A study of some fish bones from four pile dwelling settlements in the Three Lakes Region (Montilier-Dorf Strandweg, Concise-sous-Colachoz, Saint-Blaise/Bains des Dames and Hauterive-Champréveyres) casts new light on the importance of fishing in the diet between the Middle Neolithic and the Late Bronze Age (3900 and 1035 BC). In order to identify the period(s) during which fishing occurred, the study examined seasonal changes in the growth of the vertebrae of perch, Perca fluviatilis, the most abundant and best preserved of the species found. The creation of a set of extant and local reference material for this taxon allowed us to develop a model that enables estimation of the period when the fish died. Application of the model to archaeological vertebrae showed that fishing was mainly done in winter and spring during the Neolithic period and throughout the year, except in summer, in the Late Bronze Age.