1 DR. BOTHNER: 239 and 240. 



2 DR. NEFF: Of course, there is another thing for stripping. 



3 First, you have to have particles in the water column if you are talking 



4 about absorption and then you have to have something in solution to 



5 absorb. 



6 The question I would have is related to drilling. What soluble 



7 contaminants would you have in the bottom water and at the head of the 



8 canyon available to be absorbed onto the particles? 



9 DR. AURAND: I think it is reasonable to do it the way he is 



10 approaching it, in that: Does the mechanism exist? Yes or no. Then, I 



11 assume, we go from that to: Given that the mechanism exists, is there 



12 any interaction with oil and gas activity that would allow this 



13 mechanism to play a role? 



14 That is what you are now addressing, where it would come into 



15 play. 



16 DR. NEFF: Right. 



17 DR. BUTMAN: Are there other chemicals, other trace metals, 



18 radioisotopes which say that stripping is occurring. 



19 DR. BOTHNER: There are a few other metals that show the same 



20 pattern so, yes, there is a slight--it is a slight indication there on 



21 the basis of other sediment reactive elements. 



22 DR. BUTMAN: I think Jerry made a really good point that it is 



23 important to distinguish. We have established that a mechanism is there 



24 for natural --for isotopes and for metal which are in suspension now. 



25 What that means for drilling is a separate and another question. 



26 DR. RAY: Jim Ray. In the case of metals, Mike, for resuspended 



27 sediments to act as a scavenger, what species would metals have to be 



28 coming by in the water to be scavenged out by suspended particulate, for 



29 it to actually be an active mechanism to actually attach onto those 



30 metal species as they come by? What form do they have to be in for that 



31 to be occurring? 



32 DR. BOTHNER: Well, I guess they would have to be in an ionic 



33 state. They would have to be truly dissolved and the absorber could be 



34 something like manganese and iron oxides, hydroxides, which are being 



198 



