ABSTRACT
The manner in which an organism responds to a change in its environment can depend greatly on previous conditions. In this regard, lake whitesh (Coregonus clupeaformis) populations from a wide range of aquatic environments have demonstrated a variety of responses to the establishment of dreissenid mussels. A review of the literature indicated that individual growth rates and condition of lake whitesh have typically declined after dreissenid establishment where Diporeia-a key prey item of lake whitesh-have also
declined in abundance. Temporal declines in lake whitesh growth and condition occurred following dreissenid establishment despite reported increases in lake whitesh consumption rates. A review of lake whitesh populations from noninvaded systems revealed declines in lake whitesh growth and condition as a common response to resource limitation, supporting the hypothesis that typical lake whitesh responses to dreissenid establishment are a function of resource limitation. In contrast, lake whitesh populations from shallow, nutrientenriched lakes with dreissenids (Lake Erie where Diporeia has declined, and Lake Simcoe where Diporeia was absent
Michael D. Rennie
CONTENTS
Abstract .................................................................................................................................................................................661 Introduction .......................................................................................................................................................................... 662 Diporeia and Dreissenid Mussels ........................................................................................................................................ 662 Changes in Lake Whitesh Populations with Dreissenids .................................................................................................. 663
Great Lakes Populations: Consistencies ......................................................................................................................... 663 Great Lakes Populations: Inconsistencies ........................................................................................................................670 Lake Erie ..........................................................................................................................................................................671 Lake Simcoe .....................................................................................................................................................................672
