Poster

Title: Bridging building and biology: Anthropogenic impacts on marine inter-tidal community composition and biodiversity

Authors:
Pieter A.P. DeHart, Department of Biology, Mount Ida College, Deanne Moosman, and Paul R. Moosman, Jr., Department of Biology, Virginia Military Institute

Abstract:
Disturbances to ecosystems have long been understood to have potentially detrimental effects to indigenous species.  To assess the impact of a ‘necessary’ disturbance on marine community composition and biodiversity, we examined an inter-tidal habitat in East Matunuck, Rhode Island both before and after reconstruction of a roadway bridge covering the area.  The initial species examined included the Quahog (Mercenaria mercenaria), Frilled anemone (Metridium senile), Colonial tunicate (Botrylloides diegensis), Common sea squirt (Styela clava), and Irish Moss (Chondrus crispus).  We conducted random quadrat transects three times at three depths on both sides of the waterway (totaling 18 quadrats/sampling day) at low-tide over a three-month period in two years prior (1999 and 2000) and two years following (2006 and 2007) construction of the bridge.  Pre-construction analysis indicated general trends of abundance and patchiness of all species over time, with some seasonality.  Post-construction surveys indicate a shift in species composition, with a significant reduction in S.clava after construction.  Initial analysis on the influence of physical variables during the study yields bridge construction as the only significant factor affecting distribution and abundance.  Additionally, post-construction data indicates that seasonality may now play a greater role in species abundance than prior to disturbance, so additional analytical efforts should focus on elucidating this pattern.  While further research efforts should be more temporally variable and extensive to capture trends in marine species richness, future construction abutting waterways should address such efforts to yield valuable insight into anthropogenic effects on the role of species composition in overall diversity.