1 along and then they would branch off at various places when we felt we'd 



2 gotten enough coverage of an area. 



3 We also use the Alvin to collect voucher specimens of the critters 



4 because seeing it on a picture doesn't exactly tell you what it is, but 



5 if you see it on a picture and then you have an animal in hand and can 



6 key it out--so basically we use the Alvin to get areas of high relief 



7 and also to collect voucher specimens for species identification. 



8 This is a slide just showing individuals--this is megafaunal 



9 animals you can see with the naked eye on the sea floor, basically, 



10 individuals/100 m^ for the slope area, that's slope area 3 and Lydonia 



11 Canyon. 



12 One thing that you can notice is that throughout the depth range, 



13 except for one little area right here, the canyon megafauna is much more 



14 abundant than on the slope. There are several reasons for this. Most 



15 of the difference was found in the axis of the canyon in the actual 



16 axis, but also on the flanks. 



17 So, it seems that the canyon environment does extend out past that 



18 axial part and onto the flanks slightly. Basically these very, very 



19 high abundances here were due to what I think is that depositional area 



20 right in the axis. You've got a lot of sea pens in that area and you 



21 have very, very high concentrations of two brittle stars, two Ophiura 



22 species. 



23 When I say very high concentrations, I say they were not 



24 countable, they were sometimes stacked five deep over each other right 



25 in the depositional part of the axis proper. 



26 Then, some of the high concentrations here at 400 meters and say 



27 here at 500 meters had to do with another type of coral, a hard 



28 substrate coral, Unephthia flon'da, which is very common on boulders 



29 along the upper portions of the wall and also along the cliffs at the 



30 base of the wall . 



31 In here the higher abundances with regard to slope were due 



32 largely to hard substrate corals that were restricted to hard 



33 substrates, and some sponges, but also a soft substrate sponge, 



34 Asbestopluma. 



107 



