Egg Survival and Development of Atlantic Salmon (Salmo salar) in the Miramichi River System

An understanding of the early life stages of the Atlantic salmon (Salmo salar) is essential for quantifying juvenile recruitment and establishing baselines for more accurately assessing the impacts of environmental disturbances. The objective of this research is to assess Atlantic salmon egg survival and development in a range of natural spawning sites in the Miramichi River system from October - May. Three riffles in five river reaches were selected based on observed spawning activity. Within each riffle, six artificial redds were seeded with 400 eggs collected from wild broodstock, for a total of 36 000 eggs. Three redds were sampled at the eyed stage of development (at ~250 degree-days, in March), and three were sampled after the spring freshet (late May). Relative egg survival was calculated using hatchery-incubated controls. Dead eggs were collected at each sampling period and “cleared” using Stockard’s solution to determine stage of development and approximate time of death. A variety of abiotic variables are being measured over the winter incubation period. Correlations between the abiotic environmental variables measured (water temperature, DO concentration, groundwater contribution, water level, ice formation/cover and sedimentation) and egg survival and development will be presented. Implications for future salmon management will be discussed.