Five advection schemes are compared and evaluated in the context of biogeochemical modeling. Using three schemes of comparable quality that have been used in recent biogeochemical models, we found that new production estimates vary by as much as 30%. Test experiments are presented that explain the large discrepancies in terms of the different types of numerical errors inherent to each scheme. One scheme is suggested for eddy-resolving models and another one for coarse resolution models. ¿ 2001 American Geophysical Union