This is what Jamaica Bay looked like in 1924: http://gis.nyc.gov/doitt/nycitymap/?z=4&p=1031587,160265&c=orthos1924.

If you compare the 1924 Fairchild aerial image with contemporary Google satellite images of the Bay you'll notice the staggering loss of salt marsh habitat. For more information on the disappearing salt marsh islands of Jamaica Bay visit the NYCDEP "Jamaica Bay Watershed Protection Plan" web page, http://home2.nyc.gov/html/dep/html/dep_projects/jamaica_bay.shtml, and have a look at NRDC's "Saving Jamaica Bay" fact sheet, http://www.nrdc.org/oceans/files/jamaicabay.pdf.