Collapse of allis shad, Alosa alosa, in the Gironde system (southwest France): environmental change, fishing mortality, or Allee effect?

Thibaud Rougier1*, Patrick Lambert1, Hilaire Drouineau1, Michel Girardin1, Gerard Castelnaud1, Laurent Carry2, Miran Aprahamian3, Etienne Rivot4, and Eric Rochard1 Irstea, UR EPBX Ecosytemes estuariens et poissons migrateurs amphihalins, 50 avenue de Verdun, F-33612 Gazinet Cestas, France Association MIGADO, 18 Ter rue de la Garonne, BP 95, 47520 Le Passage, France Environment Agency, Richard Fairclough House, Knutsford Road, Warrington WA4 1HT, UK Agrocampus Ouest, Laboratoire ecologie halieutique, 65 rue de Saint Brieuc, CS 84215, 35042 Rennes Cedex, France *Corresponding Author: tel: +335 57 89 27 07; fax: +335 57 89 08 01; e-mail: thibaud.rougier@irstea.fr