Upwelling is a vital ecological process that delivers nutrients from the benthic zone (sea floor); however, this same process is also capable of delivering PCBs from sunken naval vessels to shallow waters.
Coastal upwelling occurs when wind blows parallel to the coast, deflecting surface water away from the coastline (Ekman Transport) as influenced by the Coriolis effect (Earth’s rotation). Surface water is pushed offshore and is replaced by cool, nutrient-rich water from the deep ocean.55 This process is also capable of delivering PCBs from sunken naval vessels to shallow waters, yet upwelling has not been assessed by the Navy as a material transport
Overturning: Deep ocean currents and water circulation produces dynamic uplift capable of delivering sediments, with which PCBs adhere,
Traditionally, this is known as Meridional Circulation Overturning, in which currents driven by wind, thermohaline [salinity and
atmospheric conditions transport deep water to
Similar to upwelling, this
naturally occurring ocean circulation has not been assessed by the Navy as a potential PCB
As evidenced, and conceptual model,
contrary to the Navy PCB material can be
transported great distances from the initial sink site via physical and biological means. PCBs and other hazardous materials left on SINKEX vessels are in no way contained to the dumping site and pose unnecessary risks to human health.
http://oceanmotion.org/html/background/upwelling-and- downwelling.htm 55
http://earthobservatory.nasa.gov/Newsroom/view.php?id=24124 BASEL ACTION NETWORK