Sediments can be made toxic in areas where there is considerable deposition of organic matter. This is assessed by measuring TOC.

The pie graph shows the proportion of the Delaware Estuary that is good (green), fair (yellow), poor (red) or missing data (blue) for sediment total organic carbon (TOC). The small symbols on the map show the rating at a particular sampling location. To see the measurements made at one of these locations, click on its symbol on the map.