Back to list

Today, the need to reduce exploitation rates in order to restore marine resources connected to fishing overcapacity in the world's oceans, is widely acknowledged. Fishing is a selective process based on size that leads to a truncation in the age structure of fish populations through the elimination of the largest, old individuals from the virgin stock.
However, the increase in resources intended for reproduction due to an increase in age for a post-natal use, has recently been shown for many  long-living fish and sharks and this is commonly known as the 'Maternal effect'. The negative effects of the maternal effect resulting from fishing are:
 - a reduction in the period and a change in the breeding grounds, 
 - a decrease in production and in the quality of the eggs and the larvae.
The current assessment models based on the fertile biomass of the breeders as an indication of reproductive potential may therefore highly under-estimate the effects of fishing and lead to over-optimistic diagnoses of the state of the stocks. Although the importance of taking the maternal effect into consideration in the management of fishing has been acknowledged, for the moment no study has been undertaken to identify and quantify the maternal effect on large, oceanic, pelagic populations.

The general aim of the EMOTION project is to  and quantify the maternal effect for large, pelagic populations via a case study on tuna and the swordtail fish in the western Indian ocean: the skipjack tuna Katsuwonus pelamis, the yellowfin tuna Thunnus albacares and the swordfish Xiphias gladius.

This project was labellised by the AQUIMER Pole of Competitiveness on the 10th March, 2011.


16 rue du Commandant Charcot
62200 Boulogne-sur-Mer F

Tel : 00 333 21 10 78 98

Fax : +33 3 21 30 33 22



Subscribe to newsletter