deposition to the west of the drilling activity: at stations 10 and 12 
along transect III, at new coring stations 50 km west of transect III, in 
sediment-trap material and sediments from the head of Lydonia Canyon, and 
from sediments near the head of Oceanographer Canyon. In addition, we 
found peaks in the concentration of Ba with time at upstream control 
stations 2 and 3, located 35 km northeast of the nearest drilling 
activity. The data from sediment-trap analyses suggest that barite which 
is originally deposited near a drill site in this area can be resuspended 
to at least 25 m above the sea floor. 
RECOMMENDATIONS FOR FUTURE WORK 
In this three year study we have shown that Ba introduced to Georges Bank 
during the exploratory phase of drilling is distributed over wide areas of the 
bank. The rates at which the concentrations of Ba decrease in the surface 
sediments near a well have been estimated. The processes responsible for the 
decrease in concentration and the redistribution of Ba are: a.) resuspension 
and transport in response to strong currents; b.) physical and biological 
mixing of the surficial sediments; and c.) possible dilution by the local 
accumulation of less contaminated sediments. Because these findings have 
application in predicting the fate of future pollutants on Georges Bank, we 
recommend that the following specific studies be continued beyond the third 
year of this monitoring program: 
1. Three replicate grab samples should be collected for chemical analysis at 
each of the 29 site-specific stations during the fourth and fifth years 
after the initiation of this program. These data are needed to more 
accurately determine the slower rate of Ba removal from surface sediments 
over a longer time interval. 
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