Henry's Lake Bio--- long winded!

[cpierce]

I attended a presentation by Jessica Buelow last night. Jessica is a Regional Fisheries Biologist for the Idaho Department of Fish and Game in the Upper Snake Region at Henry’s Lake, where she runs the Henry’s Lake Fish Hatchery, conducts fishery surveys on the lake, and serves as the Fisheries Habitat Biologist for the region. She gave a presentation on some of their findings in the last few years.

I am presenting this as my flawed memory of the facts, so please keep that in mind. I wish I had some of the graph slides so I could remember better. I also am not presenting this to argue or "prove anyone wrong" etc. Is only what the studies conducted have shown. If some others remember or know of some of the significant facts that I have forgotten or just remembered wrong, please speak up and correct me.

First off for those of you who will be ice fishing, be aware that they are being proactive on aerating the lake for the winter. They will be turning the aerators on this week so there will be thin and open areas on the lake. I think those are set up toward the hatchery, but you should check for sure.

The management goals for Henry’s are set forth in the state’s management plan.

[url "http://fishandgame.idaho.gov/public/fish/planFisheries.pdf"]http://fishandgame.idaho.gov/...sh/planFisheries.pdf[/url] p318

Quote: “Henry’s Lake has been managed as a quality/trophy trout water since 1976. Catch rate goals are 0.7 fish/hour with management goals having a catch rate of about 0.45 fish/hour for cutthroat trout, 0.15 fish/hour for hybrid trout and 0.10 fish/hour for brook trout. Size goals are 20% of hybrid trout over 20 inches, 10% cutthroat trout over 20 inches and 5% of brook trout over 17 inches.” End Quote

That full goal is not currently being met. There are several factors going on that might be influencing the size of the fish. I don’t plan on presenting my opinion (very much), but only some of the factors that have been reported or found in studies.

I know some feel that ice fishing maybe a problem. This is what the studies have shown for the ice fishing season.

1. Releasing fish: About 80 to 83% of the fish caught both in the open water season and during the ice season are released. Mortality rate of those fish wasn’t discussed.
2. Size of fish kept in the ice season is about the same as for the size of fish kept in the open water season.
3. The number of fish caught and kept in the total ice season is less than the number harvested in the three days of the Memorial Day Weekend Opener.

Mortality of the fish in the lake: Fish in Henry’s only live three to four years.

Size of the 3 yr old fish has decreased in the last year by about 1.5 inches.

Relative weight of the 3yr old fish has also been falling since 2011. It has decreased by about a pound less.

No study has been done, but there seems to be significantly fewer scuds in the lake. They don’t know why yet.

Chubs have been increasing steadily in the lake since the mid 2000s. More brook trout were stocked as it was felt that they would be more likely to eat more chubs than the YCT and hybrids. When a feeding study was done it was found that ALL of the fish were eating minnows from the 12 inch YCT on up. The good news is that this year the chub population has stopped increasing. The fish are also eating more snails.

Another good news factor is that so far no invasive species have been found in Henry’s, not even non-native water weeds.

In their population studies, which are conducted each spring, the numbers of trout have been increasing. This year the number of fish was almost double the average. For the last two years stocking has been decreased to help offset the increase of natural reproduction and minnow survival. Both natural reproduction and minnow survival also depend heavily on water years. Obviously the lake is much harder to manage with an unpredictable natural reproduction addition of fish.

Some last thoughts, even with good numbers of fish and size, some years are going to be better for catching than others. Temperature plays a big role there. During warm years the fish are harder to catch than in cooler years.

Judging from what I saw of the graphs for Henry’s over the many years it has been studied and surveyed, it has had many down years as well as good. IMHO the past wasn’t always rosy either.

In my opinion also, Henry’s has some good years ahead. It may take awhile to balance the relatively new problems of high numbers of chubs and natural reproduced trout, as the fish have a 3 to 4 year cycle, but it won’t be for lack of trying.

Remember their goals are for >20 inch hybrids, > 20 in. YCT, and > 17 inch brook trout, not just numbers of fish.
[signature]

[flygoddess]

Thanks for sitting in on the report and taking to time to pass it on to us.
It is what I thought. And I believe it can be a great lake again in time. Going with the concern for size over numbers, I hope so. It will however disappoint some, but what was that saying?.....Oh, can't please everyone.

Speaking of numbers, the totals taken from the three days of opener with there probably being hundreds of fishermen. The number of fishermen compared to Ice Fishing? I am guessing more in one day in May as compare to the whole Ice season.

Wonder what the number of fish per person during these time are.
ex: Lets say, 80 people the day after Memorial day and an average of 2 fish day and 10 people on ice with 5 poles averaging 2 fish per pole...does that make sense, or am I just really bored[laugh][laugh][laugh]
[signature]

[cpierce]

I am not really sure on what you mean on the ice fishing pole numbers. I don't know what the one day in May would be, but if I remember the total # of ice fishermen was around mid 4 thousandish and it was a small fraction of the year's fishing effort.

As I understood it the figures were for the total number of fish caught and the total numbers of fish kept. I don't know whether having 5 poles was any real advantage in catch rate. I can remember a number for per angler or angler hours in the ice season. More poles might increase the catch per hour of effort, but it still seemed to be equal or below open water catch rate, but I don't know for sure.

I know that the size of fish kept was about the same as open water and the total harvested was less than for the opening weekend in May. They will do another creel survey on the ice again this year.

I think that the way F&G sees it, is that mainly the total harvest or catch and release numbers are the ones that affect management of the fishery the most. Catch rate per hour is more of a "customer satisfaction" issue.[:p]
[signature]

[drowning_flys]

Pretty interesting thanks for passing along the information. Some of it really surprises me
[signature]

[pisces_mortem]

Great post. Thanks for sharing.
[signature]

[MMDon]

Thanks for the informative write up!

I think all of the fish over a certain size have always consumed minnows as a main protein source. Since I fish with large minnow patterns and I don't see that many Brookies, over the years, I'd have to say they are just "discovering" what many of the trophy fisherman have always known.
[signature]

[flygoddess]

[quote MMDon]Thanks for the informative write up!

I think all of the fish over a certain size have always consumed minnows as a main protein source. Since I fish with large minnow patterns and I don't see that many Brookies, over the years, I'd have to say they are just "discovering" what many of the trophy fisherman have always known. [.img]http://www.bigfishtackle.com/images/gforum/bobwink.gif[/img][/quote]







"No study has been done, but there seems to be significantly fewer scuds in the lake. They don’t know why yet. "






This couldn't have anything to do with it could it? I bet a vegetarian would eat beef if there was no other choice.[]
[signature]

[cpierce]

They really don't know yet on the scuds. If it is over the whole lake, or why. She said it is something they are going to look into.

I would think that a drop in the scud population would be a bad thing at Henry's. I believe that they were a huge food resource for the trout.

One thing that comes to my mind is that, maybe the increased number of chubs are eating all the scuds.

A larger population of trout this year has been trimming down the chubs, but there are still too many mouths to feed... both chubs and trout. Is the drop in scud population because of predation by the fish or some other reason.

Whatever the reason... there is less food available and the trout's diets have changed more to minnows and snails than before. Leeches are still a large regular diet item also.

Too many chubbs
Too many trout
Less scuds

equals

smaller fish until things get back in balance.

Still even at an average of 1.5 inches less, some of Henry's "smaller" fish are trophies to be proud of!
[signature]

[MMDon]

I've always found the Henry's fish heavy on a snail diet. The scuds made them some of the best eating however. Probably only to be rivaled in taste by the Blackfoot Res fish.
[signature]

[Ouzel]

flygoddess,
I have, as usual followed with rapt interest, the comments and updates on the ice on Henrys.
Do you believe that all ice fishermen at Henrys take advantage of the 5 pole rule?

Speaking for myself, 2 poles are plenty for me to tend and jig, likely a leftover from Wyomings 2 pole icefishing rule on most all lakes there, with just a select few being more poles allowed.


Clear ice and tight lines,

Ouzel
[signature]

[curt69]

I fish with five poles because I like to try different baits at different levels . It seams like the people using 1 or two poles do just as well because they pay better attention . I miss alot of bites . Some times when the fishing is fast you are better off with just one .
[signature]

[flygoddess]

[quote Ouzel]flygoddess,
I have, as usual followed with rapt interest, the comments and updates on the ice on Henrys.
Do you believe that all ice fishermen at Henrys take advantage of the 5 pole rule?

Speaking for myself, 2 poles are plenty for me to tend and jig, likely a leftover from Wyomings 2 pole icefishing rule on most all lakes there, with just a select few being more poles allowed.


Clear ice and tight lines,

Ouzel[/quote]



"Do I believe that ALL ice fishers use 5", no. But they can. "Can" being the key word. It doesn't up their catch and keep numbers as a limit is a limit. But it ups their success rate to actually catch. Covering more water columns.

I can fish five flies on one line in certain waters and I could be wrong but I think you could fish five lures. That means you could have 25 hooks in the water at one time...YIKES![laugh]
I have used five flies in the wash line before (on waters that allow this), but I prefer two or three but that is more because that is what I am use to using here in Utah (with three flies being new this year to us)
I do have a two pole permit and I do use it. Much like the multi rods on ice, it helps zero in on the fish. I fish the two with different sink rate to find the zone.
I also miss several fish using two rods.

But were I to catch and keep, my limit is fixed so using multi rods just helps me reach my limit faster, not more fish.
I can move on open water pretty easy, ice fishing requires drilling holes. On shallow lakes like Henry's a little hard not to scare the fish with each hole, so I see the 5 pole to give them time to return while you continue to drill in other spots.
[signature]

[Bmarsh]

On Henry's there isn't much of a water column to cover where most people fish. I usually fish 2 rods up there. Jig with one and do a dead stick on a jawjacker. Some days they like one and not the other.

Personally I think that items like a jawjacker add a larger advantage than a few extra rods ever will. That may be something to address is only allowing so many of them ect. You will miss fish on those extra rods that are dead sticked, but if they are all on a Jacker you will hook up almost every time.
Lots of things to look at there. Cutting the pole limit down so people cant have mechanical aids ect.

End of the day it seems there are a lot more contributing factors to what is going on than just the ice fishing.

More fish that are naturally reproducing, something causing a drop in scuds, and this winter most likely some winter kill could change things even more.
[signature]

[flygoddess]

Do you think this year the winter kill will be that much worse then say 2007? Isn't there winter kill every year? There is aerators by the Hatchery, so there could be clusters there at times, but it use to be a no fish zone.

As for the Jaw jackers,the limit is still the same, so as I said, you either get your limit sooner, or more C&R. Think there is much kill on the C&R?
[signature]

[curt69]

You are doing alot better than me with your jaw jackers than me . I get alot of misses . I have started setting the trigger harder and doing a little better .
[signature]

[Bmarsh]

Gut feeling is that jawjackers actually would help with mortality since they usually help to avoid the fish being able to take the lure/bait deep before the hook can be set. They set off fairly quickly.
[signature]

[Bmarsh]

[quote curt69]You are doing alot better than me with your jaw jackers than me . I get alot of misses . I have started setting the trigger harder and doing a little better .[/quote]

All depends on the wind. Calmer it is the better the rate of hookups with them.
[signature]

[curt69]

Windriver gave me several tips on how to set them up . It has helped . You are right about the hookup . They are amost always hooked on the outer edge of the mouth .
[signature]