Thornbury Fishway, Thornbury, Ontario, Canada A Chinook Salmon with a large Sea Lamprey attached maintains its position, while another Chinook Salmon with a large fresh Sea Lamprey wound swims by

Thornbury Fishway, Thornbury, Ontario, Canada A few Chinook Salmon with scars and parasitic Sea Lamprey maintain their position inside the fishway

Thornbury Fishway, Thornbury, Ontario, Canada A Chinook Salmon with a large scar and Sea Lamprey attached lingers inside the fishway while others swim by

Thornbury Fishway, Thornbury, Ontario, Canada A Chinook Salmon with a parasitic Sea Lamprey attached lingers at the fishway exit as another Salmon swims by – evidence that fish carry Sea Lampreys through fishways

Thornbury Fishway, Thornbury, Ontario, Canada Several large Chinook Salmon ascend the fishway all at once, including one with a large Sea Lamprey attached to its side