Diel Movement by White Suckers (Catostomus commersonii) in Connected Northern Lakes

Abstract

Consistently repeated daily habitat shifts by fish can expose or protect individuals from a variety of threats and influence nutrient transport between systems, yet logistical constraints make individual horizontal movement difficult to study on short time scales. As a result, diel movements by fish are often poorly documented. Suckers (Catostomidae) are a key group of fish that have been frequently examined with this in mind, as many species are large, long-lived, and comprise a large proportion of biotic biomass in many waters. Previous studies in rivers have shown that multiple sucker species exhibit complex, diel movement. We investigated the prevalence of short-term movement by the widely distributed Catostomus commersonii (White Sucker) in an interconnected, remote lake system within New York's Adirondack region using PIT telemetry. These 2 lakes were in a remote setting of New York's Adirondacks, and our tracking studies indicated a subset of the sucker population regularly traveled back and forth daily through a short, shallow channel. Direction of movement was strongly associated with time of day, and larger individuals were far more likely to engage in this repetitive behavior. Overall, these findings highlight the potential for extensive, yet generally unobserved, movement by White Suckers within connected lake systems.