Estuarine Fish Communities along a Spatial Urbanization Gradient

The human population surrounding Barnegat Bay, New Jersey, has increased dramatically in recent decades. Consequently, urbanization (anthropogenic development) of the watershed has occurred, resulting in shoreline hardening and habitat destruction. A resulting gradient of urbanization increases from the southern to the northern portion of the bay's watershed. The objective of this study was to investigate cumulative impacts of urbanization in Barnegat Bay by assessing species composition, abundance, and diversity of fish communities in relation to the large-scale urbanization gradient in the watershed. Otter trawl surveys occurred in April, June, August, and October for 3 years (2012-2014) at 40 sampling sites stratified along the urbanization gradient. The sampling sites included four different representative, subtidal subhabitats: open bay (soft bottom), submerged aquatic vegetation beds, upper marsh creek, and marsh creek mouth. Analyses did not reveal strong differences in fish communities among strata that could be solely attributed to the urbanization gradient. Fish species composition was similar among strata, whereas species abundances and diversity differed among strata. Many of the observed differences in abundance and diversity were attributed to ecological variables unassociated with the urbanization gradient. Further study on potential urbanization effects should include investigations at the species level and at smaller scales.