Category Archives: Beaver Lake Dam Antenna

Winter at Beaver Lake

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Winter is almost over and we are getting ready for a new season of tagging and tracking. We kept the Beaver Lake spillway antenna going through the winter largely running on its solar panel (which recharged marine batteries so it could run through the night). There hasn’t been a detection since early November. These are the same results we got last winter – no detections in the winter. These are some pictures I took in late January after one of our many snowfalls.  As you can see from the slideshow, snow and solar panels are not a good combination. The lake has been frozen since mid January and still remains so.  Lots of geese collected below the spillway as this one of the few spots that wasn’t frozen. In the midst of that crowd are some orange-collared geese from Canada. The same Canucks were here last winter too.



PIT-Tag Update

I have just completed an update of the PIT-tag releases thus far. You can download and see the results here: PIT-tagged trout data.

We have released 174 PIT-tagged trout since last summer. 65 of these have been detected at the Shu Swamp RR antenna and 10 at the Beaver Lake dam antenna. It looks like there is more dispersal when temperatures are cooler. In fact none of the 10 detected at the dam antenna were detected in summer months. So far there is no evidence of any kind of “migratory anadromous” movement as most of what we observe are detections soon after release.

We plan on releasing another 50 or 60 trout to complete the study.


The Further Adventures of LITU’s #101 and #102

The view upstream along Beaver Brook in April

The view upstream along Beaver Brook in April

April flower in Shu Swamp

April flower in Shu Swamp

Trout lilly

Trout lilly

Shu Swamp is in its peak spring growth right now. Lots of trout lilies, swamp cabbage and sundry other plants.

Both of the mature trout we tagged on April 10 are still trackable. Both 101 and 102 moved .6 miles downstream from their release point to the pond. We have PIT-tag detections of 102 at the railroad bridge antenna just 7 hours after release. We radiotracked 101 to the pond on April 12. We have further PIT-tag detections of 102 until 1:30 pm April 13. At that time it must have entered the lake and eventually swam at least 1/3 mile (straight line distance) to the east bank of Beaver Lake. Using a canoe we radiotracked it to this point on 4/20 and again on 4/27.

Brian and Maryanne on the RV Brook Trout as we search for #102 in Beaver Lake.

Brian and Maryanne on the RV Brook Trout as we search for #102 in Beaver Lake.

Meanwhile 101 has been on a ramble. According to radiotracking and PIT-tag detections it remained in the vicinity of the railroad bridge until 10:47 am 4/16. On 4/18 4:38 am it was detected at the Beaver Lake dam antenna (.57 miles straightline) and then turned around and was detected back at the railroad bridge antenna 13 hours later. One week later we radiotracked it .8 miles upstream in Beaver Brook where it has stayed as of the latest tracking survey (April 30). It’s current location is well upstream of the original release point.

In summary, 101 has moved a minimum of 1 mile and 102 has moved at least 2.6 miles over the past 3 weeks. You can check out it’s locations in this map:

View Larger Map

More PIT-tag results; Radio-tracking begins again

2013-04-09 17.51.30

Radio-tagged trout. You can see the antenna trailing underneath.

This is the one of two mature trout that Brian Bartlett radiotagged (thanks again Long Island TU for the donation!) and he and Maryanne Grey released into Shu Swamp yesterday to kick off the radiotracking season. They released them well upstream so hopefully they will stay within Beaver Brook and not end up in the lake. Just in case, we also have them PIT-tagged so we will know if they exit the swamp. These tags should last around 5 months.

Speaking of PIT-tags, we released another 19 PIT-tagged mature fish into Shu Swamp on April 10. As of April 14 all 19 were detected at the Railroad Bridge antenna and 5 were detected at the dam antenna. This brings to 10 the number of tagged trout released in Shu Swamp this spring (a total of 35) that have been detected at the dam. Much different results than the mere 2 detected last summer and fall out of 95 releases!

More PIT-tagged trout released and more detections at dam

We released another 19 PIT-tagged 8-9″ brook trout yesterday, bringing the total released this spring to 35. Meanwhile we checked the activity at both of our antennae. The Shu Swamp railroad bridge antenna detected three of 16 released two weeks ago. All of these had been detected previously. Nine of the 16 have been detected at this antenna so far (no change from last week). At the Beaver Lake dam antenna we had three trout detected, two of which had not been previously detected. Thus 4 of the 16 have been detected at the dam since their release. This is interesting because for the 95 releases last year only two were detected at the dam.

Here is a summary of their movements thus far. R=release; SS= detection at SS railroad bridge; BL=detection at dam.

Tag # 3/21 3/22 3/24 3/25 3/26 3/27 3/28 3/29 3/30 3/31 4/1 4/2 4/3
189 R>SS>BL BL                   BL  
216 R>SS BL                      
243 R>SS                   BL SS  
171 R>SS         SS         SS   BL

All four of these trout were detected at the SS antenna on the same day of release. 189 appears to be hanging out in the lake. At least one trout, 243 clearly didn’t exit over the dam since it is detected later at the SS antenna.

Latest PIT-Tag Release (UPDATE)

Last Thursday (3/21/2013) Brian and Maryanne released 16 PIT-tagged trout (8-9 inches) in Shu Swamp. Today I changed batteries and uploaded data from the two antennae. At Shu Swamp 9 of the 16 fish were detected, 8 in the first 12 hours after release. In the past the proportion has been more like 30-35%. Perhaps this is because of the cold water temperatures (about 7 C). Two trout were detected at the Beaver Lake antenna within about 24 hours of release. This brings to 4 detected at the dam of the 100 released thus far. And all of these are detected within 24 hours after release.

UPDATE (3/28/2013): I have observed a lot of osprey activity in Beaver Lake. While I was there yesterday I saw an osprey catch a fish. I couldn’t tell whether it was a trout or not. The water depth in the lake is one a couple of feet so any fish out in the open is going to be in a lot of trouble. I imagine that the lake represents a formidable obstacle to a migrating fish, whether trout or alewife.

While I was at the Shu Swamp antenna I had this visitor who was very curious about my activities:Swan at the Railroad Bridge

Fortunately it is isn’t nesting season yet.

Tide Gauges and Run-ins with the Law

My graduate student, Maryanne, and I visited the Beaver Lake Dam antenna today. Fortunately most of the snowfall had melted away so we were able to access the box with the data logger without too much shoveling.

We also installed a simple tide gauge. We would like to know when high tide reaches the dam and also try to calibrate tidal heights with a nearby tidal gauge (King’s Point). Whenever a tagged alewife is detected Maryanne will know based on the time what the tide height is relative to the top of the dam.

We had a little drama though. First one of Brookville’s finest decided that we can’t park where we have been parking for almost year now. He was nice about it but we will have to make other arrangements I guess. Second while we were picking up the car to leave some guy stopped his truck next to the discharged batteries and looked like he was about to pick them up! Fortunately, Maryann scared him away.

Alewives and Beaver Brook

Some members of the Diadromous Fish Working Group visited Shu Swamp to check out the area. Here we are shivering at the Cleft Road Bridge:

Alewife group 1

And here’s the spillway with antenna on this icy day:

Beaver Lake Dam Antenna with Ice

This spring mature alewives were observed trying to make it over the dam. This fall we observed young-of-year alewives shoaling in the pond just south of LIRR. There is a lot of interest in opening up more spawning areas to alewives so this looks promising. Of course the dam may be acting as a significant barrier (although apparently some are getting through). We want to see just how many are so we are going to PIT-tag arriving alewives this spring and see whether they make it into the lake.

North of Mill Creek you can see a bunch of Canada Geese resting on the ice. Four of these geese have orange collar tags around their necks. They are from Canada! Imagine that, real Canadian Canada Geese!

Geese in Mill Creek