1st PHABB workshop in Roscoff: identification of algal pathogens

The first PHABB workshop was held in Roscoff, France, from the 31st March to 4th of April, 2025.
Over the course of the week, doctoral students, researchers, and representatives from both academic and industrial associated partners came together for a rich program of scientific exchange. The workshop featured lectures, hands-on sampling activities during the exceptionally low tides along the Roscoff coastline, laboratory activities and dynamic discussions focused on (micro)algae and their pathogens.
The event fostered meaningful connections across disciplines and sectors, laying the groundwork for future collaboration within the PHABB network.
Field Sampling at low tide at La plage des Amiets, Bretagne.
Field Sampling, hunting for seaweed and their parasites in the intertidal. With the expert guidance of Dr Akira Peters, here showing a kelp to the students on Perharidy beach, Bretagne.
Field Sampling at low tide at Perharidy beach, Bretagne, Bretagne. With the exceptionally high tide coefficient he kelps become visible at low tide.
PHABB students during a boat sampling in Roscoff, France, April 2024.
The research vessel Neomysis.
Dissection of the collected seaweed in the laboratory, here a kelp.
Presentation of the Planktoscope, a modular, open-source hardware and software platform that allows for high-throughput quantitative imaging of plankton samples in aquatic biology and ecology (https://www.planktoscope.org/).
Groupe picture of the PHABB members.
Workshop program:
Day 1
Morning: Lectures
Claire Gachon, Spotlight on algal diseases, My Seaweed Looks Weird, pathogen discovery
Marianne Verberne, Presentation of HORTIMARE, professional trajectory since PhD
Afternoon: Field Sampling: seaweed biology, taxonomy, ecology. Hunting for seaweed and their parasites in the intertidal. With the expert guidance of Dr Akira Peters: owner and director of BEZHIN ROSKO, a SME specialized in Research and services on marine macroalgae.
Day 2
Morning: Boat Sampling: plankton sampling on the research vessel Neomysis. Demonstration of sampling techniques at controlled depths using Niskin Bottles and Plankton nets. Sampling will be performed at two different depths, in two contrasting locations: the offshore sampling at the ASTAN Somlit site and the Penzé river estuary.
Afternoon: practicals: Handling and preparation macroalgal and microalgal for microscopy, hunting for seaweed and microalgal parasites.
Day 3
Morning: practicals, staining techniques and microscopy, laboratory isolation and maintenance of microalgal pathosystems
Afternoon: Lectures
Pedro Murúa, Parasites and aquaculture in Latin America
Gabriel Montecinos, Brown algal cultivation and breeding, control of life cycles
Aurélie Chambouvet, Thraustochytrids and apicomplexan parasites of bivalves
Madalena Mendes, Presentation of ALGAplus, professional trajectory
Day 4
Morning: Lectures
Nicolas Henry, Introduction to Metabarcoding
Charlotte Berthelier, Metabarcoding workflow (Nextflow nf-core/ampliseq)
Laure Guillou, The Protist Ribosomal Reference (PR2) Database
Acknowledgements: