Chasing Northern Pike Under Ice: Long-Distance Movements Following Catch-And-Release Ice Angling

Catch-and-release ice angling is a popular recreational activity, but little is known about the postrelease behavior of fish in the winter. Cold water temperatures and an ambush hunting strategy may constrain Northern Pike Esox lucius, limiting their postrelease movements to a small area near the capture location. We used manual acoustic telemetry to track 15 Northern Pike ranging from 56 to 98.5 cm total length for up to 7 d after catch-and-release ice angling in Buffalo Pound Lake, Saskatchewan, Canada. All of the fish but one moved unexpectedly long distances of several km over the tracking period. For the fish that were tracked over all 7 d, path lengths traveled ranged from 1.4 to 18.4 km. The minimum daily distance traveled ranged from 0 to 4.6 km and varied significantly by tracking day; the fish moved shorter distances on day 4 postrelease. There was a significant interaction between fish size and day postrelease; larger fish moved shorter minimum daily distances and dispersed shorter distances from the release site over the first 2 d of tracking. In contrast, by 5 d after release, both the largest and smallest fish had dispersed the longest distances from the release site and intermediate-sized fish dispersed the least. The cumulative path length traveled by day 5 of tracking did not reveal any significant size-based patterns. Our study raises the possibility that relatively large movements may be common for Northern Pike in the winter despite cold water temperatures and their expected foraging behavior. In addition, postrelease behavior varies with fish size. Habitat and space requirements for Northern Pike in the winter can encompass much larger areas and more habitat features than has been previously envisioned.