Atlantic Sturgeon Seasonality and Breaching Behaviour in Minas Basin, Inner Bay of Fundy, Canada

Atlantic sturgeon Acipenser oxyrinchus oxyrinchus Mitchill, 1815 are large, anadromous fish that undergo extensive oceanic migrations along the eastern coast of North America, from Labrador to Florida. Minas Basin, inner Bay of Fundy, Canada hosts a summer feeding aggregation of Atlantic sturgeon. Breaching is a common behaviour in Atlantic sturgeon but the reasons for this behaviour remain speculative. Breaching events in Minas Basin, Minas Passage and the outer Bay of Fundy are currently being investigated. Atlantic sturgeon were sampled at an intertidal brush weir in Bramber, Nova Scotia during the summer of 2014. Six large Atlantic sturgeon (165+ cm fork length) were tagged with both a V16P acoustic transmitter and a MiniPAT. Two of six MiniPATs were physically recovered after a four month deployment allowing the detailed depth, temperature and light data archive to be examined. Analysis of MiniPAT archival data has revealed that several factors may influence breaching behaviour including tidal cycle, time of day and depth of the environment. Understanding the depth distribution of Atlantic sturgeon in Minas Passage specifically is an important step in mitigating the possible effects of tidal turbine development on the regular movement patterns of this threatened species.