Fire Island, the barrier island that runs along the center of Long Island's south shore. It is about 31 miles (50km)long but thin like a snake, being between 500' to 1,300 ' (160-400m) wide.
This island and others to the west protect the bays and low laying communities behind it. Long Island being composed of sand and some gravel is at the mercy of the raging Atlantic ocean.
Westhampton Island is just to the east, separated from Fire Island by Moriches inlet.
During the winter it is normal for some erosion to occur. Some years and some areas get it worse than others.
The sand dune in this picture has been washed away right up to some of the ocean front houses. An attempt to save them is underway. A long trench was made and big barrel shaped plastic containers will be placed in it and then back filled with sand.
This will work for awhile until a big storm or hurricane will undo it.
This work is being done near the Town of Quogue's community beach. The plastic containers are being filled in their parking lot.
The pavilion in the above picture is sitting on the ocean dune and is threatened to collapse without this work.
Some people may say this is due to the oceans rising but this action of the ocean taking sand from one spot and putting it in another has been going on for eons. Also man has contributed to the erosion by building rock groins/jetties out into the water. Doing this protected the area they were installed but caused erosion pasted where there were no groins.
Barrier Islands ... https://en.wikipedia.org/wiki/Outer_Barrier#Westhampton_Island
map ... courtesy of duckduckgo.com