¹University of Windsor, Great Lakes Institute for Environmental Research, Windsor, ON, Canada, N9B 3P4
²Fisheries & Oceans Canada, Great Lakes Laboratory for Fisheries and Aquatic Sciences, Burlington, ON, Canada, L7R 4A6
^**Current address:Fisheries & Oceans Canada, Great Lakes Laboratory for Fisheries and Aquatic Sciences, Burlington, ON, Canada, L7R 4A6

*Corresponding author: haffner@uwindsor.ca

Summary

   The Primary Production Required (PPR) model, first developed by Pauly and Christensen (1995) was applied to historic commercial fisheries catch data from Lake Erie (1950 – 2000) and current commercial catch data from the western basin of Lake Erie (2000 – 2002). The rate of energy transfer between trophic levels was determined to be 10% and equal to global estimates. Our calculations suggested that lakewide PPR reached as high as 50% of the available primary production in 1956 and, following the collapse of the blue pike (Sander vitreus glaucus) fishery, oscillated from 10 – 20 % up to 2000. In the west basin, we estimated that PPR declined from 53 – 32% of the available primary production between 2000 and 2002, corresponding to a reduction in walleye (Sander vitreus) quotas. All of these values are considerably higher than the benchmark of 8% PPR established for sustainable fisheries. The results of the PPR approach suggest that autochthonous energy may not be sufficient to support the commercial fishery. The relative importance of autochthonous and allochthonous carbon inputs, with respect to meeting the energy requirements of the fishery, needs to be investigated.