Raritan river fish ladder numbers:

[AndyS]

Got to attend a meeting. Why are the American Shad numbers dropping like a rock ?? Hope to get the numbers on trout and SMB and LMB soon also.

[Dave B.]

Some depressing shad numbers there Andy! My first thoughts lean towards the impact our recent fairly dry springs may have had. As you know the shad prefer/require a fairly substantial flow volume and depth to make their move upriver from the estuary. In light of the sub-standard spring flows we've had the past many years running that would be my first speculation. The herring don't require quite as much depth and volume so they wouldn't see the same decline in numbers as the shad, which the data seems to reflect. Hopefully I'm on the right track with this speculation as I would very much hate to find out that some manmade environmental hazard was to blame! Please keep us posted as the info becomes available to you!

[shucker]

The correct answer here is fisheries science sucks..always has and always will. We continue to make restrictions,accusations,and allot of finger pointing based of flawed data.

[FASTEDDIE29]

Where are the numbers for 2017? There were more Shad caught on the Raritan this year than any other year I’ve been fishing it! The best run of Shad happened this year, 2017! Plenty of water this past spring. Those American Shad flew up
to Dukes at light speed!

[Jigman13]

They do a count on esox and any other species?

[thmyorke1]

Where are the numbers for 2017? There were more Shad caught on the Raritan this year than any other year I’ve been fishing it! The best run of Shad happened this year, 2017! Plenty of water this past spring. Those American Shad flew up
to Dukes at light speed!

I support that claim. And the water heights for spring time match up perfectly with the shad numbers

2013, the year with the most shad complimented by a steady amount of above 6-foot flows, also some good late spring flows
https://i.imgur.com/gWR6NJf.png


2016, the worst year in terms of shad numbers complimented by worse flows. Compare late spring's 2013 with this one.
https://i.imgur.com/1RjuH2f.png



2017, booming water flows around April.
https://i.imgur.com/F5VK2Rj.png


I expect 2017's shad numbers to be better than 2013.

[AndyS]

Yes American Shad do rely on one thing, WATER !! Dismal spring rains do play a large part on migration on the Raritan river as it is a very wide and for the most part a shallow river.
Graphs and charts were also presented showing the comparison between fish movement and water gauge height.
Could be a while for trout and bass numbers and they are still working on 2017 fish counts.

[Billfish715]

The correct answer here is fisheries science sucks..always has and always will. We continue to make restrictions,accusations,and allot of finger pointing based of flawed data.

Surveys, reports, conclusions, scientific studies, whatever...........there is always something omitted from the data which, if included, would change the results. In this case, we are led to believe that there is something severely affecting the migration of American shad. What variables were included in the study? Was the water flow, or water temperature, or turbidity, or PH, etc, etc, etc. considered?

So the results of the tagging and tracking are in. Now what? I know! How about another scientific study? What have we learned from the first study? How that information will be used is the bigger question. Does anyone know the answer? I think we need a survey.

[AndyS]

Actually you are correct, we could STUDY this fish ladder for another 20 years or so and still draw no substantial conclusions.
Look at the data so far: New Jersey Freshwater Fisheries started doing a fish count on the ladder back in 1996 !!! Here we are in 2017 AND still doing fish counts etc. on the same fish ladder, some 20 YEARS LATER !!
Fish have now become a matter of "science" more than anything else and with additional "funding" the research will continue.

[AndyS]

The Lawrence Brook Watershed Partnership (LBWP) led the project’s initiation, public meetings, outreach, development of partners, review of the technical report, advisory to the study, volunteer monitoring, and overall management of the project. Princeton Hydro LLC was engaged as a contractor to undertake the technical study. The details of the partial feasibility study are described in more detail below.
A Start-Up Meeting was arranged for Monday, October 15th, 2012, at 11:30AM, at the New Brunswick Water Facility in Burnett Street, New Brunswick. Stakeholders were invited. Fourteen people attended, including five from the City of New Brunswick, Fish & Wildlife, Riverkeeper, two from E.J. Bloustein School of Planning & Public Policy, Middlesex County Planning, Princeton Hydro, and three from LBWP. An overview of the project was given by LBWP’s Alan Godber, New Brunswick City Administrator Tom Loughlin discussed the impact on the New Brunswick Water Supply, Laura Wildman of Princeton Hydro outlined the project. A field trip was taken to inspect the dams and the surrounding area for the impact of the fish ladders and site observations were reviewed.

[AndyS]

Fish Ladder Feasibility Study 2011-2013
Grant from NY-NJ Harbor Estuary Program
Report August 26th, 2013
The Lawrence Brook, a tributary of the Raritan River in New Jersey, is impounded currently by multiple dams, preventing upstream passage for fish. Following an educational presentation about the serious depletion of herring and other Atlantic fish the Lawrence Brook Watershed Partnership applied to the NY-NJ Harbor Estuary Program (NY-NJ HEP) and was awarded a grant of $47,000 for a partial feasibility study for fish ladders around the lowest two dams on the Lawrence Brook, the Westons Mill Dam and the Westons Arch Dam. A large range of stakeholders in the area were made aware of the project and invited to participate. If successful, the installation of fish ladders at these locations would add three miles of unobstructed stream habitat for migratory fish. Species that have been seen at the base of the dame include blueback herring and alewife. The dams cannot be taken out, as the Brook is a drinking water supply and has been so since the 1860’s. A private company owned it for the first for 10 years; then the City of New Brunswick took it over. The water supply is needed for the future to supply three local communities of approximately 100,000 population, along with the Delaware-RaritanCanal.

[Dave B.]

The correct answer here is fisheries science sucks..always has and always will. We continue to make restrictions,accusations,and allot of finger pointing based of flawed data.

It's sad to say but you're absolutely correct, particularly with regards to salt water species!! Freshwater data collection certainly has its drawbacks and shortcomings but compared to what NOAA and the ASMFC use to restrict our fluke, striper, sea bass, tog and so on quotas they make the freshwater biologists look like absolute rocket scientists.

[Billfish715]

Yes American Shad do rely on one thing, WATER !! Dismal spring rains do play a large part on migration on the Raritan river as it is a very wide and for the most part a shallow river..

The depth of the Raritan can definitely be a limiting factor in large, sustainable, anadromous populations. What the studies should conclude is the Raritan is a beautiful river with great potential for recreational use along with having a diverse fish population.

The posts on this site actually give the public more information about the river and the fish that live in it. NJF conducts its own survey with information provided to fishermen directly without any state or federal funding. Does anyone want information about the fish in the Raritan? Just post your question on this site and get an answer immediately without the results of someone's scientific study!

[Jigman13]

The depth of the Raritan can definitely be a limiting factor in large, sustainable, anadromous populations. What the studies should conclude is the Raritan is a beautiful river with great potential for recreational use along with having a diverse fish population.

The posts on this site actually give the public more information about the river and the fish that live in it. NJF conducts its own survey with information provided to fishermen directly without any state or federal funding. Does anyone want information about the fish in the Raritan? Just post your question on this site and get an answer immediately without the results of someone's scientific study!

Valid point.

[Eskimo]

.

Fish and Wildlife should hire Thmyorke1 to cross reference data to make sense of individual points of data.

I guess river systems are an example of "irreducible complexity" where no one piece of data can be comprehended without understanding how it fits into the bigger picture of innumerable environmental conditions and circumstances that make up the South Branch of the Raritan River.




.

[Mark B.]

In the Raritan River the American shad favored migrating during relatively low water flow (250 – 1,500 cfs, Figure 4). Studies on the Delaware River, too, have shown that major shad passage events generally occurred at times of relatively low discharge, especially, when flows were waning following periods of elevated water levels. The trigger flow for the major shad passage events on the Delaware River was approximately 30,000 cfs (personal communication Eric Guilfoos BWEC / PACE Environmental Services). On the Raritan River the trigger flow appeared to be approximately 500 cfs. Unfortunately, high turbidity associated with higher flows made it more difficult to see the fish in the video on those days. So, it is not implausible that shad may have passed by the viewing window undetected. Additionally, at higher flow rates shad can swim over the weir, thus avoiding the ladder all together.

Have you ever read this http://raritan.rutgers.edu/wp-content/uploads/2015/10/NJDEP-2013-American-shad-restoration-in-the-raritan-river.pdf ?

From which the above is excerpted.

[thmyorke1]

In the Raritan River the American shad favored migrating during relatively low water flow (250 – 1,500 cfs, Figure 4). Studies on the Delaware River, too, have shown that major shad passage events generally occurred at times of relatively low discharge, especially, when flows were waning following periods of elevated water levels. The trigger flow for the major shad passage events on the Delaware River was approximately 30,000 cfs (personal communication Eric Guilfoos BWEC / PACE Environmental Services). On the Raritan River the trigger flow appeared to be approximately 500 cfs. Unfortunately, high turbidity associated with higher flows made it more difficult to see the fish in the video on those days. So, it is not implausible that shad may have passed by the viewing window undetected. Additionally, at higher flow rates shad can swim over the weir, thus avoiding the ladder all together.

Have you ever read this http://raritan.rutgers.edu/wp-content/uploads/2015/10/NJDEP-2013-American-shad-restoration-in-the-raritan-river.pdf ?

From which the above is excerpted.

Thanks for sharing, Mark. That's actually some interesting info that more shad are counted at 500 cfs.

Comparing the discharge graphs to the gauge height graphs 500 is just a few inches above the normal flow for the Raritan.

I've seen spots on the Raritan where it would seem difficult for shad to swim up at normal flow. Yet I can't speak for the shad, it's up to them to determine whether they can swim up these spots or not.

Maybe they prefer the ladder when it's low flow? And at high flow they don't bother swimming up it? Perhaps the ladder's design is to turbulent for them at above average flows?

Or it's just the case you mentioned; can't count anything if you can't see in the murky water.

Perhaps the ladder-cam could use x-ray or something to see through the murky water.