Study Looks At Effects Of Northern Pike’s Ability To Traverse Salt- And Freshwater Habitats

Alaska Public Media has the results of an intriguing study about northern pike that can have a major impact on a fish that’s proven to be an invasive species in several Alaska regions. Here’s more on the study:

With a researcher in Fairbanks, Fish and Game started testing pike to learn whether they had traveled through saltwater. They looked for signs in their otoliths, or ear bones — which can absorb traces of the fish’s environment.

“When we got the results back, you could see on the graph that this fish actually came from somewhere, spent time in saltwater, and then went to a different freshwater location,” Dunker said. “That was very eye-opening to us.”

Wood said that ocean pathway could complicate efforts to contain pike, and he said inlet conditions could become more favorable for the freshwater fish as glaciers continue to melt.

“As to where they came from, how they ended up where they ended up, we don’t know that for sure,” Wood said. He added that the Susitna River seems to be the obvious point of origin, since pike are so widespread there.

The concerns that biologists have is more accessible paths from saltwater to other fisheries that hold native species to Alaska like salmon and other anadromous fish.