1 diversity along here was 2.03, 1.19 in the soft substrate areas and 2.91 



2 in the hard substrate areas. 



3 This was just cobbles. When you got into the canyon axis here, 



4 the mean diversity was 4.37, it was 1.86 on the soft substrate, it was 



5 higher in the soft substrate in the axis than it was anywhere else on 



6 soft substrate, but it was 8.31 on the outcrop, and here you're talking 



7 about large cl iffs. 



8 One thing we did notice you had the same pattern here of going 



9 from 3.56 on the soft substrate to 5.50 on the outcrop. One of the 



10 things that we found was that your species--that your species diversity 



11 went up with the size of the outcrop. 



12 We have a feeling that this has to do with--if you're talking 



13 about cobbles versus large boulders and cliffs and that you're talking 



14 just about a large cobble cannot support some of the biomass you're 



15 talking about and these animals don't survive and then would fall down. 



16 The idea is you have a higher diversity in the canyons, part of 



17 this is due to the substrate heterogeneity of the canyons, but not all 



18 of it. Even the soft substrate areas have higher diversities. 



19 I was also analyzing a data set from several Alvin dives from 



20 three canyons that were done in 1977. Basically Lydonia, what I was 



21 just talking about is right here. We had three Alvin dives in 



22 Oceanographer Canyon, one dive up the wall of Oceanographer, the west 



23 wall, and two dives in the canyon axis from about 1,800 meters to 1,500 



24 meters. 



25 We had three dives in a very small canyon called Heezen Canyon 



26 over here. Again we did the west wall and two in the axis, and then one 



27 up the wall of Corsair Canyon. 



28 These canyons were very, very different. Oceanographer Canyon is 



29 a rather large canyon, it has a relatively broad, wide axis, which has 



30 lots of ripples in it. It's a lot of sediment and the cliffs along the 



31 edge flanking it were not very pronounced or were low and stepped. 



32 What was interesting about Heezen Canyon is Heezen Canyon is a 



33 very, very narrow canyon. At times the submersible is maybe 3 meters 



34 wide. At times we were risking going up the axis, that is how narrow it 



113 



