Errors associated with using Archimedes' principle to determine mass and volume of small aquatic organisms

Archimedes' principle can be effectively applied to measure the mass and volume of small aquatic organisms by weighing the organism in waters of two densities, and then comparing those values with the weights of a plummet weighed in the same waters. However, the weight-in-water measurements are subject to error, and this work outlines how to calculate the standard errors of organism mass and volume, and a straightforward approach to calculating organism mass and volume itself. Guidance for the design of a plummet and setting a water density difference that minimizes the standard errors of the measurements is also presented.