For human populations, fish is a major source of long-chain n-3 polyunsaturated fatty acids, commonly known as omega 3, necessary for the maintenance of vital functions. Small exploited pelagic fish, mainly from upwelling systems, are the main contributors to omega 3 consumption by humans. The ongoing climate change, combined with the increase in the human population, is currently leading to a clear warning that the supply of omega 3 could become insufficient by 2040. There is an urgent need to assess the impact of environmental changes on the accumulation of omega 3 by small pelagic fish and their consequences on the populations of these fish in order to maintain the functioning of ecosystems and the supply of omega 3 for humans.
This is a fundamental ecological, socio-economic and public health issue that has not yet been taken into account on a global scale.
The aim of the project is to characterize the supply of omega 3 on a global scale and try to understand its evolution with global change.
Workpackage 1: the first step consists in evaluating the spatio-temporal variability of the omega 3 content of small pelagic fish at our various study sites.
Workpackage 2: this experimental part consists in trying to understand how the global change is likely to affect I) omega 3 content and II) the physiology and behaviour of small pelagics. Fish are being conditioned in the laboratory for a future scenario of increasing temperature and decreasing omega 3 in fish food.
Workpackage 3: the objective is to use the data from the first two axes to integrate these data and model the evolution of populations of small pelagics and their quality in omega 3.
Workpackage 4: We are going to test the fishing production methods on the omega 3 quality of small pelagics. If the quality of omega 3 varies according to the storage conditions and other criteria: the fishing method, the gear used, the period, the tide, the temperature, the storage time on board the boats. The quality of the omega 3 product is not only linked to the environment but can also be linked to production methods.
Workpackage 5: We will assess the representations of seafood and omega 3s by fishermen and consumers. Are we going to have to eat differently? Does the fisherman see fish as a vector of omega 3 from the sea to humans? How does the consumer perceive seafood in general? How does he perceive omega 3 in a more particular way? We will also study the acceptability of alternatives to seafood as sources of omega 3.
Workpackage 6: this last workpackage represents the training dimension which is transverse to the other axes. Two teaching units are being developed for Master students: one on modeling and the other one on setting up interdisciplinary projects.
This project will make it possible to assess the evolution of the global supply of omega 3 for the human population with a particular focus on the major source of small pelagics. This is an essential step to then understand the effects of global changes on all the compartments that make up upwelling ecosystems, small pelagics being an intermediate compartment.
In terms of international outreach, in addition to relying on foreign partners, the project will contribute to the international working group Joint ICES/PICES.
In terms of relations with the socio-economic world, this project directly involves the various players in the small pelagic fishing sector (fisheries committee, canning factories).
Source : LEMAR laboratory
LP3C : Estelle Masson
Audencia Business School : Gervaise Debucquet
LOCEAN : François Colas, Xavier Capet, Vincent Echevin
UMMISCO : Timothée Brochier
Senegal (UCAD, CRODT),