Those brook trout "fry" stockings 1891 to 1902

[Gone4Day]

I’m sure industry was “on-board” so to speak. Just like trees, all you had to do was plant new ones. Amazing they got away with such a ruse for so many years.

 

[troutbert]

Fingerlings stocked in modern times have very low survival rates.

And these were not fingerlings, they were fry, which are younger and smaller than fingerlings. So their survival was surely much lower than fingerlings.

I think many people assume that if they were stocking something, it must have had some results. That is not a good assumption when it comes to fisheries management in general, and stocking in particular.

It could be they stocked that large number of fry and were just feeding the fish and kingfishers and herons.

 

[k-bob]

"It could be they stocked that large number of fry and were just feeding the fish and kingfishers and herons."

OP mentions very large number of brook trout fry stocked circa 1900. This may have been done with a view to not wasting the potential of the state's degraded streams as a food resource after clear-cut logging. Also, as OP notes, fish may have been put in for fishing (maybe not catch and release). Brook trout may have been stocked at least in part because they taste better than other fish. If very few of the fry grew to be available and suitable for fishing or human consumption, the program probably would have been changed.

I think they wanted some of those fry to get big enough to, uh, fry

 

[franklin]

troutbert wrote:
Fingerlings stocked in modern times have very low survival rates.

And these were not fingerlings, they were fry, which are younger and smaller than fingerlings. So their survival was surely much lower than fingerlings.

I think many people assume that if they were stocking something, it must have had some results. That is not a good assumption when it comes to fisheries management in general, and stocking in particular.

It could be they stocked that large number of fry and were just feeding the fish and kingfishers and herons.

A lot of the early stockings had local people involved. They were usually familiar with the streams being stocked. It's not like they dumped a bunch of fingerlings in and came back years later to declare success.

In the cases I related, my relatives were in contact with the streams on a regular basis. They certainly were in a position to observe results.

 

[FarmerDave]

troutbert wrote:
Fingerlings stocked in modern times have very low survival rates.

And these were not fingerlings, they were fry, which are younger and smaller than fingerlings. So their survival was surely much lower than fingerlings.

I think many people assume that if they were stocking something, it must have had some results. That is not a good assumption when it comes to fisheries management in general, and stocking in particular.

It could be they stocked that large number of fry and were just feeding the fish and kingfishers and herons.

Of course the survival of fry to adulthood is much lower than it is for fingerlings to adulthood, but that doesn't equate to no success.

There are a few things you apparently are not considering either in you apples to oranges experiment. The big one is this. The fingerlings stocked today are not even close to their stream bred counterparts. These are from fish that were selectively bred to do well in a hatchery environment, rather than in a stream. That explains some of the low survival rate. That is likely part of the reason why they stocked them as fry back around 1900 rather than as fingerlings. Survival rate to fingerling stage of the native brook trout in a hatchery environment is quite low. They would actually do better in the stream. So that in itself is an apples to oranges comparison IMO.

So, lets just look at fry survival of wild brook trout.

I read the abstract of a study in Michigan from 1943-48. It started with a certain number of breeders in confined stream sections. From that they did an estimate of egg count. In six different "diversion" experiments, the range of survival from egg to fingerling was 4.5 to 31.7%

Another unconfined experiment on a different stream in 1949 to 1958 resulted in different results. They estimated number of breeders, and estimated number of eggs from egg count data. A series of 12 population estimates showed survival of eggs to fingerling to be 2.7 to 6.7%.

That is actually higher than I would have guessed, but notice, not zero.

No need for you to point out that survival of egg to fingerling is lower than survival of fry to fingerling, right?

OK, lets look at a stream that is depleted trout populations from over harvest and severely reduced spawning habitat due to siltation from logging. One that is still cold enough to support trout, but not support much reproduction.

Trout can live in such a situation. Hell, they even do well in ponds if the water is cold enough. They just have very limited spawning success.

4. With lack of predation due depleted numbers of adult fish (all species), wouldn't it be safe to assume that survival of planted wild fry would be higher than in a steam with a healthy population of trout?

What happens when we dump 20,000 fry in the stream.

If 5% survive the first year, that's still 1000 fingerlings.

And if 10% of those survive to adulthood, that's 100, is it not?

Just an example.

I agree that in some cases there was likely no success. Stream to warm, whatever. In some there likely was SOME success.

Some > None.

Most importantly,... quoting the hilldibeast. WHAT DIFFERENCE, AT THIS POINT, DOES IT MAKE!

Look, if the trout were extirpated from a particular stream, and eventually populated with wild brook trout from another stream, isn't that the next best thing since the original were extirpated?

In a stream where brook trout were not extirpated, and there was some success from this earlier fry stocking, I'd argue that nature will sort out what genetics is best for that stream at that time. It may include some of the old, and new. Diversity not destroyed.

Streams where there was no success, but later brook trout repopulated by migrating from other streams? Not a whole lot of difference there from the above. Maybe slightly better because they are more local.

I was hoping that pcray would address this, but he didn't so I responded in similar length.;-)