Fish & Water - Sounds Wild
Saltwater Pike

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Saltwater pike

A crew of set netters is working off a beach in cook inlet near the mouth of the Kenai river. As they pull salmon out of the net, they come across an unusual fish that’s definitely not a salmon. It’s not even a saltwater fish. It’s a northern Pike. This pike helped solve a mystery that’s been puzzling Alaska fishery biologists.

In 2019, an angler caught an invasive northern pike in Vogel Lake at the northern tip of the Kenai Peninsula. How did it get there? Northern pike are native to interior and western Alaska. They’ve been illegally introduced to some waters in South central and the Kenai, but it was unlikely someone would put a pike in remote and mostly inaccessible Vogel lake. The pike that the set netters caught showed that these freshwater fish can survive in marine estuaries – areas where fresh river water and salty ocean water mix. Pike can use nearshore, brackish waters to move between freshwater habitats.

Biologists began testing pike to learn if they had traveled through saltwater. They looked for Signs in their otoliths, or ear bones, which absorb traces of the fish’s environment. They found some of the pike, like the Vogel Lake pike, had lived in freshwater, spent time in saltwater, and then moved to a different freshwater location. It’s likely that pike came from the Susitna River, just across Cook Inlet from the creek that comes out of Vogel Lake, since pike are common there. Researchers recently found marine signatures in pike from Campbell Lake and Westchester Lagoon in Anchorage.