WHEN POPULATION AND PHYSIOLOGICAL ECOLOGY MEET: CHINOOK SALMON SPAWNING AND THE FATE OF THEIR PROGENY

We explore the developmental dynamics of pre-emergent chinook salmon in their natural environment (Methow River, Washington, USA). Using models of developmental processes and daily temperature changes, the emergent properties of two allopatric chinook salmon stocks are explored using data on the timing and location of spawning, characteristics of spawned smolts, life-history patterns; and annual cycles of water temperature and flooding. Development is modeled with coupled differential equations (Beer and Anderson 1997) with temperature dependent terms for anabolism, catabolism and water absorption. Embryo growth and yolk absorption depend on the daily temperature pattern which ultimately defines the developm nt rate and mass of the fish at emergence. Emergence is defined at a physiological point, either maximum alevin mass or button up, both of which are easily identified (Fig 1). The model can be run on the internet at www.cbr.washington.edu/egg_growth 60 Fig.1 Example growth trajectories tracked through time by the mode