Luca's pic

Recap of July 17, 2007 Electro-Shocking on the Batten Kill - submitted by Doug Lyons (7/2007)

Shocking Results!
On July 17th the Vermont Fish and Wildlife Department under the guidance of fishery biologist conducted the third annual trout population survey of the Twin Rivers Farm section of river, which is located approximately one quarter mile upstream from the junction of the Green River and the Battenkill. The test waters inclued a 313 foot riffle stretch and a 337 foot pool stretch. The goal of the population survey was to compare populations of yearling and older trout within these stretches to past years results. The major difference with this years survey and those of the previous two years is that last fall significant habitat restoration was done in the pool stretch and more modest but still significant habitat restoration was also completed in the riffle section.

Move 'em on out. The shocking team puts in in gear, working upstream.
The riffle section was the first area surveyed and it took very little time for the crew to begin capturing trout adjacent to the new habitat structures. After three passes through this section of river a total of 24 trout of juvenile age and older were collected as well as numerous young of year trout. There were also lots of non trout fish that were shocked but not kept for evaluation but confirms that there are a lot of calories out there for the bigger fish. Two large fish were shocked but did not make it to the collecting buckets so these were not included in the final count. The biggest one was perhaps 16 or so inches long.
So, how do the results compare to 2005 and 2006? The average number of juvenile + trout collected over the last two years was 10 fish. The number of trout collected in the riffle this year was 24 fish. All trout collected were under 10 inches and several were not quite yet at the "catchable" 6 inch length but were indeed yearling trout. As noted, two large fish were not included in the final numbers. The results show that the yearling and older population doubled over the past season.
E-Shocking 2007
Sites and structures holding fish were flagged. 		E-Shocking 2007
More fish-holding structure.
E-Shocking 2007
One of the larger browns shocked up. 		E-Shocking 2007
A sampling of various age groups surveyed.
The amount of available habitat for the trout in this section of river was improved from less than 1 % to approximately 6 % and as mentioned previously most structures that had been introduced held juvenile class fish.
While the results in the riffle were exciting it was the pool section that most of the crew were anxious to get into and find out how the trout population was faring in there. Prior to restoration the restored pool had habitat that equated to approximately 3 % of the wetted area. After the introduction of large woody debris, brush piles and a number of large slate slabs placed in the streambed habitat was improved to approximately 22 % of the wetted area. With this sort of massive habitat restoration in place all were anxious to see if the trout were taking advantage of this excellent fishy structure.

The results were, very simply, outstanding. Over the previous two years the average number of trout sampled was 10 juvenile and older trout - similar to the results of the riffle section. This year, after 4 passes through with electroshocking equipment 50 juvenile age and older trout were collected. As with the riffle stretch several were not quite at the "catchable" size but given another months growth they wil no doubt fall into the "catchable" class. This is a 5 fold increase in the number of trout over the previous two years average. As with the riffle section the trout in the pool were making good use of the new structures. An interesting benefit was that the brush cover added to the sections of river not in the main flow are attracting young of year trout. Young of year baitfish have also been observed using cover.

Teasing out the population that was collected a bit further showed 38 trout up to 9.9 inches, 9 trout from 10 to 17.9 inches and 3 trout between 18 and 21.3 inches. That too is extremely encouraging news as one of the goals of the habitat restoration, particularly in the pool section of river, is to provide more cover for the important "mid size" trout. After less than a year the structures would appear to be doing just that.

It is important to note that before declaring victory it will be necessary to demonstarte positive results such as seen this year over the next two or three years. The hope is that with an a dditional year more trout will be found within the restored area and even more mid sized fish will turn up.

Please note that if you do fish this stretch all trout sampled had their adipose fins clipped off. This is in order to determine what sort of hold over rate is occurring in the years to come. Please do not mark any fish you catch either here or elsewhere on the river - several trout captured in the survey do appear to have been marked by an angler who is probably doing informal checks to see if he or she is catching the same fish over time. If you do catch an adipose clipped trout it is not a stockie migrating up from NY.

Continued work will contine this fall. An additional 1/4 mile of river will be restored with approximately 25 structures.


Many thanks to Chapter VP Doug Lyons who attended the 7/17/07 electro-shocking, took these photos, and submitted this summary. For those of you who don't know him, Doug is one of the most dedicated and hardest working members of the SWVTTU chapter. Without his efforts and unending enthusiam, much good work wouldn't get done on behalf of the Batten Kill and the conservation efforts of the chapter overall.
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