Sedimentological and Biological Changes in the Windsor Mudflat, an Area of Induced Siltation

The causeway-induced mudflat at Windsor, Nova Scotia, was studied to determine the effect of rapid sedimentation on the sedimentological and biological characteristics of an intertidal mudflat. Compared to typical Minas Basin mudflats, the Windsor flat has high water content, (50% vs. 30% wet wt, approximately) small grain sizes, and elevated organic carbon content (0.82% vs. 0.24% dry wt). The two principal infaunal species of the Windsor flat, the amphipod Corophium volutator and the clam Macoma balthica, are less abundant than in nearby typical flats (~840 vs. ~13 000/m2 and ~640 vs. ~1500/m2, respectively), while the polychaete Heteromastus filiformis is particularly abundant at Windsor. Macoma balthica at Windsor grow faster and have a shorter lifespan (~6 yr vs. ~13 yr) than at other Minas Basin flats. Compared to other Minas Basin Macoma, the weight of Windsor Macoma increases more slowly with increasing shell size, possibly an adaptation to the more fluid Windsor sediments.These sedimentological a...