Estimating macrobenthic secondary production from body weight and biomass: a field test in a non-boreal intertidal habitat

Abstract

Production (P) and biomass (B) data of different species from three stations in the intertidal zone of the Ria Formosa (southern Portugal, 37° N) were analysed. They were compared with equations from the literature to estimate P/B ratios from body weight. Results from three species supported a body weight exponent of -0.25 for the P/B ratio, as is to be expected from a linear relationship between growth and respiration. In an interspecific comparison, the weight exponent depends on the contribution of age or growth rate to the presence of large specimens in a sample. Production in the specific habitat examined cannot be calculated properly from body weight and biomass by one simple equation which mixes interspecific and intraspecific effects; rather that both aspects should be separated into two different calculation steps. -from Author