Figure 1.
Map showing the locations of sampling sites.
Circles represent sites where quantitative benthos samples were collected, squares show sites where most samples for stable isotope analysis were collected.
Figure 2.
δ13C and δ15N isotope biplots for members of the littoral food web of Lake Simcoe.
A) Predreissenid period. B) Postdreissenid period. Only taxa with more than one replicate that were either sampled in both periods, or contribute more than 5% to pre- or postdreissenid biomass or production are shown. Error bars represent one standard deviation.
Table 1.
Mean abundance (standard error in parentheses), biomass, and annual production of benthic organisms in pre- and postdreissenid periods from 4 shallow (2 m) sites in Lake Simcoe.
Table 2.
Summary of results of 13C and 15N isotope analysis (standard deviation in brackets) for taxa collected in the pre- (1993) and postdreissenid periods (2007–2009).
Table 3.
Contribution of sestonic carbon (% sestonic) to members of the benthos in the pre- and postdreissenid periods in the shallow littoral zone of Lake Simcoe, as determined by stable isotope analysis and the IsoError isotope mixing model [30].
Table 4.
Amount of sestonic- and benthic-derived biomass and production in different groups of littoral benthos of Lake Simcoe, in pre- and postdreissenid periods, using hydropsychids and snails as the sestonic and benthic end-members for the predreissenid period and two combinations of end-members for the postdreissenid period.
Figure 3.
Contribution of sestonic (blue) and benthic (green) carbon to the littoral food web of Lake Simcoe.
A) Predreissenid period. B) Postdreissenid period. Postdreissenid values are a range between the results of mixing models based on primary producers and primary consumers. Stippled portion represents dreissenid biomass and production.