Who Knew? Inconnu

Joe Margraf | U.S. Geological Survey, Supervisor of Western Cooperative Research Units, 1135 Park Ave., Unit 904, Pagosa Springs, CO 81147. E-mail: [email protected]

Joe Margraf with an Inconnu on Selewik River, September 2004. Photo credit: Mike Millard.

In 1999, I moved to Alaska to serve as unit leader of the U.S. Geological Survey Alaska Cooperative Fish and Wildlife Research Unit and professor of fisheries in the School of Fisheries and Ocean Sciences at the University of Alaska Fairbanks. What was unusual about this move was that before this I was an easterner and southerner, having done my graduate work in fisheries at Texas A&M University and been stationed in the Coop Unit Program in Ohio, West Virginia, and Maryland. I had never worked with salmonids of any sort. To me fish with adipose fins also had whiskers! I suddenly found myself working in the land of salmon experts, and I didn’t even reliably know the names—scientific, common, or colloquial—of the five (or is it six?) common Pacific salmon species in Alaska. I had to quickly find a research niche that probably didn’t involve salmon.

Unless you’re familiar with Arctic or Subarctic fishes, you’ve probably never heard of Inconnu Stenodus leucichthys, the largest of the white fishes (Salmonidae, subfamily coregoninae). In Alaska, Inconnu are colloquially known as sheefish. They are piscivirous and can reach a size of 1.5 meters and 25 kilograms. A typical spawning-age adult is nearly a meter and 10 kilograms. Because of their relative inaccessibility to the vast majority of anglers, they are mainly a secondary (to salmon) subsistence species for many remote-living and mostly indigenous people. Like many riverine white fish, populations can be potadromous, moving up and down larger rivers to feed and spawn, or anadromous, moving into estuarine waters to overwinter. Inconnu are broadcast spawners, mainly in large riffles or runs near the upper end of their river drainage. Until recently, their spawning requirements were largely known mainly from stream-bank observations by biologists studying other species.

My first real exposure to Inconnu, which translates as “unknown” in French, was when I went to the field to visit one of my graduate students, Theresa Tanner, at her research site on the Selawik River in northwest Alaska at the U.S. Fish and Wildlife Service’s Selawik National Wildlife Refuge. Tanner, T2 to those who know her, was trying to determine the characteristics of Inconnu spawning habitat and model it on a drainage-wide basis. Her job for the Fish and Wildlife Service was also to get an estimate of the population size of Inconnu in the Selawik. To do this, she had to tag as many fish as she could while they were concentrated on their spawning run. Alas, the fish were not cooperating, and T2 and the crew had only been able to capture a few to tag. One morning while I was there in early September 2004, we went out as a crew of six in hopes of tagging a few more fish. We motored down to a bend in the river that purportedly would hold a lot of fish staging for their spawning foray at night. To catch them, we had tried large beach seines and even angling with large silver spoons outfitted with a single hook and pinched barb to prevent damage to the fish when (if) caught. That morning we tried angling. We broke into two teams of three people, one would keep their hands dry and take notes, one would net, hold the meter-long measuring board and the tagging equipment, and one would do the angling. As an elder in the group, I started as an angler. Beginning at about 9:00 AM, on the first cast we had an Inconnu; the second cast we had one; the third, etc. By about 10:30, I gladly gave up my fishing rod, so tired that I could hardly hold it anymore. At about 12:30, T2 said to stop; we all thought it was to take a lunch break; however, we had to stop because we had used all of the 100 tags that she had brought from camp that morning. In other words, we had captured, measured, weighed, tagged, and released 100 Inconnu in about 31⁄2 hours. That’s with only two of us casting at any one time. Remember that these fish average about a meter and 10 kilograms each! Now I knew Inconnu!

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