographs gave a comprehensive view of sedimentological bottom environments and also allowed us to outline locations of grounds colonised by the gastropod mollusc Crepidulafornicata L. with a precise estimate of their surface. A sedimentological map of the centre of the Marennes-O&on Bay is given, descrilbing spatial organisation of the following four types of sediment: pure mud, fine sand, coarse sand and rocks. Crepidula beds were also recognised on sonographs and were estimated to cover 181 hectares in the Fouras-Aix area and 615 hectares within the Marennes-O&on Bay. Standard sampling methods were then combined with the side-scan sonar mapping results, allowing an estimate to be made of the stocks of Crepidula fornicata (live specimens and dead shells). A stratified sampling procedure was performed in April-May 1995, including 80 stations sampled with a Smith McIntyre grab (two grabs per station). The live stock of Crepidula was estimated to be 2 494 & 3 344 tons at Fouras-Aix and 2 644 ct 1 137 tons within the bay of Marennes-OlCron. This latter estimate is similar to the previous one performed in this bay in spring 1984, i.e. I 800 + 900 tons, due to the overlap of 95 % confidence intervals. These comparable estimates within the Marennes-016ron Bay give no evidence to suggest that dredging operations (1000-l 500 tonsyr-') performed in the bay for 15 years are not efficient. However, annual landing operations of slipper limpet cannot prevent further spread of the species, as pointed out by the large development of a new Crepidula ground in the northwestern centre of the bay (north Lamouroux sand bank). Both natural processes (current action and bed load transport) and bottom-trawl activities can facilitate spread of the species in the bay, as revealed by side-scan sonar image analysis. 0 Elsevier, Paris Crepidula fornicata I mapping I stock assessment I side-scan sonar I Marennes-OlCron Bay
Filtration of oyster population (100 animals) have been followed during 16 days in raceway system... more Filtration of oyster population (100 animals) have been followed during 16 days in raceway systems with continuous recorder of the input and output of the raceway for in situ turbidity and fluorescence. Experimental conditions were fluctuated with particulate matter which varied during a tidal cycle from 40 mg.l-1 to 300 mg.l-1. During the same period the phytoplanktonic biomass presented synchronous variations forro 7 ta 20 /Lg.l-1 bound with sediment resuspension of phytobenthos and oyster biodeposit created by alternating currents. Filtration of oyster population during a neap tide cycle, variated between 1.2 and 2.8I.h-1 by animal for a calculated retention based on turbidity and between 2.4 and 4.8 l.h-1 by animal for a retention calculated with phytoplanktonic biomasses. During a spring tide cycle, oysters fùtration varied respectively from 0.7 ta 2.4l.h-1 animal and 0.5 to 4.31.h-1 by animal. Filtration of the oyster population fluctuated during the tidal cycle with the load ...
Aquatic Living Resources, 1996
Evuluution of the energetic budget of the Japunese oyster, Crassostrea gigas, in Marennes-Oléron ... more Evuluution of the energetic budget of the Japunese oyster, Crassostrea gigas, in Marennes-Oléron Huy (fiance).
This publication may be reproduced in whole or in part and in any form of educational and non-pro... more This publication may be reproduced in whole or in part and in any form of educational and non-profit purposes without special permission from the copyright holder, provided acknowledgement of the source is made. PAP would appreciate receiving a copy of any publication that uses this material as a source. No use of this publication may be made for resale or for any other commercial purposes whatsoever without prior permission in writing from PAP. For bibliographic purposes this document may be cited as: PAP/RAC: Approaches for zoning of coastal
une étude bibliographique L'analyse des données historiques des productions annuelles d'huîtres C... more une étude bibliographique L'analyse des données historiques des productions annuelles d'huîtres Crassostrea virginica a été réalisée pour la partie marylandaise de la Baie de Chesapeake. Les différentes tendances sont analysées parallèlement aux principaux évènements et aux stratégies d'aménagements qui ont été appliquées dans la baie. Trois périodes principales sont identifiées: (1) la période de forte production (1840 à 1890) avec des débarquements qui ont dépassé 600 000 tonnes. Elle est caractérisée par une forte surpêche entraînant la destruction de l'habitat des gisements d'huîtres provoquée par une utilisation abusive d'engins de récolte; (2) la période de décroissance et d'apports stables (1900 à 1980) due à l'échec du plan de repeuplement et au fort taux de sédimentation et les conditions estivales anoxiques n'a pas permis de dépasser une production de 80 000 tonnes; (3) la période de forte décroissance de la production (1981-1988) avec des apports annuels inférieurs à 15 000 tonnes est caractérisée par les fortes mortalités liées aux parasites (MSX et Perkinsus marinus), à la prédation et aux pratiques d'aménagement. Des stratégies alternatives pour la restauration de la production d 'huîtres en Baie de Chesapeake sont discutées.
Journal du Conseil: ICES Journal of …, 1991
The Japanese oyster (Crassostrea gigas) has been introduced in France on a large scale to replace... more The Japanese oyster (Crassostrea gigas) has been introduced in France on a large scale to replace cultivation of the Portuguese oyster (Crassostrea angulata), affected by a viral disease. The importation took place from 1971 to 1975, with broodstock coming from ...
Aquatic Living Resources, May 1, 2001
The production of biodeposits followed with physiological experiments. Function of the quantity a... more The production of biodeposits followed with physiological experiments. Function of the quantity and quality of the available food the production laws been designed to simulate the quantity of biodeposits produced estuarine conditions. impact of biodeposits on the vertical flux of organic have been measured as well for nitrogen, and phosphorus.
The historical landings of Eastern oyster Crassostrea virginica are described for the Maryland pa... more The historical landings of Eastern oyster Crassostrea virginica are described for the Maryland part of the Chesapeake Bay. The different trends are analyzed concurrently with the main events and management strategies whieh occurred. Three main periods are identified : (1) the great fishery when annual oyster landings from 1840 to 1890 reached 600,000 metric tons. This period was characterized by
Journal of Experimental Marine Biology and Ecology, 1994
A genetic and metabolic basis for faster growth among triploids induced by blocking meiosis I but... more A genetic and metabolic basis for faster growth among triploids induced by blocking meiosis I but not meiosis II in the larviparous European flat oyster, Ostrea edulis L.