Johannsson. O.E., R. Dermott, D.M. Graham, J.A. Dahl, E.S. Millard, D.D. Myles, and J. LeBlanc, 2000. Benthic and Pelagic Secondary Production in Lake Erie After the Invasion of Dreissena spp. with Implications for Fish Production, Fisheries and Oceans Canada.

Reprinted from Journal of Great Lakes Research (2000) 26(1): 31-54

Benthic and Pelagic Secondary Production in Lake Erie After the Invasion of Dreissena spp. with Implications for Fish Production

Abstract
Benthic and pelagic secondary production were measured at nearshore and offshore sites in the western, west-central, and eastern basins of Lake Erie in 1993 to determine the relative importance of bethic and pelagic foodwebs to the fish community after dreissenid colonization. Benthic biomass increased greatly between 1979 and 1993 because of the presence of dressenids, and > 90% of benthic production in 1993 cam from dreissenids. Biomass of "other" benthos (excluding unionids and dreissenids) did not decline. Dreissenid production was in addition to, and not at the expense of, "other" benthic  production. Zooplankton production was close to or within 995% confidence interval of that predicted from primary production (photosynthesis) based on the relationship described by Makarewicz and Likens (1979). Deviations from this relationship were correlated with summer zooplankton mean length, suggesting that planktivory was an important factor in the regulation of zooplankton production in the lake. Dreissenids therefore impact zooplankton production by reducing algal biomass and primary production particular in unstratified region, by decreasing rotifer abundance and hence biomass and production, and by producing veligers which contribute 10% to 25% to zooplankton production.

Entire Paper
Contact: Ora Johannsson, Fisheries and Oceans Canada, Great Lakes Laboratory for Fisheries and Aquatic Sciences, 867 Lakeshore Road, Burlington, ON L7R 4A6, CANADA
Key Words: Zebra_mussel, Environmental_impacts, Population_dynamics
Product Type: Research, Impact
User Type: General