Color variations in brook and brown trout

[Stenonema]

If we accept as fact that the early examples of trout were difficult to propagate and raise then we must ask ourselves Why. Why did they bang themselves against the walls of the enclosure? They obviously wanted to go somewhere. Why? To answer this idea is that you have to go back to their heritage. The early brown trout brought to this country had a significant migratory trait and instinct thereby harming themselves against the structure in a will struggle to migrate against an immovable force. I would like to know are the Brown trout that show large migration trait possible examples of early plantings.
If we accept as fact that the fish that adapted the quickest to the new setting (hatcheries) survived and handed down the traits for survival quickly altering the genetic structure. This suggests the idea that the earliest trout were and are very plastic in terms of genetics. Were the trout first stocked into our watersheds similar in plasticity. We have to ask could this make the naturalized Brown trout of today genetically unique to their respective watersheds and worthy of protection and a different management than a blanket management of all Brown trout as one fish. I guess this depends on how much value you place on naturalized brown trout populations.
I believe that at one time there were more examples of this scenario than there are today. The scenario that plays out places the bulk of a migration run at a pinch point of vulnerability which if left unprotected can decimate a population. The pinch point is the mouth of the nursery tributary. The tributary mouths are also cold water refuges for summertime temperatures in many cases. I witness this every year as the adult fish stack up awaiting the cover of darkness or a water event to push up the stream. The sport of night fishing for Brown trout in this state was generated by this staging or stacking of large Brown trout on tributary mouths. Many of these streams no longer have this migration event for various reasons but not the least of which may have been fishing pressure. Are these trout unique or significant enough to garner protection at there most vulnerable point or otherwise.
Is it possible that we overlook this significance? Is it possible that the large brown trout that make up the legend of the Letort Creek were migratory? Is it possible that they were in part coming from the Conodogunit creek. A large part of what makes up the Legend of the Letort was the terrestrial fishing that was to be had there. The terrestrial insects are very abundant during the summer months and the heat of summer. The upper Letort may have had good spawning gravel and also justified this return. Could this be an overlooked link in the resurrection of the Letort?

 

[BrookieChaser]

I agree, Steno.

That brings up a point I wanted to make in the Elwa thread. Now the "in" conservation thing is re-establishing migratory salmon and their waterways. Documentaries like "DamNation" have tackled it. But they're reintroducing hatchery fish and trying to make them migrate. Which we know has low return rates, if any.

Now I ask, where is the protection for migratory wild brown trout that are already present in the Little Juniata? Do they not deserve protection? We could protect them now, even going so far as subspecies designation on waterways. Instead of installing smoke detectors after the house burnt down, like in the case of salmon and steelhead.

I don't think your common pellethead nowdays is going to have any migratory traits left in it. Genetic dillution at its finest. So once those early wild strains, like in the Letort, are lost, they're gone.

 

[pcray1231]

Interesting point steno,

I'd add that those early hatcheries mostly reared rainbows, not browns. And second came brookies. By the time brown trout came around, the same may have happened, but I don't know that. I'd guess that the original browns that came here had already been "hatchery-ized" in Europe to some degree.

Still, yeah, I think fish in some places are more migratory than it first appears, and that this trait was probably even stronger way back then. The main reason being that the larger streams stayed colder, and hence that would have made more substantial movements easier.

And that said, specific to the Letort, it has a lot going for it even if they weren't migratory. Cover, consistent temperatures, and an abundant year round food chain.

 

[pcray1231]

If we accept as fact that the early examples of trout were difficult to propagate and raise then we must ask ourselves Why. Why did they bang themselves against the walls of the enclosure? They obviously wanted to go somewhere. Why?

Skittishness. Yeah, that's a technical term!

Seriously, though, we'd call it spookiness. Predator aversion. People walk near, fish dart away to cover. No cover? They just keep darting here and there, get all worked up, and go crazy.

Seems it is actually genetic behavior, not learned. But it only takes 2 or 3 generations to show substantial "improvement".

 

[tomitrout]

Regarding 'skittishness', don't forget about territory and 'personal space' when it comes to wild fish. Confine a bunch of 'em in a small hatchery raceway, and there's no doubt that that closeness to other trout is a contributing factor to them trying to escape thru the concrete walls.

Regarding migratory fish in the Letort, I'd be curious how much evidence there is of fish being able to get over the falls at the mouth of the stream where it meets the Conodoguinet. Not saying it doesn't happen, but I doubt it's a major contributer to the Letort's population.

 

[salmonoid]

tomitrout wrote:
Regarding 'skittishness', don't forget about territory and 'personal space' when it comes to wild fish. Confine a bunch of 'em in a small hatchery raceway, and there's no doubt that that closeness to other trout is a contributing factor to them trying to escape thru the concrete walls.

Regarding migratory fish in the Letort, I'd be curious how much evidence there is of fish being able to get over the falls at the mouth of the stream where it meets the Conodoguinet. Not saying it doesn't happen, but I doubt it's a major contributer to the Letort's population.

At least one made it (or tried hard doing it)..

From the photo section..

 

[sarce]

Anytime you think about waterfalls or low head dams as barriers to fish migration, you have to consider if that barrier becomes passable in high water.

I'd love to see a genetic study of the wild brookies in SE PA. Some of the streams they survive in are really tiny, unlikely to have ever been stocked, and flow into large unstocked warm water creeks. Quite a few isolated populations there.

 

[salvelinusfontinalis]

What fish are not crushed by locals make it over.

The migratory fish from the Letort is way overstated.
Do fish migrate out of the Letort? Yes.
Do some return? Yes
Do some find another stream for summer refuge? Yes

The population of large fish suddenly doesn't vanish from the Letort. I good number, probably 90 percent or so, stay year round.
Some trout just run.

All that said, like in Seno's cold water refuge thread, these areas during migration should be protected.

 

[salvelinusfontinalis]

It would be interesting to see some large browns in the Connie be caught and tagged just to see exactly what they are doing.

I would even be willing to bet that some stay year round after finding a cold water upwell.

 

[Chaz]

BrookieChaser wrote:
Thanks for the links, salmonoid. Unrelated, but I found it interesting that someone with my last name was a commissioner in PA during the 1879/1880 report.

Chaser, that's an unusual last name.

 

[Chaz]

pcray1231 wrote:

1) brookies didn't do well in the hatchery environment in the early days of fish culture and they don't survive stocking well.

This is true across the board. Lots of interesting hatchery history from where hatcheries started, in the Midwest (Wisconsin, Iowa, etc.).

No species did well. They captured wild fish and attempted to breed and raise them, and in the early years, struggled mightily to do so.

They wouldn't eat hatchery food. They'd run from hatchery workers. They'd run into walls and kill themselves. They weren't resistant to disease. They grew slowly and took too long to become sexually mature.

Interestingly, they thought it was learned behavior, so they started taking eggs instead of fish to raise. It did not help, even fish BORN in the hatcheries had these issues.

Though the early survival rates were low, there were survivors. They were mixed with survivors from other hatcheries. In a relatively short amount of time, "hatchery" strains were developed which were easier to maintain. As more states opened hatcheries, then hatchery strains were mixed and matched for various goals.

Of course, the hatchery strains didn't do as well once stocked. Over time, the hatchery strains grew more and more separate from wild strains.

Some states, including Wisconsin, are going back to wild strains in hatcheries, so that the stocked fish have a better chance of survival in the wild, and perhaps colonization. To do this, their more recent work involves changes to the hatchery raceways. They place rock bottoms and other cover in there. Fish densities have to be lower. Feed is changed, and they are fed by automatic feeders instead of people. It's needed to successfully raise a wild strain in captivity.

If that's not an interesting genetic study, I don't know what is! But it does lead to the concept that early hatchery trout were much more suited to the wild than today's hatchery trout. And hence much more likely to interbreed with existing wild fish or seed new populations.

Still, if streams were wiped out and re-colonized, I wasn't suggesting it was due to hatchery trout, but more often, probably nearby streams. A few travelers arriving to a healthy population = minor genetic effect. A few travelers arriving to a very poor population = major genetic affect. A few travelers arriving to an empty stream, but one which has recovered to the point where it can hold fish = seed a new population.

That's why the original browns that were established in the U.S. came from eggs shipped over here from Germany.

 

[troutbert]

Eccles wrote:

KenU wrote:
As for this mixing thing, recent studies have indicated that populations of brook trout, when moved into strange waters, can maintain their genetic identity for many generations. This means that they only interbreed with their own. How they accomplish this is not known, but it could be many things - each particular population may have evolved a different breeding strategy; different breeding time, or place; each population may have a different odor, etc. So when transplanted, wild populations may not readily interbreed with strangers.

That's interesting. I get the reproductive isolation bit but was unaware that this had been shown to such an extent for brook trout. Can you indicate which studies you are referring to?

Check this NJ study:

http://www.state.nj.us/dep/fgw/bkt_genetics.htm

It has a pretty good review of the literature before describing their own study done in NJ. And you will find a lot of info on this topic.

 

[Stenonema]

Cool photo Salmo. I have personally witnessed brown trout jumping up and swimming over a four foot high dam. I think high water would be helpful for them.
There is a study of the Sturgeon of the Chesapeake and they are finding that there are different genetic strains running and spawning at separate times. When just a few years ago they weren't sure there was one left. They had accepted the idea that they spawned in the fall because some leading authority on the subject probable said so. They were looking at the wrong time. We shouldn't accept what we think we know about fish. We should always be testing ideas, isn't the exploration for knowledge what draws us to fly fish in the first place. Just saying.
I only posed my post as an idea. I'm glad some have found it interesting. The idea raises questions more than answers. Like Salmo stated I also think it is worthy of study and protection. I don't believe that the Letort is the only stream that this is occurring on in the watershed.
I would be curious. Does anyone know the date of the die off on the Letort. I would be interested to know if it happened in the fall during the spawn.
Do we know that the brown trout migrate in and out of the Letort. The answer is yes. Do we understand the significance of those fish? NO. The Letort has to be one of the most studied and prtoected streams in the country and to my knowlege we haven't looked at this. We don't even offer them protection.
One thing that could negate the idea that the trout of legend were migrating to Vince meadow. Is there or was there anything in the war college that would negate migration past that point. I am not familiar with that area.
The instinct to migrate must be very strong in those fish. Why would they leave the fertile waters of the Letort?
Trout that do migrate in this way grow very large alot like the trout we have read about that were common targets of Legend. Today they make great targets for the trophy hunter at the mouths of streams as the trout are forced there by warm water. The fisherman has the right to catch and kill their limit of five How long before a spawning run is depleted or wiped out? Hell it's a wonder there are any at all.
These trout make for a very viable and stronger trout water in that 100 percent of the population is not in any single body of water at one time protecting at least part of the population in the case of a spill or massive die off. I believe that this trait alone is what makes the trout that do migrate worthy of investigation. They are to some degree an insurance policy. I hope that someone reads this and it leads to some new form of protection for these fish and others left like them.

 

[Stenonema]

I wish I could edit my previous ramble. I wrote it quickly in a haze after work and just before bed. Take it easy on me.

 

[Fishidiot]

Stenonema wrote:
I would be curious. Does anyone know the date of the die off on the Letort.or wiped out?

By this I'm assuming you mean the the famous fish kill in May 1981(?). At that time, the lower stream north of Carlisle was polluted and trout did not exist there. Due to the distance, I think it unlikely that trout migrated through that section and town to the FFO due to its length (although I suppose it was possible).
With that section cleaned up today, there is a lot of room to stretch it out: the Letort watershed is nearly 60 sq miles and the Conodoguinet watershed is about 5oo sq miles.

It is common knowledge among many locals who have fished many mid to large sized rivers in central PA brown trout, including large ones, are present during the cooler months.

I agree, it is not a well understood phenomena and would make for an interesting study.

 

[Eccles]

troutbert wrote:

Check this NJ study:

http://www.state.nj.us/dep/fgw/bkt_genetics.htm

It has a pretty good review of the literature before describing their own study done in NJ. And you will find a lot of info on this topic.

Thanks for putting this up. Nice study, good detailed intro and nice photos of the color range of the trout from the different watersheds. I don't know when this was done (most recent reference they use is 2006) but I'm surprised it hasn't been published.

Good starting place for anyone interested in genetic diversity as it will apply to PA and the rest of the BkTs natural distribution. Just skip all the molecular methodology which gets a bit heavy and just read the Introduction and Discussion.

 

[tomitrout]

Steno:

I hope that someone reads this and it leads to some new form of protection for these fish and others left like them.

Well, there's always hope I guess...but considering the current regulatory climate, I just don't see this happening.

And again, while there are some fish that surely make it up over the falls into the Letort, they make up a very small part of the total population of that stream. There are big ones o f 'legend' in there year round all up and down it's length, spend some quality time there and you'll realize this. And I'm sure that the fish in the stream do migrate within it's confines throughout the year, but is there a mass exodus and then subsequent influx as they migrate back in for the spawn...I just don't see it. For the number of fish in that stream you'd think there'd be something akin to a fishin' derby at the mouth when they would stack up to run upstream for the spawn, and for the most part it's just Nightstalker and a couple other fellas targeting those fish.

And if they would regulate the mouths of these waters to protect that handful of migratory fish, pretty sure Nightstalker will have to change his tactics since that appears to be his niche for posting those pics that so many ooo and ahhh over here on this site...

So as far as I know, there are no barriers in the Letort, at the War College or elsewhere. Two season's ago I caught a woefully skinny rainbow in the lower reaches and figure it more than likely worked it's way those couple of miles downstream from Letort Park after being stocked for the little fishing derby that's held there every year. Or she managed to move out of another stocked stream, swam the Conodoguinet, jumped the falls and ended up in the Letort after one hell of a journey. I'm guessing it was the former scenario...

 

[JeffK]

First oddball thought is that all salmonids have a tendency to move around. Most of the cold water environments that salmonids are the major predator in were covered by ice 10,000 years ago and the trout species were early in the recolonization. All the early studies of the Sierras rainbows (we got our bows from the Sierras first) showed a tendency to move as well since the Sierra streams are prone to droughts and floods that knock down populations, but the bows moved around a lot to compensate for local events.

Second, our major "warmwater" rivers, like the lower Delaware, have trout friendly temperatures 8 months a year. As long as they can find a summer refuge, large trout can fatten up in our major rivers most of the year. In the days of yore I had friends who specialized in trout fishing in the Delaware near Riegelsville. It was never much of a numbers game and a lot of work, but some big browns were caught.

Troutbert,
The dam was rather small - it impounded a swimming hole when the area was a YMCA camp - and has since silted in. The present owner wants to build homes with a pond view so wants to keep the dam in place, but has lowered it a bit so the pond is very small right now. However, nothing seems to be going on so what will happen is still up in the air.

 

[Stenonema]

Thanks fishidiot that information helps. The Letort isn't a stream I have ever fished regularly even though it is only 20 minutes away. The spill was in May when the big boys would have been mostly out of the stream if they were runners. They would not have been killed and would have repopulated the section quickly. Given that the lower end was polluted and was void of trout. I also doubt that my idea would then be an accurate one. I will admit here that my intentions of posing this idea had motive.

Tomitrout, thanks for your insight as well. I will say that with so little information and study done we aren't aware of the true potential that the trout that migrate into the Letort bring or how plentiful they could become.

I have been interested in seeing such protection for these types of scenarios. The DNR parameter that is the road block for such protection dictates that the population of trout must be there year round. That is what I have been told by the PFBC.

There are places in the state where this protection is needed. I thought that with the noteriety of the Letort and the funding and interest that just maybe this would light a spark in someone thereby establishing a new regulatory protection. At this point I am told there is nothing the PFBC can do regulatory to protect these fish.

This has been the most interesting thread to me that I have seen on this sight for a long time.

 

[willdeb]

I love those pictures.