Virginia DWR sample Smith River below Martinsville Dam 10-27-20

Started by Al, November 01, 2020, 18:11:12 PM

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Al

DWR started including the Smith River below the Martinsville Dam in their overall management of the trout fishery about 10 years ago. Samples from the upper river just downstream from the Philpott Dam were turning up more brown trout than the habitat could support i.e., to many fish competing for too little food. For several years hundreds of these 4-8 inch fish were marked and released below the Martinsville Dam. These marked trout joined a small number of larger trout which had successfully made their way downstream through the spillway of the Martinsville Dam.  The water below the MV dam was full of forage which soon created a very promising population of larger brown trout. Annual DWR samples routinely documented a good many 14-16 inch brown trout and several that would exceed 20 inches.

This all changed a few years ago when one of the two main power turbines at the Philpott Powerhouse finally gave up the ghost. Kudos to the Philpott to the COE power technicians because they were able to keep the turbines going for 50 plus years – but this time the damage was beyond repair. With only one turbine working the downstream flows drastically changed.  It now took twice as long to move the same amount of water. The flow itself was also half the cubic feet per second, 7000 vs 1400. The almost constant flow seemed to improve the forage situation in the upper river - samples of both trout and forage in that area actually improved.  However slower flows were allowing the water downstream of the Highway 220 Bridge to warm to the point of stressing the fish. Temperatures downstream of the Martinsville Dam in the summer often approached fish kill levels. Last year DWR samples below Martinsville revealed a declining fishery.

Last year a mudslide at the base of Philpott Dam finished off the remaining turbine with no fix in sight.  Flows are now down to approximately 700cfs unless there is a major rain event.  I accompanied DWR this spring as they sampled the river below Philpott and down through Bassett. From a layman's point of view the trout fishery appears to be thriving all the way to the Highway 220 Bridge. It begins to fade as you move further downstream. What the fishery would look like below Martinsville Dam was not clear until last week.

Virginia DWR fisheries biologists sampled the trout population below the Martinsville Dam on 10-27-20. This is normally a two day affair where the trout holding water is broken up into two sections – (1) Canoe access just below the MV Dam to the Henry County Sports Complex. (2) Sports Complex to the Mitchell Bridge. This year due to time constraints the sample only took place from the MV Dam to the Sports Complex. A small group of Smith River TU members were present.  All participants, to include SRTU members, followed Covid 19 guidelines as much as possible.
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The area directly across from and just downstream of the canoe ramp is normally a good spot to collect some nice fish – I was in a raft behind the sampling raft and did not observe much activity. A few were collected but it was not looking good.
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Our fearless leader, DWR Fisheries Biologist George Palmer – it is always a pleasure to work with this guy. He can make what is often a long backbreaking day seem like fun.
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Once a cooler full of fish are collected we pull over to a relatively shallow spot to process them. It became obvious things had changed because during this first run we passed several spots we normally pulled over but the sampling raft kept going because the cooler was nowhere near full.
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A little clove oil goes in the holding tank to calm the fish down for easier handling.
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Everything gets identified and measured (No weights taken this time).
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Even the shiners, dace, suckers and occasional bass and sunfish get documented.
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It doesn't count if it's not put down on paper – As the head biologist said, "we are all about collecting data".  This data is later entered into a computer program which reveals trends and helps make informed decisions to better manage the fishery.
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We collected some nice brown trout but nowhere near the numbers in years past. Surprisingly, not a whole lot of small browns – some, but not as many as I had expected. One observation on the larger browns was that they appeared skinny – in the past they looked like they had been spending a lot of time at an "all you can eat buffet"
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We passed over a few sections that gave the folks in kayak and canoe a little thrill but no one took on water – no wet clothes today which was a good thing.
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In years past the section between the canoe ramp below Martinsville Dam, downstream to the Sports Complex necessitates 7-9 stops to process fish.  The sample on 10-27-20 took 3. We probably only needed 2 but we wanted to pull over for lunch so made it our 2nd stop.

Loading the heavy sample raft back on the trailer at many of the Smith River canoe ramps is always a challenge – The ramp at the Sports Complex is especially tricky and requires a lot of muscle power. I'd have helped but someone had to take pictures😇
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Now you know why most DWR vehicles have 4WD and a winch.
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troutrus

Thanks for the report Al.
See many Smallmouth Bass?

Woolly Bugger

Thanks Al, if the water every comes down I'll be doing some sampling on my own! Jis sayin
ex - I'm not going to live with you through one more fishing season!
me -There's a season?

Pastor explains icons to my son: you know like the fish symbol on the back of cars.
My son: My dad has two fish on his car and they're both trout!

NCsporksman


Al

Quote from: troutrus on November 01, 2020, 18:40:08 PMThanks for the report Al.
See many Smallmouth Bass?

I think we saw one Smallmouth. The last time we did the Sports Complex to Mitchel Bridge we got several - however not sufficient numbers or size to get excited about.

Woolly Bugger

ya also have to consider that the river was at 1000 CFS this year... don't know what day(s) it was sampled last year but I'll bet it was lower than that..
ex - I'm not going to live with you through one more fishing season!
me -There's a season?

Pastor explains icons to my son: you know like the fish symbol on the back of cars.
My son: My dad has two fish on his car and they're both trout!

streamereater_101691

Quote from: Woolly Bugger on November 02, 2020, 13:32:50 PMya also have to consider that the river was at 1000 CFS this year... don't know what day(s) it was sampled last year but I'll bet it was lower than that..


Speed isn't nearly as important as conductivity. I stuck my hand in the water when the raft was a solid 150ft downstream of me. I could still feel the juice. Point is: even though the water was higher than years past(not by much), the dissolved solids in the water made very good sampling conditions. Most (70% by my guesstimate) of them down there are skinny and pale. No belly at all. The fish zach is holding in the pics never recovered, and it was one of the healthier looking fish!