Is Henry's Lake Overpopulated?

The Pendulum Swings

Through the mist rising slowly off the water, snow capped mountain tops materialized almost magically as the October sunrise burned through the fog.  For anyone that loves the outdoors as much as I do, the period of time between pre-dawn light and daybreak is an evanescent moment where anything is possible.  The thrill of the day before you fills the air, yet the world seems to be entirely still.  In this cold tranquility, all the focus of a surgeon is devoted to every cast.  Form, presentation, and stealth become paramount.  Inevitably, I will smack myself in the back of the head with my size 6 woolly bugger at least once in this small window of time alone.  I looked slowly across the lake, admiring the beauty around me while stripping in my fly line.  The only sound breaking the silence was the water dripping from my guides as I brought in my streamer.  Without warning, an aggressive Yellowstone Cutthroat trout smashed my fly.  When I set the hook, my line zipped up into the air from the water, breaking the surface tension and spraying water as it chased down my line towards the thrashing trout.  Very few places on Earth can hold embody the grandeur and wonder this world has to offer to a fisherman as Henry's Lake.

The fish that call these waters home grow freakishly fast, often developing a hump on their backs behind their head as their body weight outgrows their skeletal structure. Henry's Lake boasts a population of over 500,000 catchable trout, with the average trout caught by anglers measuring at 18".  With such a prized lake, it certainly grabbed my attention when I heard some concerning news about the declining size of the fish found here.  Recently, a video has been circulating by Tight Line Media detailing the status of the Henry's Lake fishery.  This lake has been the holy grail for trophy trout fisherman all over the country for twenty plus years, but several consecutive years of good water years have resulted in a population upswing - not in the number of fish surviving that are planted - but due to wild fish spawning.  Tributaries previously inaccessible to trout become viable again with a higher water table, resulting in miles of spawning grounds for wild fish.  Ultimately, biologists believe this is resulting in an overpopulation that is lowering the average size of the trout.

Chris Cutler with a beautiful cutbow caught on the fly last fall

After watching the video, I decided to ask around the local fishing community and see what other anglers had to say about the average size of fish in the lake.  The results could haven't have been more varied.  There were definitely the nay sayers that said the average size fish was "way down" and the F&G didn't care about maintaining the trophy quality of the lake.  From my own fishing experience I hadn't noticed any reduction in average size.  I decided to revisit the F&G website once again for some actual data to shed light on the argument.

Science has a way of polarizing sportsmen.  Either they find it fascinating and agree or vehemently disagree and point to faulty methods - swearing there must be some conspiracy afoot to discourage fishing and hunting.  I have never understood the latter, but I doubt there can be much argument for the data I found.  The following is a chart I drafted to illustrate the variation in average fish length taken by the hatchery during the spring spawning seasons from 2006 - 2010, the 2011 report is not yet available.  Looking back at 5 years of data I think we can draw some conclusions on what to expect and gain some perspective on what a change in size looks like.

The large variation in hybrid trout size is partially due to the relatively small number of cutbows that actually return to the hatchery every spring.  Since the fish are sterile, they should lack the spawning instinct and not behave as natural fish in that respect.  The success of sterilizing these fish while in infancy has fluctuated over the past 5 years from 98 - 100%, which means there are SOME fertile hybrids in the lake.  Sterilization has been increasingly successful, culminating in 2010 with only 2.9% of the total fish returning to the hatchery being hybrids.  The running 5 year total stands at 7.3%, and with a smaller sample group, greater variation can be expected to some degree.  The chart below details the exact numbers.

The Fish & Game also studied fish mortality with extended seasons and opening the lake to 24 hour fishing, and neither had measurable detrimental effects on fish mortality or trophy quality.  While we wait for the final data to be published detailing this year's spawning trout, I think it's safe to say Henry's is not in imminent danger of losing trophy status.  History teaches us that changes of great magnitude often take longer than 1 year in this fishery, so while size may be slightly down - it's unlikely that it should be of major concern to anglers.  With this fishery under close watch from biologists, a plan has already been enacted to combat the issue.

On an average year, 1.6 million trout are released in the lake, this year that will be lowered to 1.3 million, with Yellowstone Cutthroat trout seeing a 42% reduction in planted fish, while hybrid and brookie numbers won't change.  However; there is another interesting piece to this puzzle.  Amid concerns from anglers about the effect extending the ice fishing season until January 1st would have on the trophy population of hybrid trout - the Fish & Game decided to release 10,000 "super hybrids" with the annual planting this year.  These "super hybrids" have spent an extra year in captivity bulking up, and will be a  whopping 10 - 12" when released compared to the typical 3 - 4" fingerlings.  What does this mean to anglers?  These hybrids will clear the 20" mark easily within 3 years, reaching trophy proportions much quicker than run of the mill cutbows.  Survival rates should be higher among these trophy trout as well, resulting in a healthier class of upper-tier giants.

Back in the frigid waters of the lake that morning in October, I stood marveling the beauty of the trout I had in my hands.  Abundant food sources, careful management, and a remarkable marine environment combine to create a truly world class fishing experience.  I gently held the 18" cutthroat in my hands beneath the surface and watched it thrust water through its gills as it regained its strength.   In keeping with tradition, no matter how badly I want to have fresh trout that night - I loosened my grip on the fish's tail and slid it back in the waves.  The first fish of the day swam slowly towards the deep, then quickly darted out of sight.  While we may not always agree with the Department of Fish & Game, and some may question their motives behind certain decisions; it seems clear that they are very carefully monitoring the health of this outstanding fishery.  I applaud their continued efforts to maintain and improve the quality of fishing on Henry's Lake, and have complete faith that they have anglers' best interests at heart with the management of this remarkable resource.  I look forward to the day I set into one of those "super hybrids" on the fly.

As the Canadian brookies mature, more of these humped freaks will be showing up

Spring Fever

Early spring is always a season full of anxiety for me.  With so much to look forward to in the coming months, I find myself spending more time THINKING about what I'm going to do, rather than actually DOING anything.  With spring turkey and bear season just around the corner, it's time to start shooting my bow more regularly and making the endless number of small adjustments I regularly do to ensure my equipment is in perfect operating condition.  Oddly enough, no matter how many small adjustments I do to perfect my system - I will inevitably be awake until the early morning hours rechecking everything before my first hunt of the year.  The same holds true for my first spring steelhead trip of the year.  I make checklists for my equipment, and plan every aspect of the following day - where to go in inclement weather, where to go if there's pressure, the list goes on and on.  Therein lies the essence of my early spring cabin fever - I regularly suffer mild to moderate outbreaks of obsessive compulsive disorder.  One thing that I regularly obsess over, that I feel is a very worthy cause, is researching my hunting locations for the coming fall.

One of the best things about spring to a hunter is that there is always a wealth of information about the previous years' hunt that are invaluable.  The hours I spend in the early spring researching data from the previous fall dictates what hunts I apply for in several states, but most importantly here in Idaho. I think too often sportsmen overlook the mountains of data relating to their home state that can help uncover the next "honey hole."  I have known too many sportsman, myself included, that have hunted the same areas for years without ever attempting to expand into new areas.  All too often the population shifts, predation changes, hunting pressure spikes, or recreational development can alter the outlook on a favored hunting area in just one year.  Without a contingency plan - or several for that matter, one can be left very discouraged.

The first place I always turn to when researching new hunting areas, or even old ones, is the Idaho Department of Fish & Game website.  Their website has multiple reports and data compilations that can help quickly isolate an area of interest - and perhaps the first one I look at is harvest data, which is a sub-section in the Big Game Species Info section.  Both controlled hunts (special permit hunts) and general season harvest information is available, with each being broken down by year - and further yet you can view the number of hunters per unit, number of animals harvested, average days hunted per hunter, antlered vs. antlerless harvest, and % of trophy animals taken.  Comparing that data to drawing odds available in the controlled hunt information will help locate a good permit to apply for.  Any hunter that isn't utilitizing this tool in planning their hunts every fall is short changing themselves.  When analyzing unit data for deer, another great page to view is the whitetail distribution map.  Note that in the harvest data, mule deer vs. whitetail deer harvest is specified.

The second thing I do when researching a new area is to view topographic or satellite imagery of the unit in question.  Google Earth is an extremely valuable asset, particularly "Terrain View," as this enables you to see the contour of the geography, and when paired with satellite imagery, provides a wealth of information about likely holding areas for trophy animals.  As they say, to kill a giant you must hunt where giants live - and giants often live in the most remote and inaccessible locations in a given unit.  Animal survival statistics and age spikes dramatically only 1 mile from the nearest road - most hunters only venture to these areas briefly in their hunts, and almost never at times when animal activity levels are at a peak.  Most hunters simply aren't willing to work hard enough to get back into these areas, or only briefly hunt them.  A dedicated public land trophy hunter should almost EXCLUSIVELY hunt these areas.  This often requires beginning your hike long before sunrise and returning long after sunset, remember; the vast majority of your hunting day should be spent in the more remote areas you are hunting.  More on this topic will follow on future articles.  Targeting these specific locations to hunt is crucial before putting in the time and effort to scout on foot.  You can either work harder, or work smarter.  Utilizing satellite imagery and topographic maps will enable you to pinpoint these areas with far greater accuracy.  The major criteria in play for determining a potential trophy area are accessibility, water sources, bedding grounds, and feeding grounds.  The majority of these elements can be determined with relative accuracy prior to scouting trips.  Google Maps allows mapping hunting areas with phenomenal detail. My maps with all my notes are printed each time I go on a scouting trip so that I can detail any new information with pinpoint accuracy.

I happened onto this buck right before dusk in late July.  Poor lighting conditions and distance prevented a good picture, but it was great to see the fruits of my labor materialize after months of research.

These photos have enabled me to hunt this buck for 3 seasons, during which time he has grown from a respectable 160" buck to a tremendous 180" buck last season.  I'm yet to loose an arrow at this monarch.

The final step in developing a new area is obviously getting some boots on the ground.  Leg work can't be substituted by any other activity, you have to get some time on the ground to learn the geography and animal movements.  Avoid pressuring animals when doing preseason scouting, this means going to the same lengths to cover scent, be mindful of wind direction when approaching likely bedding areas or travel routes, wear full camo, and most importantly - USE OPTICS.  Optics may be your greatest asset when scouting a new potential area.  Try to view animals from a distance and minimize any time spent in or around bedding areas.  Blowing a trophy buck or bull out of his bedroom can upset his entire routine and invalidate hours of scouting.  Too many times scouting trips result in bumping an animal, only to never lay eyes on him again.  If it does happen - back out for a few days and note the location so the same mistake won't be duplicated.  On these scouting trips, remember to record information you gather.  Mental notes are not enough!  I regularly use Google Maps to mark bedding areas, feeding grounds, travel routes, water sources, rubs, wallows, etc. This information allows me to make informed decisions when trying to locate an animal that seemingly disappeared into thin air, as well as branch out into adjoining territory.

Finally, don't give up!  I often hear hunters talk about spending a few days in a new area give up because they simply aren't seeing the animals.  If the elements discussed prior are present, and animal sign indicates there are animals in the area - stick it out!  Just because there aren't many animals, doesn't mean there aren't trophy animals.  In some of my best locations I can go days without seeing an antlered animal, low animal density doesn't equal low trophy density.  Also bear in mind that hunting pressure will change an animals habits, and if you've done your research it may be possible to relocate your animal(s) using information you already know!  Another critical aspect of scouting - particularly in hunts with a short duration or early season when patterns are still predictable - arrive a day prior to the opener.  Your hunting time is too valuable to be wasted hoping that nothing has changed since your last scouting trip.

With turkey season just around the corner, the hunt is already on...