Spawning White Suckers in Medway Creek: A Springtime Spectacle 

On April 23, 2025, a local resident witnessed something truly special while walking along Fox Hollow Ravine—suckers during their annual spring spawning run in Medway Creek! 

Each spring, as water temperatures climb to approximately 10°C, adult White Suckers (Catostomus commersonii) begin migrating upstream to shallow, gravel-bottomed riffles to spawn. They’re often joined by other suckers, including Redhorses: a group that includes species such as the Golden Redhorse (Moxostoma erythrurum) and the Threatened Black Redhorse (Moxostoma duquesnei). These species take turns using the same riffles as water temperatures continue to rise, each following a finely tuned spawning window. 

Spawning Suckers

During these energetic events, males and females gather in groups, with males nudging and chasing females to encourage the release of eggs. It’s an impressive sight—if you’re lucky (and wearing polarized sunglasses to cut the glare), you might spot their dark, powerful bodies wriggling just below the surface. 

Suckers are not only key indicators of healthy streams but also play an important ecological role. Their spawning runs help kick-start aquatic food webs after the long winter. As they release eggs, waste, and milt, they inject nutrients like nitrogen and phosphorus into the water. These nutrients fuel the growth of algae and aquatic invertebrates which, in turn, support a range of fish and wildlife. 

Recent research shows that sucker spawning events significantly boost the abundance of algae, invertebrates, and fish biomass downstream, reinforcing their role as ecosystem engineers. Opportunistic fish like bass and minnows often capitalize on the bounty, feeding on the nutrient-rich eggs. 

Unlike salmon, these fish don’t die after spawning. Many return to the same tributaries year after year. That makes protecting clean, connected spawning habitat essential—not just for the survival of suckers, but for the resilience of entire stream ecosystems. 

Thanks to community members like Judith for keeping a lookout and helping us celebrate the incredible biodiversity in our local creeks! 

White Sucker