text: The remediation, or removal, of PCBs from estuarian and coastal river sediments is quite difficult due to the overlying water column and the potential for resuspension of contaminants during the removal process. The most common method of PCB extraction from sediments is to dredge an area and dispose of the sediments in a landfill. This method is troubling for a number of reasons, namely that it has a risk of resuspension of the chemicals as the sediments are disturbed, and this method can be very damaging to ecosystems.
  A potential cost effective, low risk remediation technique is bioremediation. Bioremediation involves the use of biota to remediate sediments. Phytoremediation, the use of plants to remediate soils, has been found to be effective for a broad range of contaminants such as mercury PCB and PAHs in terrestrial soils. A promising study conducted in New Bedford Harbor found that Ulva rigida, a type of seaweed common throughout the world, is effective at removing PCB from sediments. During a typical bloom in New Bedford Harbor, U. rigida forms a thick mat that lies on top of and in contact with the sediment. This allows for U. rigida to uptake large amounts of PCB from the sediment with concentrations of PCB in U. rigida reaching 1580 μg kg within 24 hours of the bloom. Live tissue tended to take up higher concentrations of PCB than dead tissue, but this is not to say that dead tissue did not still take up large amounts of PCB as well.