Stock characteristics of Atlantic salmon

The general characteristics of the main salmon (Salmo salar L.) stocks in the Massif armoricain (Brittany and Lower Normandy), in the Loire-Allier and in the Adour-Gaves-Nive have been summarized. Due to the poor quality of the previous fishing statistics, there is no clear picture of the historical evolution of the salmon stock. However, a dramatic decrease in the endemic range of Atlantic salmon in France can be shown since the mid-18th century and more particularly during the last 50 years. The lack of precise informations describing the size of the catches and the levels of exploitation at sea and in the estuaries make it impossible to estimate the impact that exploitation has led on the evolution of salmon stocks. The mean age of salmon in freshwater ranges from 1 to 1.5 years. The Loire-Allier basin is characterized by a relatively high proportion of large salmon (3 fish) in the rod catches. Fish native to Brittany and Lower-Normandy (Massif armoricain) have lover growth rates than those from the Loire-Allier and Adour-Gaves-Nice Basins. A greater proportion of the early grilse stocks (migration May-July) are males than compared with fish running later. The sex ratio of the multi-sea-winter salmon is biased towards females.