Ecophysiological Determinants of Secondary Production in Salt Marshes: A Simulation Study

Abstract

Variation in the abiotic environment is generally presumed to stress fish in estuarine marshes despite abundant food resources and refuge from predation. Chief among the important variables are dissolved oxygen, temperature, pH and salinity. With new technology for collecting high-resolution abiotic data and with mechanistic models for interpreting these data, it is possible to revisit and refine the conventional paradigm(s) of abiotics stresses and secondary production in salt marshes. With data from National Estuarine Research Reserves (NERR) and our ecophysiological model for juvenile fish, we ask "what is the relative impact of abiotic factors on growth in different marsh types?" Based on data from four NERR sites representing a spectrum of marsh hydrotypes and latitudes, we conclude that abiotically-forced variation in growth could explain much of the variation in secondary production in marshes.