Mountain Whitefish - An Unsung Idaho Native

By Steve Elle, Fisheries Technician Most Idaho anglers sing the praises of salmon, steelhead and resident trout. But few are aware of their overlooked cousin, the mountain whitefish. Whitefish are more widely distributed and occur in higher numbers than any of the other members of the trout/salmon family in Idaho. But despite their abundance in most of our larger rivers and streams, whitefish are either overlooked by Idaho anglers or purposely shunned by them because,despite their kinship, whitefish don't look like or fight like a trout. More about that later. Mountain whitefish spawn in October and November, and have smaller eggs compared to trout. One of the reasons for large populations of whitefish in our rivers is the higher number of eggs produced by the species. For example, one female whitefish sampled from the Big Wood River was loaded down with 40,000 eggs (trout average between 2,000 to 3,000 eggs with a large fish having 4,000 to 5,000 eggs). With smaller, more numerous eggs and longer-lived adults, each female whitefish contributes far more offspring to the population compared to their trout cousins. And unlike trout and salmon, which lay their eggs in a nest, or "redd," whitefish broadcast their eggs over larger gravel and boulders in fast water habitat. The fertilized eggs settle between the rocks and incubate until hatching in late winter. Young whitefish take up residence in the shallow margins of rivers or shallow tailouts of riffles. They grow rapidly through their first three to four years, reaching 10- to 12-inches and maturity during this timeframe. At this point, growth slows, and whitefish usually spawn every fall for the remainder of their lives. A four-year-old whitefish might be 12 inches long, while a 15-inch fish could be 8- to 10-years old (a 16-inch fish sampled from the South Fork of the Snake River below Palisades Reservoir was 19 years old!). Few trout in Idaho get to be that age. Their tolerance for warmer water is yet another reason why whitefish are more abundant than trout, especially in areas like the lower sections of the Boise, Payette and Weiser Rivers. Years ago, heated debate erupted regarding whether or not mountain whitefish competed with trout and steelhead and limited the numbers of these other game fish. Because whitefish occur in such high numbers side by side with trout (five to 10 times the densities of trout in the same rivers), many thought that declining trout numbers in the 1960s and 1970s were a direct result of whitefish competition. But both trout and whitefish are native to Idaho waters and have coexisted for thousands of years, long before European settlers came west. If competition between whitefish and trout/salmon was occurring, one or the other would likely not have been present in high numbers when white settlers arrived. Rather than direct competition with whitefish, trout have been negatively impacted over the past 100 years by the loss of cold water habitat and over harvest. During the past 30 years, fish managers have learned that the number of trout in our rivers can be improved by reducing harvest through lower bag limits and/or by increasing minimum size limits. These rule changes have resulted in increased trout populations in many streams (one local example is the South Fork of the Boise River). The increases enjoyed by these trout populations occurred while whitefish populations remained at high levels; the only change was a reduction in trout harvest. In the long term, we have learned that the limiting factor for trout populations in good habitat is often angling harvest, not competition with whitefish. Because so few anglers target mountain whitefish, they represent an underutilized harvest opportunity for those anglers who would like to take home a mess of fish to eat. And with a limit of 25 per day, whitefish represent quite a mess of fish! Or you may choose to pursue whitefish on a catch and release basis until your arm falls off. Some folks claim that whitefish do not fight very well, and while they do not jump like a trout when on the end of your line, they do put up a pretty fair fight. I have seen many an excited angler fighting what he thought was a trout on the end of his line, only to land a gutsy whitefish. If you want to target whitefish with a rod and reel, it is important to know that they tend to run in schools, usually in pools and deeper runs below fast water riffles during most of the year. During winter months, this schooling behavior becomes even stronger. Thus, one of the great things about whitefish is when you have found one, you probably have found a bunch. Without moving too far, you can often catch a large number of whitefish, cast after cast. Whitefish tend to focus their feeding on aquatic insects, concentrating on or near the bottom of the river. To be effective at catching them, you need your fishing gear near the bottom. Bait anglers do best using smaller hooks with grubs, a single salmon egg or small piece of worm. Fly fishermen often use some form of weight to get a midge, caddis or even stonefly imitation near the bottom where whitefish feed. In the summer, you might even find whitefish at the tailouts of pools or runs feeding on small mayflies making them vulnerable to well-placed dry fly. So that's the inside information regarding whitefish! They represent a great fishing opportunity near home, occurring in high numbers in the Boise River from Barber Park to Star. You can also find large populations in the North, Middle and South Forks of the Boise River, upstream from Arrowrock Reservoir. And don't overlook the South Fork of the Payette River through Garden Valley or the main Payette downstream from Banks. Good fishing.