Spartina or Phragmites, that is the question. Sand that has accumulated on the south side of the new jetty on the south side of Amherst Inlet has reached the very end of that jetty. As you are reading this, the sand is now spilling over into the inlet itself and is accumulating on the south side of the inlet at its narrowest point. If it continues, it’s only a matter of time before the inlet will close up and restrict boat access to almost 1000 waterfront homes.
The New Jersey Department of Environmental Protection has very strict rules and regulations of what we can, and cannot do. We cannot use bulkheads, revetments, rocks or any unnatural or hardscaped materials to stabilize the shoreline. Because of the presence of submerged aquatic vegetation (i.e. Eelgrass), we can only do very limited dredging.
Last spring, with a grant from the Barnegat Bay Partnership, BSHCA planted a 200 ft. living shoreline consisting of 2500 spartina (salt marsh) plants along Allen Road beach. This was a test pilot project to find a way to stabilize the beach to prevent Amherst Inlet from closing up. The month of June brought a series of raging nor’easters that battered the shoreline. In the fall of last year hurricane Irene took its toll.
An inventory was taken after all the storms and out of 2500 plants, 480 had survived. At present the
spartina is dormant for the winter and we are waiting to see how much emerges from the rhizomes this spring.
At this point in time, because we are losing the battle with Amherst Inlet shoaling in, we have to make a decision whether to continue with the spartina (salt marsh) or planting the much more aggressive growing phragmites (common reed) to stabilize the beach. As you may have noticed, phragmites is naturally overtaking the 30,000 American Dune Grass plants that BSHCA planted between the Allen Road boardwalk and the scarping. Eventually you will not be able to see the water from the boardwalk left unchecked. Like cancer, it is almost impossible to eradicate. The more you cut it, the faster the roots grow.
The following are some questions and answers regarding phragmites:
What is Phragmites?
Phragmites australis, common reed, is an aggressive, native, 8-16 foot tall, coarse perennial grass which frequently grows in the moist soils of tidal and nontidal wetlands. It has invaded many marshes throughout the Chesapeake Bay region by forming dense stands which crowd out other native marsh plants. Its status as a facultative wetland species (i.e., adaptable to a variety of wetland types) means that the habitat it occupies is most likely a wetland subject to federal, state, county or municipal regulation.
However, Phragmites also grows well in moist upland soils.
Does Phragmites have any value?
Like all wetland vegetation, Phragmites provides food and habitat for some organisms (e.g., rails,
muskrats and other rodents), serves to stabilize soils against erosion, and improves water quality by filtration and nutrient removal, although much less effective removing nitrogen than salt marsh (spartina).
Why is Phragmites considered to be a problem?
Ecologically, Phragmites can be a problem plant because it is an excellent colonizer of disturbed soils and once established it usually crowds out all other wetlands plants. This reduces the ecological value of the wetland by displacing plant assemblages which have better value as habitat (i.e. spartina alterniflora), for stabilizing sediment, or improving water quality through nutrient removal (i.e. nitrogen). Along shorelines, dense stands of Phragmites are objectionable because they obscure water views and encroach on naturalized and ornamental plantings. Once established, it is almost impossible to eradicate.
Spartina or Phragmites, that is the question.
Saturday, March 17, 2012
Tuesday, September 13, 2011
A PHOENIX ARISES FROM IRENE’S TOTAL DESTRUCTION
LIVING SHORELINE UPDATE
By Bill McGrath
Photo taken 9/12/2011
Two weeks ago hurricane Irene wrecked havoc on our living shoreline. When the eye passed over I quickly ran over to Allen Road Beach to inspect the damage. Allen Road was barely passable with a foot of water covering the road. I made it through only to find that most of the biologs had disintegrated or were missing. The living shoreline was entirely covered by about 18 inches of water. Even though it was covered with water, I could clearly see that ALL of the vegetation in the living shoreline was completely sheared off at the surface from the fierce wave turbulence.
The photo above was taken about two weeks after total destruction. It clearly shows amazing re-growth from protected rhizomes still intact under the Coir matting. The 470 rhizomes I inventoried before hurricane Irene were still completely intact. This should insure vigorous growth next spring after the spartina goes dormant during the winter.
The above photo shows what remains of the upland row of biologs. Notice the far background. It shows how far the living shoreline has contributed to the beach. The sand trapped by the living shoreline would have wound up in Amherst Inlet. The rhizomes are still intact under the Coir matting that is covered over with sand previously trapped by the biologs.
This photo looking south, also shows how the living shoreline increased the beach by trapping the sand before it winds up in Amherst Inlet.
Photo taken 9/12/2011
This photo shows the re-generation of the spartina after being completely sheared off at the surface by hurricane Irene.
Photo taken 9/12/2011
This photo shows the erosion from hurricane Irene along the hardpan scarping. A small amount of the upland American dune grass along the face fell victim to the storm.
The phragmites is aggressively taking over the American dune grass which will be complete in about 3 to 4 years. Hurricane Irene exposed the extremely aggressive phragmites rhizomes along the eroded scarping.
Saturday, July 23, 2011
THE ONLY BLOG ON THE INTERNET DEDICATED TO WATCHING GRASS GROW!
LIVING SHORELINE UPDATE 07/23/2011
by Bill McGrath
Photo taken 7/22/2011
I took an inventory of the living shoreline yesterday afternoon and again this morning. At this point, out of the 2400 plants that were planted, 470 survived. The ones that survived are extremely healthy and vigorous (see above photo). So much so, that it is very doubtful that any future storm could destroy them. So, from that point of view it is a success. The plants are now 16” to 20” tall. Most of the ones that didn't make it through the storms in June were covered over with too much sand to survive. Only a very small percentage were actually washed away. We have tweaked our design so this should not happen in future phases.
The 470 plants that are thriving there now have rhizome roots that will grow under the sand and spread out over the winter. In the spring you should see new sprouts coming up to fill in the bare spots. So, although we are only 20% successful, eventually nature will make us 100% successful. This is a “learn as you go” project for us and anyone else that wants to plant a living shoreline in these conditions. We are sort of blazing the trail here by trial and error.
In some areas of the country this species (spartina alterniflora) is considered an aggressive, invasive nuisance that is very difficult to eradicate. A single plant will spread into a circular clone, clones coalesce to form stands or meadows. Let’s hope that happens here.
A similar type of rhizome plant that is also very aggressive is the common reed (phragmites australis) . You will see it growing on both sides of the Allen Road Boardwalk where it is aggressively taking over the American Beach Grass (Ammophila breviligulata). Reaearch has shown that Phragmites rhizomes can spread as much as 80 to 100 feet per year.
The above drawing shows how the rhizomes are expanding under the Coir matting we laid down that is now buried under 7 to 10 inches of sand. As you can see, it is highly doubtful that a storm would rip these out after all these rhizomes are intertwined under the Coir matting.
It’s only a matter of time (3 to 5 years) before the entire 12 ft. by 200 ft. will be completely covered with vegetation. The benefits to the environment will be:
· Sucking up the harmful nitrogen runoff before it gets a chance to further degrade Barnegat Bay.
· Stopping the erosion of Allen Road Beach.
· Trapping sand from the littoral drift before it ends up in Amherst Inlet.
· They support microorganisms that neutralize pollutants found in water.
· They support a number of fragile benthic and marine life.
BSHCA is looking into the next phase of our living shoreline which may begin this summer or fall. The next phase will involve planting Spartina patens between our existing living shoreline and the scarping (cliff area). This area is shown in the photo below:
Photo taken 7/22/2011
Spartina patens is also a very aggressive cordgrass similar to Spartina alterniflora that we previously planted. Spartina patens grows better at a slightly higher elevation than the Spartina alterniflora. The site we have chosen in the photo above is perfectly suited for the Spartina patens. Also, this area is more protected from the onslaught of an occasional nor’easter.
We plan on stabilizing the scarping on the right side of the photo with the following native salt tolerant bushes:· Bayberry (Myrica pensylvanica)
· Marsh Elder (Iva frutescens)
· Grounsel Bush (Baccharis halimifolia)
Friday, June 17, 2011
LIVING SHORELINE UPDATE 6/17/2011
THE LIVING SHORELINE IS ALIVE AND WELL!
Photo taken Thursday June 16, 2011
The healthy spartina that survived a very turbulent month of May, have doubled and in some cases tripled in height since we planted them over a month and a half ago. There is no question that we lost a lot of plants. A few were lost from being undermined but, most were lost by being covered over with sand.
Right now, since many of the surviving plants are so healthy, we are talking about supplementing the bare spots with additional plants. I plan on taking an inventory and reporting on how many of the 2,400 plants survived shortly ... Stay tuned!
Photo taken Thursday June 16, 2011
Remains of votive candles on the beach behind our living shoreline
the day after the candlelight vigil for Ryan J. Worrell.
Monday, June 6, 2011
WEEK 4 -- ALLEN ROAD LIVING SHORELINE POST CONSTRUCTION REPORT
At last the winds have changed and the tide receded to its normal levels and even lower. The entire project site is covered over with 6 to 8 inches of sand on top of the coir matting. With the easterly and northerly winds the water line is about 4 feet in front of the first row of biologs.
Photo taken June 2, 2011
Photo taken June 2, 2011
Even though the spartina that was planted over a month ago was covered over with 6 to 8 inches of sand, a large percentage of the plants grew thru the sand to reach sunlight.
Photo taken June 2, 2011
At this point in time, it is not known how many plants did not survive out of the 2500 plugs that were planted. We also do not know if any additional buried plants that are not visible will grow thru the sand. Sometime next month I plan on taking an inventory of the surviving plants.
Photo taken June 2, 2011
The plant shown above grew thru the deposited sand measuring 6 inches from the coir matting where it was originally planted, to the existing beach surface. The original plants were 6” to 8” tall when planted in the coir matting.
It is apparent that it would be unwise to use the biologs in future phases of this project. It would be better to just use the 900 series coir matting and pinning it down as I have previously outlined in my week 3 report.
The biologs proved to be very effective in extending the beach by elevating it above the mean high water line.
Submitted by
BSHCA member
William E. McGrath, PLS
Riparian Consultant
WEEK 3 -- ALLEN ROAD LIVING SHORELINE POST CONSTRUCTION REPORT
The Shoreline continues to be battered with sustained southerly and easterly 15 to 25 knot winds, with tides running 1 to 2 feet above normal. Additional sand bags were place along the front row and tied together. The entire project is now covered with 4” to 8” of gravelly sand.
Photo taken May 17, 2011
Even though a substantial amount of sand covers the spartina, the rhizome plants still grow through the sand to reach the surface. At this point in time, it is not known how much sand cover it takes to prevent the plants from having sustained growth.
Photo taken May 18, 2011
It is noted that in future projects biologs may not be needed because the plants, as long as they are well anchored, seem to tolerate the water turbulence. The biologs are a hindrance because they trap sand. It would be better to just use the heavy duty 900 Coir matting alone by burying and staking the leading and trailing edges. In this way the water can easily ebb and flow over the matting and plants without accumulating any sand. In order to do this, we would have to eliminate the metal staples that don’t work very well, in favor of ½” x 1” x 16” wooden stakes with ¼” holes drilled thru the top to connect the matting to the stakes driven just below beach surface and attached with plastic zip ties. The plants could then be tied with jute twine to the matting much the same way as tomato plants are tied to stakes. The savings by eliminating the biologs for the 200 feet would be about $ 4,000. That savings could be utilized for increased shoreline footage. That would also make the project less labor intensive. We could probably do 320 lineal feet for what it cost us to do 200 feet.
Submitted by
BSHCA member
William E. McGrath, PLS
Riparian Consultant
WEEK 2 -- ALLEN ROAD LIVING SHORELINE POST CONSTRUCTION REPORT
With sustained southerly and easterly 15 to 25 knot winds, the tide continues to remain 1 to 2 feet above normal. The front row of biologs continue to be battered by heavy waves that are sometimes reaching the toe of the scarping and completely inundating the entire project with at least a foot of water.
Photo taken May 11, 2011
Note the spartina growing under water
We received 300 free recycled 50 lb. feed bags from Manchester Hills Estate Farm and Winery in Ohio. Fred Bekiarian, Bill Grochowicz, Bill & Marion McGrath continued to fill sand bags and place them along the face of the front row of biologs to help save the project from complete destruction. The spartina seems to thrive under water but, it was being covered over by more and more sand from the waves being trapped between the two rows of biologs. The accumulated sand was used to fill the sand bags and replaced out front along the face of the biologs.
Submitted by
BSHCA member
William E. McGrath, PLS
Riparian Consultant
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