John A.D. Burnett
Robert O’Gorman
2001
<p><span>Fishes were assessed in Guffin, Chaumount, and Black River bays in northeastern Lake Ontario with a 7.9-m (headrope) bottom trawl during late September and early October, 1978 to 1997. Fish density declined in the early 1990s with sharp declines in abundance of spottail shiner (</span><i>Notropis hudsonius</i><span>), trout-perch (</span><i>Percopsis omiscomaycus</i><span>), and johnny darter (Etheostoma nigrum) occurring in 1993 to 1995. Rising numbers of piscivores, walleye (</span><i>Stizostedion vitreum</i><span>) and double-crested cormorant (</span><i>Phalacrocorax auritus</i><span>), increased predation pressure, presumably acting in concert with oligotrophication to lower fish density, particularly after 1991 when large numbers of adult alewife (</span><i>Alosa pseudoharengus</i><span>) no longer migrated to the northeast basin in spring. Annual mortality of yellow perch (</span><i>Perca flavescens</i><span>) from age 2 to 5 rose from 33% in 1980–83 to 65% in 1992–95 and was positively related to piscivore numbers (</span><i>P</i><span> = 0.01, r = 0.96, n = 5). Annual mortality of yellow perch from age 0 to 2 also peaked in 1992–95. Abundance of yellow perch YOY in fall varied 40 fold and was not related to water warming in spring (</span><i>P</i><span> = 0.45, r = −0.19, n = 18) but was negatively related to the abundance of adult alewives in spring (</span><i>P</i><span> = 0.04, r = −0.49, n = 18). Although yellow perch produced moderate to strong year classes each year during 1991–95, stock size failed to increase because of rapidly accelerating mortality. Fully 85% of the variation in mean length of yellow perch YOY was explained by a multiple regression model which included YOY abundance, mean total phosphorus, and cumulative degree days > 13.5°C (</span><i>P</i><span> < 0.01, n = 15). Abundance of white perch (</span><i>Morone americana</i><span>) YOY varied nearly 200 fold and was not related to water warming or spring alewife abundance (</span><i>P</i><span> > 0.15). Variation in mean length of white perch YOY was related to cumulative degree days > 15°C (</span><i>P</i><span> < 0.01, r = 0.69).</span></p>
application/pdf
10.1016/S0380-1330(01)70652-1
en
Elsevier
Fish community dynamics in northeastern Lake Ontario with emphasis on the growth and reproductive success of yellow perch (<i>Perca flavescens</i>) and white perch (<i>Morone americana</i>), 1978 to1997
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