Marine Benthic Ecology

Trophic subsidy through ecosystems: role and dynamics of subtidal accumulations of Laminaria hyperborea detritus

My project aims at determining how kelp forests can influence and subsidise adjacent habitats after dislodgment and erosion from life cycles events and/or storms. I am particularly interested in the dynamics of kelp fragments degradation and the impact of these detritus in subtidal foodweb. My project combines in-situ experiments and diving surveys with laboratory experimental approaches.

Research topics

I am investigating the processes of kelp degradation and subsidy in a range of adjacent subtidal habitats. To understand the dynamics of these kelp subsidies I use a multidisciplinary approach combining: trophic ecology tools (lipids and stable isotopes), biochemical methods (chemical defense assays) for algal tissues and sediment, and physiological measurements (Pulse Amplitude Modulated (PAM) fluorometry & Benthic chambers).To go a step further and understand the role of bacterial communities into this process, I am collaborating  with the Laboratory of Integrative Biology of Marine Models (F. Thomas, A. Gobet).

The Project Includes :

  • Long-term in-situ experiment of L. hyperborea degradation to determine the kinetics of degradation
  • Subtidal surveys of natural accumulation at different depths and geomorphologies
  • Intertidal surveys of kelp beach wrack
  • Laboratory experiments to focus on particular processes
  • Monitoring of algal drift and accumulation to estimate the magnitude of detritus subsidy
  • Collaborative work with Ifremer and the Parc Naturel Marin d'Iroise to investigate the effect of L. hyperborea harvesting on export to subtidal habitats


  • 2016-Current : PhD candidate, Station Biologique de Roscoff, ED227, Univ. Paris VI / MNHN
  • 2012-2014 : M.Sc., Oceanography and Marine Environements, Univ. Paris VI
  • 2009-2012 : B.Sc., Marine Sciences, Univ. de Bretagne Occidentale / Univ. du Québec à Rimouski

Supervision and teaching

  • Teaching monitor (July 2017) : Taxonomy of Marine Flora, fieldwork organisation, practical coursework, assistance for the lecturers, Station Biologique de Roscoff (
  • David Lorieux : Intern Bsc. Biology/Math (3 weeks), thesis  : Degradation dynamics of L. hyperborea, change of biomass, fragmentation and macrofauna colonization.
  • Sandra Treusard : Intern Bsc. Biology (1 month), thesis  : Learn matherial and methodology used to study marine ecology focusing on experimental in situ experiment.


Other Roles and expertise

  • Scientific diver : Classe IB (~100 scientific dives)
  • Member of GDR 3716 GRET : National Research Working Group in Trophic Ecology (
  • Science outreach : Project leader « La diversité à portée de main » (Link)

Research Experiences

  • 2016 (4 months) : Research Assistant, taxonomist for BIOMANGO Project, IUEM, LEMAR, Brest
  • 2015 (6 months) : Research Assistant & Scientific Diver, Oceans Institute, UWA, Perth, Australia
  • 2014 (6 months) : Master Thesis, IMBERS, Aberystwyth / Marine Biological Association, United Kingdom: Impact of Herbivory on kelp forest population (Laminaria spp.)
  • 2010-2013 (9 months) : Intern in 4 laboratories working on coastal marine ecology (MBA/UK, LOG/Wimereux, LECOB/Banyuls-sur-mer, LEMAR/Brest, UQAR/Québec)

Awards and recognition

- de Bettignies, F., Bernard, M., 2012. Mise en place d’outils d’expertise du littoral pour la gestion des estrans rocheux bretons.Projet présenté en mars 2012 et récompensé du 2 nd prix dans la catégorie « choix du jury ».



-de Bettignies F., Dauby P., Lepoint G., Riera P., Bocher E., Bohner O., Broudin C., Houbin C., Leroux C., Loisel S., Davoult D. 2020.Temporal succession of macrofaunal community associated with kelp fragment accumulations in an in situ experiment. Marine Ecology Progress Series. 656: 109-121.  10.3354/meps13391

-de Bettignies F., Dauby P., Thomas F., Gobet A., Delage L., Bohner O., Loisel S. & Davoult D. 2020. Degradation dynamics and processes associated with the accumulation of Laminaria hyperborea kelp fragments: an in situ experimental approach. J. Phycol., 56: 1481-1492.

-Androuin T., Six C., Bordeyne F., de Bettignies F., Noisette F. & Davoult D. 2020. Better off alone? New insights in the symbiotic relationship between the flatworm Symsagittifera roscoffensis and the microalgae Tetraselmis convolutae. Symbiosis, 81: 161-171.

-de Bettignies, T., Wernberg, T., Gurgel, C. F. D., de Bettignies, F., Collier, N., 2016. Herbarium specimens reveal changes in seaweed reproduction over the past 100 years.

- de Bettignies, F., 2014. Algae-herbivore interaction between the kelp of the genius Laminaria and the blue rayed limpet Patella pellucida. 25 p. Projet présenté en juin 2014.

- de Bettignies, F., 2013 Caractérisation et dynamique des peuplements bentho-démersaux d’une aire de nourricerie intertidale : la Baie de Canche. Poster présenté en Juin 2013.