Comparative Study of Methods for Estimating Bioavailable Particulate Phosphorus

A group of chemical and biological procedures for estimating the biologically available phosphorus (BAP) in sediments, representing methods currently used for research around the Great Lakes, were compared among twelve widely different samples of particulate matter from the lower Great Lakes region. The procedures, including one biological and five chemical methods, extracted widely differing amounts of phosphorus from the sediments. Among the procedures, however, the results were highly correlated, indicating the potential for making valid conversions among the estimates, at least for most samples. Analysis of samples held in storage for several years, however, gave results by some extraction procedures that seemed abnormal. Phosphorus extracted by the procedures of Armstrong et al. [1] and Baker [2] correlated most closely with bioassay results, while that extracted by the procedure of De Pinto et al. [3] most closely approximated amounts of phosphorus taken up by algae during bioassays.