I have updated the water temperature page under environmental data with the most recent temperature data. Seven temperature data loggers have been in place since May 2012. I added temperature profile graphs for each season such as this one showing summer 2012 temperatures:
Apparently the Mill Neck otters might have an easy feast when a new fish ladder is installed at Beaver Lake. Video courtesy of NBC Connecticut,
Last Friday (5/16) the four tagged wild brook trout were released back where they had been caught. The videos show the release of two of the four. Brian’s doing the releases and Maryanne is doing the camera work. In the first video showing the release of trout #106 (named for the radiotag code), you can actually see the thin wire of the antenna trailing from the fish. Towards the end of the second video, the trout (I think this is #107) darts back to its original release location.
We have been tracking the four for a week. Thus far, unlike the hatchery trout, these guys have generally stayed put. Yesterday I used my GoPro camera o try to locate the whereabouts of a tagged fish once we had pinned down their location using the radiotracking receiver. In the video below you can see on the bottom right two, possibly three, trout hanging out just above the sandy bottom. Presumably one of these trout is #106 located about 30 meters upstream from its release site. At the same time I was filming this, Maryanne saw two more trout a few meters upstream.
Check out any river on Long Island and chances are you will find a series of dams running its length. Thus virtually every river on Long Island has compromised to completely blocked fish passage resulting in the virtual elimination of anadromous fish from our waters. The Shu Swamp/Beaver Lake watershed is impacted by four dams. About the only LI stream I can think of that doesn’t have at least one dam is Alewife Creek in Southamptom, famous for its huge alewife run in March and April, and considered an “ecosystem rarity” by New York Department of Environmental Conservation.
This past fall the Nature Conservancy was awarded Long Island Sound Future Fund money towards fish passage plan development and implementation for three sites in Connecticut and New York. The site in New York is the spillway on Beaver Lake that impedes passage to and from the brackish Mill Creek. The grant provides money to develop plans for a fish ladder and apply for the necessary construction permits. I am a matching partner on the grant, providing data on water levels below the spillway as well as observations on river herring approaching the spillway. This Monday we had a “project kickoff” meeting at the spillway in which the various partners and supporters of the project met with Josh Wilson the engineer from Fuss and O’Neill, the environmental engineering firm contracted by Nature Conservancy. As you can see, there was a pretty good crowd in attendance including Sally Harold of the Nature Conservancy, director of the project, other members of the Nature Conservancy, and representatives from the Town of Mill Neck, New York DEC, North Shore Wildlife Sanctuary, North Shore Land Alliance, USGS, Trout Unlimited, and Friends of the Bay.
It seems like the engineer is leaning towards installing a steeppass ladder, which I think is similar to this one:
The engineer hopes to have a completed “permit-ready” design by August. And assuming funds can be found and the permits are approved in a timely manner, installation may occur as early as next Spring!
So that will solve one big problem for anadromous river herring and brook trout by allowing easier passage through the Oyster Bay estuary up into Shu Swamp. I hope to document an improvement in passage through PIT-tagging studies. But we have one other really big problem. Namely, if you don’t have fish it doesn’t matter how easy it is to pass! For the past three years I have been monitoring the herring spawning runs at the spillway. The previous two years I witnessed at best a handful of alewives attempting to enter the lake (see my post from last May). This year I have yet to see a single alewife. Lifelong residents of the area report seeing hundreds perhaps thousands of alewives entering the lake, and as one person told me “backing up” in Beaver Lake like it was a traffic jam. This occurred in spite of a dam with minimal passage! What happened and how are we going to bring them back? One thought we tossed around was bringing in some spawning alewives from one of the successful runs elsewhere on Long Island. These would be used to “seed” the swamp and lake with babies imprinted to the watershed and likely to return as spawning adults in three years. This strategy may have shown some success when applied at other places such as the Bronx River.
According to Lehman College Professor Joseph Rachelin featured in the video, adult progeny of the spawning alewives released into the Bronx River in 2006 returned in 2009 indicating success. However, Queens College Professor John Waldman, reports in his excellent book, Running Silver, that the returning alewives were too old to have been progeny of the 2006 spawning alewives and were more likely native alewives, which is quite a suprise since everyone thought they had been eradicated long ago.
I think a big step forward was taken this week at Beaver Lake. Improving fish passage has been kicked around for a long time but finally people are acting. Given the amount of collaborative interest I am optimistic.
The plan yesterday was to test the swimming performance of the 4 wild brook trout we caught electrofishing. The reason we want to do this is based on the results we are getting from our radiotelemetry studies on hatchery trout released into Shu Swamp. We see a lot of downstream movement right after release. We believe that one factor that may influence movement patterns of hatchery trout released is that they are not in top physical condition. We notice a lot of fin damage due to the high density conditions in the hatchery.
Furthermore hatchery fish may not get all that much exercise since the flow rates in the hatchery are much lower than they are in a stream. To test this we determine the water speed necessary to cause swimming fatigue (called critical swim velocity). In the lab this is done by placing the fish in a special swim tank similar to an Endless Pool” for people. The fish swim upstream against the flow and the flow can be gradually increased until fatigue is observed. This video, using a juvenile brook trout, shows what should happen. Fatigue occurs when the fish rests its tail against the downstream grid and stops swimming.
Unfortunately when we tried to determine swim performance in the wild trout, they would not cooperate. They just rested against the downstream grid even at very low speeds. We tried a number of approaches to get them to swim but to no avail. The fish we are using are pretty big – 8 to 10″. On the other hand there has been no problem testing swim performance in smaller 5-6″ fish. For now it’s back to the drawing board.
After giving up for now on swim performance tests, we moved on to tagging. In short order Brian had radiotagged the 4 fish and they were groggily recovering in their temporary holding tanks. Each fish received a PIT tag (if it didn’t have one already) and a radiotag. In the figure on the right you can see the incision in the abdominal cavity where the tag is implanted. The antenna leaves the body through a small puncture above 2 inches posterior to the incision. The trout will be released today. These tags should last about 160-180 days. They emit a individually coded radio pulse once every 20 sec. To extend the battery life we have the tag active for 12 hours during daylight.
You can find more about the tagging procedure at the Tracking Trout link.
Over the next three days, we are catching, radio-tagging and releasing wild brook trout living in Shu Swamp. The plan is to compare their movements and habitat preferences to the hatchery-reared brook trout. The tags we are using can last 5 – 6 months so we may even see evidence of spawning if we are really lucky. Over the summer we hope to tag and release 10 wild trout. We just received our first batch of 5 tags and today we set out to catch 5 wild trout to take back to the Hofstra Animal Lab for a short stay: swim performance tests, tagging and then release, all within the next 48 hours. Sounds like a fun weekend at the health spa doesn’t it?
Maryanne, Brian, and I met up with Steve DeSimone, CSHFH director and operator of the backpack electrofisher you see here.
We immediately startied catching fish. The problem was they were the hatchery fish we released last month. We knew because we checked them with our portable PIT-tag reader which allowed us to identify each individual. All in all we caught and released six of the 28 we had released. Three of these had been detected before at the PIT-tag antenna downstream at the railroad bridge entering Beaver Lake, and one had been detected at the spillway antenna a mile away just 5 days ago!
Fortunately things started to pick up. All in all we managed to catch 4 wild trout, one short of our goal, before we ran out of stream to fish (we reached Frost Mill Road Dam). Three of the trout had PIT-tags attached at the previous electrofishing event back in early March and one was newbie.
Along the way we also caught some other critters including some spiny-cheeked crayfish:
And a few YOY brook trout including this beauty (be sure to compare its size to the one shown at the March survey link.
We lso had a surprise visit from about 30 students from Pasadena Elementary School in Plainview who were there to release the fingerlings they had raised through the TITC program. They got to see the brook trout we had caught as well as the crayfish featured above. The adults we had caught might very well have had their origin a few years ago in a Long Island TITC classroom maybe even their own! I think they were really excited to think that maybe their “babies” might one day reach adulthood in its native habitat. As part of the TITC experience, participating classrooms visit CSHFH in November to learn about brook trout and see the egg fertilization process. Their visit was featured on Long Island News .
The four “keepers” were transported in coolers and now reside in the animal facility at Hofstra. Here is one that is about 10″ and a 1/2 pound:
Tomorrow they all go for a swim and a quick surgical procedure. Stay tuned!
I was finishing up taking photos of three reaches that LITU surveyed last Sunday and at one of them I came across a small group of 4 or so fingerlings hanging out under an undercut bank in a reach we sampled: SW Branch #1 (You can see its location and characteristics at this link). Most of the reach is very shallow (maybe a couple of inches) except for this one spot scouring into the bank which is about 6-8 inches. I had my GoPro camera with me so I took some video.
This section of the reach is no more than 6 foot wide. The undercut is at the apex of a bend. To the right you can see a sand bar. There is a step drop off after that as the water scours out the bank. Look for these features in this three minute video.
I don’t know whether this is offspring of resident trout or Trout-in-the-Classroom releases. The site of TITC releases is just downstream from this spot and the last release was only about two weeks ago. Either way these guys are looking good!
I have published the recently completed SVAP’s for Beaver Brook here. It also can be accessed through the environmental data tab on the menu bar for the website.
The data is displayed on a map of Beaver Brook color-coded by rating level for each stream feature using ArcGIS Online. It’s fully interactive and, I hope, gives a good snapshot of present stream conditions.
This Sunday 16 volunteers, mostly fmembers of Long Island Trout Unlimited, completed 10 Stream Visual Assessment Protocols (SVAP) on Shu Swamp. This completes the SVAP surveys of Shu Swamp, bringing our total number of SVAPs to 15, 5 on the main stream, Beaver Brook, four on the main east tributary into Beaver Brook, and three each on the the main west tributaries.
As described in the Environmental Data link, an SVAP
is a procedure designed for community groups to conduct a simple assessment of stream quality. The protocol includes assessments of stream geomorphology (e.g., how natural the channel is, absence of dams, stream bank stability), characteristics of stream specifically relevant to fish (e.g., hiding places in stream, vegetation canopy, barriers to fish passage), water quality (e.g., evidence of nutrient enrichment, optimal temperature range), and characteristics of stream relevant to the invertebrate food of fish (e.g., available habitats for invertebrates, types of invertebrates). Each characteristic is scored on a scale of 1-10 (usually). An average score is determined with the higher the score the better the stream assessment.
We now have a pretty good first pass on stream quality throughout the system. More extensive and quantitative surveys (called Focused Reconnaissance Assessment Protocols (FRAP), and Detailed Assessment Protocol (DAP)) can focus areas of specific concern. In future posts I will detail the more interesting findings of our SVAPs, (with color-coded maps!). One thing I can say now as a first impression. Sand is really accumulating in the lower reaches of the main stream, particularly after that last rain event in late April. It looks like the main source of the sand is the scouring taking place on the northwest tributary that runs parallel to Dogwood Lane and empties into the main stream just south of the concrete bridge.
And as usual, Shu Swamp flora and fauna never cease to delight: