Road salt

[edhank]

Fished a new stream yesterday and it was absolutely gorgeous.there were fish caught, but not a lot and nothing with any size for a native brook trout stream. This little stream is near a very major roadway and the roadway gets to see a lot of salt. What effect does road salt have on streams? I know it can't be good.

 

[BrookieChaser]

I was curious about the same thing regarding road salt and calcium. I have yet to see any studies.

I know what it does to vehicles, and I absolutely detest it.

 

[Maurice]

Trout are anadromous fish and in a hatchery environment salt is actually applied as a surfactant for stress during high mudddy water periods. So salt ain't hurting the trouts. Unless it's an overdose..now the macros and crustaceans, that's another story. Them buggers crawl outta the raceway when the salt comes in.

 

[ryanh]

Muddy water + salt= siltation. That is why deltas form in the ocean. I don't think the chlorides are that bad in the runoff however. We would see that on usgs stream gauges as TDS or conductivity. I had this very conversation with US Fish and wildlife when they were studying the French creek drainage several years past.

 

[edhank]

Maurice wrote:
Trout are anadromous fish and in a hatchery environment salt is actually applied as a surfactant for stress during high mudddy water periods. So salt ain't hurting the trouts. Unless it's an overdose..now the macros and crustaceans, that's another story. Them buggers crawl outta the raceway when the salt comes in.

Turning some stones, I saw very few macros.

 

[3oh4]

I know that if you drive on I-68 from Cumberland to Friendsville, if you look up at the trees half of them never grow leaves on the side facing the road because the unreal amount of salt used on the roads in that area.

Deep Creek Lake area gets more snow than Anchorage, Alaska annually. Your PA-Fly Fish Fact of the Day!

 

[salmonoid]

Not a published study yet (that I'm aware of) and more of a PR news piece, but I meant to post this up in the Conservation forum when I saw it but never got around to it.

Rock salt research at PSU Behrend

I tend to minimize the affects of road salt on the fish - it's a temporary blip that gets flushed away during snow melt. But if residuals remain in sediment and affect macros, that's an angle I had not considered.

 

[jifigz]

ryanh wrote:
Muddy water + salt= siltation. That is why deltas form in the ocean. I don't think the chlorides are that bad in the runoff however. We would see that on usgs stream gauges as TDS or conductivity. I had this very conversation with US Fish and wildlife when they were studying the French creek drainage several years past.

How does salt ramp up siltation? Muddy water is easy to understand because it's muddy because of all the fine debris in suspension, aka silt.

 

[FarmerDave]

jifigz wrote:

ryanh wrote:
Muddy water + salt= siltation. That is why deltas form in the ocean. I don't think the chlorides are that bad in the runoff however. We would see that on usgs stream gauges as TDS or conductivity. I had this very conversation with US Fish and wildlife when they were studying the French creek drainage several years past.

How does salt ramp up siltation? Muddy water is easy to understand because it's muddy because of all the fine debris in suspension, aka silt.

What ryanh said is true in theory. Salt acts as a flocculant which causing fine particulates to drop out of solution much faster.

That said, I seriously doubt road salt has much effect on this in a typical stream.

1. I'd guess that salinity levels never get high enough to have much effect on a typical stream, and on the rare occasion that it might, it would be very short lived.
2. The constant mixing in a flowing stream probably prevents a concentration front (layer of separation) from forming.

I'm not a chemist, so I could be wrong on this.

 

[pcray1231]

Agree with FD. Roads have other issues, though. If dirt, then mud/silt runoff. If paved, then thermal runoff (rain hits hot pavement, goes down storm drain, directly to stream without cooling first). Also, if the roadbed is deep, it often interrupts near surface springs.

 

[FarmerDave]

pcray1231 wrote:
Agree with FD.

Oh come on. You couldn't find anything to argue about in that?

Is it because I made it a short response?

Or was it that obvious that I looked it up?

 

[pcray1231]

Nope, sorry. I doubt road salt makes much more than a blip on salinity in the water.

 

[pete41]

FarmerDave wrote:

pcray1231 wrote:
Agree with FD.

Oh come on. You couldn't find anything to argue about in that?

Is it because I made it a short response?

Or was it that obvious that I looked it up?

[Or was it that obvious that I looked it up?]

really-never would have guessed-
actually very impressed many times how skilled you are at that-saves me hours -lol

 

[FarmerDave]

pete41 wrote:

really-never would have guessed-
actually very impressed many times how skilled you are at that-saves me hours -lol

Actually I did know that salt acts as a flocculant, but I double checked just to make sure. That is where I found the term "concentration front." ;-)

 

[Hook_Jaw]

Dave please don't try to keep up on the big word saying like pcray.