Hatchery pollution

[LouM]

A question for Mike Kaufman. Could the trout hatchery on the Little Le High be the reason for the rapid decline in the trout population in the creek. Some of us who fish there were wondering if there could be a connection like Spring Creek.

 

[Chaz]

Could be, I think more likely it's floods.

 

[Bamboozle]

Is there a verified, (as in PFBC survey) decline in fish numbers or perceived, (as in fisherman skunkings) decline because my first guess would be the lack of hatchery escapees is the reason for the decline.

Back in the day so many fish escaped that there were TOO many fish in Section 8. Ever since that problem was resolved my catch rates plummeted, however I was always told there was a Class A biomass in Section 8 so I chalked my failures up to incompetence.

BTW - What ever happened to the plans to add Section 8 to the Class A list?

 

[mikesl]

In my limited experience, of fishing the LL several times per year, I had much more success catching wild browns in the LL 2-3 years ago than this past year. In the same spots, just above the FFO, in the FFO, and down in the ATW.

 

[LouM]

Chaz; I don't think its the flooding as much as the hatchery or the amount of water that is being taken from the creek. The sulfur and BWO hatches are poor at best. The creek is in
trouble and nobody is looking after it, all parks and rec cares about is non fishing activities. When the city is asked about doing stream improvements, their reply too much red tape.

 

[JeffK]

IMHO, the Little Lehigh has bigger issues than the hatchery, which has been there 100 years +. I don't know if any hatchery changes recently have made the situation worse. New food? Medications or drugs?

However, I don't think the hatchery should get a pass either. I do a lot of macro-invertebrate sampling below the NJ trout hatchery on the Pequest and the bugs are definitely degraded below the hatchery outflow. Lots of midges, planaria worms, and horse or deer fly larvae. Few mayflies and no stoneflies. Comparable stretches of local trout rivers are loaded with golden stones.

Unfortunately, we have seen a drop in sulphurs and hendricksons over here that troubles me. The stock answer is siltation of the gravel bottomed riffles that the ephemerella species prefer, and I do see the drought/flood yo-yo of late adding silt to the riffles. I still have an uncomfortable feel about it though.

 

[troutbert]

Has the hatchery changed its operations?

If not, you can't attribute changes in the wild trout population to the hatchery.

You have to look at things that CHANGED, that might have affected trout populations.

Changes cannot be attributed to things that have remained the same.

Has the physical habitat changed?

Water quality? Quantity? Siltation?

 

[troutbert]

In the OP it was suggested that hatchery pollution reduced trout populations on Spring Creek.

I don't think that is the case. I don't think that any studies, or observations on the creek support that.

The studies indicated a reduction in invertebrate diversity below the hatchery discharge. And you could see that by flipping some rocks. That is not surprising, and is typical of organic enrichment. There were loads of sowbugs, so plenty of food, and the wild trout were plentiful.

 

[Bamboozle]

Can we blame it on increased siltation and/or destruction of invertebrate habitat due to the lifting of the NO WADING regs about 6 or 7 years ago?

Just sayin' but having folks walking were no man walked before has to have had some effect...at least in Section 8 & 9.

 

[johnw]

I agree that lack of hatchery escapees is most likely the biggest reason for the decline in catch rates in the LL. One thing I have noticed in the past few years is a noticeable increase in my catch rate of rainbows and a corresponding drop in catches of Browns. Can't explain it but I don't think it's a good sign.

 

[CLSports]

I would agree that the rainbow population was up last year. I caught many more rainbows in sections that I usually catch way more wild browns. They gorge themselves on the Tricos in a different manner than a brown will and I know what the fish will be even before I hook it. There is a trout derby below the Heritage section, I think every year, and maybe they dumped more bows in this year?

I also have noticed a TON more silt in areas that used to be scoured out, but now are flat glides of fine silt bottom. Since I fish that stream quite often in the summer during the Trico hatch I notice the changes over the years. Even though they have extended the riparian buffers in the lower park section, it does not seem to be helping the siltation issues. The amount and frequency of the flooding over a given year affects the silt buildup.

 

[sarce]

Has the upstream watershed seen new development? That will cause the silt problem, and treating it requires action at the source.

 

[Chaz]

Bamboozle wrote:
Can we blame it on increased siltation and/or destruction of invertebrate habitat due to the lifting of the NO WADING regs about 6 or 7 years ago?

Just sayin' but having folks walking were no man walked before has to have had some effect...at least in Section 8 & 9.

I would say no, that wading isn't a factor. There is a marked decrease in bugs since I started fishing the LL, in the late 80's. I'd say there's been a gradual drop in the bigger mayflies than any other bugs. We used to fish the sulphur hatch until the spinners stopped dropping and would be catching fish until 10:30 or so.
That isn't the case anymore. You're luck now to even see fish let alone catch them. It seems like it's the entire stream not just the heritage section. There was a 3 mile or so stretch that held a Est. Pop. of 160 Kg/ht until about 2010. I don't think you can find a Class A population now. That's a big change. There is a T U Chapter there, but they've never been really active.
Flooding and development of the upper watershed are the most like suspects.