Public Lab Research note

Yellow Bar Island - Dredge Reuse and FAA permitting

by gwirth | July 23, 2012 11:03 23 Jul 11:03 | #2930 | #2930

The Dredge Research Collaborative and Public Laboratory (Gena Wirth and Rob Holmes) visited Yellow Bar Island in Jamaica Bay in mid-July to document progress on the Army Corps of Engineers project that aims to restore eroding salt marsh habitat with recycled dredge material.

Visible in these images is the flat expanse of newly constructed ground, composed of clean sand dredged from the Ambrose Channel, the main shipping channel leading to the port of NY/NJ.

Salt Marsh Cordgrass, (likely Spartina patens) is seen here in pixellated form, as small, approx 2'-5' diameter hummocks of preexisting marsh. These green clumps are a complex marsh matrix of sediment, Spartina, and ribbed mussel, which in a functional ecosystem colonize the base of the cordgrass and stabilize the marshland. Past the dotted fringe of cordgrass clumps is the expansive island interior, touched in a more economical fashion with a grid of fences marking Spartina plug planting zones. We speculate that the fence grid acts as a goose deterrent, preventing flocks from landing and feasting on the newly planted plugs.

Also pictured at left is the constructed island-on-a-constructed-island used by the Army Corps for material and equipment storage, located just above the high tide line.

More info at : and

Look for geolocated updates soon with historic marsh underlays. At the moment we're struggling with the fact that this island is literally "off the map" but looking for survey information to use for alignment.

An FAA permit/ waiver was required to balloon map in this zone, as the area was within 5 miles of JFK Airport (approx 2 mi west). We submitted FAA permit 7711-2 to the NY FSDO Assistant Principal Operations Inspector Bruce Limpitlaw at the NYFSDO. Prior to submitting the form we had to receive verbal confirmation from Kennedy Tower that the balloon flight at the specified diameter and proposed height (5', 300' max) would not be a problem. Kennedy Tower complied and the FSDO was able to approve the waiver, allowing us to issue the notice to airmen per Public Laboratory's instructions. It is recommended that this process begin at least 5 days in advance of any trips.



Cool Gina!

You'd asked a few questions on the list about georectifying imagery that has previous aerial reference imagery . Consider using ground control points on your next outing.

Some ground control point strategies:

You can print coded ground control points, so they can each be differentiated, although on the water paper targets might be a problem.

You can also try making coded ground control points with long "hotdog" style balloons used for making balloon animals. I think this is the most fun option, and the most likely to work in a wetland.

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Oh, great idea Mathew, thanks! While it doesn't help with the set we've got we are planning on a repeat trip. Amazing.

We've also got a good high/tide low tide condition so maybe both strategies would work.

thanks again,


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This is very cool. i love all the creeks that are incorporated into the design. in Louisiana, the sediment is so muddy that containment is usually necessary, which limits the restoration and the design options.

do you have lat long, so people can see what happened post-Sandy? I suspect that NOAA captured the change on their DHS response overflight:

Is this a question? Click here to post it to the Questions page.

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Thanks, Eustatic -- we're hoping to make a return trip soon to get some clearer images of the island. The link you sent is hepful, thanks.

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yellow bar post sandy

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Amazing! I don't have lat-long at my fingertips, but will post for you. Thanks for the link.

In the meantime, check out:

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Gina, i don't know if you saw, but over 7k people have read your post... it's currently the 2nd most popular post on the PublicLab site!

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Woah, amazing! I had no idea, thanks for the heads up. More dredge related work coming soon!

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