Whitefish Invasion!

With a title like that you'd expect this to be a Whitefish bashing blog post.  It isn't.

Admittedly, I have a soft spot for Whitefish.  In many of my home waters Mountain Whitefish are one of the few truly native species still swimming in the rivers.  This isn't unique to my waterways.  Surrounding states have similar populations of Whitefish mixed with non-native Trout in many rivers.  I'm not sure where Whitefish got their label as "trash fish", but it certainly wasn't from anyone in the know.  I've heard many a story about hooking a huge, hard fighting fish that was hoped to be a Trout but when finally brought to net was only the lowly, native, naturally reproducing (not stocked), eager to take a fly, still hard fighting, adipose fin bearing, Salmonid (relative of Trout) known as Prosopium williamsoni or Mountain Whitefish.

Some fly fishers feel Whitefish are a nuisance when too plentiful and out-compete Trout for food.  While I'm sure there are places this may be the case, I haven't fished a river where this was a problem.  Have I fished rivers where I catch more Whitefish than Trout?  Absolutely, but I believe they are still in balance.  One of my local rivers (lets call it river W) has a healthy population of "Whities" as well as great numbers of good sized Brown Trout.  A nearby river (river P) has similar flows, has its headwaters in the same mountains and shares many of the same aquatic food forms as river W, however the Brown Trout in river P are several inches smaller on average.  A few years back this wasn't the case.  At one time river P had thousands more Whitefish and while the Whities were around the Trout were larger.  Since Whitefish numbers have declined drastically on river P the Trout population has increased in number but decreased significantly in size.  Biologists in the area claim the Brown Trout are out of balance for the available food and this stunts their growth.  I think they are right, but can't believe the decline in Whitefish numbers happening at the same time is only coincidence.  I believe the Whitefish provide an important food source for the Trout.  Whitefish have young, and Trout eat small Whitefish.  Whitefish drop eggs when spawning.  Trout eat eggs.  I often hear "Whitefish eat all the Trout eggs".  I'm sure Whities enjoy their fair share of Trout eggs, but then again, so do Trout.  The difference is Trout are well equipped to eat Whitefish until the Whities are 7 inches or so.  In other words, Whitefish eat Trout, but almost exclusively in egg form, after a Trout hatches into a swimming minnow it is no longer easy prey for the Whities as they are not well adapted to feed on minnows.  A Whitefish's mouth isn't well equipped to take in large prey like a minnow.  Trout on the other hand are very well equipped to feed on minnows, and they do quite regularly.  I believe a healthy population of Whitefish helps sustain a healthy population of Trout.

Also of note, Whitefish are very susceptible to poor water quality.  When water quality deteriorates Whitefish are one of the first fish to be affected.  It could be that the missing Whitefish on river P are a sign of things to come.

There are many great rivers in the west with healthy populations of Whitefish and Trout.  Examples include:  Idaho's Henry's Fork and So. Fork of the Snake.  Wyoming's Green River.  Montana's Madison (although the Whities are vanishing on the Maddy, lets hope the Trout don't follow suit).  Colorado's Roaring Fork and Colorado River.

I'm afraid if we don't protect Whitefish all of our fisheries where they are native will suffer.  Remember that Whitefish are a native fish and many wild Trout are not native to our waters.  In my home state (Utah) most of the wild fish in rivers are Brown Trout with a few waters holding wild populations of Rainbows and Brookies.  Cutthroat Trout also reproduce on their own in many Utah streams.  Cutty's are native to Utah, but they are the only Trout touting the native label.  Don't get me wrong, I love catching Browns, Bows and Brookies but if numbers of Mountain Whitefish get too low the Federal Government will jump in to save the species from eradication.  This could be a good thing, but the Feds aren't known for their willingness to work with sports fishery state biologists when a species is in trouble.  Trout populations that are healthy and self sustaining will be removed if the Feds think the affected waterway could help bring Whitefish to healthier numbers.

The point is, respect our adipose bearing Whitefish friends.  If you have them in your rivers I know you've had a day or two saved by the fierce pull of a Mountain Whitefish.

Admittedly my opinion on this subject is non-scientific, but I'm confident it has some validity.  If you have holes to shoot in my theory please add your thoughts to the comments section below.  I welcome any input you may have.