Abstract
Tidal floodplain water bodies (TFWB’s) are pervasive features of rivers draining passive continental margins. These backwater environments connect to tidal freshwater river channels by means of tie channels, many of which have been excavated and cleared of debris to facilitate harbor development and fishing access. Therefore, these coves and ponds now receive sediment and accompanying nutrients and contaminants from the broader watershed due to enhanced tidal pumping. While sediment storage within estuaries and subaerial floodplains has been heavily studied, we have found that relatively understudied TFWB’s play a disproportionately large sediment storage role relative to their small area. Furthermore, levels of mercury within TFWB’s of the Connecticut River reach levels more than three times the maximum reported from San Francisco Bay, often regarded as the poster child for mercury contamination.