Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts
Green Seawater Discolorations (GSD) caused by the proliferation of Lepidodinium chlorophorum in southern Brittany are associated with mass mortalities of bivalves. Few information is available regarding the biology and ecology of this dinoflagellate. This work provides a first ecological conceptual...
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ftunivnantes:oai:HAL:tel-03851976v1 2023-05-15T15:59:04+02:00 Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts Propriétés écologiques des efflorescences de Lepidodinium chlorophorum : de l'écophysiologie cellulaire à l'impact sur l'écosystème Roux, Pauline LITTORAL (LITTORAL) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Nantes Université Raffaele Siano Mathilde Schapira Élodie Fleury 2022-06-23 https://tel.archives-ouvertes.fr/tel-03851976 https://tel.archives-ouvertes.fr/tel-03851976/document https://tel.archives-ouvertes.fr/tel-03851976/file/ROUX.pdf fr fre HAL CCSD NNT: 2022NANU4026 tel-03851976 https://tel.archives-ouvertes.fr/tel-03851976 https://tel.archives-ouvertes.fr/tel-03851976/document https://tel.archives-ouvertes.fr/tel-03851976/file/ROUX.pdf info:eu-repo/semantics/OpenAccess https://tel.archives-ouvertes.fr/tel-03851976 Sciences de la Terre. Nantes Université, 2022. Français. ⟨NNT : 2022NANU4026⟩ Harmful algal blooms Coastal ecology Lepidodinium chlorophorum Environmental DNA Particules Exo-polymériques Milieu marin côtier [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/doctoralThesis Theses 2022 ftunivnantes 2022-11-15T23:55:52Z Green Seawater Discolorations (GSD) caused by the proliferation of Lepidodinium chlorophorum in southern Brittany are associated with mass mortalities of bivalves. Few information is available regarding the biology and ecology of this dinoflagellate. This work provides a first ecological conceptual model of this species. L. chlorophorum is the main producer of Transparent Exopolymer Particles (TEP) and bacteria induce an overproduction of TEP. The genus Lepidodinium was detected at low abundances in the water column during the non productive period and bloom initiation may be induced by ammonium inputs. Any benthic cysts were observed in the sediment, questioning their existence. Freshwater inputs and stratification may trigger the development of a GSD. Remote sensing showed the importance of tidal currents in the spatial dynamics of the GSD. Bacterial remineralisation of TEP may sustain the bloom for more than one month. While TEP could confer an ecological benefit for L. chlorophorum, this organic matter could negatively impact the ecosystem. The physiological recovery of the oyster Crassostrea gigas exposed to GSD concentrations was studied under controlled conditions. The oyster is able to filter and ingest this dinoflagellate. However, the presence of acidic glycoconjugates within the digestive tubules, impaired filtration and disturbed assimilation have been observed, suggesting that long-term exposure could affect the cupped oyster. These first insights into the ecological properties of L. chlorophorum in southern Brittany constitute the baseline for further studies in other ecosystems impacted by this species. En Bretagne sud, les Eaux Colorées Vertes (ECV) engendrées par Lepidodinium chlorophorum sont associées à des mortalités de bivalves. Cependant, la biologie et l'écologie de ce dinoflagellé restent peu étudiées. Ce travail fournit un premier modèle conceptuel de son écologie. L. chlorophorum produit des Particules Exo-polymériques Transparentes (TEP) et les bactéries induisent une surproduction ... Doctoral or Postdoctoral Thesis Crassostrea gigas Université de Nantes: HAL-UNIV-NANTES |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
French |
topic |
Harmful algal blooms Coastal ecology Lepidodinium chlorophorum Environmental DNA Particules Exo-polymériques Milieu marin côtier [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Harmful algal blooms Coastal ecology Lepidodinium chlorophorum Environmental DNA Particules Exo-polymériques Milieu marin côtier [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Roux, Pauline Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
topic_facet |
Harmful algal blooms Coastal ecology Lepidodinium chlorophorum Environmental DNA Particules Exo-polymériques Milieu marin côtier [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
Green Seawater Discolorations (GSD) caused by the proliferation of Lepidodinium chlorophorum in southern Brittany are associated with mass mortalities of bivalves. Few information is available regarding the biology and ecology of this dinoflagellate. This work provides a first ecological conceptual model of this species. L. chlorophorum is the main producer of Transparent Exopolymer Particles (TEP) and bacteria induce an overproduction of TEP. The genus Lepidodinium was detected at low abundances in the water column during the non productive period and bloom initiation may be induced by ammonium inputs. Any benthic cysts were observed in the sediment, questioning their existence. Freshwater inputs and stratification may trigger the development of a GSD. Remote sensing showed the importance of tidal currents in the spatial dynamics of the GSD. Bacterial remineralisation of TEP may sustain the bloom for more than one month. While TEP could confer an ecological benefit for L. chlorophorum, this organic matter could negatively impact the ecosystem. The physiological recovery of the oyster Crassostrea gigas exposed to GSD concentrations was studied under controlled conditions. The oyster is able to filter and ingest this dinoflagellate. However, the presence of acidic glycoconjugates within the digestive tubules, impaired filtration and disturbed assimilation have been observed, suggesting that long-term exposure could affect the cupped oyster. These first insights into the ecological properties of L. chlorophorum in southern Brittany constitute the baseline for further studies in other ecosystems impacted by this species. En Bretagne sud, les Eaux Colorées Vertes (ECV) engendrées par Lepidodinium chlorophorum sont associées à des mortalités de bivalves. Cependant, la biologie et l'écologie de ce dinoflagellé restent peu étudiées. Ce travail fournit un premier modèle conceptuel de son écologie. L. chlorophorum produit des Particules Exo-polymériques Transparentes (TEP) et les bactéries induisent une surproduction ... |
author2 |
LITTORAL (LITTORAL) Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Nantes Université Raffaele Siano Mathilde Schapira Élodie Fleury |
format |
Doctoral or Postdoctoral Thesis |
author |
Roux, Pauline |
author_facet |
Roux, Pauline |
author_sort |
Roux, Pauline |
title |
Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
title_short |
Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
title_full |
Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
title_fullStr |
Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
title_full_unstemmed |
Ecological properties of Lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
title_sort |
ecological properties of lepidodinium chlorophorum blooms : from cellular ecophysiology to ecosystem impacts |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://tel.archives-ouvertes.fr/tel-03851976 https://tel.archives-ouvertes.fr/tel-03851976/document https://tel.archives-ouvertes.fr/tel-03851976/file/ROUX.pdf |
genre |
Crassostrea gigas |
genre_facet |
Crassostrea gigas |
op_source |
https://tel.archives-ouvertes.fr/tel-03851976 Sciences de la Terre. Nantes Université, 2022. Français. ⟨NNT : 2022NANU4026⟩ |
op_relation |
NNT: 2022NANU4026 tel-03851976 https://tel.archives-ouvertes.fr/tel-03851976 https://tel.archives-ouvertes.fr/tel-03851976/document https://tel.archives-ouvertes.fr/tel-03851976/file/ROUX.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766394854314606592 |