On the macroecology and global distribution of the ecosystem engineer : Sabellaria alveolata in a changing world

• Main Author: Curd, Amelia
• Other Authors: Laboratoire d'Ecologie Benthique Côtière (LEBCO), Dynamiques des Écosystèmes Côtiers (DYNECO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université de Bretagne occidentale - Brest, Stanislas Dubois, Louise B. Firth
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2020
• Subjects: Biological traits; Environmental Change; Functional Biogeography; Intertidal; Macrophysiology; Reef habitat; Biogéographie fonctionnelle; Changement environnemental; Habitat récifal; Macrophysiologie; Traits biologiques; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; North East Atlantic
• Online Access: https://tel.archives-ouvertes.fr/tel-03738043; https://tel.archives-ouvertes.fr/tel-03738043/document; https://tel.archives-ouvertes.fr/tel-03738043/file/These-2020-SML-Ecologie_marine-CURD_Amelia.pdf

The intertidal zone is affected by environmental change in both the marine and the terrestrial realms. All along Europe’s coast, a unique biogenic habitat buffers the shores’ environmental extremes for the high-diversity fauna it hosts: the reefs of the honeycomb worm Sabellaria alveolata. Despite being listed as a priority European Union habitat, the criteria for assessing candidate reefs have yet to be defined. As a prerequisite to defining the habitat’s ecological status, the aim of this thesis was to further our knowledge of S. alveolata’s ecological niche through an integrated, multi-scale approach. Its niche was explored through the identification and analysis of physiological condition biochemical indicators, which were linked to the outward physical appearance of the bioconstructions in which the individuals resided. Spatial and intraspecific variation in reproductive and biochemical traits were analysed in individuals sampled in ten sites between North Wales and central Portugal. This made it possible to test two divergent theories on the optimal position and environmental conditions for reproduction within a species range. Finally, by constructing a broad-scale occurrence records database which served as the response variable in a species global distribution model, predictive ‘range-long’ maps of present and future suitable habitats were generated for the whole north-east Atlantic coastline. By integrating ecophysiological and biogeographical approaches, this thesis has brought mechanistic insight to the broad-scale processes shaping the distribution of this key habitat-forming species. La zone intertidale est particulièrement touchée par les changements environnementaux et les évènements extrêmes des milieux terrestres et marins. A travers l’Europe, un habitat biogénique abritant une biodiversité unique atténue les écarts de température et d’énergie hydrodynamique caractéristiques de l’estran : les récifs de l’hermelle Sabellaria alveolata. Les critères de sélection de cet habitat d’intérêt ...