1 In our mid-Atlantic study, we used a combination of the old design 



2 and the new design. In the North Atlantic at the Lydonia Canyon area, 



3 we had the old design trays positioned at stations 5 and 6, which were 



4 at 2,100 meters just outside the canyon. 



5 This tray that was at station 15, I believe, was the new design. 



6 As you can see, the trays were left out at two of the stations for 7 



7 months and at station 15 they were left out for 14 months. 



8 Now, the thing to point out here is that these are average 



9 densities in the trays calculated per square meter. The surface area 



10 covered by the recolonization experiment itself was about .25 meter, so 



11 this is some extrapolation from the quarter meter that we were actually 



12 sampling. 



13 You can see if you put out defaunated sediment for seven months, 



14 you come back with an average density of somewhere between 33 and 37 



15 individuals/m^. Keep in mind that the densities I showed you for the 



16 same depth, 2,100 meters, are closer to 4,000 individuals/m^. 



17 So, this is a fairly significant difference compared to the 



18 natural community. There were so few individuals actually in these 



19 trays that it's difficult to say anything about the species composition. 



20 The few things that we can say, the only species that was 



21 represented at stations 5 and 6 by more than one individual in any 



22 particular experimental tray, was the species of capitella, which is 



23 known from shallow water environments as a fairly opportunistic 



24 polychaete. 



25 The only other organism that was represented by more than one 



25 individual was a tunicate called dicarpa. At station 15, in which the 



27 trays were left out for 14 months, the average densities were close to 



28 416 animals/m^, and again, that's compared to 4,000 individuals/m^ in 



29 the natural environment. 



30 Here capitella was again a fairly common species that came into 



31 the tray, and the second most common species was the polychaete 



32 Aurospio, which is the same species that is the community dominant in 



33 the natural sediments at that particular depth. 



127 



