Hernvann Pierre-Yves
Tel : +33 2 23 48 55 36 (poste 65 66)


Fisheries and Aquatic Ecology


Current Position

Scientist, Ecology and Ecosystem Health research unit (ESE), Fisheries and Aquatic Ecology Research Team, Agrocampus Ouest, Rennes (Brittany)


Modelling of the trophic functionning of the Celtic Sea ecosystem: impact of fisheries and ecosystem-based management scenarios.

Current Research Topics
Team of supervising: Didier GASCUEL (UMR ESE, Agrocampus Ouest, Rennes), Marianne ROBERT and Dorothée KOPP (LTBH, Ifremer Lorient.

My current researches aim to analyze and quantify the impact of fishing on the Celtic Sea ecosystem, which is a crucial area for European, especially French, fishing fleets. Trophic approach allows to understand how this impact, through predation (thus, through the food-web) and competition, spreads from the target species to the whole ecosystem.

My project is mainly based on trophic modelling with the widely recognized Ecopath with Ecosim software and will involve the 3 following steps:

Developing a generic method to estimate diet matrices in Ecopath models
Different kind of data such as stable isotopes analysis or stomach contents analysis will be coupled through a Bayesian network that will also take uncertainty of the estimations into account. Then, this method will be applied to data from the EATME program (IFREMER Lorient) to improve our knowledge of trophic functioning of the Celtic Sea.

Spatializing the model using Ecospace
Habitat models for the main target species will be the cornerstone of the spatialization step. Adjusting the Ecospace model on spatialized time-series of catch, fishing effort (OBSMER program – Fisheries and aquaculture Directorate / IFREMER) and abundance (EVHOE survey – IFREMER) will allow studying spatio-temporal changes in abundance of resources from 1980 and their fisheries and environmental determinants.

Using the Celtic Sea model in a predictive way
I will test several management scenarios to identify key strategies to support an effective ecosystem approach of fishing management in Europe

Potential collaborations

IFREMER - Fisheries technology and biology laboratory (LBTH), Lorient
ICES Working Group on “Multispecies Assessment Methods” (WGSAM)
Discardless - European Project H2020

Participation to the projects of the research unit


Selected recent publications

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