Measuring the tropic status of lakes sampling protocols

Studies conducted at the Dorset Research Centre have resulted in long-term records of phosphorus, chlorophyll a, Secchi depth, and oxygen in lakes. These are the measures most commonly used to estimate the trophic status of lakes. Analysis of these long-term data series are presented with a practical view for setting up sampling programs for the determination of the trophic status of a lake. Depending on the accuracy desired, the minimum number of samples required to produce a good estimate of each of several trophic status measures are presented. Sample collection techniques are reviewed and cautions noted about the collection of samples, and the submission of samples to the laboratory. Consideration is also given to the collection of data for use with current models such as the Trophic Status Model (Lakeshore Capacity Study), in addition to oxygen and chlorophyll models.