Figure 4. Status of lake sturgeon in the province of Ontario, Canada.at the narrower cross sections. These can obstruct
fish passage and reduce the amount of spawning
habitat available. Erosion and siltation during and
after road construction impairs water quality. In-
paired reproduction in such areas has also been sug-
gested (Duckworth et al. 1992). Pulp and paper mill
effluent deposits organic debris and decreases wa-
ter quality by reducing dissolved oxygen and dis-
rupting benthic communities.
Current status of lake sturgeonWe categorized regions of the postglacial distribu-
tion of lake sturgeon into areas where the species
was cithcr common, rare, or absent (extirpated)
(Figure 3-5). Data sets describing the distribution
and abundance of lake sturgeon in the provinces of
Ontario, Manitoba, and Quebec differ considera-
bly, and interpretation was required to categorize
geographical regions into the above categories. Da-
ta for Ontario are from the Ontario Ministry of Nat-