We assessed the effects of trophic structure on phosphorus (P) recycling by fishes, Chaoborus, and zooplankton in lakes with different food web configurations. Fishes in a piscivoredominated system recycled little P compared to that regenerated by zooplankton and Chaoborus. In a plan ktivore-dominated lake, excretion by fishes (especially young of year) dominated P recycling to algae; Chaoborus and zooplankton recycling was decreased due to intense predation by fishes. The sum of P incorporated into primary production and lost to sedimentation in the piscivore-dominated lake was only 77% of that in the planktivore-dominated lake, Our analyses suggest that the 30% greater primary production in the planktivore-dominated system may be accounted for by the greater than 40% increase in estimated P recycling that was directly due to differences in food web structure, Diel vertical migrations by Chaoborus concentrated P excretion in the epilimnion during night hours. In the plan ktivore-dominated system...