Poole Harbour (UK), one of the world's largest natural harbours, supports terrestrial and marine habitats that are protected under National, European and International designations. Recent introduction of mechanical dredging in the cockle (Cerastoderma edule) fishery raised concerns among conservation groups that this new method may have a damaging effect on infaunal benthic communities that form critical food resources for shorebirds. This research investigated ecological impacts of cockle dredging on infaunal communities, using statistical analysis to look at community change in fished and non-fished sites over a 2 year period. Results suggested increased fishing activity led to the removal of adult cockles and a reduction in cockle settlement and recruitment, reducing the adult population for the following year. This has the potential to impact on oystercatchers (Haemotapus ostralegus), which are in direct competition with fishermen for adult cockles. Similar changes in community structure of both sites suggested eastern Poole Harbour may have experienced anthropogenic disturbance in addition to cockle dredging.