To evaluate the effect of selective ditching for mosquito control on productivity, unditched and ditched sections of short form Spartina alterniflora Loisel, marsh were sampled in New Jersey. Standing vegetational biomasses, densities of fiddler crabs (Uca pugnax), isopods (Philoscia vittata) and salt marsh snails. (Melampus bidentatus) were sampled 3 and 4 years after the marsh was ditched. Significantly higher total (live and dead) vegetational biomasses were found in the mosquito ditched marsh (1462.3 dry g/m2) compared to that of the unditched marsh (852.5 dry g/m2). This difference was probably the result of the increase in tidal circulation and possible nitrogen fixation in the ditched marsh. The mosquito ditched marsh seemed to be progressing towards a more productive-low marsh community as evidenced by: I) significant increases in fiddler crab holes and isopod densities; 2) decreases in salt marsh densities; and 3) increases in individual S. alterniflora stem biomasses.