Brook trout production dynamics in the streams of a low fertilityNewfoundland watershed

摘要

Production of brook trout Salvelinus fontinalis ranged from 99 to 651 g .100 m(-2) . year(-1) among headwater streams of the Copper Lake watershedin insular Newfoundland. Ratios of annual production to mean annualbiomass (P/(B) over bar) ranged from 0.9 to 1.5 among the same streams.Empirical models developed from stream salmonid populations in the UnitedStates successfully predicted modal production based on water alkalinityand P/(B) over bar ratios based on age-class structure of the populations.Differences in production among streams were consistent with previous workin low-fertility headwater systems, which suggests habitat attributes ofthe stream define salmonid production within the range dictated by thewater fertility. The most important of these attributes in this study wasfood abundance. Substrate composition and habitat complexity may haveplayed secondary roles in determining production in the most productivestream. [References: 33]