7,000 
6,000 
5,000 
4,000 
Ba, IN PPM 
3,000 
2,000 4 
|,000 + 
| Se 
=1000 1000-500 500-210 2I0-I05 
6 
\ 
\ 
\ STATION 16 
\ M4=X—— 
\ MIO-O—— 
\ 
\ 
\ 
\ 
\ 
\ 
O 
\ 
\ 
\ 
\ 
x \ 
\ 
O 
Xx 
105-60 60-30 30-10 10-1 <| 
SEDIMENT-SIZE CLASSES, IN ym 
FIGURE 13B.—Concentrations of barium in different size fractions of bottom sediments collected on cruises 4 and 10 at regional 
station 16 on Georges Bank. 
Ba,IN PPM 
FIGURE 14.—Concentrations of barium in the fine fraction of 
material collected in sediment traps deployed at the head of 
Lydonia Canyon on different deployment dates. Traps were 
recovered just prior to the next deployment. 
28 
wide areas of the bank. The rates at which the con- 
centrations of Ba decrease in the surface sediments 
near a well have been estimated. The processes re- 
sponsible for the decrease in concentration and for 
the redistribution of Ba are (1) resuspension and 
transport in response to strong currents, (2) phys- 
ical and biological mixing of the surficial sediments, 
and (8) possible dilution by the local accumulation 
of less contaminated sediments. Because these find- 
ings 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 
