Distribution and Feeding Ecology of Larval Cisco Coregonus artedi in Chaumont Bay, Lake Ontario

Cisco Coregonus artedi are an important prey fish for many Great Lakes predators, including lake trout Salvelinus namaycush and Atlantic salmon Salmo salar. Their numbers have declined drastically in the last century due to the impacts of invasive species such as sea lamprey Petromyzon marinus and alewife Alosa pseudoharengus, overfishing, and habitat degradation. Chaumont Bay, New York contains one of the last remaining spawning populations of cisco in Lake Ontario. In 2014 the first confirmed cisco larvae in Chaumont Bay in decades were found. Larvae were sampled weekly using light traps and surface neuston net tows. Larvae were identified using both traditional visual methods and genetic barcoding of the mitochondrial CO1 gene. Concurrent zooplankton samples and larval gut contents were used to examine feeding ecology and prey selectivity. After hatching, larvae quickly moved into shallow nearshore locations away from the spawning shoals. Larvae fed on both zooplankton and chironomids, indicating that both benthic and pelagic foraging habitats are utilized. The larval stages of fish development are critical time periods, and understanding the early life history of Chaumont Bay cisco is instrumental in identifying recruitment limitations that may be affecting this essential and poorly understood population.